some experiments on the effect of age upon the rate of regeneration

SOME EXPERIMENTS ON THE EFFECT OF AGE UPON THE RATE OF REGENERATION’

BY

CHARLES ZELENY

INTRODUCTION A N D GENERAL METHOD

The experiments described in the present paper were under- taken with the object of determining the relation between the age of an animal and its rate of regeneration. T h e general fact has been known since the time of Spallanzani that as a rule the regeneration of lost parts is not as rapid in old animals as in young ones.2 It is not, however, always clear whether by this is meant the total time necessary for the replacement of a removed part or the actual rate of proliferation of the new tissues. Further- more, exceptions to the general rule of decrease with age have been noted?

The data to be given were obtained as a part of the study of several of the factors controlling the rate of regeneration. They are imperfect in that there is no instance of the working out of the rate during a complete life history. A full discussion of the general methods employed and the elimination of sources of error is given in the introductions to the papers on successive regeneration and the effect of the degree of injury in this number of the Journal of Experimental The statements made there are applicable to the present experiments and need not be repeated here. T h e individual catalogue numbers are given in

1 Contributions from the Zoological Laboratory of Indiana University. * “Die Regenerationsfdhigkeit nimmt mit zunehmendem Alter eines Tiereremplares ab.” Przibram,

1 9 9 . Experimental-Zoalogie 2. Regeneration, p. 221.

s “Die scheinbare Unterbrechung auf mittleren Entwicklungsstadien in gewissen speziellen Fallen laszt sich auf den nachweislichen Wechsel in der Konsistenz oder der Gewebsverteilung zuriickfiihren.” Przibram, 1909, 1. c., p. 221.

The effect of the degree of injury upon the rate of regeneration. This Journal.

THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. VII. NO. 3.

No. I 10. ,

4 Successive Regenerations: additional observations and general discussion. This Journal.

564 Charles Zeleny

many of the tables of data in order to make possible the identifi- cation of animals used for more than one purpose.

I n about one-half of the experiments the animals used were reared in the laboratory and the age is determined. In the cases in which the animals were not reared it is necessary to take the size of the animal as an indication of its age. T h e possibility of error in this connection is evident since individuals of the same size may be different in age.

As in the other papers on the factors controlling the rate of regeneration the data are divided into two groups including (A) those on non-molting and (B) those on molting animals. T h e molting habit introduces a factor which is difficult to control. T h e animals with this habit however possess some very obvious advantages. For a discussion of these points see the other papers in this number of the Journal.

EXPERIMENTS ON ANIMALS WITHOUT A MOLTING HABIT

I The Regeneration of the Oral Arms in the Scyphomedusan, Cassiopea xamachand

For the conditions of the experiment the reader is referred to the paper with the original data. T h e data bearing on the effect of age are given here in Table I . T h e size of the animal is taken as an indication of its age. .

I n each of the six degrees of injury the average length of regenerated material is greater in the two larger individuals than in the two smaller ones. O n the other hand the regenerated length per unit of disk diameter is less in the larger than in the smaller individuals. In other words when one or more oral arms are removed the actual proliferation of material is faster in the larger than in the smaller animals, but the increased rate is not sufficient to complete the removed arms as soon in the former as in the latter.

The full data are published in the paperon “The effect of degree of injury, successive injury and func- tional activity upon regeneration in the Scyphomedusan, Cassiopea xamachana.” Journ. Erp. ZoOI. , vol. v, no. a. 1907.

Effect of Age upon Regeneration 5%

2 T h e Arms of the Brittle-star, Ophioglypha lacertosae

T h e conditions of the experiment are given in the paper with the original data. T h e data bearing on the effect of age are given here in Tables 2 , 3, 4 and 5. T h e disk diameter is taken as a measure of age with the reservation mentioned on the preceding page.

An examination of the tables shows that in general the actual regenerated arm lengths a t any time are the greatest in individuals of medium size. Both the smaller and the larger individuals show shorter regenerated arms. When the regenerated length per unit of disk diameter is taken there is less difference between the smaller and medium individuals and more between the medium and larger ones. In other words the actual rate of regeneration in length is evidently greatest in medium sized individuals with a disk diameter of i2.5 to 15.0 mm. Both larger and smaller individuals regenerate new material less rapidly. T h e same is true (though not so markedly in the smaller individuals) for the specific length of regeneration. T h e smaller individuals ranging in size from 4.8 to 12.5 mm. therefore seem to constitute an exception to the general rule that the rate of regeneration decreases with age. This is true both of actual length and of specific length of regeneration. T h e data are not wholly satisfactory because of the large degree of variation and the small number of individuals. T h e larger individuals very evidently follow the rule of decrease both in actual length and in specific length of regeneration.

3 T h e Tai l i n Amblystoma jefiersonianum7

T h e data are taken from 181 individuals reared in the laboratory. A comparison is to be made especially between the younger individuals (Tables 6, 7 and 8) and the older individuals (Tables 9, 10 and 1 1 ) . All the salamanders are still in the larval stage. T h e animals were used for the determination of other factors

The full data are published in the paper on “Compensatory Regulation,” Journ. Exp. ZoBI., vol. ii, no. I , 1905.

7 Based wholly on new data.

566 Charles Zeleny

than that of age and they therefore unfortunately are subject to the error of difference in length of the regeneration period. The rate of regeneration in length following an operation is at first slow, then increases rapidly to a maximum, after which it declines slowly to zero, which it reaches at the completion of regeneration. Table 6 is especially subject to this error because it covers a much longer period than the others. This factor however in no way invalidates the general conclusion to be drawn from the data.

The average specific rate of regeneration of the tail in length is 0.0439 for individuals with a total body length of 22.6 mm., age of 28 days a t the time of the operation and a regeneration period of 24 days; 0.0396 for those 26.5 mm. long, 34 days old and with a regeneration period of 15 days; and 0.0368 for those 26.8 mm. long, 48 days old and with a regeneration period of 15 days.

This is considerably greater than the specific rate for the older salamanders. For those 51.6 mm. long, 131 days old and with a regeneration period of 14 days the specific rate is 0.0148; for those 54.1 mm. long, 134 days old and with a regeneration period of 1 1 days it is 0.0126; and for those 51.6 mm. long, 135 days old and with a regeneration period of 10 days i t is 0.0167.

The above applies to the cases in which nearly the whole tail was removed. A similar result is obtained when one-half of the tail is removed. The respective specific rates are then 0.048 0.042 and 0.038 for the younger and 0.020, 0.018 (-), and 0.014 ( - ) for the older animals.

Not only is the specific rate less in the older than in the younger individuals but also the actual length of regenerated material is less.

The individuals with the whole tail removed are considered first. For age 28 days, length 22.6 mm. and regeneration period 24 days, the length of the regenerated tails is 9.36 mm. or 0.39 mm. per day; for age 34 days, body length 26.5 mm. and regeneration period of 15 days, the length of regenerated tails is 6.22 mm. or 0.41 mm. per day; and for age 48 days, length 26.8 mm. and regeneration period of 15 days the length of regenerated tails is 5-87 mm. or 0.39 mm. per day.

The Ipec i f i c rate of regeneration.

Actual length of regenerated material.

Effect of A g e upon Regeneration 567

In older individuals the length of the regenerated tails is less; for age 131 days, length 51.6 mm. and regeneration period of 14 days i t is 4.22 mm. or 0.30 mm. per day; for age 134 days, length 54.1 mm. and regeneration period of 1 1 days i t is 2.96 mm. or 0.27 mm. per day; and for age 135 days, length 51.6 mni. and regeneration period of 10 days it is 3.4 mm. or 0.34 mni. per day.

A similar result is obtained when only one-half of the tail is removed. For age 28 days, length 22.6 mm. and regeneration period of 24 days in the one individual available thelength of the regenerated tail is 7.7 mm. or 0.32 mm. per day; for age 34 days, length 27.3 mm. and regeneration period of 15 days in the six individuals available the average length of the regenerated tail is 3.8 mm. or 0.25 per day; and for age 48 days, length 26.7 mm. and regeneration period of 15 days it is 3.8 mm. or 0.25 mm. per day in the fourteen available individuals.

For the older individuals there is a decrease in the actual length and rate of regeneration as compared with the younger ones. For age 131 days, length 49.1 mm. and regeneration period of 14 days the average length of the regenerated tail in the four available individuals is 3.0 mm. or 0.21 mm. per day; for age 134 days, length 52.4 mm. and regeneration period of 1 1 days it is 2.3 ( - ) mm. or 0.21 ( - ) mm. per day; and for age 135 days, length 51.9 mm. and regeneration period of 10 days it is 1.75 ( - ) mm. or 0.17 ( - ) mm. per day.

T h e data as a whole show that in the salamanders 131 to 135 days old the rate of proliferation of new material in length is less than i t is in salamanders 28 to 48 days old. T h e specific rate is obviously still more strikingly less than the actual rate of proliferation.

568 Charles Zeleny

EXPERIMENTS O N ANIMALS WITH A MOLTING HABIT

4 T h e Chelcz of the Gulf-weed Crab, Portunus sayi:8

T h e age factor is discussed in detail in the original paper in which Tables 10, I I A and 12 refer especially to it. T h e general result only need be mentioned here. In 66 crabs ranging in cephalo-thoracic length from 3.9 to 14.5 mms. not only the rate of formation of new material but also the specific rate or rate per unit of cephalo-thoracic length increases with increase in size of the crab. T h e increase in specific rate is however associated with a corresponding increase in length of the normal uninjured chelae in larger individuals. Perfectly normal chelae should therefore be obtained as quickly in large (old ?) individuals as in small (young?) ones between the sizes mentioned.

5 T h e C h e h of Cambarus propinquus. ( T a b l e s 12 to 17)~

The data are taken from two series of young crayfish reared in the laboratory, one with 70 and the other with 93 individuals and one series of old crayfish with 74 individuals.

T h e young individuals (Tables 12 and 13) are compared with adults (Tables 14 to 17) and among the adults the smaller individuals are compared with the larger ones (Tables 14, 15, 16 and 17).

Taking first the comparison between young animals and adults i t is found that crayfish operated upon two days after the fourth molt have regenerated on the average 2.12 mm. of the propodite of the removed chelalo in 14.6 days in two molts. T h e specific amount is 0.326 and the specific rate 0.0229. T.iose operated upon one day after the fourth molt have regenerated 1.86 mm.

Two comparisons are made.

8 The full data are published in the paper on “Kegeneration in the Gulf-Weed Crab, Portunus

9 Based partly on new data and partly on data from the paper on “The effect of the degree of injury

10 Throughout the paper in speaking of the “length of the chela” the greatest length of the propo-

sayi,” Carnegie Institution Publications. Tortugas Laboratory Reports, vol. 2.

upon the rate of regeneration.” Joum. Exp. Zool., vol. ii, 1905.

dite is meant.

Effect of A g e upon Regeneration 569

of chela in 13.8 days in two molts. T h e specific amount is 0.27 mm. and the specific rate 0.0195.

Adult crayfish on the other hand take a much longer period to complete a single molt and the propodite of the regenerated chela is on the average 6.47 mm. long in males and 6.14 mm. in females. This gives a specific amount of regeneration of 0.444 and a specific rate of 0.0049 for the males and a specific amount of 0.400 and a specific rate of 0.0030 for the females. Likewise in case both chelz are removed the length of the regenerated chelae is 6.4 for males and 6.07 for females and the corresponding specific amounts and specific rates are 0.435 and 0.0080 for the males and 0.404 and 0.0078 for the females.

T h e specific rates are therefore decidedly greater in the young crayfish than in the adults. T h e young however have had two molts as opposed to one in the adults.

If the smaller (younger ?) adults are compared with the larger (older I) ones the actual regeneration lengths are greater in the larger than in the smaller ones. T h e specific amounts are practically alike in both groups. The specific rates however are slightly greater in the younger than in the older individuals, so that the former should complete their chelz slightly sooner than the latter.

T h e data on Cambarus propinquus are unsatisfactory as regards the comparison between very young animals and adults because the regeneration periods under observation are so different. This criticism does not apply to the comparison between small and large adults.

When very young individuals are compared with adults there is evidently a greater rate of regeneration in the younger than in the older individuals not only in the sense of the time necessary to complete a new organ but also in the sense of rate of proliferation of new material. When younger and older adults are compared however, i t is seen that the actual rate of proliferation is greater in the older individuals but the time necessary to complete the missing chela is nevertheless greater.

T h e second comparison concerns the adults alone.

570 Charles Z elen y

6 The Chelce of Cambarus bartoni. (Tables 18 to 21)”

The crayfish used in these comparisons were all reared in the laboratory from one mass of eggs. Fifty individuals were obtained in this way.

Two comparisons are made, one between individuals with a single chela removed and the other between individuals in which both chelae were removed. The comparison in each case is made between individuals operated upon one day after the fourth molt and others operated upon after the eighth, ninth or tenth molt. In each case the actual length of proliferated material is greater in the older individuals but the specific rate is less in the older than in the younger ones. The specific amounts of regeneration are nearly the same in the crayfish of all ages with a single chela removed and greater in the younger than in the older ones in the individuals with both chela removed.

The data as a whole favor the view that the actual rate of proliferation is greater in the older than in the younger individuals but not great enough to enable them to complete the lost part as soon as in the younger ones.

7 Palamon tenuicornis. (Table 22)’~

The data are obtained from a set of twenty-one individuals operated upon in June, 1906, a t Tortugas. A comparison is made of the rate of regeneration of a single removed chela during one molt. Six individuals were taken during their third regeneration of a chela and three during their second regeneration. Ineach case the length of the regenerated chela increases with increase in size (age ?) of the animal. The specific rate, however, decreases. For the specific amount of regeneration during the single molt no definite conclusion can be reached.

The data here as in the case of Cambarus bartoni show an increase in the rate of proliferation of material between the sizes of 6.8 and 13.1 mm. but this increase is not sufficient to enable

11 Based wholly on new data. 12 Based wholly on unpublished data.

Effect of Age upon Regeneration 571

the older ones to complete the whole organ as soon as i t is completed by the younger ones.

8 Palmmonetes vulgaris. N o s . 1775-1805 and 1806--1861. (Tables 23, 24, 25 and 26)13

T h e individuals in each table are arranged according to cephalo- thoracic length. They range in size from 6.1 mm. to 13.6 mm.

In individuals Nos. 1755-1805 (Table 23) there is on the whole a slight increase in length of the regenerated chela during a molting period with increase in size, but this is probably associated with the increase in length of the molting period. I n specific amount there is no evident difference in individuals of different size.

In individuals Nos. 1806-1861 (Tables 24 to 26), where the comparisons are made in every case eight days after the operation, there is on the whole no evident change in rate with change in size. but the specific amount and rate of regeneration evidently decrease with age.

As far as any general conclusion may be drawn from the data on Palaemonetes vulgaris i t may be said that there is no change in rate of regeneration of a removed organ with increase in size in the sense of rate of formation of new material. I n specific rate there is either no change or a decrease in rate.

GENERAL RESULT

T h e data cover eight species of animals, Cassiopea xamachana, Ophioglypha lacertosa, Amblystoma jeffersonianum, Portunus sayi, Cambarus propinquus, Cambarus bartoni, Palaemon tenuicornis and Palaemonetes vulgaris.

In most cases the rate of regeneration of an organ in the sense of actual increase in length of the proliferating part is greater in older individuals than in younger ones. T h e comparison is however made only in individuals in which increase in size is an accom- paniment of increase in age. Examples are: Cassiopea, Ophio-

* Based wholly on unpublished data.

5 72 Charles Zelen y

glypha (up to 15 mm.), Portunus, Cambarus propinquus (10.6 to 19.0 mm.), Cambarus bartoni and Palaemon. I n one case there is no evident change with age (Palaemonetes) and in a few there is a decrease with age (Ophioglypha above 15 mm., Ambly- stoma and Cambarus propinquus young as compared with adults).

?'he specific rate of regeneration or the rate per unitof length of the individual is however usually less in older than in younger individuals, so that it takes them longer to complete a removed appendage than in the younger ones. Examples are: Cassiopea, Ophioglypha, (above 15 mm.), Amblystoma, C. bartoni, C. propinquus, Palamon, Palaemonetes (in part). In a few cases there is no change in specific rate with age (Ophioglypha, medium individuals, Portunus ( ?),14 Palaemonetes, in part), or there is an increase with age (Ophioglypha, smaller individ~als , '~ Por- tunus ( ? ) ' 8 ) > .

DISCUSSION

T h e experiments as a whole confirm the general conclusion that in older individuals it takes longer to complete a removed organ than in younger ones.'? This general result is usually evident in extremes of age without the use of any accurate measurements. As has been previously pointed out there are however undoubted exceptions to the rule, the most marked in the present set of experiments being the chelae of Portunus and probably the younger individuals of Ophioglypha.

T h e accurate measurements of regenerating appendages has brought out the point upon which special emphasis needs to be laid, and this is the fact that in a majority of the species studied the actual rate a t which new tissue is proliferated is greater in the older individuals than in the younger ones. The older individuals when they lose an appendage obviously have more material removed than do the younger ones, but the proportionof removed material to the whole mass of the body is not materially changed in those forms in which growth does not involve a change

"See special condition affecting the size of the chelz, p. 568 of this paper. 18 Data not conclusive. 18 See special conditions affecting the size of the chelae, p. 568 of this paper. 17 A full bibliography is given in Przibram. Experimental-Zoologie. 11. Regeneranon. 1909.

Effect of A g e upon Regeneration 5 73

in shape. In general the rate of regeneration in any individual increases with increase in amount of material removed. This is clearly shown by a study of the effect of the degree of injury and by such organs as the tail of the frog tadpole, where the rate is directly proportional to the distance of the cut from the tip. It follows therefore that if a length of the appendage in the older individuals equal to its total length in the younger ones were removed there would undoubtedly be on the whole a less rapid rate of regeneration than in the younger whole appendage. It also follows that if it were possible to conceive two animals of the same species, age, sex etc., and with the same environment but markedly different in size, the larger appendage in the larger one would be completed at the same time as the smaller appendage in the smaller one. Otherwise the above experiments show an increase in regeneration potential with age.

The age factor in those animals in which increase in age is accompanied by increase in size does not bring about a decrease in rate of proliferation when an appendage is removed, in the sense of the actual material produced, but a decrease as compared with a hypothetical young animal of the same size as the older one. The probable rate in this hypothetical, enlarged younger animal is based upon the data obtained from experiments on the rate of regeneration with different degrees of injury to the individual and from different levels of an appendage.

SUMMARY

I In larger individuals of Cassiopea xamachana with a disk diameter of 26 to 42 mm. the actual proliferation of material in a regenerating arm is faster than in smaller individuals with a disk diameter of 8.4 to 21.0 mm. This greater rate, however, is not sufficient to complete the arms as soon in the older as in the younger individuals.

In Ophioglypha lacertosa individuals with a disk diameter of 12.5 to 15.0 mm. have the greatest rate of regeneration. Both smaller and larger individuals have a lower rate. The sameis true of the rate per unit of disk diameter, though the difference

2

574 Charles Zeleny

between the smaller and medium sized isnot very pronounced and may not be significant.

In Amblystoma jeffersonianum, larvae 131 to 135 days old as compared with those 28 to 48 days old regenerate the new tail less rapidly both when the whole and when half the tail is removed. This is true of the actual rate of increase in length as well as the rate per unit of total body length.

In individuals of Portunus sayi ranging from 3.9 to 14.5 mm. with increase in size of the animals there is an increase not only in the rate of proliferation but also in the specific rate. T h e increase in specific rate corresponds with an increase in specific size of the chela! in uninjured individuals in such a way that in-all crabs of the sizes studied new chelae are completed in the same period of time.

Adult individuals of Cambarus propinquus regenerate less rapidly than young ones of the fourth to the sixth molt in actual rate of prolification as well as in time necessary to complete the removed organ. Among adult individuals ranging in length from 10.6 to 19.0 mm. the larger (older?) ones have a greater rate of regeneration but the time necessary to complete the removed part is on the whole greater in the older than in the younger ones.

6 In Cambarus bartoni all individuals were reared in the laboratory and their actual age was determined. The rate of regeneration is greater in the older individuals than in the younger ones but the specific rate is less and therefore the time necessary to complete the whole removed part is greater.

In Palomon tenuicornis with cephalo-thoracic lengths vary- ing from 6.8 to 13.1 mm. the same rule holds as for Cambarus bartoni.

In Palaemonetes vulgaris with cephalo-thoracic lengths ranging from 7.2 to 13.6 mm. there is no evident change in rate of proliferation of new material with change in size. T h e specific rate either shows no change or a decrease.

T h e general result is clear that in a majority of the cases the actual rate of proliferation of new tissue is greater in older than in younger individuals, but this is not sufficient to reproduce the removed organ as soon in the older as in the younger individuals.

3

4

5

7

8

9

Effect of A g e upon Regeneration 5 75

TABLE I

?a xamachana-ReEeneration period, 24 days Casric

SMALLER INDIVIDUALS LARGER INDIVIDUALS

Size8.4to 2x.omm.Av;=16.5mm iize 26.0 to 42 mm. Av = 39.9 mm.

Degree of injury Average ength of regener- ted arms

Specific amount if regeneration

Specific .mount of regenera-

tion

Length if regener. ated arms

Disk diameter

Disk diameter

0.5

I .o 0.048

0.059 29 .o 42.0

I .o

3 .o 0.034 0.071

10.5

17.0

13.7

8 *4 21 .o

14.7

11 .a

15.5

13.3

9 .o 16.5

12.7

10.8 17.5

14.1

10.8 16.5

13.6

One arm at base.. .........

Average. ................... 0.75 0.053 35.5 2 . 0 0.052

1.5 2-5

0.179 0.119

29.0 42.0

0.060 0.119

........ i Two arms at base..

Average.. .................. 2.0 0.149 35.5 3.37 0.089

Four arms at base.. ' , ......... 2.0

3 .o

0.179 0.194

35.0 36.0

4.7 4.0

0.134 0.111

Average.. ................. 2.5 0.186 35.5 4.35 0.122

2 . 5

2 . 5

0.278 0.151

26.0 37.0

2.85

4.5 0. I I 0

0.122 Six arms at base.. ........ .I

Average.. ................. 2.5 0.214 31.5 3.67 0.116

0.185 0.143

28 .o

34.5 2 .o

3 .o 0.072

0.087 ....... i Eight arms at base..

Average.. .................. 2.25 0.164 31.2 0.079

Whole mouth, apparatus including the eight arms.. ...

I .6 2 . 0

a.148 0.121

28.0 32.5

2.15 5 .o

I .8 0.11s Average. .................. 3-57 0. '34 30.2

Table I. Under each degree of injury there were five individuals in the experiment. The two smallest are compared with the two largest, the medium individuals not being ipduded in the present table. T h e animals were not fed during the experiment. The specific amount of regeneration is the regenerated arm length per unit of disk diameter.

576 Charles Zeleny

TABLE 2

Ophioglypha l a c e i t o s e 0 n c arm removed at h e

a2 DAYS 33 DAYS 46 DAYS

Length of regenerating a m

Length of regenerating arm

Specific amount of regenera-

tion

Disk diametei


tion

Specific lmount of regenera-

tion

Remarks Length of regenerating arm

4.8 6.5 6.6

11.0

11.2

13.2

' 3 . 5 14.5 19.8

0.15

0.45 1 *4 0.6 2 . 0

0.2

I .o 0.0

0.03

0.07

0.05

0.18

0.21

0.01

0.07

0.2

0.1

2.4

3 -0

2.0

2 . 0

0.0

0.04

0.36 0.18 0.27

0.15

0.01

0.0

0.0

3 *o

4.0 3 . 1

2.0

0.0

0.45 0.18 0.36 0 . 2 3

Tabks 2, 3 ,4 and 5. The animals are arranged in order of size. The specific amount of regeneration is the regenerated length per unit of disk diameter. The individuals were not fed during the course of the experiment.

TABLE 3

Ophioglypha 1acertosFTwo arms iemoued at base

22 DAYS 3 3 DAYS 46 DAYS

Average length of .egenerat- .ting arms

Average length of regenerating arms


tion


tion

Disk diameter


tion


Remarks

6.0

6.5 8.7

10.8 13 .o 13.5 14.0 15.0

'9.3

dead (22

dead (22 )

0.55 1.9 1 .8

1 .25 . I .8 0.85 0.0

0.45 1.9 1 . 6

2 .3

3 .o 2.6 0.0

0.07

0.15

0.17

0.17

0.22

0.21

0.08 0.22

0.17

0.09 0 . 1 3 0.06

0.0

2 . 0

0 .65

3 . 5 3 -3 4-05 0.0

0.23

0.06

0 . 2 6

0.24

0.27

Disk diameter

5 - 5

9 .o

12.5

12.5

13.8 14.3

6.5

11.0

20.0

22 DAYS

Disk diameter

4.9 6.0 8 .z

11.3 12.3 12.8 1 2 . 8

15.2

18.3

33 DAYS

Effect of Age upon Regeneration


TABLE 4

OphioKlypha lacertosa-Three arms remoued at base


tion

Specific Bmount of regenera-

tion

Average length of

egenerating arms

0.6

1.15

1.35 2.25

1.1

1.1

0.05


0.09

0.10

0 . 1 1

0.18 0.08 0.08 0.00

1 .OS

I .75 2.35 4.25 3.4 I .7 0.35

specific amount of regenera-

tion

0.16

0.16 0.19 0.34 0.25

0 .12

0.02

3 *os 3.2 6.65 4.9 2.15

I .O

46 DAYS

0.28

0.26 0.53 0.36 0.15

0.05

Average length of

regenerating arms

* 65

2.45 I .85 2.15

0.6 1 .55

1.75 1 .o

I .O

Specific amount of

regeneration

0.13

0.17 0.30 0.16 0.17 0.05

0.12

0.05

0.12

TABLE 5

Average length of

regenerating arms

0.45 1.9 6.2 5.3 7.' 4.05 4.85 5 .55 3 -65

Ophioglypha Iaccrtosa -Four arms removed at base

Specific amoht of

regeneration

0.09 0.32 0.76 0.B

0.58 0.32 0.38 0.37 0.20

Average length of

regenerating arms

I .O

I .65

3 -65 4.6

4.3 2.1

2'9

3 . 3 I .75

Specific amount of

regeneration

0 . 2 0

0.27 0.56 0.52

0.35 0.16 0.23 0.22

0.10

577

Remarks

dead (22)

dead (46) dead (22)

578 Charles Zeleny

TABLE 6

Amblyrtoma jeferronianum. Nos. 2032-2076. First regeneration. rounger individuals. Reper- &ion period = 24 dayf (February 17 to March 13, 1907). Age at time of operation - 28 days

CATA-

LOGUE

NUMBER

w33 2039 2043 2046 2049 m53 2058

4 1

2072

2g6

Average..

2054

PART O F TAIL

REMOVED

(APPROX.)

whole whole whole whole whole whole whole whole whole whole

........... I

half

TOTAL

LENGTH OF

ANIMAL

22.0

20.0

24.0 23 .o 35 .o 21.5

21.5

22.0

24.0 23 .o

22.6

19.0

LENGTH OF REMOVED

TAIL

8.4

9.8 8.1

9.’ 10.1

8.4 8.5 8.5 9.4 9.’

8.94

6.7

LENGTH OF

1EGENERATP.D

TAIL

9.5 8.1 8.1

10.6 10.6 9 *2 8.6 9.4 9.5

10.0

9.36

7.7

SPECIFIC

AMOUNT OF

REGENLM-

TION

I .I3

0.83

I .os I .26 I .08

I .a,

1.10

I .OI

I .oo I .04

I .os

1.15

SPECIFIC

RATE OF

REGENERA

TION

0-47 0.w 0.035 0.046 0.044 0.052

0.045 0.042 0.042 0.044

0.0439

0.048

Tables 6 to 11. The eggs were collected on the morning of Janualy 20, 1907, and were probably laid during the previous night, all being in early cleavage stages at the time of collection. Nos. 2000 to 2014 arc exceptions, being collected on January 8. The specific amount of regeneration is the amount pw uniz of remooed mil. The h a 1 measurements made on June ao are from the animals as killed in Gilson’s fluid and preserved in 8.5 per cent alcohol. In Table 10 “no” regeneration means less than a mm. in, Table 11 it means less than I mm.

Effect of A g e upon Regeneration

8PfCIFIC

\MOUNT O F

REGENERA-

TI ON

0.56 0.68 0.77 0.59 0.4Y 0.60 0.48 0.60

0.596

0.65 0.75 0.60 0.57 0.51

0.72

0.63

5 79

SPI!CIPIC

RATE O F

REGENERA-

TI ON

0.037 0.045 0.051

0.039 0.033 0.040

0.032

0.040

0.0396

0.043 0.050

0.040 0.038 0.034 0.43

o .0422

TABLE 7

Amblystoma jcffersonianum. Nos. 2172-2214. First regeneraion. Toungcr individuals. Regener- orion period = 1s dr (February 23 t o March 10, 1907). Age a! time of operation - 34 days

CATA-

LOGUE

NUMBER

2172 2174 2180 2182 2191

2204 2213

Average..

2183 2186 2196 2199 2208

22x2

220 I

'ARTOF T N L

REMOVED

(APPROX.)

whole whole whole whole whole whole whole whole

...........,

half half half half half half

Average. . . . . . . . . . . . . . .

TOTAL

LENGTH OF

ANIMAL

27.5 26.0 25.0

27 .o 28 .o 27 .o 22.5

29 .o

26.5

28 .o 26.0 27 .o

28 .o 26.5

28.5

27.3

LENGTH OF

REMOVED

TAIL

11.3 10.5 9 *o

10.6 11.3 10.2

9.6 11.7

10.52

6.5 5.6 5.5 6.8 6.5 5.7

6.1

LENGTH Or

REGENER-

ATED T N L

6.3

6.9 6.3 5 . 5 6.1 4.6 7 .o

6.22

7.1

3.8

580 Charles Zeleny

TABLE 8 Amblystoma jefrrsonianum. Nos. zg7-2r7I. First regeneration. Tounger individuals. Regenera-

iion period - 15 &ys (March 9 to March 24, r w ) . Age at time f operation - 4 ahys ~

SPECIFIC

LMOUNT OF

REGENERA-

TION

SPECIFIC

LATE OF RE-

GENERA-

TION

CATA-

LOGUE

NUMBER

2078 2080

M85 toss 2091

2103

2118

2121

2123

2x28 2132 2'34 2141 2152

2'54 2158

.2160

2165 2168

2101

2111

.ENGTH OF

REGENER-

\TED TAIL

PART OF

AIL REMOVE1

(APPROX.)

whole whole whole whole whole whole whole whole whole whole whole whole whole whole whole whole whole whole whole whole whole

OTAL LENGTH

OF ANIMAL

LENGTH OF

EMOVED TAII

6.1 5.7 6.1 4.6 4.5 6.1 3 *8 5.6 7.5 4.4 6.8 4.9 5.4 7 .o 4.5 7.2 5.9 6 .7 7 .o 6:2 7.2

0.51

0.55 0.46 0.41 0 . 5 1

0.38

0.64 0.44 0.62 0.48 0.56 0.67 0.39 0.64 0.53 0.62

0.70

0.62 0.71

0.58

0 . 5 8

0.034 0.039 0.037 0.g1

0.027

0.034 0.025

0.039 0.043 0.029

0.041 0.032 0.037 0.045 0.026 0.043 0.035 0.041 0.047 0.041 0.047

28 .o 24.0 27.5 27 .o 26.5 29.0 25.0

24.5 29.0 26.0 28 .o 27 .o 25.0

27 .o 28 .O

28 .O

27.5 27.0

26.0 25.5 a7 .o

26.79

12.0

9-8 XI .o 10.0

10.9 12.0

10.0

9.7 11.7 10.0

11.0 10.2

9-7 10.4 11.5

11.2

10.8

11.2

10.0

10.0 10.2

10.63 Average.. ........... 5.87 0.0368

0.035 0.039 0.028

0.035 0.041 0.037 0.032

0.036 0.039 0.043 0.050

0.044 0.041 0.039

0.0385

2084 2087

2094

2107 21x2

2119 2124 2'33 2'35 2138 2x50

2156 2170

2098

half half half half half half half half half half half half half half

28 .o "5 .5 24.0 27.5 27 .o

26.0 29.5 27-5 26.5 25 .o

27.5 27.5 26.0

27 .o

7.2 6.5 6.4

6-9 6.5

5-6

7.1

7-9

6.6 6.0 7.1 6.1

6.0 6.4

0.53 0.58 0.42 0.52

0.61 0.55 0.48 0.54 0.59 0,65 0.75 0.66 0.62 0.58

0-577 Average.. ._._....... 26.75 6-59 3.80


I I I I

TABLE 9

Amblystoma jeflersonianum. Nos. Z O ~ Z - Z O ~ ~ . First regeneration. Older inquiduals. Regenera- tion period - 14 h y s (June 6 to yune 20, IW). Age at time of operation - 13r days

LENGTH OF

REMOVED

TAIL LENGTH

CATALOGUE

NUMBER

LENGTH OF

REGENtR-

ATED TAIL

Average . . . 2048 2057 2064 2062

24.5 25.7 24.4 26.0 27.1

Average ...

18.5 4.2 20.2 5 .O

20.2 3 -6 a0.4 3.2

23.1 5.'

PART O F

TAIL RE-

N O V t D

(APPROX.)

whole whole whole whole whole

, . . . . . . . . . half half half third

, . . . . . . . . .

TOTAL

LENGTH OF

ANIMAL8

8PtCIRC

AMOUNT 01

BEGENEM-

TED TAIL

0.23 0.25

0.18

0.16 0.22

51.62

48.3 51.7 47.5 49.0

23.5 10.4 24.9 8.1

0.208

0.24 0 . q

0.29

0.33 I I I I

SPECIFIC

RATE OF

REGENEM-

TION

0.016 0.018

0.013

0.016 0 . 0 1 1

0.0148

0.017 0.018

0.024 0,021

0.020

Charles Z elen y

PART OF

TAIL

REMOVED

TABLE 10

Amblystoma jejersonianum. Nos. 2077-2r7X. First regeneration. Older individuals. Regmeration period - X I days (June 9 to yune 20, I W ) . Age at time of operation - I34 &ys.

TOTAL

LENGTH 01

ANIMAL

CATA-

LOGUE

NUMBER

208 I

lo90 2099 2105

2117 2126 2130 2142 2147

2110

whole whole whole whole whole whole whole whole whole whole

Average . .

52.5 5 1 . 2 56.0 55.0 53.3 59.1 5 5 . 0 52.1 50.8 56.0

2082

2108

2114

2136 2151

2164

2100

2122

Average ..

I ..........

41.2 half 56.0 half 58.3

50.0 half 51.6 half 54.2

52.45 ..........

'AIL LENGTF

27 .o 24.9 27.8 28.2

25.9 29.6 27.9 25.4 24.3 27.8

26.88

26.9 26.9

'9.9 29.2

29.3 25.6 25.3 26.8

26.24

.ENGTH OF

REMOVED

TAIL

22.3

'9.4

23 .o

24.0 22.0

20 .5

18.9 23.1

21 .2

20.0

21.43

15.0

8.8 '3.9 12.9 12.9

12.8

12.2

11.1

'2.45

.ENOTH OF

REGENER-

\TED TAIL

3.9 3.6

I .8( ?) 2.0

2 . 5

4.0 3.3

2 .8

3.7

2 . 0

2.96

2 . 0

none

2.5 2.6 none none 2.1

none

SPECIFIC

MOUNT OF

REGEXLR-

%TED TAIL

0.18 0.19 0.09 0.08 0.12

0.17 0.15

0.15 0.16

0.10

0-139

0.13

0 .28

0.19

0.19

SPECIFIC

RATE OF

REGENLR-

ATION

0.016 0.017 0.008 0.007

0.015

0.014 0.009 0.014 0.015

0.011

0.0126

0.012

0.025

0.017

0.017

Efec t of A g e upon Regeneration

CATALOGUE

NUMBER

2175 2181 2185 2193 2198 2203 z a g 2214

Average . . . a=?? 2188 2194 zaos 2209

Average . . .

583

PART OF

TAIL

REMOVED

(APPROX.)

whole whole whole whole whole whole whole whole

. . . . . . . . . . . half half half half half

. . . . . . . . . . .

TABLE 11

Amblysroma jefferronianum. Nos. 2172-2214 First regeneration. Older individuals. Rcgenera- tion period = 10 days (June 10 to June 20, 1907). Age at time of operation - I35dayr

.ENGTH OF

REMOVED

TAIL

LENGTH OF

REGENER-

ATED TAIL

TOTAL

LENGTH

OP

ANIMALS

20.0

20.4 21.1

18.5 a1 .o 21.3 21.2

20.2

51.6

56.2 54.1 49.8 47.4 52.1

3.7 4.4 3 .o

1 .5

4.0 3 * 8 4.3

2.8

51.9

TAIL

LENGTH

24.2

26.1 27.9 23.5 25.9 27.6 25.4 24.1

25.6

28.7 27 .? 23.4 24.4 26.6

26.2

SPECITIC

AMOUNT

IF REGEN-

EMTlON

0.18

0.14 0.15

0.07

0.19 0.18 0.21

0.22

12.1

11.0

11.3 none 11.5

0.167

0.16 0.08 0.20

0.14

I I

SPECIFIC

RATE O F

REGLNER-

ATlON

0.018

0.022

0.014 0.015 0.007 0.019 0.018 0.021

0.0167

0.016 0.308 0 . 0 2 0

0.014

584 Charles Zeleriy

TABLE IZ Cambarus propinquus. Nos. 2jq-298. RQht chela removed 2 & rh molt

>.OIS

).023 ).023 >.025

,.023

~ 0 2 3 ). 026 LO25

Average ................I 14.6 I 5.4 I 6.52

Table 12. In all chela measurements in this and the following tables “chela length’’ means the greatest length of the propodite. The specific amount of regeneration is the amount per unit of cephalo-thoracic length. The average length of the right chela in a control series of 17 unoperated individuals was 3.41 mm. at the sixth molt.

TABLE 13 Cambarus propinquus. Nor. 2391-2483. Right chela removed one day after fourth molt

+ 2402 2406

2409 24IZ

2435 2477

4-6 4-6 4 4 4-6 4-6 4-6

14

‘3 ‘3 16 ‘ 5

I2 5.3 5.3 5.3 5.3 5.3 5.3

6.72 6.69 6.88 7.22 7.14 6.58

0.46 0.54 0.47 0.44 0.57 0.62

0.033 0.045 0.036 0.031 0.036 0.04’

13.8 5.3 6.87 3.61 I 1.86 0.52 0,037 Average .................

Table 13. The average length of the right chela in a control series of 18 unoperated individuals was 3.52 mm. at the sixth molt.

i:

??

??

??

??

??

??

??

i I B

88JJHH223B 8

8 B

w

0

OIv

l N

-b

- N

o

ww

- wv

-

CA

TA

LO

GU

E

NU

MB

ER

DA

YS:

O

PER

AT

ION

TO

MO

LT

CE

PH

AL

MH

OR

AC

IC L

EN

GT

H

LE

NG

TH

O

F

UN

INJU

RE

D

LE

m

CH

EL

A

LE

NG

TH

O

F R

EG

EN

ER

AT

ED

RIG

HT

CHELA

SPECIFIC A

MO

UN

T OF R

EG

EN

ER

-

AT

ION

SPE

CIF

IC R

AT

E

OF

R

EG

EN

ER

A-

TlO

N

LE

NG

TH

O

F R

EG

EN

ER

AT

ED

CHEI

A P

ER

UN

IT O

F U

NIN

-

JUR

ED

CH

EL

A

LE

NG

TH

R

EG

EN

ER

AT

ED

PER

DAY PER

UN

IT OF

UN

IN-

JUR

ED

CH

EL

A

Q 3

586 Charles Zelenj

DAYS:

OPERATION

TO MOLT

'35 '$0

1x9 104 I06

'63 I08

'65 1$2

I33 I 53 167 I 8 1

'44

TABLE 15 Cambat us propinquus. Nos. 733-806. Adult females. Single chela removed.

CEPHALO-

THORACIC

LENGTH

11 .o 11.3 14.0 14.6 15 .0

15.2

15.4 15-7

'5.9 16.2 17 .o 17.0 18.0

18.8

CATA-

LOGUE

NUMBER

SPECIFIC

AMOUNT OF

REGENERA-

TION

SPECIFIC

RATE OF

REGENERA-

TION

LENGTH OF

UNINJURED

LEFT CHELA

LENGTH OF

SEGENERATEI

SIGHT CHELA

791 807 775 785 743 784 738 760 799 796 75' 805 770 759

6.4 5.6 9-1 8.3 9.' 9 -6 9 .o 9-4 10.4 10.6

10.5

11.1

10.0

12.2

4.6 3.8

6.3 6.4 6.0 6.9 6.0 6.8 6.7 6.2 6.1 7.0 7.1

6.0

0.418

0.429 0.432 0.427 0.395 0.448 0.382 0.427 0.414 0 * 365 0.359 0.389 0.378

0.336 0.0031

0.0024 0.0036 0.0042 0.0040 0.0024 0.0042 0.0023 0.0030

0.0031

0.0024 0.0021

0.00ZI

0.0026

6.14 0.400 0.0030 Average. . . . , . . . , . . . . . . . . , . . . . , . . . . . . . . . . . , . . . . , . . TABLE 16

Cambarus propinquus. Nos. 73j-806. Adult maler. Both chele and last t w o pairs of walking legs removed

LENCXH OF REGENERATING CHELE SPECIFIC

RATE OF

EOENERA-

TlON

SPECIFIC

MOUNT OF

E GENE RA-

TION

CATA-

LOGUE

NUMBER

DAYS:

>PERAT1 ON

TO MOLT

EEPHALO-

rHORACIC

LENGTH Right Left Average

789 739 792

801

740

803

764 780 7 9 0 748 732 773 76s

34 33 44 42 65 76 84

48 83 69 95 73

44

1 1 . 0

12.2

'3.4 '3.5 '4.3 14.7 14.7 14.8 ' 5 . 5 15.8 16.5 16.9 17 .5

4.6 5 -2 5 *2 5 *O

6.75 6.7 7.1 6.8 6.7 6.3 6.3 7.6 8.2

0.418 0.434 0.388 0.393 0.469 0.459 0.43 0.473 0.432 0.402 0.385 0.450 0.471

0.0123

0.0132

0 .0088

0.0094 0.0072 0.0060 0.0057 0.0107

o.Oo90 0.0048 0.0056 0.0047 0.0065

6.4 0.435 0.0080 Average . . , . . . , . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . , .

Effect of Age upon Regeneratioti 58 7

TABLE 17

Cambarus propinquur. Nos. 733-806. Adult females. Both chele and last t w o pairs of walking

CATA-

LOGUE

NUMBER

-___

734 74' 794 742 747 795 787 800 793 772 779

73' 749 763 755 771 756 782 750

769

DAYS:

JPERATION

T O MOLT

27 29 37 3' 3' 35 32 37 33 TI8 I08 32 '34 1 I7

52

"5 '43 148 147

I21

CEPHALO.

THORACIC

LENGTH

11.8 11.9 12.4 12.6 '3.5 '3 * 5 '3.7 '3.9 14.0 14.0 15.0

15.2

16.1 16.4 16.9 '7.3 17.8 17.8 18.8 19.0

legs removed

LENGTH OF REGEYERATING CHELA3

Right

4.9

5.3 5 . 5 6.2 5.6 5.6 6.1 5.3 6.1

6.2 6.8 6.1 6.7 6.8 7.2 7 ,O

7 .O

6.8

5.6

Left

4-9 4-7 5 .o 5-4 6.1 5.4 5.7 5.9 5.4 6.3 5 . 6

6 .9

6 . 9

6.2

6.2

7 .o 7 .o 6.9

6.3 7.4

Average.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Average

4.9

5.15 5.45 6.15 5 . 5 5.65 6.0 5.35 6.2 5.6 6.2 6.85 6.15 6.8

4.7 ( 9

6.9

6-95

6.55

7.1

7.2

6.07

SPECIFIC

MOUNT OF

ECENERA-

TION

0.415 0.395 0.4'5 0.433

0.407 0.412 0.432 0.382 0.443 0.373 0.408 0,425 0.375 0.402 0.399 0.399 0.390 0.383 0.345

0.456

0.404

SPECIFIC

RATE OF

LEGENERA-

TION

0.0154 0.0136

0.0140

0.0116

0.0129 0.0117 0.0116 0.0038 0.0035 0.0127

0.0032 0.0032 0.0077

0.0033 0.0035 0.0027 0.0026

0.0023

0.0112

0.0147

0.0078

588 Charles Zeleny

TABLE 18

Cambarus bartoni. Nos. 22x8-2267. Single chela removed. Regeneration during molts four io six

AVERAGE

CEPHALO-

THORACIC

LENOTH

MOLTS 4, 5

SPECIFIC

X O U N T OF

EGENERA-

T l O N

SPECIFIC

RATE OF

REGENERA-

TI ON

.ENOTH OF

J N l N J U RET

CHELA

LENGTH OF

REGENERAI.

I N G CHELA

CATA-

LOGUE

NUMBER

INTERVAL

I N DAYS MOLTS

2223 2262 2218

2219

2259 2239 2298 2227

2238

2252

L2242

4-54 4-54 4-5-6 4-5-6 4-5-6 4-54 4-5-6 4-5-6 4-5-6 4-5-6 4-5-6

23 '9 "3 26 '9 31 "4

23 28

20

20

6.5 6.5 6.6 6.6 6.6 6.7 6.7 6.8 6.8 6.8 6.9

4.0 4.7 4.7

4.9 4.4 4.4 5 . 1

5 * o 4.8 5 . 5

4.74

4.6

0.54 0.45 044 0.53 0.45 0.4 0.46 0.53 0.53 0 .51

0.45

0.488

0.023

0.024 0.019

0.024 0.015

0.015

0.0265

0.023

0.018

0.0225

0.020

0.021 2 3 . 3 6.68 3.26 Average. . . . . . . . . . . . . . .

Tables 18, 19, 20, and 21. The specific amount of regeneration is the length of the regenerated chela propodite per unit of cephalo-thoracic length.

TABLE 19

Cambarus bartoni. Nos. 2218-zz67. Single chela removed. Regeneration during molts eight to nine and nine to ten

SPECIFIC

RATE OF

REGENERA-

TION

LENGTH OF

REGENERA-

TING CHELA

4MOUNT OF

TION

CATA-

LOGUE

NUMBER

CEPHALO-

THORACIC

LENGTH

LENGTH 01

UNINJUREI

CHELA

INTERVAL

I N DAYS MOLTS

I 2241 2246 2267 2221

2220

8-9 8-9 8-9 9-10 9-10

27 30

27 43

20

10.5

10.5

11.5

11.7

IO.S(?)

7 .o 7.1

7.4 8 .o

6.7

0.019 0.018

0.021

0.017 0.012

0.46 0.50

5.36 0.484 '0.94 7.24 0.017 Average . . . . . . . . . . . . . , 29.4


CATA-

LOGUE

NUM-

BER

MOLTS

589

INTERVAL

I N DAYS

TABLE 20

Cambmus bartoni. Nos. 2218-2267. Both Chela removed. Regenermion during molts four to six

LENGTH OF REGENERATING C H E m SPEC'F1C AMOUNT OY -1 REGENERA- TION

SPECIF1o

RATE OF

REGENERA- TION

2253 2245 2237

4-5-6 4-5-6 4-54

20

26 27

Average I . . . . . . . . . . I 24.3

3.05 4.0 4.2

CEPHALO

rHORACIC

LENGTH

80LTS 4,5

0.46 0.58 0.59

6.7 6.9 7.1

8-9 8-9 8-9 9-10

10-11

. . . . . . . . .

6.9

INTERVAL

I N DAYS

22

20

27 25

30

24.8

.ENGTH OF REGENERATING CHELAE ~ P E C I F I C

o .023 0 .022

0.022

5.' 4.1 5.4 5.9 6.8

3.77 I 3.73

5 -0

4.5 5.5 6.0 6.6

TABLE 21

Cambarur bartoni. Nos. 2218-2267. Both chela removed. Regeneration during molts 8-9, 0-10

-

CATA-

LOGUE

NUM-

BER

3228

2240 2222

2258

2233

Averag

CEPHALO

PHORAClC

LENGTH

10.2 (?; 10.5.

10.9 11.9

12.1

1 1 . 1 2

Left I Right

' 5.46 I 5.52

SPECIFIC

RATE OF

UXENERA-

n ON

0.022

0.0205

0.019

0.018 0.020

0.020

590

CAT+

LOGUE

NUMBER

14332 1441

1450 1452

1442 '439 '45'

Charles Zelenv

FINAL

CEPHALO-

LENGTH

6.8 7.4 9-7

10.6 11.0

13.1

7.6 8 .o

11.8

SPECIFIC

4NOUNT OF

REGENERA-

TION

0.296

0.374 0.326 0.284 0.382

0.338 0.351 0.356

0.341

TABLE 22

Palamon ten u icorn i s . Nos. 1432-1452

I SPECIFIC

RATE OF

REGENERA-

TI ON

0.044

0.039 0.031 0.026

0.029

0.044 0.044 0.030

0.046

FINAL

REGENERA-

TION

LENGTH OF

REGENER-

4TED CHELA

third third third third ( ?) third third

second second second

LENGTH 0

MOLTING

PERIOD

ENOTH 01

ININJURE1

CHELA

2 .OI

2.52 3.63 3.46 3.12 5 - 0 0

2.56 2.81 4.20

?

2.95 4.18 4.25 3.81 6.56

2.80

5.03

?

8. 10

8

8 I1

I0

I 0

I1

I2

Table 22. The specific amount of regeneration is the regenerated chela propodite length divided by the final eephalo-thoracic length, i. e., the length regenerated per unit of cephalo-thoracic length. The length of the uninjured chela is not as good a standard as the body length because its length may be affected by the removal.

Effect of A g e upon Regeneration

First regeneration

591

Second regeneration

TABLE 23

in cephdo-thoracic lengih Palamonetes vulgaris. Nos. 1755-1805. Regeneration of the chelrs in individuals 7.2 to 13.6 mm.

0.27 0.16 0.14 0 .20

0.20

0.16 0.24

0.18

0.27 0.22

0 .25

0.21

0 .22

u a * u w o m

$ 5 S "

I777 '77'

I779 I765

I758 1778 179' 1761 1780 I789 1795 1801

I757 I776 '759 1763 1787

1783 1784 1785

1768

1797 1766 I782 1781 1762 1767 1786 '770 1773 1804

Average

I

I

I

1

I

I

2

I

a 2

2

2

2

I

z " - F & s 5

$ $ Z $

5!

D

21

I2

8 I2

10

I2

17 I 1

I 1

18 14 14 17 16 16 17 9

'3 17 ' 5 17 17 ' 5 13 16 14 ' 5

10

I2

I2

20

. . . . . . .

0.22

0.23 0.21

0.16 0.16 0.18

0.24 0.24 0.25

0.20

0.20

0.23 0.19 0.22

0.22

0.17 0.17 0.22

7.2 8.9 9.5 9.8 9.9 9.9 9.9

10 0

10.0

10.0

10. I

10.1

10.2

10.2

10.4 10.7 10.7 10.9 11.0

11.0

11.0

11.0

1 1 . 1

11.1

11.2

1 1 . 5

1 1 . 5

13.0 13.2 13.6

12.0

2.20 0.22

2.30 0.22

2.27 0.21

1.62 0.15 1.65 0.15

2.07 0.19 2.48 0.23 2.52 0.23 2.63 0.24 2.17 0.20

2.12 0.19

2.35 0.21

2.22 0.19 2.41 0 . 2 1

2.65 0.22

2.27 0.17 2.26 0.17 2.88 0.21

........ I

.ENGrA I OF3GI- IAL RE- MOVED CHELA - LEIT E RIGHT

12.01

r 2.77 r2.73 12.69 r 2.79 12.83 12.96 r2.87

13.18 13.12 '3.14 r 2.79

r2.67 r3-45 12.98 r3.22

13.15

12-94

13.43 12.90

13-32

14.33

r3.65 13.45 r 4.59 r 5.65 '4.92

12.98

r3.11 13.06

r 3.42

........

FIRST MEASURE-

MI -

:ngth o ninjurec chela

2.06 2.83 2.85

2.83 3-14 3.06 3.12 3.23 3.43 3-14 3.14 3.02 3.10 2.93 3.44 3-17 3 *33 3 -45 3-19 3.16 3-53 2-45

4.40 3.75 3,74 2.72 4.44 4.99

2.98

3.38

4.89

,...... -

r

ength o regener- ted chel;

I .25

2.19 1.61 2.38 1.75 I -93 2.43 1.99. 2.38 2.76 2.09 2.27 2.29 2.37 2.47 2.66 2.54 2.63 2.16 2.40 2.35 2 .7a I .78 2.67 2-09 2.79 2.72 2.67

3.24 3.10

2.01

. . . . . . .

Lengtk

1-93 I .45 I .32 I .93 I .96 I .63 2.40 2 .07 I .78 2.71

2.5'

2.29

2-35 2.25

I .70 I .73 I .96 2.60

2.64 2.71 2.27 2 .22

2.59

2.50

2.67 2 . 2 5

1.27 2.97

2.20

2.21

2.20

2 .20

-

Sp. arnt. I Length I Sp. arnt.

0 . 2 7

0.19

0.14 0.19

0.19 0.17 0.24

0.18 0.27 0.22

0.24 0.22

0.w

2.17

Table 23. The individuals are arranged in order of final cephalo-thoracic length. The specific amount (sp. amt.) of =generation is the length of regenerated chela propodite per unit of cephalo- thoracic length.

592 Charles Zeleny

T.4BLE 24

Palamonetes uulgaris. Nor . 18061861. Relation of size (age I) to ihe rate of regeneration. Right chela alone removed

Without a molt

With a molt . . .

CATALOGUE

N U M B E R

F I N A L

CEPHALO-

THORACIC

LENGTH

8 .o 9.7 9 .7

10.0

6 . 1 9.'

11.1

11.1

RlGHT.CHEL-4

F I N A L

L E F T CHELP

2 . 5 1

2.75 2.95 3.11

2 . 0 0

2.74 3 .7? 4.07

2.52

2.81

2.95 3 -4

I . 88 2 .62

3.59 4.02

0 . 5 2

0.79 0.70

0.85

0.60 0 . 5 2

0.48 0 .55

A M O U N T O F

REGENERA-

T I O N P E R

U N I T OF RE-

MOVED C H E L A

LENGTH

0.20

0.30

0.27

0.23

0.32

0.13 0.14

0.20

Tables 24, 25 and 26. The specific amount of regeneration is the regenerated chela propodite- The short period of regeneration eliminates the proba- length per unit of removed chela propodite.

bility of error due to change in length of the uninjured chela.

TABLE 25

Pahmonetes vulgaris. Nor. 1806-1861. Relation of s i u (age?) to rate of regeneration

Without a Molt

With a Molt. . .

CATALOGUE

N U M B E R

1858 1 8 1 6

1 8 5 2

1846 I828 I 840

1834 I810

1822

F I N A L

CEPHALO-

THORACIC

LENGTH

9.' 9.3

10.5

11.1

1 2 . 1

12.2

8.4 9.3

11.6

F I N A L

R I G H T

C H E L A

LENGTH

2 .65 2.80

3.41 3.81 4.04 4.43

2.70

2.85

3.89

L E F T CHELA

3.81 0.82 4-00 0.69 4.52 0.79

2.64 2.88 3.68

1.10

0.62 0.62

SPECIFIC

A M O U N T OF

REGENERA-

T I O N

0.27 0.27

0.24 0 .22

0 . 1 7

0.17

0.42

0.17 0.22


Rep- erated length

0.74 0.59 0.61

0.59 0.81 0.83 0.85

0.62

0.84

0.77 0.76 1.26 0.79 0.52 0.65 1.48 1.41

0.94

593

Specific amount

0.29 0.23

0.25

0.26 0 . 2 5

0.24

0.18

0 .20

0.19 0.39 0.53 0.32 0.18

0 . 2 1

0.48 0.41

0 . 2 2

0.24

TABLE 26

I’dernoneter zulgaris. Nos. 18061861. Relation of size (age ?) to the rate of regeneration. Both chela remowed

0.74 0.59 0.66

0.59 0.89 0.89 0.81 0.90 0.56 0.93 0.77

?

1.36 0.80 0.52

0.68 1.48 1.37

Without a

Molt

With a

Molt

0.29

0.23

0.26

0.28

0 . 2 7

0.23

0.23

0.16

0.27.

0 . 2 2

0.19 ?

0.57 0.32

0.18 0.22

0.48 0.40

CATA-

LOGUE

NUMBEB

1854

1857

I 809

1836 1824 1851

1861 1818

1827 1845 1839 1812

1860 1806

1830 1842

1821

1833

F I N A L

CEPHALC

THO-

RACIC

LENGTH

8.4 8.9 9.0 9.’ 10.4 11.6 !1.7 11.8

11.9

12.7

7.9

9.2

12.1

6.5

8.3

9.8 10.0

10.0

Original length

2.56 2.. 62 2.44 2.69 3.12 3.35 3.48 3.92 3.55 4.24

1.93 2.37 2 4 2.89 3.06 3.11 3 -40

3.96

L E F T C H E L A

Original length

2.56 2.62

2.52

2.69 3-14 3.35 3.48 3.92 3.55 4.24

I .93 2.37 2.48 2.90

3.13 3.11

3.40

3.96

RIGHT CHELA

I Specific amount

Regen- erated length

some experiments on the effect of age upon the rate of regeneration

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