div class=ts-pagebutton class=gotoPage data-page=1Page 1button div class=ts-imageimg data-url=length-of-gestation-period-and-menstrual-cycle-in-the-chimpanzeehtmlpage=1 data-page=1 class=ts-thumb lazyload alt=Page 1: Length of Gestation Period and Menstrual Cycle in the Chimpanzee loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader036vdocumentssitereader036viewer2022080320575067d51a28ab0f07ad5db5html5thumbnails1jpg width=140 height=200 divp© 1936 Nature Publishing Grouppdivdiv class=ts-pagebutton class=gotoPage data-page=2Page 2button div class=ts-imageimg data-url=length-of-gestation-period-and-menstrual-cycle-in-the-chimpanzeehtmlpage=2 data-page=2 class=ts-thumb lazyload alt=Page 2: Length of Gestation Period and Menstrual Cycle in the Chimpanzee loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader036vdocumentssitereader036viewer2022080320575067d51a28ab0f07ad5db5html5thumbnails2jpg width=140 height=200 divp© 1936 Nature Publishing Grouppdiv