16 THE DESCENT OF MAN. Part I. 



carefully copied from two works of undoubted accu- 



racy. 11 



After the foregoing statements made by such high 

 authorities, it would be superfluous on my part to give 

 a number of borrowed details, shewing that the embryo 

 of man closely resembles that of other mammals. It 

 may, however, be added that the human embryo like- 

 wise resembles in various points of structure cer- 

 tain low forms when adult. For instance, the heart 

 at first exists as a simple pulsating vessel ; the excreta 

 are voided through a cloacal passage ; and the os 

 coccyx projects like a true tail, ' ' extending considerably 

 " beyond the rudimentary legs." 12 In the embryos of 

 all air-breathing vertebrates, certain glands called the cor- 

 pora Wolffiana, correspond with and act like the kidneys 

 of mature fishes. 13 Even at a later embryonic period, 

 some striking resemblances between man and the lower 

 animals may be observed. Bischoff says that the con- 

 volutions of the brain in a human foetus at the end of 

 the seventh month reach about the same stage of deve- 

 lopment as in a baboon when adult. 14 The great toe, as 

 Prof. Owen remarks, 15 " which forms the fulcrum when 

 " standing or walking, is perhaps the most characteristic 



11 The human emhryo (upper fig.) is from Ecker. 'Icones Phys.,' 

 1851-1859, tab. xxx. fig. 2. This embryo was ten lines in length, so 

 that the drawing is much magnified. The embryo of the dog is from 

 Bischoff, ' Entwicklungsgesckichte des Hunde-Eies,' 1845, tab. xi. fig. 

 42 b. This drawing is five times magnified, the embryo being 25 days 

 old. The internal viscera have been omitted, and the uterine appen- 

 dages in both drawings removed. I was directed to these figures by 

 Prof. Huxley, from whose work, ' Man's Place in Nature,' the idea of 

 giving them was taken. Hackel has also given analogous drawings in 

 his ' Schopfungsgeschichte.' 



12 Prof. Wyman in ' Proc. of American Acad, of Sciences,' vol. iv. 

 I860, p. 17. ' 



13 Owen, ' Anatomy of Vertebrates,' vol. i. p. 533. 



14 'Die Grosshimwindungen des Menschen,' 1868, s. 95. 



15 'Anatomy of Vertebrates,' vol. ii. p. 553. 



