16 THE DESCENT OF MAN. [Part I. 



After the foregoing statements made by such high 

 authorities, it would be superfluous on my part to give a 

 number of borrowed details, showing that the embryo of 

 man closely resembles that of other mammals. It may, 

 however, be added that the human embryo likewise resem- 

 bles in various points of structure certain 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, " ex- 

 tending considerably beyond the rudimentary legs." 12 In 

 the embryos of all air-breathing vertebrates, certain glands 

 called the corpora Wolffiana, correspond with and act like 

 the kidneys of mature fishes. 13 Even at a later embryo- 

 nic period, some striking resemblances between man and 

 the lower animals may be observed. Bischoff says that 

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

 of the seventh month reach about the same stage of de- 

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

 as Prof. Owen remarks, 16 " which forms the fulcrum when 

 standing or walking, is perhaps the most characteristic 

 peculiarity in the human structure ; " but in an embryo, 

 about an inch in length, Prof. Wyman 16 found that the 

 great toe was shorter than the others, and, instead of be- 

 ing parallel to them, projected at an angle from the side 

 af the foot, thus corresponding with the permanent condi- 



internal viscera have been omitted, and the uterine appendages 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 waa 

 taken. Hackel has also given analogous drawings in his 'Schopfungs- 

 geschichte.' 



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

 1860, p. 17. 



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



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



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



ls 'Proc. Soc. Nat. Hist.' Boston, 1863, voL ix. p. 186. 



