2 THE STRUCTURE OF MAN 



receiving immense support from the Mosaic cosmogony, which 

 assigned to Man a sovereign position over nature, and especially 

 over the animal kingdom. Every attempt to shake this sover- 

 eignty was regarded as heresy. Even the laity persistently 

 refused to submit Man to the same strict scientific analysis 

 which, with increasing clearness, was being applied to the 

 surrounding forms of life by the existing schools of natural 

 philosophy. 



In spite of this opposition, however, the theory of descent 

 steadily gained ground, and its advance was especially favoured 

 by new and surprising results attained in the three closely 

 allied branches of science Palaeontology, Comparative Anatomy, 

 and Embryology. The proofs of the great changes which must have 

 taken place in both the animal and vegetable kingdoms, during 

 the immeasurable periods consumed in the development of our 

 planet, became more and more convincing. 



The earlier assumption of repeated separate acts of creation 

 gave way to a more satisfactory and strictly scientific conception 

 of the fundamental unity of all organic nature. " Blood relation- 

 ship, and not some unknown plan of creation, forms the invisible 

 band which unites organisms in various degrees of similarity," 

 and in this great family Man must find his place. He forms 

 but a link in the chain, and has no right to consider himself an 

 exception. To claim for himself a special act of creation, in order 

 to account for his appearance in the series of living creatures, would 

 be nothing less than a denial of the unity of physiological science. 



It may be that we have not as yet succeeded in tracing back 

 the primitive history of Man beyond diluvial times by the light 

 of palseontological discoveries, for no certain proof of the actual 

 existence of tertiary Man has been obtained. But this " break 

 in the record " cannot in the least impair the evidence of mor- 

 phology as to the real ancestry of Man. Comparative morpho- 

 logy points not only to the essentially similar plan of organisa- 

 tion of the bodies of all Vertebrates, and to the agreement in 

 their entrance into life, individual existence, and final dissolution, 

 but also to the occurrence in them of certain organs, or parts of 

 organs, now known as " vestigial." 



By such organs are meant those which were formerly of greater 

 physiological significance than at present. In the course of 

 generations, in consequence of the adaptation of the body to special 

 conditions of life, they have been, so to speak, put out of the 

 running, subjected to reduction or degeneration, and now persist as 



