2 THE STRUCTURE OF MAN © 
recelving 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- 
elgnty was regarded as heresy. Even the laity persistently 
refused to submit Man to the same strict scientific analysis 
which, with increasing clearness, was being appled 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—Paleontology, 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 earler 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 paleontological 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 
a 
