224 Proceedings of Royal Society of Ediribiirgh. [sess. 
thus referred to by Darwin : — “ It is notorious that Man is con- 
structed on the same general type or model as other animals. All 
the bones in his skeleton can he compared with corresponding hones 
in a monkey, hat, or seal ; so it is with his muscles, nerves, blood- 
vessels, and internal viscera. The brain, the most important of all 
the organs, follows the same law, as shown by Huxley and other 
anatomists. Bischoff, who is a hostile witness, admits that every 
chief fissure and fold in the brain of Man has its analogy in that of 
the orang ; but he adds that at no period of development do their 
brains perfectly agree ; nor could perfect agreement be expected, for 
otherwise their mental powers would have been the same ” (^Descent 
of Man, p. 6). This correspondence becomes still more apparent 
when we examine the phenomena of the foetal life of animals. Hot 
only does the human embryo start from an ovule similar to, and. 
indistinguishable from, that of other mammals, but its subsequent 
changes follow on precisely the same lines. Moreover, all the 
homologous organs in the full-grown animals, as the wing of a bird, 
the flipper of a seal, and the hand of Man, are developed from the 
same fundamental forms. “Without question,” says Professor 
Huxley, “ the mode of origin and the early stages of the develop- 
ment of Man are identical with those of the animals immediately 
below him in the scale” {CoUeeted Essays, vol. vii. p. 89). 
The illustrious von Baer, who first directed special attention to 
embryology, formulated a law to the effect that the structural 
differentiation in foetal development was from a general to a special 
type. Haeckel, looking at the same phenomena from a different 
standpoint, came to the conclusion that the development of the 
individual is a recapitulation of the historic evolution of the race. 
This is a most astounding statement; and, if true, the study of 
embryology should supply the anthropologist with a much shorter 
way to the goal of his inquiry — a way by which the progressive 
phases of man’s corporeal structure would be reduced to the com- 
pass of an experimental illustration within the precincts of the 
laboratory. Hot being a practical physiologist, I am unable -to 
determine the precise value to be assigned to this analogy between 
the two evolutions, but, on other grounds, I should say that it is 
true only in a very general way. If embryology is as conservative 
of energy as other organic processes, I would expect that some 
