88 EVOLUTION AND MAN S PLACE IN NATURE 



phenomena presented by the development of animals. 

 We see the most diverse forms, a mollusc, a frog 1 , 



* ^ O 



and a mammal, arising from apparently identical 

 primitive cells, and progressing for a time by very 

 similar initial changes, but thereafter each pursuing 

 its highly complex and often circuitous course of 

 development, with unerring certainty, by means of 

 laws and forces of which we are totally ignorant. 

 This is the testimony from the newly-developed 

 department of embryological science. The size of 

 the particles which are derived from the parents, 

 called the male and female pronuclei, the potentiality 

 of which is so utterly out of proportion to their bulk, 

 is almost inconceivably small when compared with 

 the magnitude of the adult body. l This minute 

 fertilised ovum from which the elaborate organism 

 springs, apparently a simple sphere with a pin-point 

 centre as the nucleus of life, is yet complex in 

 chemical and molecular character, and has within it 

 provision for unfolding all the features of differen 

 tiated organism common to its species. What we see 

 in the dog, the horse, or the ape, when maturity has 

 been reached, is lying in germ within the ovum from 

 which the life-development takes its rise. The 

 ovum, in its young condition, is obviously nothing 

 but a simple cell/ 2 Thus, it is in no way necessary 

 that a germ should have the character of a minia 

 ture. 3 The marvel is further extended, when it is 

 added in the words of Professor Huxley, that it is 



1 Sir W, Turner s Address to British Association, 1889 : Nature, 

 vol. xl. p. 526. 



2 Comparative Embryology, by F. M. Balfour, vol. i. p. 19. 



Cyples s Human Experience, p. 490. 



