6 INTRODUCTION. 



disposed of both Darwin's " gemmules " and Herbert 

 Spencer's " primordial units," while Eimer breaks a 

 lance with Weismann in defence of Darwin, and 

 Herbert Spencer replies for himself, assuring us that 

 " either there has been inheritance of acquired charac- 

 ters or there has been no evolution." 



It is the greatest compliment to Darwinism that it 

 should have survived to deserve this era of criticism. 

 Meantime all prudent men can do no other than hold 

 their judgment in suspense both as to that specific 

 theory of one department of Evolution which is called 

 Darwinism, and as to the factors and causes of Evolu- 

 tion itself. No one asks more of Evolution at present 

 than permission to use it as a working theory. Un- 

 doubtedly there are cases now before Science where it 

 is more than theory the demonstration from Yale, 

 for instance, of the Evolution of the Horse; and from 

 Steinheim of the transmutation of Planorbis. In these 

 cases the missing links have come in one after an- 

 other, and in series so perfect, that the evidence for 

 their evolution is irresistible. " On the evidence of 

 Paleontology," says Mr. Huxley in the Encyclopcedia 

 J3i'itannica, " the evolution of many existing forms of 

 animal life from their predecessors is no longer an hy- 

 pothesis but an historical fact." And even as to Man, 

 most naturalists agree with Mr. Wallace who "fully 

 accepts JVTr. Darwin's conclusion as to the essential 

 identity of Man's bodily structure with that of the 

 higher mammalia and his descent from some ancestral 

 form common to man and the anthropoid apes," for 

 " the evidence of such descent appears overwhelming 

 and conclusive." * But as to the development of the 

 1 Darwinism, p. 451. 



