EVOLUTIONAL ZOOLOGY 2ig 



The almost unparalleled excitement throughout the civil- 

 ized world which his views produced when they became known, 

 and also the storm of opposition and abuse which broke over 

 his head are facts familar to all. Only a very few men of 

 science placed themselves at the beginning on the side of 

 Darwin, but the number rapidly increased and a fierce battle 

 was waged between the advocates and opponents of evolu- 

 tionism. The early fight took place, not so much over natural 

 selection as a causal explanation of transmutation, as over the 

 truth or falsity of the doctrine of descent itself, for the dis- 

 tinction was not sharply drawn in the early discussion between 

 the method and the fact of evolution. Darwin himself took 

 little part in these controversies, and it was largely due to the 

 spirited eflforts of a handful of loyal supporters, notably of 

 Huxley in England and Haeckel in Germany, that the brilliant 

 victory for the descent theory was finally won. 



As the eyes of naturalists were at last opened, a flood 

 of light burst on the mass of accumulated facts which grad- 

 ually began to assume an orderly arrangement and to take 

 their proper positions according to the general principle of 

 descent. The breath of life had been breathed into the science 

 of biolog>\ 



As the evidence for the theory of descent was largely 

 drawn from two great sources, namely, comparative anatomy 

 and embryolog}', it was but natural that with the acceptance 

 of the doctrine these departments of zoological investigation 

 should have sprung forward with giant leaps in the feverish 

 haste of workers to gain further evidence for Darwin. For 

 many years afterwards the greatest attention was directed to 

 the construction of "phylogenies," or ancestral histories, based 

 on homologies of structures and the assumption of "recapitula- 

 tion," and. as a direct result, our knowledge of comparative 

 anatomy and embryology was rapidly increased. As every 

 epoch-making discovery by a master-mind has set the trend 



