XIX. ADDRESS TO THE DEPARTMENT OF ANATOMY AND 

 PHYSIOLOGY OF THE BRITISH ASSOCIATION, 1880. 



IN the spring of the present year, Professor Huxley delivered 

 an address at the Royal Institution, to which he gave the felici- 

 tous title of ' The coming of age of tJie origin of species! It is, as 

 he pointed out, twenty-one years since Mr Darwin's great work 

 was published, and the present occasion is an appropriate one to 

 review the effect which it has had on the progress of biological 

 knowledge. 



There is, I may venture to say, no department of biology the 

 growth of which has not been profoundly influenced by the 

 Darwinian theory. When Messrs Darwin and Wallace first 

 enunciated their views to the scientific world, the facts they 

 brought forward seemed to many naturalists insufficient to sub- 

 stantiate their far-reaching conclusions. Since that time an 

 overwhelming mass of evidence has, however, been rapidly accu- 

 mulating in their favour. Facts which at first appeared to be 

 opposed to their theories have one by one been shewn to afford 

 striking proofs of their truth. There are at the present time but 

 few naturalists who do not accept in the main the Darwinian 

 theory, and even some of those who reject many of Darwin's 

 explanations still accept the fundamental position that all ani- 

 mals are descended from a common stock. 



To attempt in the brief time which I have at my disposal to 

 trace the influence of the Darwinian theory on all the branches 

 of anatomy and physiology would be wholly impossible, and I 

 shall confine myself to an attempt to do so for a small section 

 only. There is perhaps no department of Biology which has 

 been so revolutionised, if I may use the term, by the theory of 

 animal evolution, as that of Development or Embryology. The 

 reason of this is not far to seek. According to the Darwinian 



