TO THE LOWER ANIMALS 289 



A common stock are fertile, and their progeny are fertile 

 with one another, that link will be wanting. For, so 

 long, selective breeding will not be proved to be com- 

 petent to do all that is required of it to produce natural 

 species. 



I have put this conclusion as strongly as possible before 

 the reader, because the last position in which I wish to 

 find myself is that of an advocate for Mr. Darwin's, or 

 any other views if by an advocate is meant one whose 

 business it is to smooth over real difficulties, and to persuade 

 where he cannot convince. 



In justice to Mr. Darwin, however, it must be admitted 

 that the conditions of fertility and sterility are very ill 

 understood, and that every day's advance in knowledge 

 leads us to regard the hiatus in his evidence as of less 

 and less importance, when set against the multitude of 

 facts which harmonize with, or receive an explanation from, 

 his doctrines. 



I adopt Mr. Darwin's hypothesis, therefore, subject to 

 the production of proof that physiological species may be 

 produced by selective breeding ; just as a physical philo- 

 sopher may accept the undulatory theory of light, subject 

 to the proof of the existence of the hypothetical ether ; or 

 as the chemist adopts the atomic theory, subject to the 

 proof of the existence of atoms ; and for exactly the same 

 reasons, namely, that it has an immense amount of prima* 

 facie probability ; that it is the only means at present 

 within reach of reducing the chaos of observed facts to 

 order ; and lastly, that it is the most powerful instrument 

 of investigation which has been presented to naturalists 

 since the invention of the natural system of classification, 

 and the commencement of the systematic study of 

 embryology. 



But even leaving Mr. Darwin's views aside, the whole 

 analogy of natural operations furnishes so complete and 

 crushing an argument against the intervention of any but 

 what are termed secondary causes, in the production of 

 all the phenomena of the universe ; that, in view of the 

 intimate relations between Man and the rest of the living 

 world ; and between the forces exerted by the latter and 

 all other forces, I can see no excuse for doubting that 

 all are co-ordinated terms of Nature's great progression, 

 from the formless to the formed from the inorganic to the 

 organic from blind force to conscious intellect and will. 

 66 j 



