3o8 Prof, Huxley's Lecture 



many hold particular applications of it without committing them- 

 selves to the whole ; and many, on the other hand, favour the 

 general doctrine without giving an absolute assent to its particular 

 applications. 



Thus, one who adopts the nebular hypothesis in Astronomy, or is 

 a Uniformitarian in Geology, or a Darwinian in Biology, is, so far, 

 an adherent of the doctrine of Evolution. 



And, as I can testify from personal experience, it is possible to 

 have a complete faith in the general doctrine of Evolution and yet 

 to hesitate in accepting the Nebular, or the Uniformitarian, or the 

 Darwinian hypotheses in all their integrity and fullness. For many 

 of the objections which are brought against these various hypotheses 

 affect tliem oidy, and even if they be valid, leave the general doctrine 

 of Evolution untouched. 



On the other hand, it must be admitted that some arguments which 

 are adduced against particular forms of the doctrine of Evolution, 

 would very seriously affect the whole doctrine if they were proof 

 against refutation. 



For example, there is an objection which I see constantlj^ and con- 

 fidently urged against Mr. Darwin's views, but which really strikes 

 at the heart of the whole doctrine of Evolution, so far as it is applied 

 to the organic world. 



It is admitted on all sides that existing animals and plants are 

 marked out by natural intervals into sundry very distinct groups : — 

 Insects are widely different from Fish — Fish from Eeptiles — Eeptiles 

 from Mammals — and so on. And out of this fact arises the very 

 pertinent objection, — How is it, if all animals have proceeded by 

 gradual modification from a common stock, that these great gaps 

 exist ? 



We, who believe in Evolution, reply, that these gaps were once 

 non-existent ; that the connecting forms existed in previous epochs of 

 the world's history, but that they have died out. 



Naturally enough, then, we are asked to produce these extinct forms 

 of life. Among the innumerable fossils of all ages which exist, we 

 are asked to point to those which constitute such connecting forms. 



Our reply to this request is, in most cases, an admission that such 

 forms are not forthcoming, and we account for this failure of the 

 needful evidence by the known imperfection of the geological record. 

 We say that the series of formations with which we are acquainted 

 is but a small fraction of those which have existed, and tliat between 

 those which we know there are great breaks and gaps. 



I believe that these excuses have very great force ; but I cannot 

 smother the uncomfortable feeling that they are excuses. 



If a landed proprietor is asked to produce the title-deeds of his 

 estate, and is obliged to reply that some of them were destroyed in a 

 fire a century ago, that some were carried off by a dishonest attorney, 

 and that the rest are in a safe somewhere, but that he really cannot 

 lay his hands upon them ; he cannot, I think, feel pleasantly secure, 

 though all his allegations may be correct and his ownership indis- 

 putable. But a doctrine is a scientific estate, and the holder must 



