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principles on which the idea of the Unity of Creation rests. There 

 is not such a thing as Solitude in nature. As freedom and free 

 institutions do not consist in every man doing exactly what he likes ; 

 ■ — but in every man knowing and remembering that everybody else 

 has equal rights with himself, and in those equal rights being equally 

 respected by all ; — so, all the facts of every branch of science are 

 more or less intimately related to each other ; and, unless the Rela- 

 tions of every alleged fact be well considered, the statement of it 

 will turn out to have been, not the statement of a truth, but of a 

 false fact, — one which will be delusive and misleading, instead of 

 leading on to farther truth. I can illustrate this highly important 

 point by a few instances, that touch the relations,, as well between 

 different remains of animal life as between the conditions of parti- 

 cular animal remains and rocks, and between different rocks. 



Some years ago, I found, in what seemed, superficially, the solid 

 wall of a familiar chalk-pit, about thirty feet from the top, a horse's 

 tooth. The naked fact was, — a horse's tooth found in the chalk. 

 If I had been content to stop there, I might have announced indeed 

 a grand discovery, — as everybody knows that such a fossil had never 

 yet been found in such a place. But I knew that the fact which 

 seemed thus naked, was extremely unlikely to be a real fact, being 

 contrary to the Unity of Science, so far as this has vet been ascer- 

 tained in' regard to such a matter. So, instead of glorifying myself 

 on the discovery of a horse in the chalk, I went to work to prove that 

 it was not a true fact at all. And I succeeded. The chalk seemed 

 solid enough; but, by careful examination, I became thoroughly 

 satisfied that there had been a crack in the chalk bed, reaching up 

 to the surface of the earth ; and that this tooth — which I still show 

 in my cabinet to warn the too eager discoverer — had, in the course 

 of ages, got washed down through this crack, though the latter was 

 imperceptible without close search; — and had so become lodged 

 where I found it. This is an example of the relations between a 

 fossil and the rock in which it is found. 



Let me take another example, — and this shall be one of the re- 

 lations between one form of animal life and another. All who are 

 familiar with the chalk, know that dklerent shapes of the oyster are 

 very common in its beds. These vary much. On the varieties I can- 

 not now enter. But no one has long worked the chalk without 



