Xlll 



to sink out of siglit. On the continent, indeed, they had never excited 

 much attention, and were for the most part ignored as mere vague spe- 

 culation ; in this country they had been only partially adopted even by 

 those who professed to belong to the Huttonian school : so that it was, 

 in one sense, as a new doctrine that they were taken up by Lyell, and 

 enforced with a wealth of illustration and cogency of argument which 

 rapidly gained acceptance for them in Britain, and eventually led to their 

 development in every country where the science is cultivated. 



In one important respect Lyell's teaching differed from that of his pre- 

 decessors. Up till his time little had been made of organic remains as 

 monuments of former physical changes as well as records of the history 

 of the progress of life upon the surface of the earth. The stratigraphical 

 labours of William Smith, followed by the pal^eontological researches 

 of Cuvier and Brongniart, opened fields of inquiry of which their pre- 

 decessors never dreamed. The old beliefs were being rudely shaken, and 

 in this transition-state of the science there was needed a leisured 

 thinker who could devote a calm judgment and a facile pen to the task of 

 codifying the scattered observations which had accumulated to so vast an 

 extent, and of evolving from them the general principles which they 

 seemed to establish, and which, when clearly announced, could not fail 

 greatly to stimulate and guide the future progress of geology. 



Such was the task which Lyell set before himself half a century ago. 

 In its discharge he devoted himself with special ardour to the development 

 of that biological side of geology v^-hich owes, if not its existence, at least 

 its rapid and wide spread to his influence. Though not himself, in the 

 strict sense, either a zoologist or botanist, he kept himself throughout his 

 life abreast of the progress of the biological sciences, and on terms of 

 intimate relationship with those by whom that progress was sustained in 

 this country and abroad. He was, in the true meaning of the word, a 

 naturalist. He had in his day few equals in the grasp which he could 

 take of natural-history subjects in their geological bearings. Thus the 

 geographical distribution of plants and animals received more and more 

 ample treatment from him as he advanced in years ; the succession of 

 living forms in time gave him a theme for accurate and eloquent descrip- 

 tion. In fact the breadth of his conception of what geology ought to be 

 was perhaps even more conspicuously marked in this biological side than 

 in that which treated of inorganic operations. He enlisted in his service 

 every branch of natural history which could elucidate the story of the 

 earth and its inhabitants ; and not merely the published information on 

 these questions, but many of the floating ideas of discoverers, found their 

 first exposition and illustration in his pages. 



Probably no scientific work, except the ' Origin of Species,' has during 

 the lifetime of its author exercised so powerful an influence upon the 

 science which it illustrates as Lyell's ' Principles of Greology.' l^o fewer 

 than eleven editions appeared, each of them marking a distinct and some- 



