274 OBITUARY X 



character of most of the productions of the 

 Galapagos Archipelago, and, more especially, by 

 the manner in which they differ slightly on each 

 island of the group ; some of the islands appearing 

 to be very ancient in a geological sense. 



" It was evident that such facts as these, as well 

 as many others, could only be explained on the 

 supposition that species gradually become modi- 

 fied ; and the subject haunted me. But it was 

 equally evident that neither the action of the 

 surrounding conditions, nor the will of the organ- 

 isms (especially in the case of plants) could account 

 for the innumerable cases in which organisms of 

 every kind are beautifully adapted to their habits 

 of life ; for instance, a woodpecker or a tree-frog to 

 climb trees, or a seed for dispersal by hooks or 

 plumes. I had always been much struck by such 

 adaptations, and until these could be explained it 

 seemed to me almost useless to endeavour to prove 

 by indirect evidence that species have been modi- 

 fied." (I. p. 82.) 



The facts to which reference is here made were, 

 without doubt, eminently fitted to attract the at- 

 tention of a philosophical thinker ; but, until the 

 relations of the existing with the extinct species and 

 of the species of the different geographical areas 

 with one another, were determined with some 

 exactness, they afforded but an unsafe foundation 

 for speculation. It was not possible that this 

 determination should have been effected before 



