48 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



species were peculiar to each island respectively. So that while the 

 fossils differed in course of time, the species differ in space. Speaking 

 of the shells, Darwin says : — " At the Galapagos Islands we have a 

 halting-place (between the east and west) where many new forms have 

 been created " * ; and he asks " Why were the vast majority of all 

 the land animals, and more than half of the flowering plants, which are 

 aboriginal productions, created on American types of organization ? "f 

 No one doubted "immediate" creation before he left England. 



This question is the first indication of any doubt as to the method 

 of origin which appears to have passed through his mind. 



Darwin could not fail to see that the various kinds were adapted 

 to their places, severally. 



A hint as to " adaptations " appears in a remark about the blindness 

 of the Tucutuco, % an animal burrowing like a mole. " Lamarck would 

 have been delighted with this fact, had he known of it, when speculating 

 (probably with more truth than usual with him) [another hint of 

 a growing belief in Evolution ?] on the gradually- acquired blindness 

 of the Aspalax, a gnawer living underground, and of the Proteus 

 [a reptile living in dark caverns], of which animals the eye is in an 

 almost rudimentary state." 



Writing subsequently in 1842, he says : — " I had been greatly 

 struck with the characters of the South American fossils and of species 

 in the Galapagos Archipelago. These facts were the origin of all my 

 views § . . . But I did not become convinced that species were 

 mutable until, I think, two or three years had elapsed." || 



In 1836 Darwin returned to England. 



1838. Darwin read Malthus' Essay on Population.^ — " Being 

 well prepared to appreciate the struggle for existence, which every- 

 where goes on, from long-continued observation of the habits of animals 

 and plants, it at once struck me that under these circumstances favour- 

 able variations would tend to be preserved [i.e. by delimitation] and 

 unfavourable ** ones to be destroyed. The result of this would be the 

 formation of new species. Here, then, I had at last got a theory by 

 which to work. . . . [Now follows a very important statement.] 

 But at that time I overlooked one problem of great importance . . . 

 the tendency in organic beings descended from the same stock to 



* Naturalist's Voyage, p. 391. 

 f Op. ext. p. 393. 



% Op. cit. pp. 50, 52 (Ctenomys brasiliensis). 

 § Foundations, p. xii. (1842). 

 || Op. cit. p. xiii. 



% Malthus' object was to in vestigate the causes of the limitation of population 

 in an isolated area, where the production of food would be limited, but the 

 population would increase indefinitely. Therefore there would be a limit to the 

 means of living. Consequently starvation and diseases would be the chief causes 

 of depopulation. 



Among a batch of seedlings, starvation accounts for the majority — though 

 all are perfectly healthy — being overcrowded and so perishing. Darwin calls 

 this " fortuitous " destruction. 



** This word, or " injurious " (in the Origin), is the fatal mistake in the theory, 

 by which it falls ; such variations never occur. 



