NOTE-BOOK OF 1837. 369 



" It is a wonderful fact, horse, elephant, and mastodon, 

 dying out about same time in such different quarters. 



" Will Mr. Lyell say that some [same ?] circumstance 

 killed it over a tract from Spain to South America ? 

 (Never). 



" They die, without they change, like golden pippins ; it 

 is a generation of species like generation of individuals. 



" Why does individual die ? To perpetuate certain peculi- 

 arities (therefore adaptation), and obliterate accidental varie- 

 ties, and to accommodate itself to change (for, of course, 

 change, even in varieties, is accommodation). Now this 

 argument applies to species. 



" If individual cannot propagate he has no issue so with 

 species. 



" If species generate other species, their race is not utterly 

 cut off : like golden pippins, if produced by seed, go on 

 otherwise all die. 



" The fossil horse generated, in South Africa, zebra and 

 continued perished in America. 



" All animals of same species are bound together just like 

 buds of plants, which die at one time, though produced either 

 sooner or later. Prove animals like plants trace gradation 

 between associated and non-associated animals and the story 

 will be complete." 



Here we have the view already alluded to of a term of life 

 impressed on a species. 



But in the following note we get extinction connected with 

 unfavourable variation, and thus a hint is given of natural 

 selection : 



" With respect to extinction, we can easily see that [a] 

 variety of [the] ostrich (Petise), may not be well adapted, 

 and thus perish out ; or, on the other hand, like Orpheus [a 

 Galapagos bird], being favourable, many might be produced. 

 This requires [the] principle that the permanent variations 

 produced by confined breeding and changing circumstances 

 are continued and produced according to the adaptation of 

 such circumstance, and therefore that death of species is a 



