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 



