20 SUMMARY 



Hawfinch to Sylvia) selection and habit might 

 lead old birds to vary taste (?) and form, leaving 

 their instinct of feeding their young with same food \ 



-or I see no difficulty in parents being forced 

 or induced to vary the food brought, and selection 

 adapting the young ones to it, and thus by degree any 

 amount of diversity might be arrived at. Although 

 we can never hope to see the course revealed by 

 which different instincts have been acquired, for 

 we have only present animals (not well known) to 

 judge of the course of gradation, yet once grant the 

 principle of habits, whether congenital or acquired 

 by experience, being inherited and I can see no 

 limit to the [amount of variation] extraordinari- 

 ness (?) of the habits thus acquired. 



Summing up this Division. If variation be 

 admitted to occur occasionally in some wild animals, 

 and how can we doubt it, when we see [all] thousands 

 (of) organisms, for whatever use taken by man, do 

 vary. If we admit such variations tend to be 

 hereditary, and how can we doubt it when we 

 (remember) resemblances of features and character, 

 disease and monstrosities inherited and endless 

 races produced (1200 cabbages). If we admit selec- 

 tion is steadily at work, and who will doubt it, when 

 he considers amount of food on an average fixed 

 and reproductive powers act in geometrical ratio. 

 If we admit that external conditions vary, as all 

 geology proclaims, they have done and are now doing, 



-then, if no law of nature be opposed, there must 

 occasionally be formed races, [slightly] differing from 

 the parent races. So then any such law 2 , none is 



1 The hawfinch- and Sylvia-types are figured in the Journal of Researches, 

 p. 379. The discussion of change of form in relation to change of instinct 

 is not clear, and I find it impossible to suggest a paraphrase. 



2 I should interpret this obscure sentence as follows, "No such opposing 

 law is known, but in all works on the subject a law is (in flat contradiction 

 to all known facts) assumed to limit the possible amount of variation." In 

 the Origin, the author never limits the power of variation, as far as I know. 



