DOMESTICATION. 241 



the hills, and bow the poor beast had contrived to manage 

 her drove in her state of suffering is beyond human calcula- 

 tion, for her road lay through sheep the whole way. Her 

 master's heart smote him when he saw what she had suffered 

 and effected ; but she was nothing daunted, and, having 

 deposited her young one in a place of safety, she again set 

 out full speed to the hills and brought another and another, 

 till she brought her whole litter, one by one ; but the last one 

 was dead." 



There is still one respect — and this a most suggestive one 

 — in which artificial instincts resemble natural instincts, over 

 and above that of obliteration by disuse or acquirement by 

 training and selection. In order to show this it will be sufii- 

 cient to quote the following passage from Mr. Darwin's MSS, 

 part of which has already been published in the " Variation 

 of Animals and Plants under Domestication " (vol. i, 

 p. 43):- 



" It is Avell known that when two distinct species are 

 crossed, the instincts are curiously blended, and vary in the 

 successive generations, just like corporeal structures. To 

 give an example : a dog kept by Jenner (Hunter's " Animal 

 Economy," p. 325), which was grandchild, or had a quarter- 

 blood of the jackal in it, was easily startled, was inattentive 

 to the whistle, and would steal into fields and catch mice in 

 a peculiar manner. Now I coirid give numerous examples of 

 crosses between breeds of dogs, both having artificial instincts, 

 in which these instincts have been most curiously blended, 

 as between the Scotch and English sheep-dog, pointer and 

 setter: the effect, moreover, of such crosses can sometimes be 

 traced for very many generations, as in the courage acquired 

 by Lord Orford's famous greyhounds from a single cross with 

 the bull-dog (" Youatt on the Dog," p. 31). On the other 

 hand, a dash of the greyhound will give a family of sheep- 

 dogs a tendency to hunt hares, as I was assured by an intel- 

 ligent shepherd." 



Our a posteriori proof of Proposition VII is now concluded, 

 and with its proof our considerations on the origin and 

 development of instinct are drawing to a close. For we have 

 now seen that instincts may arise under the influence of 

 natural selection alone, under that of lapsing intelligence 

 alone, or under both these influences combined. And in 



