NECESSARY TRUTHS— EFFECTS OF EXPERIENCE. 681 



to overestimate the importance, both practical and theo- 

 retical, of such an extension of its sway. In principle, in- 

 stincts would then be assimilated to * secondarily -automatic ' 

 habits, and the origin of many of them out of tentative ex- 

 periments made during ancestral lives, perfected by repe- 

 tition, addition, and association through successive genera- 

 tions, would be a comparatively simple thing to understand. 



Contemj)orary students of instinct have accordingly 

 been alert to discover all the facts which would seem to 

 establish the possibility of such an explanation. The list 

 is not very long, considering what a burden of conclusions 

 it has to bear. Let acquisitiveness and fear of man, as just 

 argued for by Spencer, lead it off. Other cases of the latter 

 sort are the increased shyness of the woodcock noticed to 

 have occurred within sixty years' observation by Mr. T. A. 

 Knight, and the greater shyness everywhere shown by large 

 than by small birds, to which Darwin has called attention. 

 Then we may add — 



The propensities of 'pointing,' 'retrieving,' etc., in 

 sporting dogs, which seem partly, at any rate, to be due to 

 training, but which in well-bred stock are all but innate. 

 It is in these breeds considered bad for a litter of young if 

 its sire or dam have not been trained in the field. 



Docility of domestic breeds of horses and cattle. 



Tameness of young of tame rabbit — young wild rabbits 

 being invincibly timid. 



Young foxes are most wary in those places where they 

 are most severely hunted. 



Wild ducks, hatched out by tame ones, fly off. But if 

 kept close for some generations, the young are said to be- 

 come tame.* 



Young savages at a certain age will revert to the woods. 



English greyhounds taken to the high plateau of Mexico 

 could not at first run well, on account of rarefied air. Their 

 whelps entirely got over the difliculty. 



Mr. Lewes somewhere t tells of a terrier pup whose 

 parents had been taught to ' beg,' and who constantly 



* Ribot : De I'Heredite, 2me ed. p. 26. 



f Quoted (without reference) in Spencer's Biology, vol. i. p. 247. 



