Chap. VIIL] IN DOMESTICATED ANIMALS. 327 



How strongly these domestic instincts, habits, and 

 dispositions are inherited, and how curiously they be- 

 come mingled, is well shown when different breeds of 

 dogs are crossed. Thus it is known that a cross with a 

 bull-dog has ailected for many generations the courage 

 and obstinacy of greyhounds; and a cross with a grey- 

 hound has given to a whole family of shepherd-dogs a 

 tendency to hunt hares. These domestic instincts, when 

 thus tested by crossing, resemble natural instincts, which 

 in a like manner become curiously blended together, 

 and for a long period exhibit traces of the instincts of 

 either parent: for example, Le Eoy describes a dog, 

 whose great-grandfather was a wolf, and this dog showed 

 a trace of its wild parentage only in one way, by not 

 coming in a straight line to his master, when called. 



Domestic instincts are sometimes spoken of as ac- 

 tions which have become inherited solely from long-con- 

 tinued and compulsory habit; but this is not true. No 

 one would ever have thought of teaching, or probably 

 could have taught, the tumbler-pigeon to tumble, — an 

 action which, as I have witnessed, is performed by young 

 birds, that have never seen a pigeon tumble. We may 

 believe that some one pigeon showed a slight tendency 

 to this strange habit, and that the long-continued selec- 

 tion of the best individuals in successive generations 

 made tumblers what they now are; and near Glasgow 

 there are house-tumblers, as I hear from Mr. Brent, 

 which cannot fly eighteen inches high without going 

 head over heels. It may be doubted whether any one 

 would have thought of training a dog to point, had not 

 some one dog naturally shown a tendency in this line; 

 and this is known occasionally to happen, as I once saw, 

 in a pure terrier: the act of pointing is probably, as many 

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