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Changes of Habit or Instinct Chap. viii. 



crawl forward with a peculiar gait ; and another kind of wolf 

 rushing round, instead of at, a herd of deer, and driving them to a 

 distant point, we should assuredly call these actions instinctive. 

 Domestic instincts, as they may be called, are certainly far less 

 fixed than natural instincts; but they have been acted on by far 

 less rigorous selection, and have been transmitted for an incompar- 

 ably shorter period, under less fixed conditions of life. 



How strongly these domestic instincts, habits, and dispositions 

 are inherited, and how curiously they become mingled, is well 

 shown when different breeds of dogs are crossed. Thus it is known 

 that a cross with a bull-dog has affected for many generations the 

 courage and obstinacy of greyhounds ; and a cross with a greyhound 

 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 Koy 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 actions which 

 have become inherited solely from long-continued 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 selection 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 pro- 

 bably, as many have thought, only the exaggerated pause of an 

 animal preparing to spring on its prey. When the first tendency 

 to point was once displayed, methodical selection and the inherited 

 effects of compulsory training in each successive generation would 

 soon complete the work ; and unconscious selection is still in 

 progress, as each man tries to procure, without intending to improve 

 the breed, dogs which stand and hunt best. On the other hand, 

 habit alone in some cases has sufficed ; hardly any animal is more 



