Chap. I. SERVICEABLE ASSOCIATED HABITS. 45 



carrion as do smaller dogs, which are probably descended 

 from jackals. When a piece of brown biscuit is offered 

 to a terrier of mine and she is not hungry (and I have 

 heard of similar instances), she first tosses it about and 

 worries it, as if it were a rat or other prey; she then 

 repeatedly rolls on it precisely as if it were a piece of 

 carrion, and at last eats it. It would appear that an 

 imaginary relish has to be given to the distasteful 

 morsel; and to effect this the dog acts in his habitual 

 manner, as if the biscuit was a live animal or smelt 

 like carrion, though he knows better than we do that 

 this is not the case. I have seen this same terrier 

 act in the same manner after killing a little bird or 

 mouse. 



Dogs scratch themselves by a rapid movement of one 

 of their hind-feet; and when their backs are rubbed 

 with a stick, so strong is the habit, that they cannot 

 help rapidly scratching the air or the ground in a use- 

 less and ludicrous manner. The terrier just alluded to, 

 when thus scratched with a stick, will sometimes show 

 her delight by another habitual movement, namely, by 

 licking the air as if it were my hand. 



Horses scratch themselves by nibbling those parts of 

 their bodies which they can reach with their teeth; 

 but more commonly one horse shows another where he 

 wants to be scratched, and they then nibble each other. 

 A friend whose attention I had called to the subject, 

 observed that when he rubbed his horse's neck, the 

 animal protruded his head, uncovered his teeth, and 

 moved his jaws, exactly as if nibbling another horse's 

 neck, for he could never have nibbled his own neck. If 

 a horse is much tickled, as when curry-combed, his wish 

 to bite something becomes so intolerably strong, that he 

 will clatter his teeth together, and though not vicious, 

 bite his groom. At the same time from habit he closely 



