THE NERVOUS AND DIGESTIVE SYSTEMS. 399 



THE BRAIN AND NERVOUS SYSTEM. 



The nervous system is highly developed in those hreeds which 

 have been carefully attended to, that is, where individuals of 

 high nervous sensibility have been selected to breed from. 

 This is therefore remarkable in the bulldog, selected for gene- 

 rations for courage ; in the pointer, where steadiness in pointing 

 has been the prominent cause of choice ; and in the greyhound, 

 whose characteristic is speed ; all requiring a high development 

 of the nervous system, and all particularly liable to nervous 

 diseases, such as fits, chorea, &c. On the other hand, the cur, 

 the common sheep-dog, &c, seldom suffer from any disease 

 whatever. 



THE DIGESTIVE SYSTEM'. 



The stomach of this animal is extremely powerful in dissolving 

 bones, but it is also very liable to sickness, and on the slightest 

 disturbance rejects its contents. This appears to be almost a 

 natural effect, and not a diseased or disordered condition, as there 

 is scarcely a dog which does not wilfully produce vomiting 

 occasionally by swallowing grass. Few medicines which are at 

 all irritating will remain down, and a vast number which are 

 supposed to be given are not retained on the stomach, while 

 others are only partially so. The bowels are extremely liable to 

 become costive, which is in great measure owing to the want of 

 proper exercise, and this also is very apt to produce torpidity 

 of the liver. It may, however, be observed that in almost all 

 particulars, except the tendency to vomit, the digestive organs of 

 the do? resemble those of man. 



