80 tH^EASES OF THE HO^. 



which are received into the alimentary canal are 

 capable of development, in a healthy state of this 

 structure, as worms are sometimes found in the 

 stomach and intestine of the hog. There are cer- 

 tain conditions of these organs which are favor- 

 able for the breeding of worms, such as indiges- 

 tion, the accumulation of undigested food and of 

 mucus and diseases of the intestine. The kind 

 of food the animal eats in a raw condition contain- 

 ing the ova of worms makes the pig more liable 

 to worms than other animals. All kinds of vege- 

 table and animal food should be cooked: grains 

 can be eaten raw with impunity; hogs should 

 not be allowed to eat diseased meat unless it has 

 been thoroughly cooked. I have knowm healthy 

 pigs which w^ere given the flesh of animals that 

 died from disease to become badly affected with 

 worms. 



THORN=HEADED WORHS. 



Figure 74. 



Figure 74. — This worm is quite frequently found 

 in the intestines of pigs; it is easily known by the 

 peculiar proboscis which bears several circles of 

 small but sharp hooks. They locate usually in the 

 small intestines of the pig, where they fasten them- 

 selves by means of the spiny proboscis mentioned 

 above, this being pushed into the lining membrane 

 of the intestine; in some cases they bore through 



