812 BOA U- 1 1 (tF AGRICULTURE. 



cr.Mwliiifr or l).v driltiii;; alonj; in the blood until it rcaL-hos Iho liver. 

 AI»ou( foni- (liiys aftt'r infection it tan be stM-n in this orjjan, lodfjed in the 

 tiner branches of the blood vessels which it transforms into tubes, and 

 havinfr the apitearanco of a small round kernel. After remaininj; here for 

 a shoi-t time, it leaves the liver and falls into the l)ody cavity and usually 

 encysts on the omentum. Here it remains until fully developed, which 

 requires several months. In time, as is the case with the cysticercus, it 

 underjjoes degenerative clianges. If the cyst is eaten liy a Jog the scolex 

 or head is freed from the cy.st by tlie digestive .juices, and the suckers 

 and hooks attach them.selves to the wall of the intestine and development 

 of the segments of the tapeworm begins. 



Symptoms. — The sjMni)t()ms i)roduced by tlie bladder worms are not 

 noticeable. No deaths have ever been reported in hogs from infection 

 from this worm. When the infection is heavy, intiammation in the body 

 cavities as a result of the migrations of the larvae may occur. "When this 

 does occin', the symptoms manifested by the animal are not diagnostic. 

 The affection tlien. can not lie diagnosed in the living animal. Even if it 

 could, the treatment would not differ from that recommended in periton- 

 itis and pleurisy. 



The larvae of the Taenia m.-irginata is not of as much economic im- 

 portance as the larvae of the Taenia solemn. It does not cause as serious 

 a line of symptoms in its host as the cysticercus and does not infect man. 



Trichinosis of the Pig.-^Trichinosis is a disease caused by the muscles 

 of the body becoming infested Avitli a very small round worm, the Trichi- 

 nelle spiralis. This disease is seen in man and other mammals. It 

 occurs in two forms in the one animal; the intestinal, which represents 

 the adult parasite, and the muscular which represents the larval stage of 

 the parasite. Tlie examination of the pork for trichinella, is an important 

 part of the government inspection of pork sent to Germ;iny. From one 

 to three per cent, of the pork examined contains trichinella. 



Description and Life History.— The adult T. spii-alis is a very small 

 worm the male a little over one twenty-tiftli of an incli long, the female 

 al)out three times the length of the male. The digestive tract can be di- 

 vided into a buccal o[)ening oesophagus, stomach, intestines, anus and 

 cloacal slit. Tlie genital apparatus in the male consists of testicular tulie, 

 excretory canal and genital orifice. In the female of (tvaries, uterus, 

 vagina, and vulva. Internal im])regnation takes jdace i\nd the eggs de- 

 velop in the uterus of the female to the number of at least a thousand 

 and are born alive. These embryonic! worms within a shoil time after 

 birth penetrate through the walls of the intestines and migrate through 

 the tissues until they reach the involuntary muscles. It then enters the 

 muscle fiber, coils itself up and rests. In about tAvo weeks the cyst can be 

 seen and embr.yos become transformed into larvae. The tissue in the 

 iieighborhood of the embryo is the seat of cellular infiltration. The muscles 

 in the region maj' become swollen, and may undergo more or less degener- 



