TRICHINA 53 



into the body again. In the genus Trichuris, the typical whip- 

 worm, the anterior portion of the body is of thread-like slender- 

 ness and longer than the posterior heavy portion of the body. 



B. There are several species of whipworms belonging to the 

 genus Trichuris, all of which partake of the characters above 

 mentioned. 



Examine and draw specimens of the following species. 



a. Trichuris (Trichocephalus) trichuris is a common whip- 

 worm of humans. Note the following characters; position of 

 mouth, length of thread-like cesophageal region as compared 

 with the thick body; total length, color. In a male specimen find 

 the spicules. 



b. Trichuris oms is a common whip worm of sheep, cattle and 

 goats. 



EXERCISE 29b 



TRICHINA 

 PHYLUM NEMATHELMINTHES, CLASS NEMATODA, FAMILY TRICHO- 



TRACHELLID.E 



Trichinella spiralis is the cause of trichinosis of humans and 

 other mammals. The adult trichinae inhabit the large and 

 small intestines of several species of mammals, among them 

 man, the domestic pig and the rat. The worms find their way 

 into the intestine with infested flesh eaten by one of the animals 

 mentioned. In the intestine copulation takes place between 

 male and female trichinae; the female gives birth to living young 

 in great numbers; these are carried by the lymph and blood to 

 many parts of the body, finally finding lodgment in the muscles, 

 where they invade the connective tissue and even the fibres, 

 later becoming encysted. 



a. Examine under a compound microscope a prepared piece 



