146 PARASITOLOGY. 



tie; they are blood suckers of the worst type, and 

 myriads robbing the host of blood cause an un" 

 thrifty condition; in calves they cause a stunted 

 growth ; later anemia, emaciation and possibly death. 



Treatment. — The same as for the Strongylus Con- 

 tortus. 



Uncinaria Cernua. (Cernuus — bent down). 



Synonyms. — Hook worm. Dochmius Cernua. 



Distrib2ition. — Frequently found in Southern 

 United States. 



Description. — A thread-like worm, yellowish white 

 in color ; the body is rigid and attenuated at both 

 ends; the mouth is circular and provided with four 

 hook-like teeth; the buccal cavity is ovoid in shape; 

 the male is one-half to three-fourths of an inch long, 

 the female one inch. 



Life History. — The ova, reaching water or moist 

 earth, hatch into the embryonic state ; if conditions 

 are favorable they moult in three days; in five days 

 they moult the second time ; when taken into the 

 intestinal tract at this time they invade the mucous 

 membrane (if not taken in at this stage they will 

 perish in about four weeks) ; they now fasten them- 

 selves to the mucous membrane and develop into 

 the mature worm in about fifteen days; during this 

 time they moult twice. 



Aniriials hifested. — The sheep and goat. 



Parts Infested. — Small and frequently the large 

 intestines. 



Mode of hifestation. — Like other worms of the 

 family Strongylidae, the pools of water, ponds, 

 pastures and other food become contaminated by 

 feces from infested sheep, laden with the ova; here 



