Ascaridæ, NEMATODA

Worms with stout body, and bearing three lip-like papillæ, at the head end; e. g., the round worms ( Ascaris lumbricoides and Oxyuris Vermicular is ), parasitic in IMG:content-0329.png:[blocks in formation] the intestines of man, and the Ascarides , parasitic in the blood ve els of the horse. The eggs develop in damp places and the embryos probably get into some intermediate host before they attain their sexual stage. A. Lumbri coides resembles the earth-worm in appearance, is sometimes a Head, dorsal view. foot or more in length, and inhabits the small intestine, though occasionally it reaches the stomach and is vomited. It gives rise to colic, diarrhœa.and, rarely.convulsions, and is easily expelled Head, ventral view. by santonin and cathartics. The A. Mys tax is smaller, and is most common in cats, but sometimes found in man.