3 2 



ECONOMIC ZOOLOGY 



met with in the country (where sewage disposal is often crude) than 

 in cities. There are usually from one to half a dozen worms in one 

 patient, but as many as 600 in one person have been reported. 

 They may merely cause diarrhea and other discomforts or they may 

 be fatal. The condition may be identified by finding the worms or 

 their eggs in the patients' stools. The history is simple, no second 

 host being necessary. The eggs that are passed out of the body in the 

 feces may be taken into the digestive tract of the same or of another 

 person in drinking water, upon unwashed fruits, vegetables or salads, 



talk 



esc. 



ovt 



v.v 



tct 



FIG. 23. Transverse section of Ascaris lumbricoides. X 15 cu, cuticle; 

 dl, dorsal line, der. epthm, epidermis; ex.v, excretory tube; int, intestine; lot. I, lateral 

 line; m, muscular layer; ovy, ovary; ut, uterus; v.v. t ventral line. (From Hegner, 

 College Zoology, after Parker and Haswell, from Vogt and Yung.) 



or by simply eating with dirty hands; possibly the eggs may be carried 

 to man's food or water by flies. It is thus easy to understand how 

 young children may be infected and why women, who generally handle 

 the raw fruits and vegetables, are more subject to the disease than men. 

 Also how bad sewage may spread the eggs. After entrance into the 

 body it takes from one to several months for the eggs to develop into 

 the adult worms. 



Santonin and calomel are the usual drugs used to rid the intestine 

 of the eel worm. 



