WHIPWORM 277 



testine occupy the thicker posterior part of the body. Th e fe-_ 

 male whipworms, which are always far more numerous than the 

 males, are about two inches long, while the males are a little 

 smaller. — — ^ 



The human whipworm is found in almost every part of the 

 world,^but i s espe cially prevalent in warm countries; it para- 

 sitizes both man and monkeys. It usually makes its home in 

 the coecum but occasionally establishes itself in the appendix 

 "of large intestine. It is usually said to transfix the wall of the 

 OBCum with its threadlike anterior portion, but there is some evi- 

 dence to show that it merely buries its long head and " neck " 

 between the folds of the intestinal wall. 



Usually the only evidence of the presence of whipworms is 

 the appearance of the characteristic dark-colored, barrel-shaped 

 eggs (Fig. HOB) Jnrth^ faeces, JThese eggs, hke those of Ascaris, 

 develop^ in water or moist soil. The embryo-containing eggs are 

 very resistant to adverse conditions and may live for years 

 without losing their vitality. Jnfection, as far as known, occurs 

 as in th e case of Ascaris. The worms may attain maturity 

 and produce eggs in less than a month after the eggs have been 

 swall owed. Although the whipworm feeds on blood to some 

 extent, and undoubtedly produces toxins, as evidenced by the 

 increase in eosinophiles (see p. 203) in the blood which nearly 

 always occurs in case of whipworm infection and by the occa- 

 sional mental disturbances and other nervous symptoms, this 

 worm usually produces very slight, in fact often unnoticeable, 

 effects. It is, however, thought by some workers to be one of 

 the intestinal parasites most frequently involved in causing 

 appendicitis. It^is very difficult to dislodge the whipworm by 

 the usual methods used for expelling intestinal parasites^ prob- 

 ably due to its very firm attachment by the long slender " neck." 

 OiToT^chenopodium administered as for hookworm^ (see p. 264) 

 is probably the most effective remedy. 



Pinworm. — One of the most froc^uent and widely distributed 

 intestinal parasites of man is the pinworm, Oxyuris vennicularis ^ 

 (Figs. 106 and 111), ^his parasite occurs almost universally in 

 children at j)ne_time or another in temperate as well as tropical^ 

 countries; it inhabits the low er part of the small intestine and 

 the coecum. 



The adult females (Fig. Ill 9 ) are whitish worms about two- 



