(ESOPHAGOSTOMUM 



283 



mals in Egypt occasionally parasitize man. The eggs of Tri- 

 chostrongylus (Fig. 61Y) resemble those of hookworms, but they 

 are a little larger and frequently contain more than four cells. 

 The life history is similar to that of the hookworms. Ternidens 

 (or Triodontophorus) deminutus (Fig. 106) is a worm about half 

 an inch in length, normally found in the large intestine of monkeys 

 in central East Africa, and not uncommon in natives; (Esopha- 

 gostomum apiostomum (brumpti) is a parasite which forms tumors 

 in the large intestine of monkeys and occasionally man, in 

 central Africa and in the Philippines. It produces symptoms of 



FIG. 114. Trichostrongylus instabilis; 

 A, female, showing pointed tail and 

 vulva (v.) ; B, male, showing smaller 

 size and bursa (b.). X 25. (After 

 drawings and measurements by 

 Looss.) 



BCX/0) 



FIG. 115. (Esophagostoma stepha- 

 nostomum var. thomasi. A, immature 

 female in cyst in large intestine of 

 man in Brazil; B, same, removed 

 from cyst. (After Thomas.) 



dysentery. An allied worm, 0. stephanostomum var. thomasi, 

 a variety of a species normally found parasitic in gorillas in 

 Africa, has been found once in man in Brazil. In this case there 

 were 187 tumors (Fig. 115 A) in the small and large intestines 

 each containing one worm (Fig. 115B). This species will prob- 

 ably be found to be normally parasitic in some species of South 

 American monkey. 



These and a number of still rarer human parasites are of little 

 interest as far as man is concerned, except as medical curiosities. 



In connection with the intestinal nematodes there should be 

 mentioned three species of spiny-headed worms (class Acantho- 



