NEMATODES 135 



that A. lumbricoides and Oxyuris vermicularis do not produce 

 toxic materials, and Boycott * obtained a negative result with 

 extracts of A. lumbricoides filtered through porcelain to exclude 

 bacteria. Allaria 2 also obtained negative results, and could 

 demonstrate no hemolytic properties. On the other hand, 

 Cattaneo 3 claims that filtered culture-media in which Ascaris 

 has lived for some time is toxic for guinea-pigs. 



Weinland first demonstrated that Ascaris and other intestinal 

 worms are able to live in the digestive fluids of the intestine 

 because they contain an active antitrypsin. Dastre and Stassano 

 considered the active agent an antikinase, but Weinland's view 

 has been confirmed by Hamill. 4 



Glycogen has been found abundantly in ascaris, and chitin 5 is 

 present in the external covering of some forms. Reichard 6 found 

 that in A. lumbricoides and A. sipunculides the cuticle is formed 

 of an albuminoid material, but in the Hirudines it is a true chitin. 



Trichinella spiralis unquestionably produces toxic sub- 

 stances, as shown by the profound intoxication and febrile con- 

 dition of persons suifering from infection with this parasite. As 

 to the nature of the poison, however, we know nothing, except 

 that it causes cellular degeneration, and is particularly chemo- 

 tactic for eosinophiles. 



Uncinaria duodenalis, which has for its chief effect the pro- 

 duction of a severe anemia, seems to cause this anemia by pro- 

 ducing repeated small hemorrhages rather than by any toxic 

 action. The abundance of this loss of blood is explained by L. 

 Loeb 7 as due to the presence, in the anterior portion of the para- 

 site (Ankylostoma caninum), of a substance that inhibits the 

 coagulation of the blood, analogous to the "hirudin" of the leech. 



Filaria seem not to produce any appreciable amount of toxic 

 material, if we may judge by the slight evidence of intoxication 

 shown by infected individuals. An exception may be made in 

 the case of the guinea-worm (Dracunculus or F. medinensis). 

 This parasite causes chiefly mechanical injury unless its body is 

 ruptured, which may happen in attempting to remove it forcibly ; 

 this accident is followed by violent local inflammation or gan- 

 grene, which indicates that some powerfully irritant substance is 

 liberated from the torn body of the worm. 



Loc. cit. 2 Kef. in Cent. f. Bakt., 1905 (35), 539. 



Eef. in Biochem. Centr., 1903 (1), 806. 

 Jour, of Physiol., 1906 (33), 479; literature. 

 Weinland, Zeit. f. Biol., 1902 (43), 86. 



" Ueber Cuticular- und Geriist-substanzen bei wirbellosen Tieren," Heidel- 

 berg, 1902. 



7 Cent. f. Bakt., 1904 (37), 93 ; 1906 (40), 740. 



