4o6 Journal of Agricultural Research voi.xxn.No. s 



active at low temperatures. It also differs from the hemolysin in its rela- 

 tive specificity for certain species of erythrocytes. 



VI. THE EFFECT OF ASCARIS LUMBRICOIDES FLUID ON COAGULA- 



TION OF BLOOD 



As has already been stated, Weil and Boye {19 lo) found that as a re- 

 sult of injecting the fluid of Ascaris equorum into rabbits the coagulation 

 of the blood was retarded by 20 minutes. These investigators state, 

 however, that they obtained negative results with rabbit blood in vitro. 

 Leroy (19 10) likewise observed that the blood of dogs which had received 

 injections of the body fluid of A. equorum exhibited a delayed coagula- 

 tion time. Flury (1912) made observations on the coagulation of dog 

 blood in contact with the fluid of ascarids in vitro and records a decided 

 delay. His experiments with human blood were likewise positive. 



In view of the contention of Weil and Boye with reference to rabbit 

 blood in contact with Ascaris equorum fluid in vitro, the writer tested 

 freshly drawn rabbit blood to which various quantities of A . lumbricoides 

 fluid were added, in order to determine if the coagulation power would 

 be affected. The addition of 3 to 5 drops of the fluid to lo drops of blood 

 delayed the coagulation time about 15 minutes as compared with that 

 of normal blood. The addition of 8 drops of fluid to 10 drops of blood 

 produced a 35-minute delay, whereas the addition of 10 drops of fluid to 

 an equal quantity of blood resulted in a delay of 42 minutes. 



The body fluid of Ascaris lumbricoides retards the coagulation of blood 

 in vitro as well as in vivo, but its power in this respect is rather limited. 



VII. EXPERIMENTS WITH HOOKWORM HEMOLYSIN (ANCYLOSTOMA 



CANINUM) 



The anemia which occurs in cases of infestation with hookworms has 

 been ascribed to several different factors. The direct abstraction of 

 blood by the parasites, the possible absorption of toxic substances from 

 the digestive tract as a result of the ulceration of the mucosa, hemorrhages 

 following the laceration of the mucosa by the worms (Loeb and his collab- 

 orators), and the absorption by the host of hemolysins secreted by the 

 parasites have been advanced as explanations. The last view was ac- 

 cepted as a plausible explanation before any experimental evidence in 

 favor of it had been advanced. That the data with reference to the pro- 

 duction of hemolysins by hookworms appear to show that such absorp- 

 tion probably occurs has already been pointed out elsewhere in this 

 paper. 



