404 Journal of Agricultural Research voi. xxii, no. 8 



case of the ether-soluble hemolytic substance of A . lumhricoides appears 

 probable from the experiments described above. 



It should also be stated that a 95 per cent alcohol extract of Ascaris 

 lumhricoides developed a precipitate when kept in solution in 95 per 

 cent alcohol at 8° C. This precipitate went into solution when the 

 alcohol containing the extract was transferred to room temperature. 

 The removal of this precipitate by filtering in a refrigerator yielded a 

 whitish substance which had no hemolytic power, nor did the removal 

 of this substance interfere with the hemolytic potency of the extract. 



8. PROPERTIES OF* ASCARIS lyUMBRICOlDES HEMOI^YSIN 



At low temperatures ranging from 6° to 10° C. hemolytic extracts of 

 Ascaris lumhricoides lose their potency. Mixtures of extracts and sus- 

 ceptible corpuscles that showed complete hemolysis after 2 hours' incu- 

 bation at 37° showed no trace of hemolysis after 24 hours at 8°. 

 After being removed from the low temperatures and transferred to an 

 incubator hemolysis occurred rapidly in such mixtures. 



In order to determine whether the hemolytic substance of Ascaris 

 lumhricoides is absorbed by the red blood cells at low temperatures the 

 following experiments were performed. 



Mixtures of washed red blood cells (rabbit and sheep) and hemolytic 

 extracts were put in a refrigerator at 8° C. After 24 hours the super- 

 natant fluid was removed from the corpuscles and the latter were washed 

 three times in succession to free them from traces of extracts; to the 

 washed corpuscles from which the supernatant fluid had been removed 

 an equal quantity of salt solution was added, and the tubes were thor- 

 oughly shaken and placed in the incubator. Hemolysis set in slowly. 

 The supernatant fluid which was removed from the corpuscles was also 

 tested as to its hemolytic potency, with inconstant results. In some 

 cases it was found that it had lost its hemolytic potency completely, but 

 in a number of cases it still retained its blood-destroying power. That 

 the potency of the fluid that had been in contact with susceptible cor- 

 puscles had been considerably reduced was evident, since it had but 

 slight hemolytic power as compared with that of intact extract. Whether 

 the hemolytic substance in contact with susceptible corpuscles at a low 

 temperature becomes fixed to the cells or whether it is precipitated at a 

 low temperature and escapes removal despite repeated washing has not 

 been determined. 



Hemolytic extracts of Ascaris lumhricoides are highly resistant to heat. 

 Heating at temperatures ranging from 56° to 60° C. for 30 minutes did 

 not weaken the potency of the extracts. An exposure to 70° for two 

 hours failed to destroy the hemolytic substance. Salt-solution extract 

 as well as alcoholic extracts were heated to boiling, and after cooling 

 they were tested on susceptible red blood cells. It was found that as a 



