Nov. 19. 1921 Hemotoxins from Parasitic Worms 397 



from the tissues of worms. Better results were obtained by grinding up 

 fresh worm material with sand and shaking the mixture of worm frag- 

 ments and sand for a number of hours, followed by extraction in an 

 incubator for a number of days. This procedure necessitated the addi- 

 tion of a preservative to the extract in order to prevent bacterial contam- 

 ination. In experiments in which this procedure was followed, sufficient 

 carbolic acid was added to make a 0.25 per cent solution; and in hemo- 

 lytic tests controls involving the use of salt solution containing a similar 

 quantity of carbolic acid were included. F'ollowing the procedure 

 described above an extract of fresh worm material was made as follows : 

 A few pieces (10 gm. by weight) of worm material from a number of dif- 

 ferent specimens were ground up with sand and suspended in 100 cc. of 

 physiological salt solution containing 0.25 per cent of phenol. The 

 mixture was shaken for a few hours in a shaking machine and then in- 

 cubated, usually for three days, at 37° C. The extract was then filtered 

 and a clear filtrate tested on various samples of red blood corpuscles as 

 follows. 



The filtrate was tested on washed erythrocytes of a number of cattle, 

 sheep, hogs, rabbits, guinea pigs, and rats, with positive results. In 

 most experiments it was found that 0.4 cc. of the extract hemolyzed 

 I cc. of a 5 per cent suspension of red blood corpuscles. In a number 

 of tests 0.2 cc. of the extract hemolyzed i cc. of the suspension of cor- 

 puscles. As a control on the phenol which was added as a preservative, 

 0.5 cc. and i cc. of a salt solution containing }4 per cent of phenol was 

 tested on each sample of blood corpuscles used in the hemolytic tests, 

 with negative results. Tests to determine whether normal serum con- 

 tains antibodies were nearly always positive. From 0.2 to 0.5 cc. of 

 serum was sufficient to inhibit hemolysis of i cc. of corpuscle suspension 

 by from 0.2 to 0.4 cc. of the extract. Sometimes o.i cc. of serum brought 

 about the same results. 



That the activity of the hemolysis is independent of the acidity of the 

 solution was shown by the fact that as a result of neutralizing the extract 

 its activity was not destroyed. Furthermore, the hemolytic potency 

 of the extract was not due to secondary degeneration products asso- 

 ciated with acid production, because the hemolytic power of the extracts 

 remained intact for a long period (several months), during which it was 

 tested from time to time against different species of corpuscles. More- 

 over, filtrates of extracts of worms that were prepared by thoroughly 

 triturating the specimens and adding a few drops of chloroform to inhibit 

 bacterial growth during the few hours that the extracts were kept in 

 a refrigerator were found to be hemolytic. An example of the results 

 of experiments with salt-solution extracts of A scar is lumhricoides on 

 red blood ceils is given in Table I, in which a few experiments are sum- 

 marized. 



