Nov. 19. 19" Hemotoxins from Parasitic Worms 415 



Usami and Mano {191 8) concerning the insolubility in water of the hook- 

 worm hemolysin. That Loeb and his collaborators used dried material 

 has already been stated. 



The fact that normal blood serum has antilytic properties and inhibits 

 the action of the hookworm hemolysin accounts for the negative results 

 obtained by Loeb and Smith {1904) and for the weakly positive results 

 obtained by Whipple {1909). In this connection it is important to 

 recall the observations of Noc {1908) with reference to the presence of 

 antihemolysins in the blood serum of normal persons and of those recover- 

 ing from hookworm disease and from beriberi, and the absence of anti- 

 hemolysins in patients suffering from these diseases. Noc's observa- 

 tions are decidedly significant and do not bear out Whipple's view that 

 the hookworm hemolysin probably bears no relation to the secondary 

 anemia of ancylostomiasis. De Blasi's observations with reference to 

 the presence of hemolysins in the blood serum of patients infected with 

 hookworms and Noc's discovery that under certain conditions the anti- 

 lytic action of the blood serum may become impaired appear to indicate 

 that the hookworm hemolysin has potentialities of causing anemia and 

 that in severe infections it probably plays an important role in the disease. 



Since cold (6° to 8° C.) inhibits the action of the hookworm hemolysin 

 in vitro, and the supernatant fluid from tubes in which susceptible blood 

 corpuscles and potent hookworm extract have been in contact for a num- 

 ber of hours at a low temperature no longer has hemolytic properties, the 

 view that the hemolysin is a complex organic substance, not unlike a 

 toxin, in that it apparently consists of haptophore and toxophore groups, 

 appears to be justified. By means of the haptophore group union 

 between the hemolysins and blood corpuscles takes place, but the dis- 

 solving or lytic action is produced by the toxophore group. Inasmuch 

 as low temperatures do not appear to interfere with the absorption of 

 the hemolysin by the corpuscles despite the fact that the latter remain 

 undissolved, it is permissible to believe that the toxophore and hapto- 

 phore groups of the hookworm hemolysin act independently of each 

 other. This view is purely speculative, however, and further experi- 

 mentation is required before it may be accepted without reservation. 



VIII. EXPERIMENTS WITH EXTRACTS OF CA.TTLE HOOKWORMS 

 (BUSTOMUM PHLEBOTOMUM) 



Hookworms belonging to the genus Bustomum occur as parasites in 

 the small intestine of ruminants. Bustomum phlebotomum is the species 

 that infests cattle. According to observations of several investigators, 

 cattle infested with hookworms show symptoms not unlike those of 

 human beings that harbor species of Ancylostoma or Necator. 



Experiments with extracts of Bustomum phlebotomum similar to those 

 performed with extracts of Ancylostoma caninum showed that the former, 

 like the latter, contain a powerful hemolytic agent. The extracts 



