388 Journal of Agricultural Research voi. xxn. No. 8 



similar to those produced by the secretions of helminths. Weinberg (1908) investi- 

 gated the hemotoxic properties of the fluid of these parasites and obtained the following 

 results: Extracts of the intestine and of the red cells of the fatty bodies of the larvae 

 contain a soluble hemolysin, nonspecific in its action and susceptible to heating for 

 }4 hour at 56° C. , which does not destroy it but merely weakens its potency. Weinberg 

 found, moreover, that these extracts have an inhibiting action on the coagulation of 

 the blood of several species of animals. 



SUMMARY 



Summarizing the results of hitherto recorded investigations on hemo- 

 toxins from parasitic worms, it may be stated that while there is more 

 or less contradictory evidence in the literature the following facts have 

 apparently been established: 



1. Certain parasitic worms secrete substances that affect the blood 

 of their host deleteriously. These substances, which may be designated 

 as hemotoxins, are in general nonspecific in the sense that they are also 

 active toward blood of animals other than their normal host. 



2. Diphylloboihriu7n latum, a tapeworm which is known to cause severe 

 anemia, contains a hemolytic agent. It appears questionable that this 

 agent is oleic acid, as claimed by Faust. 



3. Concerning hemolysins in cestodes other than DiphyUobothrium 

 latum no definite conclusions can be drawn from the literature on the 

 subject, but that hemolysins are present in several species appears 

 probable. 



4. Schistosoma japonictmi secretes an ether-soluble hemolysin. 



5. Hookworms (Ancylostoma and Necator) secrete a hemolysin and 

 an anticoagulin. 



6. Whipworms {Trichuris trichiura) apparently secrete a hemolysin. 



7. Worms belonging to the genus Ascaris contain a hemolysin which is 

 closely bound to the tissues of the worms and is therefore but slightly 

 soluble in water, which fact accounts for the negative results obtained 

 by certain investigators. These parasites also appear to secrete a feeble 

 anticoagulin. 



8. Worms of the genus Strongylus secrete a hemolysin and an anti- 

 coagulin. The hemolytic principle of these parasites is apparently an 

 alkaloid, although other substances found in them show hemolytic power. 



9. Haemonchus contortus apparently secretes a weak hemolysin. 



10. Extracts of Macracanthorhynchus hirvdinaceus are apparently de- 

 structive to erythrocytes. 



1 1 . Hemolytic and anticoagulating properties are found in extracts of 

 the larvae of species of Gastrophilus. 



12. Hemolytic substances from parasites are soluble in alcohol* and 

 ether, thus resembling lipoids. 



13. With respect to their resistance to heat, hemolysins from animal 

 parasites vary, but in general they are thermostabile. 



' According to Alessandrini the hemolysin lxoraMacracanthorhynchushirudinaceusKms.o\nh\& in alcohol. 



