396 Journal of Agricultural Research voi. xxii, no. s 



tube containing i cc. of a mixture of washed sheep red blood corpuscles 

 and specific antiserum in the proper proportion as determined by previous 

 titration, one unit of normal guinea-pig sei'um (complement) was added. 

 (The unit of complement was determined by titration.) Hemolysis 

 resulted. To a second tube containing a mixture of washed sheep red 

 blood cells and spscific antiserum one unit of inactivated complement 

 (heated to 51°) was added. No hemolysis resulted. To a series of 

 tubes containing washed sheep red blood corpuscles and specific anti- 

 serum various combinations of inactivated guinea-pig complement and 

 alcoholic extract of A. lumhricoidcs were added. No hemolysis was 

 produced in any of these tubes. It is evident, therefore, that A. lum- 

 hricoides not only lacks complement but that an alcoholic extract of 

 the worm freed from all ether-soluble substances combined with inacti- 

 vated normal serum can not act as complement. 



In this connection it is of interest to note that Holland (19 19) found 

 that the blood of insects lacks complement and that this substance is 

 also absent from the blood of mollusks. Cantacuzene {1919) examined 

 the fluids of a number of invertebrates as well as of tunicates but failed 

 to find complement. He succeeded, however, in producing complement 

 in a crab (a species of Eupagurus) by artificial immunization with sheep 

 red blood corpuscles. 



Summarizing, Ascaris lumbricoides in common with other inverte- 

 brates lacks complement, a substance that is known to play an important 

 role in the immunity processes of higher vertebrates. That A. lumbri- 

 coides and other internal parasites which live in parts of the body where 

 bacteria are more or less abundant protect themselves against bacterial 

 invasion is probable. The intestine of A. lumbricoides contains bacteria, 

 as has been recorded by several investigators. The present writer found 

 bacteria in the intestine, but the body fluid of fresh ascarids when col- 

 lected under aseptic precautions was found to be sterile. That the body 

 fluid and tissue extracts of ascarids and of other internal parasites con- 

 tain bactericidal substances has been afiirmed by a number of writers 

 (Alessandrini, 191 3). 



4. EXPERIMENTS WITH EXTRACTS OE ENTIRE WORMS 



It has already been stated that Weinberg {1907), Whipple (1909), and 

 Alessandrini (1913) failed to find hemolysins in salt-solution extracts of 

 ascarids. Garin {1913) records the results of 10 experiments with extract 

 of worms of the genus Belascaris, of which 8 yielded negative results and 2 

 yielded positive results on dog-blood corpuscles. These investigators 

 experimented with extracts of fresh specimens made by macerating the 

 worm material in physiological salt solutions. The present writer found 

 that as a result of extracting Ascaris lumbricoides material by macerating 

 fresh worm substance in salt solutions the hemolysin is seldom liberated 



