PARASITOLOGY. 227 



a lipase capable of digesting the fat contained in horse 

 serum. 



Antibody Studies in Parasitism. — Guiart found the 

 guaiac blood test to be positive in thirteen cases where 

 the ova of trichocephalus were found in stools and 

 eggs were never found without the positive reaction. 



Weinberg found a clear sterile liquid obtained from 

 the ascaris megalocephalus when dropped into the eyes 

 and nostrils of horses not harboring this species of 

 worm gave a marked reaction, while no reaction was 

 noted in those which harbored this species indicating 

 immunity in the latter case. 



Meyer found that aqueous and alcoholic tapeworm 

 extracts gave complement binding reaction in infested 

 individuals. The complement binding antibodies are 

 genus specific rather than species specific. This anti- 

 gen appears to be a lecethin like lipoid. 



Bondouy found an alcoholic extract of strongiles to 

 possess strong hemolytic properties. They secrete a 

 lipase which is capable of digesting fat in horse 

 serum. 



Vallillo has shown that the toxin produced by the 

 Strongylus bidentatum possesses a positive chemo- 

 tropism for the polynuclear eosinoplile leucocyte. 



Yorke has proven a hemolytic complement in cases 

 of tryposomiasis. 



Protozoa. — These are the single celled parasites and 

 possess all the chemical characteristics of the cells 

 of the higher animal bodies. These parasitic pro- 

 tozoa co*ntain proteolytic enzymes. They secrete an 

 acid which aids in the digestion. Spontaneous re- 

 covery takes place in many of the protozoan infesta- 



