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, contain proteolytic enzymes. They secrete an 
acid which aids in the digestion. Spontaneous re- 
covery takes place in many of the protozoan infesta- 
