Few studies have been made of the presence and distribution of lipase or phosphatase in helminth parasites. Lipase was detected in Strongylus equinus by Bondouy ('10) and in S. edentatus and Ascaris lumbricoides by Rogers ( '41). Schwartz ('20) was unable to detect lipase activity in the acanthocephalan, Macracanthorhynchus hirudinaceus. Rogers ( '28) in his Teztbook of Comparative Physiology states that pepsin, trypsin, rennin, lipase, maltase, and amylase are absent in trematodes and cestodes. That little change has taken place in our knowledge of digestive enzymes during the past decade or so is illustrated by the following remarks of Florkin ('44, p. 192) :
Le parasitsme offre de nombreux exemples de reversibith. Si par exemple on compare les Platodes parasites avec les membres de la m2me classe menant unt vie libre, on constate que chez ces derniers, la lipase a Line activith analogue a celle qu'on observe chez les autre Vertebres, tandis que chez les Trematodes et les Cestodes parasites, son activitit est devenue tr2s faible. Alors que chez les Platodes libres on observe un arsenal d'enzymes proteolytiqnes, on ne troave plus ces enzymes chez les Cestodes parasites.
Contribution from the Zoological Laboratories of the Vniversity of Illinois under the direction of Prof. Harley J. Van Cleave in partial fulfillment of the requirements f o r the degree of Doctor of Philosophy.