ANIMAL PARASITIC INFECTIONS 461 
Isospora felis Wenyon, 1926, and Eimeria felina Nieschulz, 1924, have also 
been reported in the faeces of lions in menageries in Berlin and Leningrad.' 
Metcalf ? in a most interesting article has recently discussed the aid which 
parasites give in the problems of taxonomy, geographical distribution and 
paleogeography. Hegner* further points out that the protozoan parasites of 
monkeys and man belong for the most part to the same species or are so similar 
in their structure, life cycle and host-parasite relations as to be practically in- 
distinguishable. He concludes that if the proposition is valid that close re- 
lationships of parasites indicate a common ancestry of their hosts, then the facts 
available regarding the protozoan parasites of monkeys and man furnish evi- 
dence of importance in favor of the hypothesis that monkeys and man are of 
common descent. Possibly zoologists may find in the occurrence of Cylico- 
sptrura so far only in the leopard, tiger, and lion a somewhat similiar relation- 
ship of common ancestry in these animals. 
1 Rastegaieff: Bull. Soc. Path. Exot. (1929), XXII, 641. 
2 Metcalf: Smithsonian Misc. Col. (1929), LX X XI, 1. 3 Hegner: Loc. cit. 
