Parasites of the Spleen. 367 



uterus short, massed on opposite side from ovarj'. Eggs oval, 80 

 to 100 ju. by 56 \x.. Ciliated embryo develops after eggs are laid. 

 Sporocyst, redia, cercaria, and intermediate host, unknown. 



Development. Washed free from sputum and kept in water at 

 80° to 94° F. the ovum in 40 to 60 days develops an embryo, 

 ciliated in its posterior tworthirds only. (Manson). The further 

 changes have not been demonstrated, but analogy with the dis- 

 toma would indicate an intermediate host, probably a mollusc, as 

 necessary to the development of the cercaria which can again in- 

 fest the mammalian lung. (See Distoma Hepaticum). 



Animals Infested. In Japan this parasite is extremely common 

 in tnan and dog ; it has also been found in Europe in the tiger, 

 and in America in cat, dog, SLtid pig. There is reason to believe 

 that its apparent absence from other animals may be largely due 

 to the iufrequency of exposure and to the lack of thorough inves- 

 tigation. 



LUNG FLUKES IN CAT AND TIGER. 



The parasite was found by Kerbert in the lungs of two tigers 

 which died in 1878 and 1881 respectively, in the Zoological gar- 

 dens of Amsterdam and Hamburg. The Asiatic origin of the 

 tigers sugge.sts that they were probably infested in the east. He 

 found the parasites '^ always two together, on the outer surface of 

 the lungs, in rather thick, hornlike capsules, which immediately 

 attract attention by their rather blue color." In 1891 Weber 

 found a third case in the royal tiger of Sumatra. The lungs con- 

 tained 33 cysts containing 2 parasites each ; one contained 3 para- 

 sites and I a single fluke. 



Kerbert describes the paragonimus as devoid of spines on the 

 caudal as well as the cephalic end, but Leuckart and Nakahama, 

 after examination of his specimens, pronounced them identical 

 with those of man. 



The Paragonimus was found in 1894 in the lungs of a domestic 

 cat, at Ann Arbor, Mich., by Ward. In Friedberger and Froh- 

 ner it is noted that cats suffer in Japan. It showed no clearly 

 distinctive feature from the parasite of man. The source of the 

 infection in the Mich, cat is not shown, but it is altogether prob- 

 able that it took in the fluke in America. There is the further 

 probability that the parasite had been imported in an infested 



