192 ENTOZOA. 



tliis organ. Similar mistakes have occurred before, as Dujardin 

 and otliers liave pointed out. 



In tlie case of the Distoma ojpMlialmobiiim Gescheidt found four 

 specimens in the eye of a child five months old, born with lenticular 

 cataract. No one of the examples exceeded half a line in length. 

 They were situated between the lens and its capsule, in which place 

 they could be recognized as so many dark spots on the surface of 

 the lens. From the original description in Yon Ammon's "Zeit- 

 schrift fiir Ophthalmologic" we are scarcely warranted in conclud- 

 ing that the specimens were sexually mature. The author speaks 

 of ovaries, but they were "indistinct," and they are not repre- 

 sented in the carefully executed figures given in Yon Ammon's 

 writings.* One can scarcely escape the conviction, moreover, that 

 Yon JSTordmann's Monostoma lentis is identical with this worm ; 

 and I perceive that Dr. Weinland, of Frankfort, entertains a simi- 

 lar suspicion. Kuchenmeister's idea that this Monostoma may be 

 a young Gysticercus celluloses is not at all convincing ; for no one 

 ever heard of eight Gysticerci occupying one eye-ball, and much 

 less is it likely that they should occur thus gregariously in the 

 human lens. Trematodes are seldom sohtary ; and all the circum- 

 stances render it probable that the worms extracted by Pro- 

 fessor Jlingken, in his case of cataract, were identical with those 

 removed after death from the eye of the httle girl who died from 

 infantile atrophy whilst under Yon Ammon's care. As just hinted, 

 there were eight specimens in this case, the worms having an 

 average longitudinal measurement of about §o of an inch. Finally, 

 into speculative questions as to how these parasites came into the 

 eye, one does not care to enter, especially as it would lead us at too 

 great length into the consideration of similar phenomena observable 

 in the lower animals. 



4. Distoma ceassum. 



D. crassum, Busk ; Cobbold ; Leuckart ; etc. 



* " Klinische DarstoUungen der Krankhciten cles menschlichen Auges," vol. i. t. 12, 

 and vol. iii. t. 14. 



