No. 7.] OSLER — PARASITES IN BLOOD OF FROCi. 409 



parasitic form. The blood examined by the student on tliat day 

 was taken from two bull frogs (^Rana Mugiens), but only one 

 contained the parasites. The organism presents the following- 

 characters: — Body an elongated oval, sausage-shaped, ends coni- 

 cal, one sometimes narrow and prolonged. Length somewhat 

 more than half a red corpuscle. The protoplasm is homogeneous 

 and more translucent than that of colorless corpuscles and shows 

 two or more small central vacuoles (?) with a few granules. 

 Movements slow and creeping, accompanied by an occasional 

 bend or twist of the body, go on at ordinary temperature ; a 

 little accelerated but not altered in character on the warm stasre. 

 The tail-like end though produced does not terminate in a ciliuni. 

 Fi- 3. 



This parasite was originally figured by Ray Lankester, when- 

 describing the Undulina (Trypanosoma) but he has only recently,, 

 in the Quarterli/ Journal of Microscopical Science, for January^ 

 1882, given a full description of it, and established its position. 

 He calls it Drepanidium ranarmn. Dr. Gaule, of Leipzic, has 

 studied these bodies and has come to conclusions as remarkable 

 as those at which he arrived concerning Trijpanosoma . He 

 calls them " Wurmchen," vermicles. and believes that they are 

 protoplasmic portions of the corpuscles of the blood which assume 

 an elongated form and display movements. He has found them 

 within the cells not only of the blood but of the spleen, kidney 

 and liver and has seen them penetrate and enter blood corpuscles 

 by their active movement. 



Dr. Lankester shows very clearly that these organisms are 

 truly parasites belonging to the Gregarinidoe or Sporozoa. those 

 lowly protozoal forms, many of which at some time of their exist- 

 ence are parasitic in the interior of cells. He suggests that it is 

 a young stage and the more developed or Gregariniform condition 

 of the parasite exists in some part of the body of the frog. He 

 points out that these bodies have a striking resemblance to 

 those figured by Lieberkilhn. as spores or pseudo-navicula from 

 Vol. X. z 2 No. 7.. 



