GENUS: TRYPANOPLASMA 643 



Keysselitz (1906) published au account of the trypanoplasmas of fish 

 which he had seen in Perca fluviatilis, Acerina cernua, Lota vulgaris, 

 Barbus fluviatilis, Cyprinus carpio, Carassius vulgaris, Tinea tinea, Ahramis 

 bratna, Leuciscus idus {Idus melanotus), L. cephalus {Squalius cephalus), 

 L. ergthrophthalmus {Scardinius erytkrophthalttius), L. rutilus, Esox lucius, 

 and Cobitis barbatida. He regarded them as all bejpnging to the one 

 species, T. borreli, to which Leger, L. (1904/), had ascribed a form seen 

 by him in the minnow, PJioxinus Icevis. 



The various species described differ from one another merely in their 

 dimensions, in the position of the nucleus, and other details. The parasites 

 are usually scanty in the blood of fish, so that in most cases the observa- 

 tions have been made on only a few individuals. It is impossible to be 

 sure, therefore, that the forms do not belong to one species, as Keysselitz 

 maintains. 



Trypanoplasma borreli Laveran and Mesnil, 1901. — This flagellate, as 

 described by Laveran and Mesnil, is a flattened elongate organism with a 

 rounded anterior end, and usually a somewhat pointed posterior end 

 (Fig. 151). It is distinctively curved, so that one side of the flattened body is 

 convex and the other concave. The nucleus lies just behind the anterior 

 third of the body near the convex border. In properly fixed specimens it is 

 seen to consist of a nuclear membrane and central karyosome. Opposite 

 the nucleus, and near the concave border, is the kinetoplast, consisting of 

 an elongate parabasal, just anterior to which are two closely applied ble- 

 pharoplasts. From one of these arises an axoneme, which passes forwards 

 round the anterior end of the body, and thence backwards on the edge of 

 the undulating membrane along the convex border to the posterior end, 

 where it becomes a flagellum. From the other blepharoplast there arises 

 an axoneme, which passes into the anteriorly directed flagellum. The 

 body of the flagellate is about 20 microns in length by 3 to 4 microns 

 in breadth. The two flagella are about 15 microns in length. Slightly 

 larger or smaller forms occur, while in preparations many curious distorted 

 flagellates result from the metabolic nature of the body. Reproduction 

 in the blood of the fish is by longitudinal division, and follows very closely 

 the process as described above for Crgptobia helicis. 



The trypanoplasm of the rudd is not only inoculable to uninfected 

 rudd, but also to minnows, as proved by Laveran (19046). Similarly, the 

 naturally occurring trypanoplasm of minnows is inoculable to rudd. 

 Plehn (1903) succeeded in inoculating the trypanoplasm of carp to other 

 carp. 



Ponselle (1913) has succeeded in cultivating the trypanoplasm 

 {T. varium) of the loach. The medium employed consisted of a 2 per cent, 

 agar in tap water without the addition of salt, to which one volume of 



