1909.] BLOOD-PARASITES OF FRESHWATER FISHES. 29 
parasite évolue exclusivement chez | Hemiclepsis et ne passe 
jamais dans la gaine de la trompe, ce qui permet de le distinguer 
des especes déja connues de la Carpe et des Loches.” 
The occurrence of trypanoplasms in the bream has also been 
noted by Keysselitz (Arch. Protist. vii. 1906, p. 3). 
1 found trypanoplasms fairly abundantly in all the bream 
examined by me at Sutton Broad. It is unnecessary to give a 
detailed description ; my figures show their general appearance. 
The body is rather slender and not very granular. The anterior 
flagellum is fairly long, the posterior free flagellum moderately so. 
The trophonucleus is about on a level with the hinder end of the 
kinetonucleus. I did not staim any preparations with iron- 
hematoxylin, so can say nothing about the minute structure of 
the nuclei. I did not find any trypanoplasms of large size, as in 
other species. 
In its characters 7rypanoplasma abramidis appears to be more 
or less intermediate between 7’. keysselitzi and 7. gurneyorum, but 
distinct from either. 
TRYPANOPLASMA BORRELI Lav. & Mesn. (Plate IIT. fig. 55.) 
The trypanoplasm of the Rudd (Leuciseus erythrophthalmus) is 
the type-species of the genus 7rypanoplasma; it was described 
under the name 7’. borreli by Laveran & Mesnil in 1902 (Arch. 
Protist. 1. p. 489). The Rudd and Roach are very abundant: in 
Sutton Broad, perhaps the two commonest species of fish there, and 
Texamined a great number of specimens of each species for blood- 
parasites ; only in one rudd, however, was I successful in finding 
them. J saw one trypanoplasm in the fresh blood, and made 
several smears from the same fish. After very prolonged 
searching of the smears a single trypanoplasm was found, which 
both from its occurrence in the Rudd and from its resemblance 
to the figures of Laveran & Mesnil and Léger, I have no 
hesitation in identifying as 7’. borreli. From the single specimen 
before me, 7’. borreli appears to resemble 7’. keysselitzi in the length 
of its free flagella, but differs in having the trophonucleus further 
back (fig. 55). 
EXPLANATION OF PLATES I.-YV.' 
All figures are drawn with the camera lucida to a magnification of 2000 linear; 
with the exception of fig. 77, Plate IV., and figs. 94, 95, Plate V., which are drawn 
from the living object freehand. 
Prate I, 
Figs. 1-7. Trypanosoma granulosum of the Eel, a series to show the gradations in 
size between the smallest and the largest forms. All from the same 
blood, and all, except fig. 7, from the same slide. Preparations dried 
off, then fixed with absolute alcohol and stained with Giemsa’s stain. 
Figs. 8-14. Trypanosoma perce of the Perch, various forms. 8-11, small forms ; 
12, medium-sized form with long free flagellum; 13, 14, stout forms 
with short free flagellum; 8 & 12-14 from preparations dried off 
and fixed with absolute alcohol; figs. 9-11, from preparations fixed 
with osmic vapour followed by absolute alcohol; all stained with 
Giemsa’s stain. 
