28 PROF. E, A. MINCHIN ON PROTOZOAN [Jan. 12,. 
the number is constant, so far as my observations extend. One 
karyosome is often slightly larger than the other. When the 
trypanoplasm lies in a certain position, the karyosomes may be 
quite hidden under the opaque kinetonucleus, and then the tro- 
phonucleus cannot be made out at all. In the large forms, on the 
other hand, the trophonucleus shows either one large karyosome 
which almost fills the nuclear cavity (fig. 69), or one large and 
one or two smaller karyosomes (figs. 67, 68). There are further 
differences to be observed in the trophonuclei of the large forms 
which appear to be correlated with differences in the kinetonuclei. 
Usually a large trophonucleus with a very large karyosome is 
correlated with a relatively short kinetonucleus (fig. 69). On the 
other hand, a small trophonucleus may be found combined with a 
very long kinetonucleus (fig. 67). According to Keysselitz the 
large forms of the trypanoplasm are gametes, those with the 
large kinetonucleus being male forms, and those with smaller 
being female. I am not in a position to criticise or comment 
upon this statement. 
The kinetonucleus is situated on the side of the body furthest 
from the undulating membrane, and is remarkable for its great 
length, being narrow and band-like, never rounded, oval or pear- 
shaped. As already stated, its length varies in different specimens. 
With iron-hematoxylin it always stains an even black and shows 
no structure: in one specimen which had been very much ex- 
tracted (fig. 72) it appeared very narrow and linear in form, with 
a clear space in the cytoplasm on one side. 
In front of the kinetonucieus are situated the two minute 
blepharoplasts from which the flagella arise. I believe them to 
be always two im number, but in iron-hematoxylin preparations 
they are so minute and often so close together that it is impossible 
to resolve them as two granules and they may appear as a single 
dot. There appears to be a streak or fibre connecting the 
kinetonucleus with the blepharoplasts, but the length of the 
connection, that is the distance between the two structures, is 
variable. 
The following is an attempt at a brief diagnosis of 7rypano- 
plasma keysselitzi :—Oceurs under two forms, distinguished by 
size and by structural characters; in both forms the two nuclei 
very close together at the anterior end of the body; kineto- 
nucleus very elongated, trophonucleus small; posterior free 
flagellum long in the smaller forms, short in the larger forms. 
Host, Tinca vulgaris, Norfolk. 
8. TRYPANOPLASMA ABRAMIDIS Brumpt. (Plate ITI. figs. 49-54 ; 
Plate 1V. fig. 77.) 
The trypanoplasm of the Bream has been described by Brumpt 
(CR. Soe. Biol. lx. 1906, p. 164) in the following words :— 
* Dans le sang de la Bréme. Vu seulement a l'état frais. Le 
corps posséde alors 30u de long sans compter les flagelles, Pantérieur 
ayant environ 15, de long, le postérieur 5 et 64 seulement. Ce 
