180 
C. H. MARTIN. 
(3) The kinetonucleus increases in length and divides by a 
simple transverse constriction. 
In some rare cases of division it would appear that part of 
the cytoplasm, with part of the kinetonucleus, is split off, 
leaving the trophonucleus spindle in the other individual 
(PI. 9, fig. 1). As a result of this very rare form of division 
forms have been found containing only a kinetonucleus. 
These, I believe, degenerate. The other individual in this 
division gives rise, I believe, to rather large forms with two 
trophonuclei (PI. 9, fig. 2). I have not been able to discover 
what the final fate of these forms is. 
In addition to the abnormal division forms described above 
I found some stages of a curious process of rounding-up 
which seems comparable with that found in some Trypano- 
somes. In the early stage of this process the Trypano- 
plasmas assume a characteristic head-to-tail position, the 
anterior and posterior ends being closely approximated. The 
membrane flagellum now becomes loosened, at first near its 
anterior end, and this loosening seems then to travel back 
from that part to the animal’s posterior end. At the same 
time the approximated body-walls on the inner side dis- 
appear, so that in the next stage (PI. 9, fig. 3) the body of 
the Trypanoplasma is, roughly, apple-shaped. In this stage 
the two flagella arise together from a point near the anterior 
pole, both flagella gradually shorten, and in the still later 
stages both the flagella have disappeared. The nuclei now 
begin to undergo a series of changes, the significance of which 
is by no means clear. The kinetonucleus, which originally 
showed a bunched, compact appearance, becomes a strand- 
like structure, and at the same time an elliptical vacuole 
appears in its neighbourhood. The vacuole increases in size, 
so that it includes the twisted strands of the kinetonucleus, 
which at first form a darkly staining axis to the vacuole, but 
later break up into rod-like masses of chromatin. 
The trophonucleus appears to become slightly enlarged in 
the intermediate stages of this process, but the final form of the 
Trypanoplasma appears to be a spherical animal with no trace 
