274 
Intestinal Protozoa in Termites 
entering into division, the chromatic granules are small and numerous, em¬ 
bedded in the ground substance, and arranged in the form of a thick spindle 
(PL XIII, fig. 47). A short strand makes its appearance at the pole lying under 
the body wall, and the above-mentioned mass of chromatic granules is found 
hanging in the nuclear sap, attached to the nuclear membrane just at the 
place where the short strand is formed. The chromatin granules break up 
and become rearranged to form a certain number of looped threads with 
their ends attached to the ends of the strand. The strand and the threads 
now become gradually more and more distinct; the strand becomes thickened 
and elongated, though rather slightly, and the threads become thick and uni¬ 
form chromosomes (PI. XIII, figs. 48 and 49). In early stages there are usually 
two long threads and some shorter ones; the former assume the form of U- 
or V-shaped loops, fixed at both ends of the strand, while the latter are found 
hanging from either end. The former threads are those that persist as chromo¬ 
somes through the later stages. I have counted one to three additional threads 
in nuclei at a rather advanced stage in division, but they disappear later. 
The chromosomes having the shape of a loop divide transversely into two 
at the middle, and each limb becomes a daughter chromosome. PI. XIII, fig. 50 
represents one of the specimens in the most advanced stage which I could 
study. In this stage the strand measures 4-5 /z, and is fused with the nuclear 
membrane. It is fairly thick, pointed at both ends, and stained deeply with 
iron-haematoxylin, showing occasionally a fibrous structure. The individual 
shown in PI. XIII, fig. 51 is also in the most advanced stage, and the daughter 
chromosomes are distinct, but the strand is invisible, owing to its disposition. 
The next stage which I have been able to find shows the already completely 
separated daughter individuals. I could not follow accurately the later stages 
of division. It will not be unreasonable, however, to suppose that the strand 
becomes further elongated, as in the preceding genera; but I am inclined to 
suppose that the nucleus is quickly divided after the above stage is reached. 
In young animalcules lately divided, the nucleus is round and the two 
daughter chromosomes are found hanging side by side from the anterior pole. 
In many cases, the greater portion of the chromatin becomes, sooner or later, 
aggregated into an oval mass, hanging in the nuclear sap at two points, and 
then disintegrates, forming the characteristic structure of the resting nucleus, 
with a rather feebly stained ground substance containing intensely stained 
granules embedded in it (PL XIII, fig. 52). As the animalcule grows, the nucleus 
becomes gradually flattened and elliptical in outline, and the points of attach¬ 
ment of the chromatic body become separated gradually from each other. 
Parallel with the alteration of the position of the points of attachment to the 
membrane, the shape of the chromatic body becomes also altered so as to 
form a band or spindle, which may be divided into two halves. In some 
cases, the daughter chromosomes remain in a rod-shaped condition for a long 
time; or they may become divided into two, three, or four pieces, and persist 
in that condition. 
