264 
Intestinal Protozoa in Termites 
A single large nucleus is situated at a short distance behind the axial 
column. It appears usually oval in shape, measuring 10 /x or rather more in 
diameter. It is not suspended freely in the endoplasm, but is enveloped in 
a sac, the nuclear sac, hanging from the base of the axial column of the head. 
The sac has the shape of a flask with an ovoidal or globular body and a slender 
neck. It is, moreover, provided with a flange-like extension in the horizontal 
plane at the equator of its globular portion. The nucleus almost fills the 
main body of the sac, which fits itself very closely round the nuclear membrane; 
and consequently the sac is usually inconspicuous on the surface of the 
nucleus, which seems to be united to the base of the axial column by means 
of a membranous tube at its anterior pole, and provided with a horizontal 
extension at its equator. This horizontal flange or plate is distinct in the 
vicinity of the nucleus and becomes gradually indistinct towards the body 
wall, so that its entire course can be clearly followed only in good preparations. 
The tubular neck of the sac varies somewhat in length, according to the 
condition of the head and the size of the nucleus. During the movements 
of the animalcule, the shape of the nucleus is also frequently modified by the 
pressure exerted by the sac, especially when the nucleus itself is large. The 
nuclear sac is continuous at its anterior end with the substance filling the 
space between the rind and the core of the axial column of the head. I am 
of the opinion that the sac is homologous with the corbule of Trichonympha, 
which keeps the nucleus in connexion with the body wall. 
The nucleus is of the same type as in Trichonympha. No trace of linin 
reticulum is to be seen, and fairly large chromatic masses are found assembled 
at the middle portion, leaving a wide zone of clear ground substance peri¬ 
pherally. In some forms the chromatic bodies are distinct in outline, as is 
common in Trichonympha’, while in some others they are united to form a 
rough network, as in Pseudotrichonympha. A single nucleolus is clearly dis¬ 
cernible in nearly all individuals, situated near the centre of the nucleus and 
surrounded by a clear space. 
As already noted, the body is provided with numerous transverse ridges 
on its wall. In the normal state each of the ridges has the shape of a drawn 
out and flattened fold, inclined backwards so that a distinct groove is formed 
under it (Text-fig. B, a). The ridges, however, are not necessarily distinct in 
every individual, and when the body is abnormally elongated they almost 
disappear (Text-fig. B, b). In some cases, on the other hand, they are pressed 
so closely against the body that the grooves entirely disappear, and the 
surface then appears almost smooth (Text-fig. B, c). 
In the endoplasm two portions are distinguishable. The main portion is 
similar to that of Trichonympha or Pseudotrichonympha, being more or less 
coarsely granular and appearing grey in colour in the living animal. The 
ridges, on the other hand, consist of a transparent and structureless proto¬ 
plasm of dense consistency. 
The body wall differs from that of the preceding forms, and the mode of 
