M. Koidzumi 
273 
The nucleus is situated near the anterior end, embedded in a mass of special 
protoplasm, transparent, dense, and homogeneous, and staining somewhat 
deeply with eosin. In the young forms this peculiar protoplasm is only 
distinctly recognizable around the nucleus; but in large ones it is remarkably 
dense, and is also found strongly developed both in front of and behind the 
nucleus. In front it assumes the shape of a cone, reaching anteriorly to the 
tip of the body. At the sides and behind the nucleus, one, two, or three 
columns of it, gradually decreasing in thickness towards the hind end, are 
found hanging in the endoplasm (PI. XIII, fig. 46). These columnar structures 
are remarkably distinct in some individuals and appear fibrous. Hartmann’s 
description of the Brazilian species of Holomasligotoides contains no account 
of any corresponding structures, but quite similar structures are described 
and figured in H. mirabile and H. hemigymnum by Grassi. I am inclined to 
doubt the accuracy of Hartmann’s observations on this point. 
The nucleus of mature individuals appears usually elliptical in outline, 
measuring 20-26/x by 10-15/x, the major axis being situated transversely. 
The nuclear membrane is very distinct, and the special protoplasm im¬ 
mediately surrounding it is dense. The internal structure of the resting 
nucleus is somewhat peculiar in this organism. In some individuals a chro¬ 
matic body, resembling a band or a spindle and consisting of deeply stained 
granules embedded in somewhat deeply stained ground substance, is found 
crossing the nucleus transversely (PI. XIII, figs. 43 and 45). The granules are, 
in some individuals, large in size and few in number, while they are minute and 
numerous in others. In some cases the chromatic body is divided into two 
halves situated side by side (Fig. 46). It is also common that the chromatic 
substance appears as a small number of globular masses or rod-like bodies, 
stained rather intensely and homogeneously with iron-haematoxylin (Fig. 44). 
The nuclear sap is not structureless and homogeneous as in the preceding 
forms, but fine granules, faintly stainable with iron-haematoxylin, are present 
in it. These granules are found, as a rule, apart from the chromatic bodies 
and distributed chiefly at the periphery of the nucleus. The situation of the 
chromatic bodies in the nucleus is noteworthy in this species. When they 
form a band or spindle, it lies transversely, as mentioned above, and is found 
commonly connected with the nuclear membrane at both its ends: when two 
masses are present, they are situated symmetrically at both sides, and they 
are also commonly kept in connexion with the membrane at symmetrical 
points. At the point of connexion of the chromatic bodies with the membrane 
a minute granule is frequently recognizable. 
The process of division of the nucleus in this spepies appears somewhat 
peculiar. The nucleus, when going to divide, changes its position. It is 
drawn near one side of the body, and usually becomes narrowed towards the 
point drawn near the body wall. These changes are sometimes not so dis¬ 
tinctly seen, or are unnoticeable because of the position of the nucleus under 
the microscope, but they are very conspicuous in some cases. In the nucleus 
Parasitology xm 18 
