248 
Intestinal Protozoa in Termites 
The knob and the narrow portion of the axial core stain intensely with 
iron-haematoxylin, as well as with eosin. The wall of the columnar part also 
stains deeply, while its contents do not take any dyes at all, but contain 
deeply stained granules. The inner layer stains only slightly or not at all, 
while the outer layer appears rather deeply stained. In well-stained prepara¬ 
tions further differentiation, which has been overlooked by previous authors, 
is discernible in the inner layer. This consists of a zone, somewhat darkly 
stained, close to the axial core, and measuring some one-fourth of the layer 
in its thickness. The boundary between the inner and the outer layers stains 
intensely with haematoxylin, thionin, fuchsin, and other dyes. The existence 
of such a zone, and the structure of the axial core and the inner layer, afford 
us, together with the result of studies of living specimens, strong evidence 
for believing that the flagella arise from this zone. 
It has already been remarked that the bell is distinctly differentiated from 
the rest of the body, especially as regards its wall. The wall is very thick and 
one can easily detect the outer and the inner layers both in the living animal 
and in stained preparations. These layers are of the same structure as the 
corresponding layers enclosing the axial core, and are apparently continuous 
with them. There is, however, as pointed out by previous authors, a circular 
fissure (“citartrosi” of Grassi) encircling the base of the nipple and reaching 
the base of the axial core. It is, therefore, by means of the axial core only 
that the nipple is connected with the body. As in the nipple, the outer layer 
of the bell is much thicker and stains more deeply than the inner layer. The 
latter stains feebly or not at all, excepting a zone at the base, which stains 
more deeply like the corresponding zone in the nipple. In the living animal, 
the inner layer at once attracts the observer’s attention as a transparent zone. 
In stained preparations the deeply stained zone at the boundary between the 
two layers is much more conspicuous than in the nipple. The numerous long 
flagella undoubtedly arise from this zone and traverse the outer layer. 
The descriptions of the structure of the nipple and the wall of the bell in 
T richonympha agilis, given by previous authors, do not agree with the results 
of my observations in several points. As for the axial core, to begin with, 
the descriptions of Porter (1897) almost agree with mine, except that he 
describes a slight difference in its shape. Grassi’s descriptions seem mostly 
to agree with mine, but differ in the following point. According to him, the 
anterior knob is not solid, but consists of two parts, namely, wall and contents, 
just as in the columnar part; the contents of both parts being the same, and 
continuous with each other. The axial core of the Portuguese species, de¬ 
scribed by Fran£a, is of a quite peculiar structure. He described (1916) and 
illustrated (1918) this structure as consisting of a mushroom-shaped body and 
a projecting transverse disc, connected with each other by a commissure. 
He did not mention any differentiation of its wall and contents. According 
to Kofoid and Swezy (1919), the structure of the nipple is very peculiar in 
T. campanula. There is no deeply stainable tubular wall, but several longi- 
