The löle of the chondriosomes in the cells of the guinea-pig’s pancreas. 263 
latter condition is especially noticeable in the cells sitnated near or on 
the margins of a section, and is almost certainly due to over-differentiation. 
Although these graniües are not extruded from the cells as granules, 
yet it is an open question whether they may not in some way take part 
in the elaboration of the pancreatic secretion. 
The chondriosome and the zymogen granules. 
The chondriosome in the pancreatic cells is made up of chondriokonts 
and mitochondria. 
The latter are not so numerous as the former, and are generally con- 
fined to the extreme base of the cell (Figs. 4, 6, 7 and 10 m). They are 
of a greater diameter than the thickest chondriokont, and are easily dis- 
tinguished from cross-sections of the latter, in the lower half of the basal 
zone, by careful focussing, when it will be seen that they are discrete 
granules, and not the cut ends of rods. 
Although they are stained in haematoxylin treated sections similarly 
to the zymogen granules, yet they are to be separated from the latter by their 
Position, (being c-onfined to the basal zone) and also by the fact that they 
are not stained at all by Saffranin, which does stain zymogen. Thus 
in Fig. 3, it will be seen that the inner zone of the cells is full of zymogen 
granules, while the mitonchodria which lie in the basal zone, are not stained 
at all. 
The chondriokonts (Figs. 4 to 10, 12 and 13) which form the other 
element of the chondriosome, are long rods. These are most numerous 
in the basal zone, although in certain conditions of the cell they may 
extend beyond this limit into the lower half of the inner zone. Under no 
cireumstances are they ever to be found in the extreme apex of the cell, 
that is, that portion which faces the lumen of the alveolus. They are 
generally of an even diameter throughout, but sometimes may be thicker 
at the end which is directed towards the base of the cell. They Vary in 
length from 0.6 (.i to 8 /t and are occasionally more than half as long as 
the cell. 
Except the zymogen granules, which rernain to be dealt with, all 
the bodies which are to be seen in the cytoplasm of the cell, have now been 
indicated. It is therefore observable that there is no structure in the 
cells of the guinea-pig’s pancreas resembling the form of Nebenkern which 
has been described by various authors in the pancreas of the Amphibia. 
In the latter, the chondriosome or Nebenkern takes the form of a concrete 
mass, more or less closely applied to the periphery of the nucleus, and 
which can sometimes give evidence of a fibrillär nature Nussbaum (1882). 
