E. N. Pavlovsky and N. N. Anitchkov 
313 
In addition to the pigment cells the outer areolar connective tissue of the 
capsule contains a small number of the following other cellular structures: 
(a) small cells with a spherical dark nucleus and basophil protoplasm, and 
(b) larger cells with a pale peripheral nucleus and vacuolar amoeboid proto¬ 
plasm. Compared with the cells of higher vertebrates the former cells (a) may 
be referred to the lymphocytes, while the latter ( b) may be regarded as so- 
called polyblasts (macrophages, histiocytes) of the granulation tissue. It is 
remarkable that in the protoplasm of the last-named cells, as well as in that 
of some of the fibroblast cells, separate granules of pigment are encountered, 
similar to those of the pigment cells. In a few cells of the polyblast type, the 
accumulation of pigment was so great that it was difficult to decide whether 
these cells belonged to polyblasts having phagocytised a large number of 
pigment granules or to the young pigment cells, which probably develop 
from polyblasts. 
Similar cases of accumulation (or production?) of pigment granules by 
polyblasts have been previously observed by Eberhard (1907) in experimental 
aseptic inflammation in the turtle (Emyslutaria europaea). 
Development of the Cyst. 
The examination of the histological structure of the connective-tissue 
capsule formed around the parasites allows us to reconstruct, in its main 
features, the process of the gradual development of the capsule: 
The parasites having reached the pancreatic gland first of all evoked 
around them an exudative cellular inflammation followed by necrosis of the 
elements of the exudate (the granular layer of the capsule) and of some of 
the pancreatic lobules. A granulation tissue was then developed at the expense 
of the surrounding connective tissue stroma of the pancreas and peritoneum. 
In some areas this process proceeded on a small scale till the death of the host, 
since areas with areolar granulation tissue have been observed in the outer 
layers of the capsule. However, the main mass of granulation tissue formed 
around the parasite had been already transformed into cicatricial tissue which 
entered into the composition of the fibrous capsule. This circumstance indi¬ 
cates that the reaction had taken place long before for it is known that in 
cold-blooded animals inflammatory processes develop very slowly. Owing to 
cicatrisation and pressure of the cysts, the surrounding lobules of the pancreas 
have atrophied considerably. The visceral portion of the peritoneum being also 
involved into this process, pseudo-adhesions between the latter and the parietal 
portion have been produced, i.e. adhesive peritonitis has developed. 
The foregoing shows that the reaction in Schizothorax around the 
parasitic cysts of Tetracotyle is similar to that found in other vertebrates 
and especially in cold-blooded animals as described by Maximow (1906), 
Eberhard (1907) and others. Our case shows a later stage of the inflammatory 
process with certain characteristic changes concerning the pigment. But the 
