900 
B. O. MINGE. 
be found curved in a loose loop, in the shape of the figure 3 ; 
or in a spiral. They remain in this form until they pass in the 
encysted stage. Trichinae pass through the soft myolemma and 
thus change into a cellular sheath. 
The cyst is at first very soft and thin, but gradually thickens, 
thus becoming transparent and homogeneous, forming two 
poles. By the assistance of these poles the cyst is separated 
from the surrounding tissues. There are various ways of find¬ 
ing the cyst while under different conditions. Generally the 
cyst has the appearance of a lemon, although it is sometimes 
found in different forms, the large axis being parallel with the 
muscular fibres. Length 30 to 50 mnr, breadth 20 to 40 mnr. 
The trichina in the definitively constituted cyst is in a dormant 
condition. Corpuscles are added, thus changing the pigment 
granules, from a yellow to a brown. The tissue of the cyst may 
undergo fatty or calcareous degeneration. Fatty degeneration 
is defined by the forming of small fatty granules in the interior 
of the cyst cells. When the fat granules have been set free and 
invaded the cyst, the calcareous degeneration begins. No traces 
of nutrition in the cyst have been observed, but it can be seen 
that carbonate and phosphate of lime are formed in layers in the 
interior of the cyst, thus rendering the cyst opaque. This cal¬ 
cification is not frequently formed, because it takes about seven 
months after infestation, and the animal is usually killed before 
that time. Trichinae more than 13 years old have been found 
in man—even as old as 20 years. These trichinae were said to 
have been living, and would have answered for experimental 
purposes. It has not been proven that any new infestation 
would or did take place during observation. Occasionally in 
the infested muscles there will be found fatty pigmentary or 
calcareous degenerations. 
A cyst leads to a fat deposit which first appears at one pole 
and takes on a new formation. Trichinae when arrested in this 
state appear as fatty masses containing very little protoplasm, 
and can only be located by a fatty cluster. In the fatty clusters 
is found the worm in the embryonic state, which very seldom 
