264 DISEASES OF DOMESTICATED BIRDS 
or cysts attached to them. The cysts contained a small amount of 
serous fluid similar to that found in the abdominal cavity. Only 
one cyst occurred on a nodule. The proventriculus and gizzard 
showed only a few nodules. These were small varying from 2 mm. 
to 2 em. in diameter. No cysts were found on the nodules of these 
organs. 
Only a few nodules were attached to the liver and spleen. Those 
on the spleen were of the smaller variety and did not show cysts. 
There were several large nodules on the liver, the largest one meas- 
uring 6 cm. in diameter and contained a cyst. The stalk of this 
tumor seemed to extend down through the capsule into the liver 
tissue proper. The serous coverings of the small and large intestines 
were affected alike and showed the attachments of many tumors 
of varying size. Section of a medium sized nodule showed it to 
contain several cysts containing thin, straw colored fluid. The cut 
surface of the tumor was white in color, tinged with pink. It was 
firm in consistency and numerous blood vessels were seen. 
Histological examination of the tumors shows them to be made up 
of rather loose fibrous connective tissue stroma, relatively scarce in 
cells. Scattered irregularly through the stroma, and occupying 
approximately one-fourth of the area of the tumor are numerous 
alveoli, varying in size from a solid cord made of two or three 
epithelial cells to large cysts 5 mm. in diameter, in the larger 
nodules. The alveoli are lined with epithelium which range from 
squamous to columnar in type. The alveoli vary greatly in shape. 
Some are irregularly oval, while others are much elongated and com- 
paratively narrow, resembling the duct of a gland. Still others are 
found where numerous branching has taken place, giving the tumor 
the appearance of a papillary adenoma. The epithelium is, as far 
as can be determined, attached to a very thin basement membrane 
and the cells are only one layer thick. The connective tissue stroma 
of the tumor is exceedingly well supplied with blood vessels. The 
serous covering or capsules of the tumors are composed of rather 
dense fibrous connective tissue, which serves as the connection of 
the tumor to the serosa of the intestine. At the point of contact of 
the tumors with the liver, the liver cells have been replaced to a con- 
siderable extent with connective tissue stroma like that of the 
tumor. 
