Leukemia of the Fowl. 1” 
Peritoneal Cavity—Omental fat entirely absent. Lower margins of 
right and left lobes of liver extended almost to the pubes, 7. ¢., far 
below xiphoid. 
Iiver—Enormous. Dimensions and weight not taken. Its surface 
was extremely mottled. It was reddish brown and specked with 
innumerable gray or slightly yellow spots from a pin-point to a few 
millimeters in diameter, frequently closely packed to form irregular 
areas, the largest 1 cm. in diameter. In addition there were scat- 
tered gray or slightly yellow nodules, averaging about 2 mm. in 
diameter. Sectioned surface similar in appearance. The blood-vessels 
were surrounded by a gray zone. 
Spleen.—Enormous. Dimensions and weight not taken. It was 
about the size of a small hen’s egg. Diffusely gray. 
Heart—-At the apex there were several gray spots, pin-point in size. 
Kidneys—Greatly enlarged. Both showed nodules, similar to those 
in liver. 
Bone-marrow.—Abundant, gray, with absence of fat. 
Thyroids, Parathyroids, Lungs, Gastro-untestinal Tract, Pancreas 
and Adrenals—Apparently uninvolved. 
MICROSCOPICAL. EXAMINATION. 
Cervical Lymph-glands—The normal structure was somewhat 
changed. There was complete disappearance of the interlobular fat 
with approximation of the greatly swollen parenchymatous lobules. 
Here and there were intra- and inter-lobular foci of myeloid tissue. 
These frequently enclosed an artery or vein. There was also a more 
diffuse infiltration of the parenchyma by myeloid cells, filling capillaries, 
veins, arteries and in places breaking through the lobular capsule into 
the interlobular tissue. Of the infiltrating cells two predominated: (1) 
A large mononuclear, usually round, at times slightly polygonal due to 
pressure, with a single, round, oval, or indented, vesicular, at times 
multiple, nucleus with one or more nucleoli. Its cytoplasm was non- 
granular and slightly basophilic. (2) The mononuclear myelocyte 
with eosinophilic granules, described under normal bone-marrow. 
Mitoses of these two cells were quite common. Normoblasts and 
megaloblasts appeared to be present. 
Liver—Here the process was most extreme. Very little liver tissue 
remained. Everywhere were closely packed masses of myeloid cells 
from which the liver trabecule had completely disappeared. These 
