Leukemia of the Fowl. 15 
2. Polymorphonuclear myelocyte with eosinophilic granules * (b): 
Round, about same size. Nucleus has two or more slightly vesicular 
lobes. Cytoplasm colorless with bright red granules. 
3. Mononuclear myelocyte with eosinophilic granules (a): Round, 
or oval, varying in size, mostly larger than 1 and 2. Nucleus round, 
oval, or horseshoe-shaped, eccentric, slightly or very vesicular. Cyto- 
plasm colorless with bright red granules. 
4, Large mononuclear myelocyte* (d): Round, slightly larger. 
Nucleus round, very vesicular, one or more nucleoli. Cytoplasm baso- 
philic, moderate in amount. 
Reticular Cell—Branched. Nucleus elongated, vesicular, several 
nucleoli. Cytoplasm pink, giving off delicate fibers to form reticulum. 
Lymphocytes, mast cells, platelets, mitoses of red and white cells 
were not seen. Letters in ( ) =order of predominance. 
Heart, Pancreas and Kidney: For all practical purposes similar to 
the human. 
TII. A Case oF Spontangous LEuKa@MIA. 
On October 31, 1912, a typical case of leukemia of the fowl was 
brought to the pathological laboratory. The animal, a Plymouth Rock 
hen, had just been killed, and its body was still warm. Nothing is 
known of its clinical history. An abstract of the findings is here 
given. 
BLOOD. 
The study of the blood was limited to smears taken from the heart 
just after the animal had been received at the laboratory. They were 
stained by Wilson’s method. A detailed description of the cells of 
leukeemic blood will be reserved for the experimental leukemia where 
far better opportunities for careful study of the same were offered. 
Suffice it here simply to enumerate and briefly comment upon those 
cells which were present. 
Blood Smears. There was an enormous increase in the white blood 
cells, the proportion of whites to reds being 1: 1.3. The predomina- 
ting cells were the large mononuclear and the mononuclear myelocyte 
with eosinophilic granules. The latter is abnormal to the blood, 
* These are obviously the polymorphonuclear with eosinophilic rods, the 
polymorphonuclear with eosinophilic granules and the large mononuclear 
cell of the normal blood. 
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