Leukaemia of the Fowl. 15 



2. Polymorphomiclear myelocyte with eosinophilic granules * (6) : 

 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. 



III. A CASE OF SPONTANEOUS LEUKEMIA. 



On October 31, 1912, a typical case of leukaemia 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 

 leuksemic blood will be reserved for the experimental leukaemia 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. 

 2 



