Leukaemia of the Fowl. '. ./.'. * "..-' :'-i3'. 



areas. Butterfield, in comparing the histological findings in Mohler's 

 cases with his own, finds a convincing similarity between, or identity 

 of, the infiltrating cells. In Mohler's cases, the infiltration was more 

 diffuse and not so regularly arranged about the portal tissue. Above 

 all, the white blood cells were markedly increased in all the blood- 

 vessels, from the intraacinar capillaries to the largest veins. The 

 predominating white cell was indistinguishable from the cells in the 

 tumor masses of both these and Butterfield's cases. From the fore- 

 going, Butterfield felt justified in granting "the existence of a 

 leuksemic and aleukaemic lymphadenoid hyperplasia in hens." 



Butterfield and Mohler deserve the credit of showing that leukaemia 

 occurs in the fowl. Their studies were limited to post-mortem 

 findings. 



To Warthin, 8 in 1907, we are indebted for the first complete study 

 of this disease in fowls. He had the good fortune to secure a living 

 animal, which he kept under observation for two and a half months 

 before it died. During this time he had an opportunity of care- 

 fully studying the clinical course. The blood showed a great reduction 

 in the total number of red blood cells. These varied greatly in 

 size and shape, and contained less haemoglobin than normal. The 

 total number of white cells was greatly increased. Differential counts 

 showed a striking increase of the " large lymphocyte " at the ex- 

 pense of the other cells of the normal blood. Numerous mononuclear 

 forms of the eosinophiles, cells abnormal to the blood, were seen. 

 From the blood changes Warthin felt justified in making a diagnosis 

 of " lymphatic leukaemia of the large cell type." A careful autopsy 

 revealed the following findings: The liver was greatly increased 

 in size and was pale yellow in color. The spleen and kidneys were 

 also enlarged; both showed numerous yellowish spots from pin- 

 point to pin-head in size. In the haemorymph nodes small yellowish 

 nodules were found. The bone-marrow appeared as solid plugs, red- 

 dish-yellow and friable. The tissue changes were summarized as 

 follows: (1) Tumor-like nodules and infiltrations of lymphoid cells 

 in all the organs, particularly in the liver, spleen, kidneys, bone- 

 marrow and haemolymph nodes ; (2) replacement of the normal white 

 cells of the blood by cells of the large lymphocyte type, more or less 

 atypical in character, but identical with cells in the tumor masses. 

 From the findings, both in the blood and in the tissue, Warthin made 

 the diagnosis of leukaemic lymphocytoma. 



