20 Harry C. Schmeisser. 
2. In the Organs—(a) A diffuse and circumscribed, at times 
nodular, infiltration of myeloid cells, in which the large mononuclear, 
and mononuclear myelocyte with eosinophilic granules predominated, 
although the other cells of the normal bone-marrow were at times 
present. This myelosis involved especially the liver, spleen, kidneys and 
bone-marrow, resulting in an extreme enlargement of the first three 
organs. Almost all of the remaining organs showed infiltrations, but to 
a less degree. (b) A change in the contents of the blood-vessels. The 
proportion of white to red cells was greatly increased. The predomina- 
ting cells were the same as those of the infiltration. 
CONCLUSION. 
In conclusion, if we consider that the cells, characteristic of both 
leukemic infiltrate and blood, were the same, and that under normal 
conditions the mononuclear myelocyte with eosinophilic granules 
occurs only in the bone-marrow and the large mononuclear only in the 
marrow and blood, it is evident from the summarized facts, that the 
above case must be considered a typical case of myeloid leukemia. 
IV. EXPERIMENTAL LEUKZMIA. 
With material from the above case, the disease was successfully trans- 
mitted into the fifth generation. A total of 105 animals were used in 
conducting many different kinds of experiments. Of this number, 22 
in all have developed leukemia. In four additional animals, a definite 
diagnosis could not be established, although the appearances were highly 
suggestive. The strain has now been running for more than 13 months. 
This paper will be confined to a report of those series which deal with 
simple transmission of the disease by the injection of an organic 
emulsion. 
Five of these series were conducted, each consisting of 5, 10 or 15 
fowls. The percentage of positives per series varied from 20-40 per 
cent. Of the total number of 40 chickens injected, 13 became leukemic, 
1. 32.5 per cent. In addition, a definite diagnosis could not be made 
in three, although the findings were very suggestive. 
PREPARATION OF MATERIAL, METHODS OF INJECTION, ETC. 
The material used for transmission was an emulsion of liver, and 
sometimes of spleen also. It was prepared by thoroughly macerating 
