34 MASS. EXPERIMENT STATION BULLETIN 370 



bone marrow cells, for the proof of which he irradiated the marrow from chick 

 embryos or glycerinated marrow of adult chickens which was then injected into 

 the experimental chickens. Osteitis fibrosa, erythremia, anemia, and myeloid 

 leukemia were observed in these chickens. These conditions was transmitted for 

 two serial passages. No instances which could be interpreted as erythroblastic 

 leukosis were found among these chickens and the myeloid reaction might well 

 be looked upon as leukemoid in character. 



Furth (72) and Jarmai and Balo (104) both report attempts to produce a condi- 

 tion of erythroleukosis by removal of large quantities of blood, but they found 

 that the appearance of polychrome erythrocytes in the circulation was only 

 transient. Wirth and Kubasta (217) noted that the anemic condition of the 

 blood of chickens after removal of approximately half the blood volume quickly 

 returned to normal (within eight days following one blood letting and nine to 

 fifteen days following a second removal of blood). Pyrodine (acetylphenyl- 

 hydrazine) was found effective in producing an erythroblastic hyperplasia of the 

 bone marrow, but the blood picture of the birds thus treated was that of a re- 

 generative anemia (Furth, 72). There was no tendency of the immature cells in 

 the blood to undergo stasis in the organs of these chickens, a characteristic of the 

 pathology in leukosis as produced by the agent of transmissible fowl leukosis. 

 Ricin, saponin, and toluylene diamine were studied in a similar manner by Furth 

 (72). He found that they did not produce a condition of erythroblastic leukosis. 



Thomsen and Engelbreth-Holm (198, 199) injected a carcinogenic tar into the 

 tibial bone marrow of chickens at five-day intervals. There were 62 chickens in 

 the experimental group that received tar injections and some also received irradia- 

 tion with roentgen rays. After one to four and a half months of treatment nine 

 birds developed a condition similar to spontaneous "myeloid leukosis" and two 

 erythroleukosis. The livers and spleens of the nine animals were enlarged, with 

 foci of myeloid metaplasia consisting principally of myelocytes and in some there 

 was a marked increase in the number of circulating leukocytes, principally of the 

 granulocytic series. One of the two cases of erythroleukosis was of the anemic 

 variety. The blood picture of both types of reaction was not as severe as was 

 usually noted by these workers in spontaneous cases of leukosis. Their attempts 

 to transmit the condition produced by the tar injection to other experimental 

 chickens by the methods usually employed for transmission of leukosis gave only 

 inconclusive results. Nine chickens were given repeated doses of the tar emulsion 

 intravenously, but the injections were without effect.* 



Jarmai and Balo (104) report that subcutaneous injection of a tar-benzol 

 mixture every ten days for seven months resulted in the development of a leukosis- 

 like condition in four of nineteen chickens thus treated. The leukocyte count of 

 the blood was increased (75,000 to 95,000 cells per cu. mm.) and myeloblasts, 

 myelocytes, and large cells similar to an endothelial cell appeared in the blood. 

 The spleens and livers of these animals were enlarged and contained foci of myeloid 

 metaplasia. Tests for transmission resulted in the development of a transient 

 myeloid reaction without causing death of the experimental animals. 



Oberling, Sannie, Guerin, and Guerin (153) report the production in chickens 

 of a non-transmissible condition similar to leukosis by injection of either colloidal 

 benzpyrene solution or benzolbenzpyrene solution. The occurrence of two cases 

 of transmissible erythroblastic leukosis in a group of ten chickens receiving bi- 



*An experiment was conducted by Bernard (13) in which he brought about a myeloid disturbance 

 by the injection of tar into the marrow cavity of white rats. An erythrocytosis and erythroblastosis 

 were produced and about half of the animals showed changes of the leukocytes. He was unable to 

 transmit the condition to other rats. 



