8 MASS. EXPERIMENT STATION BULLETIN 337 



in susceptible chickens. Both intravenous and intraperitoneal inoculations 

 were tried, with results recorded in Table 5. 



Table 5. — Results of Inoculating Chickens with Portal Blood 

 Containing Lymphoblasts 



All of the chickens which came down with lympholeukosis showed typical 

 symptoms and at necropsy lesions comparable to those found in field cases. 

 A common symptom was anemia and paleness of the face, comb, wattles, and 

 mucous membranes. The breasts and legs were emaciated, but the abdomens 

 remained large and full, and the birds ate fairly well. Necropsy revealed the 

 abdominal weight in the livers. The bone marrow was devoid of fat, and hyper- 

 plasia was confined to the lymph spaces only. Tissues taken from the liver, 

 spleen, and lymph nodes along the digestive tract showed hyperplastic infil- 

 trations. 



Table 5 shows that 25 chickens were inoculated with portal blood containing 

 lymphoblasts and 12 contracted the disease. Since this experimental study is 

 concerned primarily with neurolymphomatosis, it is pertinent to point out 

 that infiltration of the nervous system was not observed in any of these cases or 

 injany of the field cases submitted for this investigation. 



Next, 20 chickens of various ages were inoculated intraneurally with fresh 

 portal blood from birds dying of lympholeukosis and none of them showed more 

 than a scar at the point of inoculation. The median nerve, which is visible 

 through the skin in Rhode Island Red chickens, was selected in 10 cases and 

 the sciatic nerve was chosen in the others. These chickens were held for six 

 months and none of them showed any indication of disease. The nerves 

 appeared to be refractory to the lymphoblastic cells in the inoculum, and the 

 dose was apparently too small to induce generalized lympholeukosis. 



In order to determine what part, if any, the plasma played in the trans- 

 mission of this disease, the cells were removed from portal lympholeukotic 

 blood by slow centrifugalization and passed through 2 percent collodion filters 

 under two atmospheres of negative pressure. The ultrafiltrate was inoculated 

 intravenously into 10 chickens two months old, so that each received 2 cc. of the 

 plasma. None of these chickens came down with the disease in six months, 

 while four out of five control chickens inoculated in the same manner with whole 

 blood contracted lympholeukosis. At the end of six months the 10 experimental 

 birds were inoculated intravenously with 3 cc. of whole lympholeukotic blood, 

 and seven came down with the disease, while three were resistant. 



