ANNUAL REPORT, 1937 93 



from eggs inoculated with saline-brain suspensions prepared from affected chicks 

 developed the disease. Birds eight to ten weeks old, inoculated intracerebrally 

 with saline-brain suspension prepared from affected chicks, developed the disease. 

 This disease is of economic importance to the chick mdustry and studies are being 

 continued to determine the source or reservoir of the disease-producing agent in 

 order to develop possible methods of control and prevention. 



6. Feeding of Sumac Fruit to Chickens. Since wild birds utilize sumac fruit as 

 one source of feed, an effort was made to determine the palatability and toxicity 

 of this fruit when fed at will and by means of force feeding. Four chickens, ap- 

 proximately six months old, and the fruit of the staghorn sumac {Rhus typhina) 

 were used in the feeding trials. Force feeding of 16 grams of ground sumac per 

 da\- for five days did not appear to have a toxic effect. Using a mixture of ground 

 sumac fruit and laying mash and permitting the birds to eat at will, resulted in 

 little or no feed being consumed, which suggested that the sumac was not palatable 

 for birds employed in this experiment. This investigation was conducted in co- 

 operation with the Department of Forestry. 



7. Viability of S. pullorum. Viability studies, which are still in progress, have 

 shown that 5. pullorum has remained alive in a dry piece of cloth for a period 

 of five years. 



8. Farm Department Brucellosis Control and Eradication. The laboratory 

 cooperated in this work by testing 878 bovine blood samples for Bang's di.sea&e 

 and 52 porcine blood samples for Brucella infection. The standard tube agglu- 

 tination method was used. 



Studies of Neoplastic and Neoplastic-like Diseases. (Carl Olson, Jr.) Various 

 investigations of fowl leukosis, fowl paralysis, lymphocytoma and other neo- 

 plastic-like diseases of the domestic chicken are under way. One object of these 

 researches is to seek the similarities or dissimilarities of these diseases from a 

 biochemical point of view by means of a study of the tissue respiration, which 

 it is hoped may be of considerable value in the understanding of these disease 

 processes. Another sphere of activity has to do with a study of the relative in- 

 cidence of various types of neoplasia among chickens selected from various sources. 



Two strains of transmissible fowl leukosis are being maintained and studied. 

 One of these strains originated with material obtained from Dr. J. Furth, Depart- 

 ment of Pathology, Cornell University Medical College, New York, N. Y. 



The other strain of transmissible fowl leukosis was derived from a poultry 

 flock in Massachusetts where several instances of the disease had occurred. 

 This flock was composed of 47 chickens, among which there were no losses from 

 disease until the>- were 1 10 da> s of age. During the succeeding two months seven 

 birds became ill and died with either fowl leukosis or neoplastic disease. Two of 

 these instances of fowl leukosis were demonstrated to be transmissible to experi- 

 mental chickens and the transmissible agent has as yet produced only trans- 

 missible fowl leukosis. Two cases of neoplastic disease with tumors of the visceral 

 organs have been used as a source of material for the inoculation of experimental 

 animals. One of these tumors has been transplanted into a third generation of the 

 experimental chickens, which procedure has as yet induced no instances of fowl 

 leukosis. The transmissible strains obtained from this flock must be carried 

 through many more experimental chickens before it is possible to tell whether 

 only one or more than one disease-producing agent was responsible for the out- 

 break of disease noted in the flock selected for studv. 



