78 MASS. EXPERIMENT STATION BULLETIN 315 



Comparative Studies of Toisson's Fluid and Hayem's Fluid Containing 2 

 percent Eosin for Counting Erythrocytes and Leukocytes in Avian Blood. (C. S. 



Gibbs, R. F. Sturtevant, K. \V. Chapman, and C. G. Johnson.) Hayem's fluid 

 containing 2 percent eosin is superior to Toisson's fluid in that there is less clump- 

 ing of the cells, and less danger of the stain precipitating during a count and 

 thus making it necessary to repeat the process with fresh stain. A higher leukocyte 

 count is obtained with Hayem's fluid than is secured with Toisson's fluid with 

 the same blood under the same conditions. Therefore, Hayem's fluid is preferable 

 to Toisson's fluid in counting avian blood cells. 



The Oxydase Test in Avian Pathology. (C. S. Gibbs and K. W. Chapman.) 

 Oxydase tests on representative samples of leukemic and normal avian blood 

 were made by the Graham, Goodpasture, Washburn, and Sato and Sekiya's 

 techniques. The method of Sato and Sekiya was found superior to the others 

 from the standpoint of the keeping qualities of the stain, and the rapidity of 

 staining. If the sole object is to determine the number of cells containing oxydase 

 granules in a given smear of avian blood, then Sato and Sekiya's technique should 

 receive first choice. But if it is desired to make a complete differential count of 

 all cells in a smear, then Washburn's technique should be selected on the basis of 

 this study, because it is the only stain that will answer the purpose. The oxydase 

 test was found to be of value in differentiating leukemic from non-leukemic 

 avian blood. 



Leukosis and Avian Paralysis. (C. S. Gibbs and C. G. Johnson.) Myeloleukosis 

 and to a lesser extent erythroleukosis may be transmitted by direct inoculation 

 of affected blood into healthy chickens, by contact infection, and by inoculation 

 into eggs in which the bone marrow cells of the embryo have been formed. Lympho- 

 leukosis, monoleukosis, and neurolymphomatosis are not readily transmitted by 

 inoculating either affected blood or diseased tissues into healthy chickens and 

 fertilized eggs. The experimental data thus far indicate that neurolymphomatosis 

 in particular is transmitted naturally through the egg. Direct transmission from 

 iowls having diseased ovaries has been observed in a few instances, but in most 

 cases the method of transmission is obscure, indicating that further work must 

 be done before the pathology of this disease is understood. 



Field experiments indicate that mortality from both leukosis and avian 

 paralysis may be reduced by removing diseased birds from the flock as soon as 

 symptoms are noticed and so disposing of them that they can never get into the 

 flock again. For reasons which are not understood at present, this method of 

 control is more effective for neurolymphomatosis than it is for myeloleukosis 

 and erythroleukosis. 



Proventriculitis and Ventriculitis. (C. S. Gibbs and K. L. Bullis.) A necrotic 

 disease of the tissues lining the proventriculus and the ventriculus has been 

 noted at this station for some time. Attempts to determine the cause of this 

 condition have been unsuccessful in that significant microorganisms have not 

 been isolated. Finally, one of us suspected that it might be due to paralysis of 

 the nerves supplying these organs. Since then considerable data have been 

 collected, indicating that one cause, if not the sole cause, is paralysis of important 

 branches of the vagus and coeliac nerves which supply these organs. Apparently, 

 proventriculitis and ventriculitis are but further manifestations of avian paralysis. 



Infectious Coryza. (C. S. Gibbs and K. L. Bullis.) Next to leukosis and avian 

 paralysis, infectious coryza is the most baffling of any of the diseases of poultry 



