16 MASS. EXPERIMENT STATION BULLETIN 308 



and histological examination as irregular fori of neoplastic growths embedded 

 in the visceral organs and other tissues, while lympholeukosis appeared to be 

 limited to the liver, spleen, and sometimes the kidney, and always involved the 

 whole of the affected organ. 



Blood smears from birds suffering from er\ throleukosis showed immature forms 

 of erythrocytes, as shown in Fig. 10. Histological examination of tissues from 

 the liver, spleen, and kidneys revealed intravascular accumulations of these 

 immature cells in the capillary spaces, so that the organs were in a state of disten- 

 tion. Sometimes the distention was so great that hemorrhage occurred. The 

 hemoglobin was reduced in erythroleukosis and the clotting of the blood delayed. 



The blood of a representative number of birds for each disease included in 

 this study was examined hematologicalh'. It was impossible to examine all 

 on the experiment because the methods were time consuming, and it was con- 

 sidered better to make a thorough stud\- of a selected number rather than to 

 attempt all of them hurriedh . 



The Hematology of Birds from Flock C 



The results of the examination of the blood of representative birds from Flock 

 C are contained in Table 5. 



The white blood counts recorded for Group 1, were higher than normal in 

 birds Nos. 2, 11, 16, 18, and 19, and lower than normal in No. 1. Differential 

 counts showed that the increase in birds Nos. 11, 16, and 18 was in eosinophilic 

 granular leukoc>tes, while in bird No. 19 the eosinophilic leukocytes with rods 

 were above normal. Also bird No. 18 showed a high hniphocxte count. The 

 blood of Nos. 3 and 17 was normal, or the same as for health}- birds. 



In Group 2, the white cell count was above normal in birds Nos. 13 and 20. 

 Differential counts indicated that the increase in white cells in No. 13 was in 

 polymorphonuclear leukocytes, while that of No. 20 was in small Kmphocytes. 

 The blood of Nos. 10 and 14 was normal. 



The average white blood cell count was higher in the birds severeh affected 

 with parahsis (Group 3) than in Groups 1 and 2. The differential count in- 

 dicated that this increase was due in general to lymphoc>tosis, as all of the birds 

 except No. 6 shewed relatively high h'mphoc>te counts. It was found at nec- 

 ropsy that No. 6 had a heavy infestation of roundworms, which ma>' have been 

 responsible for leukocytosis and the probable masking of the hmphocyte count. 



The birds in Group 4 were examined hematologically when first brought to 

 the laboratory from the range and again just before death. The symptoms of 

 paralysis had increased in every case. A stud\' of this table shows in most cases 

 a leukocytosis accompanied b\- a progressive lymphocytosis. The hemoglobin 

 and blood clotting time were not determined in bird No. i3. 



The averages of the first and last hematological examinations show some 

 interesting comparisons as follows: The red blood cells are less in the last average 

 count than in the first; the white blood cells are more in the last average count 

 than in the first; the comparison of the first ax'erage leukocyte count and the 

 first average lymphocyte count with the corresponding last counts indicates that 

 leukocxtosis is giving way to lymphocytosis. 



Group 5 contains the results of the hematological studies of birds selected 

 from Flock C that were down and unable to arise, but showed no lesions of paral- 

 ysis at necropsy. Bird No. 52 ga\e a low white blood cell count when first 

 examined, but three da\ s later the count was nearly normal. Bird No. 53 showed 

 a marked leukocxlosis in which eosinophilic leukoc>tcs with granules predomina- 



