When smears were taken from pheasants, it 

 was noted that the blood had a surprisingly high 

 viscosity. When the drop collected on the pusher 

 slide had been touched to the smear slide, it did 

 not spread easily to the opposite corners, as does 

 the blood of chickens and geese. Only after 

 considerable moving around of the pusher slide 

 did the drop spread laterally to form a uniform 

 column of substance. This property of the 

 pheasant blood made it difficult to obtain a thin, 

 uniform smear. 



The erythrocytes of the species of ducks, 

 cuckoos and the hawk mentioned in table 11 were 

 larger than those of the chicken ; the erythrocytes 

 of all the other species had approximately the 

 same size as those of the chicken. These state- 

 ments are based on visual comparisons and not 

 on measurements. Wintrobe (1933) has given 

 the length and width of erythrocytes for the 

 chicken, guinea, goose, and pigeon. A further 

 discussion of the size of erythrocytes in the 

 chicken will be given when table 12 is considered. 



Immature stages of development and erythro- 

 plastids of all sizes were found in many of the 

 species of wild birds; they were especially 

 numerous in some of the slides from ducks and 

 from the indigo bunting. In mature cells, the 

 nucleus was slender and rodlike with dense chro- 

 matin clumps like figure 5. In slides from some 

 specimens of mallard ducks the nuclei were so 

 contracted and slender that the dense chromatin 

 clumps bulged outward, giving it a mulberry ap- 

 pearance. Scarcely any spaces could be seen be- 

 tween the clumps. 



Smears from ducks and pigeons showed eryth- 

 rocytes that were distributed in pairs and in a 

 crossed position. With each erythrocyte in a 

 pair crossing the other at 90 degrees, and with 

 the centers coinciding, a pinwheel effect was pro- 

 duced. This peculiarity has never been ob- 

 served in chicken blood. 



The thrombocytes in the shoveller duck, tur- 

 key, pheasant, pigeon, dove, owl, black-capped 

 chickadee, cuckoo, and white-breasted nuthatch 

 were larger than those in the chicken. Except 

 for these differences in size, the thrombocytes in 

 all the species listed in table 11 were similar to 

 those of the chicken. The specific granules of 

 the turkey thrombocyte were usually in vacuoles. 



There is always a possibility that thrombocytes 

 will be confused with lymphocytes. Confusion 

 is especially likely to occur in the case of the 



pigeon. In this species the cytoplasm of throm- 

 bocytes takes a more intense coloration than it 

 does in most avian species, and the cells are 

 nearly round. Moreover, the thrombocytes of 

 pigeons appear to disintegrate less readily when 

 the smear is made than they do in most species; 

 thus the form of the cell is retained. This, of 

 course, aids in holding the specific granule of the 

 thrombocyte intact so that identification can be 

 made easily when neither lymphocytes nor throm- 

 bocytes have disintegrated. If the cytosome of 

 these two cell types has been lost they can still be 

 separated by the fact that the nucleus of the lym- 

 phocyte is larger than that of the thrombocyte. 



Lymphocytes in all species of wild and domes- 

 tic birds examined appeared the same as in 

 chickens. Magenta bodies or reactive lympho- 

 cytes, or both, were found in nine species, includ- 

 ing a species of duck. 



Monocytes in other species are the same as 

 found in the chicken. Those of the great horned 

 owl were large with round nuclei and large, dense 

 chromatin clumps. 



Heterophils were variable within an individual 

 or a species, as they were in chickens. Differ- 

 ences in the shape of the rods in ducks have al- 

 ready been mentioned; in turkeys the I'ods dis- 

 solve readily as they do in chicken cells; in the 

 owl the rods were of the "typical" type, pointed 

 at both ends. In other species of birds, as well 

 as in the chicken, central bodies exist inside the 

 rods, but their occurrence is not constant. 



The eosinophils for some ducks have been pic- 

 tured. Figure 402 represents the granular type, 

 figure 404 the large sphere type, and figure 405 

 the rod type; in figure 411 these have been dia- 

 gramed as E, B, and B', respectively. In the 

 pintail duck the specific bodies are spheres and 

 vary in size from medium to large; in the green- 

 winged teal, rods and granules are mixed; and 

 in the shoveller duck small granules are clumped 

 to form rods. The Canada goose and the owl 

 have small granules, and the pheasant and the 

 dove have large ones. In many of the passerines 

 they are like those in the chicken but in the red- 

 eyed vireo and purple finch they have fine gi'an- 

 ules and in the robin the bodies aie almost re- 

 fractile. 



Basophils in other avian species appear as they 

 do in the chicken except that the cells of the tur- 

 key are larger and those of the owl are smaller. 

 The nucleus of the pigeon basophil is often ec- 



210 



