Blood of Australian Animals >i\] 



well as an increase, in size (12.8//. 1 cS. l^n). Percentage counts were 

 never very Large, reaching the highest in P. breviceps (female with 

 young), where these cells numbered 35.7 per cent, of the total 

 leucocytes. Degenerating cells (cf. Burnett) were common, while in 

 others the nucleus tended to become vacuolated (cf. Erhlich (6), 

 and <me cell of T. vulpecula seemed to be clearly dividing-. The 

 chromatin <>f the nuclei in many showed very distinctly. 



Transitional forms, between the mononuclears and the poly- 

 morphs, were observed in four cases, and in size corresponded most 

 nearly with the polymorphs, hut in no ease did they amount to 

 .'5 per cent, of the total leucocytes. 



Polymorphonuclear cells were numerous, reaching as high as 70 

 per cent, of the total leucocytes in the female wombat. In size they 

 approximated, on an average, to the eosinophils, being particularly 

 small in one species of Echidna histrix, in which the cyloplasm 

 stained very indistinctly. In T . vulpecula, on the other hand, 

 they showed hue acidophil granulations (cf. Schafer (11) p. 34). 



Eosinophil cells never gave a high percentage count, falling 

 particularly low in echidna, in which, neither in the young nor 

 adult form, did they reach 1 per cent, of the total leucocytes. They 

 seemed to average slightly larger than the polymorphs, though this 

 was not an absolute rule. The granules of some were very scattered, 

 while in others they were very fine, resembling the finely granular 

 polymorphs of some forms. In the young platypus they were only 

 distinguishable with Giemsa's stain. Erhlich (<>), p. 179, notes 

 among the atypical forms of white corpuscles which may be present, 

 dwarf forms of the eosinophil variety, and I found that these 

 were also very common in many marsupials. Macrophages were 

 also present in the form of large basophil mononuclear cells, con- 

 taining partially disintegrated corpuscles of various types. 



