Blood of Australian Animals. 1*>7 



Aves. (Plate XIX. ; Figs. 34-37.) 



Bed Corpuscles. — The actual counts varied, but scarcely beyond 

 the limits of the figures given by Burnett (4) for the blood of the 

 domestic fowl, the highest being found in the Black Mountain Duck, 

 and tlu- lowest in the White Pekin. In size they averaged smaller 

 than those of reptiles, the largest being found in the Spoonbill 

 .(1 6. 1/x x .S.7/x). The cells of young individuals showed an increase 

 in size as compared with those of the adult. Basophil types 

 (thrombocytes or erythroblasts of Fantham?) were not common, 

 but were observed in the Chestnut Breasted Teal and young Mud- 

 lark and Heron, and averaged smaller than the ordinary forms. 

 In the Heron a few cells resembling the spindle forms of reptiles 

 were seen, but this smear was full of cocci, and in all probability 

 not normal. In the Spoonbill, young Mudlark, and young Moun- 

 tain Duck the basophil cells were also well marked, and showed 

 £reat variety of shape, some even approaching that of spindle 

 -cells. It is worthy of note, from the standpoint of evolution, and 

 in view of the occurrence of these cells in amphibia and reptiles, that 

 they were more conspicuous in the younger forms of the birds 

 examined, which is to be expected if they are a primitive type. 

 ■Gruner, however, states they are present in all vertebrates below 

 mammals. In the Spoonbill and young Mudlark also, the nuclei of 

 many red cells were slightly moniliform, and in some cases almost 

 completely divided, with the most dense chromatin at the centre of 

 the nucleus. This aggregation of chromatin was best marked in 

 the basophil forms, in which also division of the nucleus was well 

 seen. Degenerate cells, resembling those found in reptiles, and 

 <le-crilted by Fantham (5), and consisting apparently of free 

 nuclei, non-nucleated fragments and nuclei surrounded by a thin 

 film of protoplasm, were also observed. 



Lymphocytes. — These varied in size from '3.8/x in the Black 

 Mountain Duck [Anas superciliosa) , to 6.7/* in the Spoonbill. 

 Their percentage counts were fairly high, running to 75.8 per cent, 

 of the total leucocytes in the Chestnut Breasted Teal. In the 

 young Mudlark the count was extraordinarily low (15.8 per cent.). 

 These cells have a decided tendency to aggregate (cf Fantham (5)); 

 ■and degenerating forms appearing like large nuclei of lymphocytes 

 were present in certain smears, being in many cases difficult to 

 distinguish from the true cell (cf. Burnett (4)). In the young 

 Mudlark they are surrounded by a clear ring of cytoplasm. 



Mast Cells. — These were not found on any slide, with the pos- 

 sible exception of the Chestnut Breasted Teal (Cosarco tador- 



