1 y 4 Gwynneth Buchanan r 



data in regard to the native Australian animals, and have tried 

 to obtain as many types in each group as possible. 



The chief difficulty has been the fact that the native animals 

 available can seldom be said to exist under normal conditions, 

 being principally captive specimens, mainly from the Zoological 

 "Gardens; and in many cases the smears were so distinctly patho- 

 logical as to be useless for comparative purposes. Bearing this in 

 mind I have been careful in forming generalisations from my 

 results unless the material has been sufficient and reliable enough 

 to warrant so doing. I have to acknowledge my indebtedness to 

 Professor Spencer and Dr. Sweet, of the Biological School. Mel- 

 bourne University; for the use of books, specimens, and apparatus; 

 to Dr. Gilruth, sometime Professor of Veterinary Pathology ; 

 Acting-Professor MacDonald, Dr. Dodd, and Mr. H. R. Seddoii — 

 all of the Veterinary School. Melbourne University — for the use 

 •of books, smears, and for advice as to methods of staining, etc. ; 

 also to the members of the Biological Laboratory, past and present, 

 •especially to Mrs. J. L. F. Woodburn, for smears from wild and 

 native forms of X.S.W. 



Methods. 



Actual (Jounts were only made in a few cases-. The instrument 

 used was the Thoma Zeiss Haemoeytometer, with Hayem's diluting 

 fluid. Where possible the blood was taken from the ventricle, imme- 

 diately after death; and in most cases, for lack of time, the white 

 corpuscles were counted with the red. 



Smears. — Wherever possible the smears were fixed in alcohol 

 before staining, and several specimens were obtained, so that at 

 least two varieties of stains might be employed. Those stains found 

 to give the most consistent results were those of .Tenner and (iifinsn 

 •("Tabloid" brand). These, however, do not both react in the 

 same way to the various classes of white cell, making the determi- 

 nation of a differential count somewhat uncertain at times. Thus 

 most cells were found to differentiate Letter with Giemsa, and in 

 some cases only with that stain, though Burnett (-1) describes mast 

 cells whose granules take a purple stain with .lenner. Mononuclear 

 forms, especially of amphibia, showed best with Giemsa; while 

 ■cells with eosinophil characteristics stained more satisfactorily 

 with Jenner — with the doubtful exception of one marsupial form — 

 and the crystalloid eosinophil cells showed their preference for 

 this slain markedly. These observations are borne out by the 

 •tfttemeot of Daniels in " Laboratory Studies in Tropical Medi- 



