54 NORMAL BLOOD IN DOMESTICATED ANIMALS 



is from 75 to 85. The thrombocytes are given by Albertoni and 

 Mazzoni as averaging 45,500 and by Mack as 55,200. The leu- 

 cocytes apparently have a wide normal variation. Averages are 

 reported from 18,000 to 36,000. Warthin found the normal range 

 to be from 12,000 to 29,000. Taylor gives it as 17,000 to 30,000. 

 Care must be taken in securing blood for examination from any 

 bird. The drop used must not be exposed to the air longer than 

 necessary as the thrombocytes undergo change quickly. De- 

 generated thrombocytes resemble degenerated leucocytes. Films 

 for histological examination must be made quickly and in a dry 

 place. It is very difficult to make films in a damp place that may 

 be used because of the liability of the thrombocytes to change. 



Table XVII. — Summary of Examinations of the Blood of Normal 

 Domestic Fowls by Different Investigators 



1 This study of Mack's was made in the laboratory of Comparative Pathol- 



