INTRODUCTION HEMATOLOGICAL studies on chickens have long been hampered by the lack of a quick, readily applicable, and quantitative method for the enumeration of the leucocytes. This problem stems from the fact that the nuclei of bird erythrocytes are not destroyed in the usual procedure for mammalian blood cell enumeration and therefore cannot be distinguished from the leucocytes. LITERATURE The first method for counting leucocytes in avian blood was proposed by Warthin (1906) who suggested an indirect method for counting these cells. This method entails the use of a diluent which preserves all the blood cells. The total leucocyte count can be calculated by determining the total number of cells in a cu. mm. of blood (leucocyte and erythrocyte) and subsequently ascertaining the ratio between these cells in a stained smear. In using the indirect method, one must assume that the blood cells are equally distributed throughout the smear. This . . .
Natt et al. (1952) studied this question.