132 



Scientific Proceedings (75). 



Hirschfeld 1 reached much the same conclusions, but reported 

 finding normoblasts in the blood. He recorded a leucocyte count 

 of 180,000 in one rat with an ulcerating sarcoma. No normal 

 standard of number or of differential count of leucocytes was re- 

 ported in either of these papers. The blood plates were not 

 enumerated or described. 



In the work presented here the leucocytes and blood plates 

 were counted after the method of Wright and Kinnicutt 2 designed 

 for plate counting. It was modified by the procedure of first 

 drawing the fixing fluid to the mark .5 in the stem of the white 

 cell pipette in order to prevent the blood from coming in contact 

 with a dry surface. A 1-20 dilution was invariably used. Two 

 pipettes were used for each count and five drops counted from each 

 to determine the number of leucocytes. One hundred small 

 squares (Turk's stage) from the dilutions in each pipette were 

 counted to determine the number of blood plates. The following 

 table shows the results of eighteen studies on the blood of eight 

 apparently healthy albino rats. For the blood plates the figures 

 given represent the nearest 50,000; for the leucocytes the nearest 

 500. 



Average number blood plates per ccm 



(Variation 850,000 to 1,200,000) 

 Average number of leucocytes per ccm. . . . 



(Variation 12,000 to 30,000) 

 Average number of red blood cells per ccm 



(Variation 9,000,000 to 10,500,000) 



Differential leucocytes (300 cells counted) : 



Average polymorphonuclear cells 50 per cent. 



(Variation 30 per cent.-6o per cent.) 

 Average mononuclear cells (small 30 per cent., large 14 percent.) . 44 per cent. 



(Variation in proportion great) 

 Average transitional cells 5 per cent. 



(Variation 2 per cent.-i4 per cent.) 

 Average eosinophil cells 1 per cent. 



(Variation 0-3 per cent.) 



It will be seen from the table for normal rats that the blood 

 plate count shows an unusually small degree of variations. The 



1 Fol. Hemat., Vol. X, 2, p. 393. 



2 Jr. A.M. A., 1911, LVI, p. 1457. 



1,000,000 

 19,000 

 10,000,000 



