OBSEEVATIONS ON THE BLOOD OF GROUSE 315 



(/3) The presence of Leucocytozoon lovati (vide' chapter xiv. p. 3 18) in the blood 

 of Grouse is associated with mononuclear leucocytosis. A differential leuc- with Leu- 

 ocyte count of the blood of one of the Grouse containing L. lovati gave : 2^!' 



Lymphocytes . . . 63 '0 per cent. 



Large mononuclears . . 28 '0 



Polymorphonuclears . . 5 '5 ,, 



Eosinophiles . . . . 2'5 ,, 



Mast cells . . . . I'O 



There was also evidence of polychromatophilia in the red cells of Grouse in- 

 fected with Leucocytozoon lovati. 



(y) Eimeria (Coccidium) avium (vide chapter xi. p. 235) also has its effect, 

 indirectly, on the blood. Birds suffering from Coccidiosis became anaemic. The 

 paleness of the blood is due to the diminished number of red cells in the 

 blood. Estimations of the hsemoglobin-value by Tallqvist's scale * gave Eimeria 

 60-70 in the case of Grouse chicks suffering from Coccidiosis, 80-90 for 

 healthy Grouse chicks. 



There is an increased number of polymorphonuclear leucocytes (crystalloid 

 eosinophiles). Differential leucocyte counts of two Grouse chicks dying from 

 Coccidiosis gave : 



Polymorphonuclears . . . 31 '5 to 39 '5 per cent. 

 Eosinophiles ..... 3'5 to 5'5 ,, 



Large mononuclears . . " . 13 '5 to 3 TO ,, 



Lymphocytes 26 '0 to 50 '0 



Mast cells . . . . . 0'6 per cent. 



In mammals an increase in the number of polymorphonuclear leucocytes occurs 

 in inflammation, especially locally. The increase in polymorphonuclear leucocytes 

 (crystalloid eosinophiles) is probably to be associated with the intestinal inflamma- 

 tion caused by the presence of coccidian parasites. 



Similarly in a fowl chick dying of Coccidiosis, I obtained the following 

 differential leucocyte count : 



Polymorphonuclears . . . . 47 per cent. 

 Eosinophiles ..... 2 



Mononuclears . . . . . 29 '5 

 Lymphocytes . . . . . 20 - 5 

 Mast cells ...... 1 



1 Tallqvist's scale was used because it is easily carried in the pocket, and can be used for rapid work. 



