316 THE GROUSE IN HEALTH AND IN DISEASE 



The blood of this fowl chi'ck 1 contained basophile spindle-shaped cells (PL 

 XLV., Fig. 18). 



($) Helminthiasis is common in Grouse. The various worms found in Grouse 

 have been well described by Dr Shipley (vide chapter x. p. 207, chapter xv. 

 with P' 334 ancl P- Z -S-> 1909) and by Dr Leiper (vide chapter x. p. 219). 

 helminthi- Grouse which would be considered perfectly healthy by keepers often 

 contain worms. One of the causal factors of disease in adult Grouse is 

 the larval stage of Trichostrongylus pergracilis. The adult Trichostrongylus 

 occurs in the caeca of Grouse, and sets up inflammation therein. In the blood 

 of three adult birds dying on the moors from " Grouse Disease," I obtained 

 differential leucocyte counts which may be thus summarised : 



Eosinophiles . . . . 23 '5 to 42 '0 per cent. 



Polymorphonuclears ... 7'5 to 14'0 ,, 



Mononuclears . . . . 6'0 to lO'O 



Lymphocytes .... 44'0 to 62'5 



Mast cell 0'5 per cent. 



Contrasting these counts with those given for normal Grouse, the occurrence of 

 eosinophilia is deduced. All three of these birds, dying of " Grouse Disease," had 

 many Hymenolepis microps in their duodenum in addition to Trichostrongylus in 

 the cseca. 



Eosinophilia is often associated with helminthiasis in mammals. Helminthiasis 

 in Grouse results not only in an increase in the number of eosinophile leucocytes, 

 but also in a diminution of the number of erythrocytes in the diseased birds. 

 Thus the number of red cells found in an adult cock Grouse dying from helminthiasis 

 was 3,250,000 per cubic millimetre the number of red cells for a normal cock 

 Grouse being about one million more. The haemoglobin value estimated by 

 Tallqvist's scale was 60 for a Grouse suffering from helminthiasis and 80-90 for 

 healthy adult Grouse. 



In spite of the incomplete character of this investigation of the blood of the 

 Grouse (due to the lack both of material and time at my disposal), I think that 

 there are sufficient results contained herein to emphasise the importance of parallel 

 investigations of the blood in connection with all animal diseases. 



1 Burnett gives the following differential leucocyte count of normal fowl's blood : Polymorphonuclear 

 28'8 per cent. ; eosinophiles 3'3 per cent. ; large mononuclears 5'5 per cent. ; lymphocytes 58 per cent. ; mast 

 cells 4'3 per cent, 



