THE FOOD OF THE RED GROUSE 107 



has received considerable attention without any results being 

 arrived at sufficiently definite to be worth reporting. There 

 is a curious lack of information available regarding the fall of 

 dew, the districts in which dew is most prevalent, etc. There 

 is probably a close connection between dew and the infection 

 of Grouse by the nematode worm Trichostrongylus pergracilis. 

 In view of the fact that the larvae of this worm can only climb 

 the heather shoots, or indeed exist on them, when they are 

 slightly damp, it would appear that this is one of the questions 

 which might be further investigated with advantage. 1 



PART IV. GRIT. 



The health of Grouse and of other game-birds is greatly 

 dependent on the nature of the grit they take to assist in the 

 assimilation of their food. During the autumn of 1906 the 

 Committee made a collection of the grits from the gizzards of 

 Grouse and other game-birds. These grits were obtained from 

 the gizzards of Ptarmigan from Ben Mohr in Sutherlandshire ; 

 Grouse from Ross-shire, Inverness-shire, Aberdeenshire, and 

 North Wales; Blackgame from Ross-shire and Exmoor ; and 

 Partridges and Pheasants from various counties in England and 

 Scotland. 



The gizzards of Grouse naturally received most attention ; 

 but for purposes of comparison those of other game-birds 

 were also examined. The quantity of grit found in a single 

 gizzard varies very slightly. Samples taken from adult cocks 

 were each found to be equal in bulk to an ounce of shot, although, 

 of course, much lighter, and the number of grains* in each 

 ranged from three hundred and fifty to five hundred and fifty. 

 It was also noticed that, especially in the case of Pheasants, 

 the cock birds have a larger quantity of gritty material, while 

 the individual grains also appear to be larger. This is doubtless 

 correlated with the larger size of the bird, for in the smaller 

 varieties of game - birds and in immature individuals it is 



1 Vide chap. viii. p. 235. 



