104 THE GROUSE IN HEALTH AND IN DISEASE 



marked falling off of insect food and a proportionate increase 

 in the vegetable diet. 1 The crops are arranged, so far as possible, 

 in order of age, beginning with the youngest. The ages of the 

 birds are estimated by the length of the keel of the sternum or 

 breast-bone. 



This table also showed that the crops of young chicks in 

 the first week or two contain, in addition to insects, the follow- 

 ing vegetable food-stuffs in varying proportions : Calluna 

 shoots ; only the very fresh young green shoots are eaten. 

 Calluna flowers, in full bloom, and flower-buds. Moss fruit- 

 capsules, or spore cases. Blaeberry flower-buds, and ripe 

 blaeberries occasionally (V actinium myrtillus). Blaeberry leaves 

 and young stalks. Fern leaves (Blechnum and Pteris). Rush- 

 heads, in flower and seed (Juncus sq.). Tormentilla seed-heads. 

 Shoots of Empetrum nigrum. 



Of these the most constant are the fresh young shoots of 

 Calluna ; then the fresh blossoms of Calluna, and then the 

 spore capsules of moss. While insects are commonly eaten, 

 many crops of the youngest chickens contained no trace of 

 them. It is practically certain that by eating some such 

 animal food the cystic stages of the intestinal worms which 

 infest young birds even in the first weeks of their existence 

 are introduced. Until this matter has been further investigated, 

 it is needless to say more here. 2 



PART III. WATER. 



There are various opinions regarding the Grouse's require- 

 ments in the way of water. The majority of moor-owners 

 and naturalists are firmly convinced that Grouse require water, 

 and quote in support of their view the undoubted fact that 

 when springs and drains are periodically kept open the stock 

 is more healthy and numerous. Others state that water is 

 not necessary, and that the fact that drains and springs are 

 not allowed to become choked may have beneficial results 



1 " The Grouse in Health and in Disease," vol. i. p. 91. 

 - See also chap. vii. pp. 190 et stq. 



