110 THE GROUSE IN HEALTH AND IN DISEASE 



One portion of the alimentary canal remains to be mentioned, namely, 



the rectum (Pis. xxvi. (R.), xxvu., Fig. 1 (h), XLIV.) This measures but 4|- 



to 5 inches ( = 115 to 127 mm.) from the point of entrance of the 



Rectum. 



caecal appendices to the anus. The internal appearance of the normal 

 healthy rectum is shown on PI. xxix., Fig. 2 ; in this figure the dark staining 

 about the caecal orifice is due to the proximity of the liver. 



The rectum appears to evacuate its contents almost immediately after 

 receiving anything from the main gut or the cseca. When examined by 

 dissection it is generally empty, or at the most but sparingly occupied by 

 material ; but there is one marked exception to this statement. In the hen 

 Grouse, during the laying of eggs and incubation, but especially during 

 incubation, the want of exercise, and the necessity for keeping the nest clean, 

 leads to an excessive accumulation of faeces, always of the harder, formed 

 kind, in the lower part of the rectum. 



There is a great increase of size and of development in the ovary and 

 oviduct in the breeding hen Grouse, and the rectum appears to accommodate 

 itself to this. The massed and bulky droppings of a sitting hen Grouse, 

 or "clocker" as she is called, are well known to the gamekeeper as affording 

 the most reliable and useful information he can have concerning the number 

 of nests upon his moor. These droppings, due to want of exercise and the 

 brooding instinct, result in an enlargement and distention of the lower part 

 of the rectum and the cloaca, which recover themselves only after incubation 

 and hatching are completed. 



As these bulky "docker's" droppings are only to be seen on the moor 

 in the nesting season, it is perhaps not surprising that the keeper alone 

 recognises what they mean. It is a very common thing for a keeper to 

 congratulate himself upon their abundance along the side of every burn he 

 comes to. Such places are used habitually by sitting hens when they leave 

 their nests, perhaps once or twice a day, for food and water, and these droppings 

 supply far more satisfactory evidence than could be gained by disturbing the 

 birds on their nests. 



This then is, as briefly as possibly, the normal course of the digestion and 



Variations absorption of food in the alimentary tract of the Red Grouse, and 



digestive it remains now to speak of the more common pathological variations 



and disturbances which affect this process and which upset the health 



of the bird. 



