ANATOMY AND PHYSIOLOGY OF RED GROUSE 175 



often great masses of Davainea, but no redness of the mucous 

 membrane. 



The only pathological appearance which is commonly seen 

 in the rectum of the Grouse is a reddening along the glandular 

 ridges, due to villous engorgement. The cause of this villous 

 engorgement is obscure. It does not appear to be dependent 

 upon disease or sickness, though apparently sometimes it has 

 some relation with an excessive number of tapeworms in the 

 main gut. 



In the caeca of the Grouse lies the whole origin and cause 

 of " Grouse Disease " in the adult bird. In these blind guts 

 live Trichostrongylus pergracilis, and these, when present in 

 enormous numbers, produce an excessive amount of irritation 

 and congestion of the vessels, and so much disturbance of the 

 proper functions of this portion of the gut that the contents, 

 consisting of food, mucus, nematode worms, and nematode ova 

 in a pasty and decomposing mess, not only become use- 

 less as food, but may be a grave danger to the bird owing 

 to the amount of toxins produced and absorbed into the 

 circulation. 



With regard to other organs of the body of the Grouse 

 there is more to be said of the lungs than of any other. On this 

 subject the reader may be referred to chapter xii. of the Com- 

 mittee's Report, where Dr Cobbett and Dr Graham Smith have 

 described in detail the appearance of really fresh lungs, 

 exposed in birds just dead, and their appearance after being 

 more or less stained by post-mortem fluids and decomposing 

 blood. 



It is unnecessary here to repeat the discussion upon the 

 question of " Grouse Disease " and pneumonia. For this refer- 

 ence must be made to chapter v., where reasons are given for 

 the belief that Klein's explanation of " Grouse Disease " as 

 an acute infectious pneumonia is not the correct one. 1 



The normal colour of quite fresh healthy lung is a very 



1 Fide p. 159. 



