i6 THE GROUSE DISEASE chap. 



the crop contained only little or no food; and in 

 such cases the disease of the lungs is as a rule, 

 but not without exception, not very extensive, only 

 a portion of one or both lungs being congested. 

 Such is the case in some birds in the spring and 

 summer epidemic ; such is the case in birds that die 

 in the autumn. In the majority of instances in which 

 the dead birds are found plump — as for instance 

 during the height of the spring epidemic — the lungs 

 show a great deal of congestion, the crop is full, and 

 the legs are not bare. I conclude from this that, in 

 these cases the disease being severe, it rapidly kills 

 the animal, or more correctly, if the animal rapidly 

 succumbs to the disease it will show less loss of 

 flesh, and the crop more full of heather than when 

 the animal lingers on for somfi time — for then the 

 fever would inevitably cause great loss of flesh, and 

 the animal, as is to be expected, would present appear- 

 ances of emaciation. This view, enunciated by Dr. 

 Farquharson and Mr. Wilson, seems to me the best 

 to harmonise with the facts. 



The chief changes are undoubtedly those found 

 in the lungs. The mucous membrane of the larynx 

 and trachea is of a dark colour, hyperaemic ; this 

 is the more pronounced the more marked the 

 lung change. The latter shows deep coloration 

 in the greater part of either one or both organs, 



