GROUSE DISEASE 567 



but imperfectly acquainted with post-mortem changes, firmly 

 believe in the existence of this " disease," and it may be that 

 it really exists and that it is the misfortune of the Inquiry that 

 in their researches the investigators have not come across it. 



If we now turn from what must seem rather negative 

 criticism to the more positive results attained by the investi- 

 gation of the last four years, we may begin by pointing out 

 some of the difficulties which confronted the Inquiry. 



In considering exceptions it is so immensely important to 

 know the rule. In studying disease our starting-point should be 

 the normal, the healthy ; yet until lately no one has studied 

 the healthy grouse, and indeed it is almost impossible to find a 

 normal grouse, i.e. one free from parasites. A grouse cannot 

 express to us its feelings ; the state of its tongue, the rate of 

 its pulse, even its temperature tell us nothing because we have 

 no norm and no means of estimating the extent to which a 

 diseased bird has departed from the standards of a healthy 

 grouse. The nature of the numerous kinds of blood corpuscles, 

 which alter in proportion so markedly in animals when they 

 become parasitised, was but a few months ago quite unknown, 

 the " blood count " uninvestigated ; in fact, the Inquiry started, 

 as regards the cause and symptoms of the diseases which affect 

 grouse, practically at " scratch." It was, of course, known 

 that the suffering birds lose their activity and are more easily 

 caught than healthy grouse ; their flight is slow and limited in 

 length; they are said to seek water; the " call" becomes feeble 

 and hoarse ; the feathers of the back and throat lose their 

 lustre and become ruffled ; the eye is dimmed. But these 

 external symptoms may be associated with several diseases 

 and diagnostic of none. Nearly all of them occur in the two 

 diseases Coccidiosis and Strongylosis which, according to the 

 Inquiry, are responsible for a very large percentage of deaths 

 among grouse. 



Each of these diseases is caused by an animal parasite, and 

 the investigation of the parasites attracted the attention of the 

 scientific advisers of the Inquiry from an early date. I am 

 afraid that in describing these organisms I shall have to use 

 some rather long words ; in extenuation I can only say, slightly 

 altering Captain Kedgick's retort to Martin Chuzzlewit, " Well ! 

 I didn't fix the zoological language, and I can't unfix it, else 

 I'd make it pleasant," 



