CAUSES OF MORTALITY IN THE RED GROUSE 149 



sickness takes an undisputed pre-eminence above all others for a century, as 

 has been the case, apparently, with the Red Grouse sickness, there is some 

 justification for the use of such an expression as " The Grouse Disease," and 

 some excuse for the view held, by those who cannot go into the minutiae of 

 microscopic work or of dissection, to ascribe all mortality on a moor to this one 

 disorder. 



It has been the object of the "Grouse Disease" Committee to investigate 

 this question, and to find out amongst other things : 



The objects 



(1) Whether the sickness described universally as "The Grouse of the 

 Disease " in all the literature of the past century which deals with 

 the subject is, in truth, a single disease with individual character peculiar to it 

 alone ? (2) Whether a distinction can be discovered between various recorded 

 outbreaks of the so-called " Grouse Disease " which will justify the opinion 

 held by many writers that two distinct forms of disease, due to two distinctive 

 causes, are confused under the one term ? (3) In the event of a finding in favour 

 of the belief in two or more distinct epidemic diseases, what are their respective 

 causes and effects, and by what distinctive titles and characteristics should they 

 be known ? (4) In the other event of a finding in favour of the belief that only 

 one epidemic disease exists, is Professor Klein's view right, that the only 

 serious disorder amongst Grouse, to which all past records of disease refer, is 

 the one which has for its cause a Bacillus of the B. coli group, and for its chief 

 morbid characteristics the lesions of an acute pneumonia in the lung, and 

 "all the characters of an acute infectious epidemic disease"? Or, (5) is Dr 

 Cobbold's view right, that there is a pseudo-epidemic disorder amongst Grouse, 

 answerable for all the recorded outbreaks of disease, which has for its cause 

 a nematode worm of the genus Trichostrongylus, and for its chief morbid 

 characteristics certain lesions in the caeca due to chronic irritation, leading 

 to extreme emaciation ? (6) Is there any other form of " Grouse Disease " 

 which is the cause of extensive mortality, but which has hitherto been 

 overlooked ? 



These are questions which have to be answered before it can be said 

 that we understand the forms of " Grouse Disease " sufficiently to classify them 

 systematically. With a view to defining the main divisions under 

 which the next five chapters are arranged, it may be well at this Com- 



, . , , . mittee's 



stage to give in anticipation a brief summary of the conclusions at investiga- 

 which the Committee has arrived. 



