202 THE GROUSE IN HEALTH AND IN DISEASE 



1. To prove that the amended view of Klein's work was the right one, 



and that the "Grouse Disease" which he saw and described as a 

 form of infectious pneumonia was in reality not different to the 

 "Grouse Disease" which the Committee were seeing constantly, 

 and were describing as Cobbold's Strongylosis. 



2. To make every effort to obtain fresh and living samples of wild Grouse 



actually suffering from " Grouse Disease," for systematic laboratory 

 work, with a view to discovering whether this or any other wide- 

 spread form of " Grouse Disease " was caused by bacterial infection 

 or not. 



3. To complete the investigation of the Grouse parasites, ectozoa as well 



as entozoa, with a view to determining whether by any possibility 

 " Grouse Disease " could be considered attributable to some of them, 

 or even to one of them. 



4. To investigate the blood of the Grouse in health and in sickness, and 



especially to try and discover the presence of toxaemia with its 

 resultant anaemia and changes in the respective proportions of 

 leucocytes. It was thought possible that the toxins produced by 

 Helminthes in the intestine might be the cause of some increase in 

 the eosinophil corpuscles. 



5. To make certain that " Grouse Disease" did not result from the presence 



in the intestines, or in the blood, of any protozoan parasite for 

 the transference of which we knew the Grouse had ticks, bird -lice, 

 flies, fleas and other external parasites. 



6. To make a complete and special investigation of the life-history of the 



Trichostrongylus pergracilis or the Strongyle of Cobbold, with a 

 view to understanding its mode of infecting Grouse, its action when 

 in the caecum of the Grouse, its method of reproduction, its dis- 

 semination, and the conditions which enable it to hatch from the 

 egg, to pass from the larval stage to encystment, to survive on a 

 Grouse moor, and to ensure its being swallowed by the bird at a 

 stage when to be swallowed means completing the cycle of parasitic 

 life, instead of being merely digested. The life history of this 

 threadworm was obviously required in its smallest details, in order 

 that Strongylosis might be understood. 

 How these various questions were dealt with may now be explained. 



