126 THE GROUSE 



quite a number of diseases, they are agreed 

 that by far the greater mortality arises 

 from one or other of two main disorders, 

 both of them parasitic, viz. : the 

 Strongylus threadworm ( Trichostrongylus 

 peigracilis) discovered by Dr. Cobbold 

 • thirty - seven years ago, and the disease 

 investigated by Dr. Klein, who described 

 it as "an acute infectious pneumonia 

 caused by an organism probably belong- 

 ing to the ' colon ' group, and is found 

 chiefly in the lung of the infected bird." 

 Klein's disease of the grouse known as 

 Coccidiosis is the acute form of dis- 

 ease, while Strongylus, described by Dr. 

 Cobbold, is the chronic form, which have 

 been already referred to. Both of these 

 grouse maladies have been subjected by 

 the Committee to very searching scientific 

 examination from every point of view. 

 Besides these main troubles, which are 

 the immediate factors of the illness and 

 death of innumerable grouse, there are 

 many subsidiary parasitical enemies of the 

 bird, some of which living on the skin 



