22 Mr. Arthur E. Shipley [Feb. 3, 



disease is diarrhoea ; the legs show weakness, and the feathers, 

 especially round the legs, are in poor condition ; flight is feeble, and 

 the bird loses weight. Internally the alimentary canal is inflamed 

 and digestion greatly impaired ; perityphUtis is set up around the 

 caeca, which become greatly enlarged. The blood corpuscles also 

 undergo marked alteration and an ana3mic condition prevails. 

 Further, the destruction of the lining wall of the alimentary tract 

 allows the escape of bacteria which are all very well in their place — 

 i.e. the cavity of the intestine — Ijut which are apt to set up trouble 

 when they make their way into other tissues. This is, however, but a 

 subsidiary matter ; the real injury caused by the Goccidium is the 

 destruction of the Hning membrane of the alimentary canal. 



Coccidiosis may be spread from moor to moor by the agency of 

 flies. The maggots of certain flies readily eat the cysts, and it has 

 been shown both experimentally and on the moor that the cysts pass 

 through the bodies of both maggot and fly undigested and unharmed. 



Several other one-celled microscopic organisms or protozoa 

 besides Eimeria {Goccidium) avium, as is mentioned above, have 

 been found in the intestines of grouse and also in their blood, l)ut in 

 no case, so far, has any of these parasites been shown to have a 

 markedly dangerous effect on the bird harbouring it. Some of these 

 parasites, in fact, occur in perfectly healthy grouse and apparently 

 are almost innocuous. 



Strongylosis. 



The second disease which the Inquiry has found responsible for 

 grouse epizootics observed between 1905 and 1910 is one to which 

 Cobbold drew attention in 1878, though he attempted little in the 

 way of pathological investigation. According to him it is caused by 

 the presence of a round-worm, now . known as Trichostrongylus per- 

 gracilis, in the ca^ca. We may call the disease " Strongylosis of the 

 grouse." The worms are minute, transparent, very slender, a little 

 less than half an inch in length, and they may exist in enormous 

 numbers, 10,000 occurring in the two ca3ca of one bird They are 

 about equally divided between the two bhnd-guts. We may recall 

 the fact that in the grouse the cffica are of unusual size, and that in 

 these birds the digested food is absorl^ed in this region of the alimen- 

 tary canal alone. 



The worms seem to be most numerous at the proximal end of the 

 caeca, and when they exist in large numbers the contents of these 

 most important diverticula of the alimentary canal become hard and 

 very adherent to the mucous membrane, forming whitish patches 

 when seen from the outside. After washing away the flocculent 

 matter, which can only be effected with time, the mucosa frequently 

 appears reddened. There was no reason to believe this inflammatory 

 state is due to post-mortem changes. The ridges which run along 



