GROUSE DISEASE 205 



recently been found in a flea by Professor Minchin, 

 and these cysts have been shown by Mr. Nicoll to 

 grow into Hymenolepis diminuta in the intestine 

 of the rat. Hence the suggestion, first made by 

 Dr. Leiper, that the fleas of the grouse may be 

 the second host of H. micwps is well worth 

 following up. 



It is curious to note that this tape-worm dis- 

 appears during the winter months, a fact which 

 may afford some hint as to its second host. The 

 large tape-worms, on the other hand, remain all 

 the year round and must be of quick growth, 

 for they are found 35 cms. in length in a young 

 grouse but three weeks old. 



Three other round-worms have also been shown 

 to exist in the grouse. One of these in the duo- 

 denum may prove of importance. This species 

 (Trichosoma longicolle) is allied to a form which 

 lives in the human appendix, and at times is 

 the cause of appendicitis. 



COCCIDIOSIS 



Beside the worms we have in the grouse seven 

 distinct unicellular or protozoan parasites which 

 live in the intestines or in the blood of the grouse. 

 Most of these are uncommon and comparatively 



