GROUSE DISEASE 197 



parasites whilst in the nests, the bird-lice falling 

 from one bird to another when they are con- 

 tiguous. They have also been known to cling 

 to the grouse-fly, and in this manner may be 

 transported to a new host. In no case was 

 any specimen of either of these two genera 

 found in the crop of the grouse. 



Two fleas are found on grouse, one rare, but 

 the other is a well-known bird-flea, which has 

 also been found in the nest of the Hawfinch, 

 the Dipper, the Blackbird, the Moorhen, and 

 others. Since it is known that a certain dog-flea 

 is the second host of one of the cestodes (tape- 

 worm) of the dog, and a rat-flea of a tape-worm of 

 the rat, it seems possible and even very probable 

 that one of these fleas may be the intermediate host 

 of one of the chief worms which infests the ali- 

 mentary canal of the grouse. We have, however, 

 not succeeded in finding the cysts, neither have 

 we found specimens of the flea in the crop of 

 the bird. 



Then there is a tick, the common rice or dog- 

 tick, usually attached below the jaw of the 

 bird or to the eyelid or to some other position 

 where the beak cannot reach it. Ticks are 

 responsible for the transference of a very fatal 



