CAUSES OF MORTALITY IN THE RED GROUSE 183 



through having been hatched late in a second brood. In the one case the 

 birds are full grown and healthy to begin with, but have been unable to 

 stand the strain of breeding and moulting. In the other case they have 

 never had a chance to become full grown. In either case the course of natural 

 taxation is the same, the parasitic infestment is the same, and the final 

 result to the bird is the same. The only thing which differs is the primary 

 cause of weakness, and this may be one, or several, of a very considerable- 

 number that lie in wait for the life of the Red Grouse on every moor. 



Of accidents which may happen in the process of laying, there is ona 

 which is well known in captive birds, but must be rare in nature, namely, 

 a shortage of lime rendering the eggs deficient in shell. Soft- "goft 

 shelled eggs not only fail to stimulate the muscles of the oviduct, but ^^<^"" 

 give them no purchase upon which to act. The consequence is that the 

 egg is not expelled, but is broken in the duct, and is followed by other eggs 

 until the bird dies either from exhaustion or from a rupture of the oviduct 

 involving the peritoneum. Soft-shelled eggs in wild birds generally appear 

 in a second clutch laid shortly after the loss of the first nestful. 



Gastro-uterine gestation must always be rare, but one well-marked case in 

 a Grouse was sent up for examination. The egg, when shed by the ovary, 

 failed to enter the open upper end of the Fallopian tube, and so passed 

 into the body cavity. By causing irritation there it became adherent "terine 



. . . gestation. 



to the peritoneal covering of three portions of the gut. The adhesions 

 formed a firm support, and presumably the egg was for a short time carried 

 safely. Eventually, however, it was broken in the peritoneal cavity, and the 

 bird was shot, and owing to her unwillingness to take flight was forwarded 

 as a case of suspected disease. 



Disease of the skin is a very rare thing in wild Grouse, and Diseases of 

 generally results from the irritation produced by innumerable ectozoa, ^^'^ ^^'°" 

 such as ticks and lice. 



No. 1634 was an adult hen Grouse of 20 ounces, shot on August 12th,. 

 1908 in Lanarkshire. The bird was very unprepossessing in appearance, as 

 the feathers had failed to make their way through the skin of the head and 

 neck especially, and to some extent all over the body. The skin was of a 

 very deep yellow colour, and there were sebaceous cysts of varying sizes 

 scattered all over the bird, and so thick on the head and neck that hardly a 

 feather appeared. The gamekeeper's view was that it looked " like a hen that 



