ANATOMY AND PHYSIOLOGY OF RED GROUSE 177 



The spleen of the Grouse varies very much in size, and this 

 fact appears to have some connexion with Strongylosis. It 

 is comparatively large in young and healthy birds, and is large, 

 as a rule, and of a fresh, red colour in healthy adult birds ; but 

 in cases of Strongylosis it becomes very small and very dark, 

 an appearance which is noticeable in fresh, dead cases of 

 disease, and even more noticeable as post-mortem changes 

 advance. 



The kidneys appear to suffer very little from the general 

 congestion which must be considered a symptom in Strongylosis. 

 The colour of the kidney in a freshly killed healthy bird is a 

 reddish brown, a good deal paler than the colour of the liver. 

 Normally the lobes lie very flat against the dorsal wall of the 

 abdomen, fitting into the inequalities of the skeleton. 



In the breeding season, and in a breeding bird, there can be 

 no doubt whatever as to the sex, for the ovary is a conspicuous 

 bunch of more or less developed ova in the hen ; and in the 

 cock the testes are conspicuous round white objects as large 

 as the kernels of good-sized hazel-nuts on each side of the 

 backbone. 



There is but one ovary, and it lies always on the left side of 

 the backbone of the bird. There are two testes, one lying on 

 each side of the backbone, the left one generally at a slightly 

 lower level than the right. This development of the ovary 

 only on one, the left side, is the reason for advising the examina- 

 tion to be made as described above, on the left side always. 

 One testis or the ovary cannot then be missed. 



If the bird examined thus is not breeding, as may often be 

 the case with birds found dead of disease in April and in May, 

 the discovery of the ovary is still a matter of comparative ease, 

 and the discovery of the testes even easier. The testes are 

 always somewhat enlarged in the spring months, whether the 

 bird be diseased or not, and they may be the size of a pea or 

 larger, and will generally be white. The ovary may be small, 

 but will always be like a portion of hard cod's roe, in which the 

 ova, though no bigger than a pin's head, are distinct and numer- 

 al 



