1910.] PLUMAGE OF THE HED GROUSE, 1027 



No discussion is more apt to produce difi'erent opinions than that 

 which arises upon the age or the sex of certain stages of moulting 

 Grouse either at the luncheon hour upon the moor or in the 

 gauae-larder when the day's bag has been overhauled, sorted out, 

 and hung upon the hooks. It must ba at once admitted that 

 thei'e are individual cases, by no means very rare, in which 

 it is almost impossible to tell the sex with certainty until the 

 bird has been cut open and the internal anatomy examined. In 

 these doubtful cases the only way to settle the point is to cut 

 the bird open down the middle of the abdomen, carefully turn 

 over the whole of the intestines from the right to the left — that 

 is, from the bird's left side to the bird's right side, — without 

 tearing the attachments, and then, having exposed to view the 

 flattened reddish portions of the kidney wliich lie closely packed 

 on each side into tlie inequalities of the backbone and pelvis, to 

 see whether the uppermost portion has overlying it an ovary or a 

 testis. 



In the bieeding-season, and in a breeding bird, there caii 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 testis is a conspicuous round white object as large as the 

 kernel of a good -sized hazel-nut 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 tlie 

 reason for advising the examination 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 IMay, the 

 discoveiy of the ovary is still a matter of comparative ease, and 

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

 somewhat enlarge<l 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, ai-e distinct and numerous. The 

 undeveloped ovary of an adult female Grouse would about cover 

 a threepenny piece, but is always rather long and triangular in 

 shape instead of circulai-. 



The oviduct in a breeding hen is a lai-ge and conspicuous part, 

 and may, of course, contain an egg with the shell in course of 

 formation, being pigmented in preparation for laying. The 

 oviduct in a barren bird or in a hen not in the breeding-season is 

 a very much less conspicuous object, and will be less easily found 

 than the small and undeveloped ovaiy. 



If no ovary is seen on examination, and a very small blackish, 

 or whitish, or parti-coloured object is found in its place which is 



