LOCAL VARIATION IN PLUMAGE OF GROUSE 61 



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 numerous. The undeveloped ovary 

 of an adult female Grouse would about cover a threepenny piece, but is 

 long and triangular in shape rather than circular. 



The oviduct in a breeding hen is a large and conspicuous duct, 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 at other times than the breeding season, is a very much less conspicuous 

 object, and is less easily found than the small and undeveloped ovary. 



If no ovary is seen, but a very small blackish, or whitish, or parti- 

 coloured object is found in its place which is suspected of being a testis, 

 the intestines must then be gently separated from their attachments about 

 the middle line of the back, and the other testis must be sought for in about 

 the same position on the opposite side. Even in a young bird the ovary 

 shows ova with sufficient distinctness to make doubt as to its sex an 

 impossibility ; but in a very young male bird the testes may be so small, 

 and, being very often black, may look so unlike what is expected that both 

 should be sought for and found before arriving at a certain conclusion as 

 to sex. 



It is easy, if the intestines are roughly handled, and the attachments 

 torn carelessly away, to carry away the testes or the ovary from their 

 proper position, and to remove them with the intestinal attachments. The 

 peritoneal folds are delicate and require careful handling, and they overlie 

 the generative organs and the kidneys; but a very little practice will enable 

 any one to do the necessary dissection with certainty, and to arrive at an 

 irrefutable diagnosis as to sex. 



It may be said that there is no other infallible means of arriving at the 

 sex of a Grouse at certain times of the year, for it has so often happened 

 that experienced and careful gamekeepers, who have handled Grouse for a 

 lifetime, have certified a specimen as a cock, when the specimen has turned 

 out to be a hen, and vice versd. The mistake is unavoidable and excusable, 



