. Handbook of birds of eastern North America . and Zoological Collecting (Scribner,$). Sexing.—A specimen without a sex mark on its label is of com-paratively little value. The sex in many birds can of course be dis- the wing-bones in to remove the flesh from them, they should be pushed backonly far enough to enable one to see plainly the elbow or bend of the wing out-side of the skin. This prevents the wings from hanging, and, to further keepthem in place, it will be well at first to tie the ends of the bones (humeri) to-gether. 28 CATALOGUING AND LABELING. tinguished by their color, but
. Handbook of birds of eastern North America . and Zoological Collecting (Scribner,$). Sexing.—A specimen without a sex mark on its label is of com-paratively little value. The sex in many birds can of course be dis- the wing-bones in to remove the flesh from them, they should be pushed backonly far enough to enable one to see plainly the elbow or bend of the wing out-side of the skin. This prevents the wings from hanging, and, to further keepthem in place, it will be well at first to tie the ends of the bones (humeri) to-gether. 28 CATALOGUING AND LABELING. tinguished by their color, but the young male frequently resemblesthe female, while in some instances the female has been known to as-sume the plumage of the male. Dissection, therefore, is the only safeway to determine sex. Upon reaching stage 36, in the operation ofmaking a birdskin, cut through the left side of the body from thevent to the neck, taking care not to disturb the internal organs. Forcethe edges of the opening apart, and, pressing the intestines gently to. Fig. 1.—a completed birdskin. (Reduced). one side, look for the sexual organs, which will be found on the wallsof the small of the back very near to the backbone. The male organs(testes), two in number, are usually dull-white, elongate bodies lyingside by side. The female organs (ovaries) are composed of numerousround bodies lying in a mass or cluster. In the breeding season thesexual organs of birds become much enlarged, and at this season thetestes of a male Chipping Sparrow are about the size of a pea, whilethe ovaries of the female have been likened to a bunch of grapes, thelargest being the size of the yolk of the egg of this species. After thebreeding season the sexual organs decrease in size, and in adults in thewinter and young birds are sometimes difficult to find. The testes ofa male Chipping Sparrow at that season are about as large as a smallpinhead, while a hand-lens is required to plainly distinguish the ova-ries of the fem
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbirds, bookyear1896
