Not all familiar with partridges know how to distinguish the cocks from the hens by the few minute differences in plumage. In flight the birds are so alike in size that it is impossible to tell them apart--unless, perhaps, they are in pairs, and one goes away ahead of the other on being put up, when the cock may be the hindmost bird. The usual test of sex is the chestnut horseshoe of the breast. The cocks display a fine bright horseshoe badge, while the hens have a few chestnut spots on a whitish ground. However, some insist that this test is not always infallible. One to be trusted absolutely, so far as we know, is the striking difference in the lesser and median wing coverts. In each case there is a light buff stripe down the shaft; but the cock's feathers have a chestnut stain which is lacking in the hen's feathers, while the hen's feathers have zigzag buff cross-bars (of the same hue as the shaft stripe), which are lacking in the cock's feathers. There are other differences which the experienced eye sees at once; and there are differences also in the neck feathers. In the adult cock they are grey, with no shaft stripe; in the hen they are brown, with a light shaft stripe. The age of birds is to be determined to a certain extent quite simply. Those with bright yellow legs are birds of the year. Those with their first pen-feathers rounded are more than a year old, for in the young birds these feathers are pointed at the tip. * * * * * On Finding Feathers