. Beginners' Zoology . Fig. 294. — Dorsal and of Plucked Bird, showingregions where feathers grow. 158 BEGINNERS ZOOLOGY like the leaves of trees, are delicate structures and loseperfect condition with age. Hence the annual renewal^ of the feathers is an advantage. Mostbirds shed twice ayear, and with manythe summer plum-age is brighter col-oured than the win-ter plumage. Whena feather is shed on one side, the corre-sponding feather onthe other side is always shed with it. (What need for this .?) A large oil gland is easily found on the dorsal side of the tail. How does the bird a
. Beginners' Zoology . Fig. 294. — Dorsal and of Plucked Bird, showingregions where feathers grow. 158 BEGINNERS ZOOLOGY like the leaves of trees, are delicate structures and loseperfect condition with age. Hence the annual renewal^ of the feathers is an advantage. Mostbirds shed twice ayear, and with manythe summer plum-age is brighter col-oured than the win-ter plumage. Whena feather is shed on one side, the corre-sponding feather onthe other side is always shed with it. (What need for this .?) A large oil gland is easily found on the dorsal side of the tail. How does the bird apply the oil to the feathers ? $. - B. Wing of Birx). Fig. 295 /, false quills (on thumb) ; 2, primaries; 3, secondaries;tertiaries (dark) are one above another at right;a, b, coverts.
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Keywords: ., bookcentury1900, bookdecade1920, bookidbeginnerszoo, bookyear1922
