. Half hours with fishes, reptiles, and birds . h barb has numerous little barbules (Fig. 99), whichhook into those on the opposite some birds there are no barbules,and the feathers are called plumes,as those of the ostrich. This won-derful coat of feathers sheds water,being provided with oil which the birdtakes from a gland near the tail. Whenbirds are seen p r eenin g,they are oftenoiling theirfeathers, whichawater-tight roofto protect thesensitive is not necessary for birds to have food prepared for them, as their digestive apparatus (Fig. 100) accomplishes this work. Food,
. Half hours with fishes, reptiles, and birds . h barb has numerous little barbules (Fig. 99), whichhook into those on the opposite some birds there are no barbules,and the feathers are called plumes,as those of the ostrich. This won-derful coat of feathers sheds water,being provided with oil which the birdtakes from a gland near the tail. Whenbirds are seen p r eenin g,they are oftenoiling theirfeathers, whichawater-tight roofto protect thesensitive is not necessary for birds to have food prepared for them, as their digestive apparatus (Fig. 100) accomplishes this work. Food, as seeds, is eaten whole and passes into a crop (c), and from here into the true stomach, then reaches the gizzard {g\ where it is ground up as thoroughly as though teeth had been employed. Many birds aid in this by swallowing pebbles and sand. The birds are warm-blooded animals. Their hearts are four-cham-bered. They breathe by taking in air at the nostrils. Fig. 99. —Barb from a thus becomeGoose Quill. Showing the hookletshighly Fig. 100. Digestive Apparatus of aBird : c, crop ; g, gizzard;illustrating passage of foodfrom the mouth.
Size: 1115px × 2241px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1906
