. A manual of zoology. Zoology. Fig. 59;. Fig. 503. Fig. 50:?.—Brain of pigeon (from Wiedersheim). HH. cerebellum; Lot, olfactorj- lobes; MH, mid brain; XH, medulla oblongata: VH, cerebrum. Fig. 503.—Eye of owl (after Soemmering and FranzV c7j. chorioid; c~«!, ciliar>' muscle: Co, cornea; C""-, \'itreous body; HK^ posterior chamber: Jr, iris: Kn, sclerotic bone: L, lens: Op, optic ner\"e: P, pecten; Pc, ciliar}' process; Rt, retina; 5c, sclera; Tn, tapetum nigrum; FA', anterior chamber. the ear is highly organized, the lagena of the labyrinth lieing greatly en- larged and the
. A manual of zoology. Zoology. Fig. 59;. Fig. 503. Fig. 50:?.—Brain of pigeon (from Wiedersheim). HH. cerebellum; Lot, olfactorj- lobes; MH, mid brain; XH, medulla oblongata: VH, cerebrum. Fig. 503.—Eye of owl (after Soemmering and FranzV c7j. chorioid; c~«!, ciliar>' muscle: Co, cornea; C""-, \'itreous body; HK^ posterior chamber: Jr, iris: Kn, sclerotic bone: L, lens: Op, optic ner\"e: P, pecten; Pc, ciliar}' process; Rt, retina; 5c, sclera; Tn, tapetum nigrum; FA', anterior chamber. the ear is highly organized, the lagena of the labyrinth lieing greatly en- larged and the sound-conducting apparatus (columella, tympanum, etc.) well developed. The beginnings of an external ear are seen in the deeper position of the drum membrane. Since the power of llight neces- sitates vision at great distances, most birds have exceeilingly sharp sight, and the eye itself (fig. 593) has a special apparatus (Crampton's muscle) for different distances. Peculiarities of the bird's eve, alreadv weaklv developed in the reptiles, are the pecten (/'), a comb-shaped growth of the chorioid into the vitreous l)ody, the scleral ring, a circle of bones developed in the sclera and supporting the outer part of the eye, and a nictitating membrane besides the ordinary eyelids. Among birds there is spirited rivalry for the females, especially among polygamous sjiccics. At the time of mating the males seek to win the favor of the females either through striking motions (dances), by singing, or by beauty of plumage. All of these peculiarities are confined to the male and frequently lead to a marked sexual dimoqihism. The distinction in plumage is commonly strengthened at this time, the male reeei\ing the brilliant wedding Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Hertwig, Richard, 1850-1937;
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectzoology, bookyear1912
