. Biology of the vertebrates : a comparative study of man and his animal allies. Vertebrates; Vertebrates -- Anatomy; Anatomy, Comparative. 2^2 Biology of the Vertebrates apparatus. Each time, as the snake molts the outer layer of epidermis, a button, or ring of corneum, remains behind to record the fact. These rings are dry and loose enough to make a rattling noise when the thrill felt by an excited snake reaches the tip of the \ i,i,* Fig. 188. The rattle of a rattlesnake, Crotalus, with eleven rattles. The lower fig- ^J&ftSjl ^3-s) ure is a long section, showing the vertebrae in
. Biology of the vertebrates : a comparative study of man and his animal allies. Vertebrates; Vertebrates -- Anatomy; Anatomy, Comparative. 2^2 Biology of the Vertebrates apparatus. Each time, as the snake molts the outer layer of epidermis, a button, or ring of corneum, remains behind to record the fact. These rings are dry and loose enough to make a rattling noise when the thrill felt by an excited snake reaches the tip of the \ i,i,* Fig. 188. The rattle of a rattlesnake, Crotalus, with eleven rattles. The lower fig- ^J&ftSjl ^3-s) ure is a long section, showing the vertebrae in black with the horny rattles fitting loosely one over the other. (After Fig. 189. Spur of a fight Garman.) ing cock. Horny beaks are epidermal structures characteristic of the toothless turtles, birds, and monotremes. Among birds particularly they exhibit a great variety of form, and serve a wide range of uses. Some male birds, such as game cocks for example, also develop horny spurs upon the legs with which they settle questions of supremacy upon the avian field of honor (Fig. 189). The male jacana that strikes at its rival with out- spread wings is armed with effective wing spurs (Fig. 181). The great sheets of "whalebone" (Fig. 190) with their frazzled edges that fill the mouth cavity of toothless whales, in the form of an elaborate mechanism for strain- ing the myriads of small marine organisms upon which these giants feed, are not bone at all, but horny epidermal structures. Thick at the base, each plate thins out rapidly and breaks up into a long fringe of slender, closely set processes like the teeth of giant combs. Camels and dromedaries are provided with thick corneal knee-pads to protect these heavy animals when they collapse to a kneeling posture before lying down upon the sands. Similar though smaller corneal pads of less obvious function, called "chestnuts," are found on the inside of a horse's Please note that these images are extracted f
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Keywords: ., bookcentury1900, booksubjectanatomycomparative, booksubjectverte
