Richard Owen
Published: 2013-09
Total Pages: 222
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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1866 edition. Excerpt: ...fig. 192, and fig. 159, 65, 66; articulated to two elements, 63 and 64, of the pelvic arch, which, as in Fishes, arc loosely suspended in the flesh. The successive gradational steps by which the pentadactyle condition of the limb or appendage is attained are selected from the series of hoofed Mammals in fig. 193. The pelvic limb, fig. 195, shows the same monodactyle simplicity as the pectoral one, in the Horse. The ossicles developed in the connective substance between the second and third principal segments of the long-jointed ray, are the ' astragalus, ' a, 'calcaneum, ' cl, ' naviculare, ' s, ' mesocuneiforme, ' cm, ' ectocuneiforme, ' ce, ' cuboides, ' b. The metacarpal supporting the three joints or 'phalanges' of the digit articulates chiefly with the ectocuneiform, e, which accords in size. The largely developed digit, or continuation of the main limb-ray, fig. 193, answers to the third, in, of the pentadactyle foot. At its base are rudiments of the metatarsals of the second, II, and fourth, iv, digits. In the Ox the naviculare, ib. s, is connate with the ' cuboides, ' b: and, as this supports one-half of the single metatarsal, such half is held to be the developed homologue of the rudimental fourth metatarsal in the Horse: whilst the half supported by the ' ectocuneifonne, ' ce, in the Ox, is held to answer to the metatarsal of the developed digit, in, in the Horse. Embryology here lends partial proof to this view: the so-called 'cannon-bone' being developed from a single centre and epiphyses in the Horse, and from a pair of shafts or centres and epiphyses in the Ox: it accordingly supports a pair of toe, which answer to the third, in, and fourth, iv, in the pentadactyle foot. The Camel and Giraffe have not rudiments of any other t