. Sur l'anatomie des vertébrés. L'anatomie comparée des vertébrés ;, ; 1866. LOCOMOTION DES REPTILES ÉBRANCHÉS. 263 102 Crapauds, semipalmatc avec pieds, avoir un maladroit, l)ut pas toujours lente, la progression sur terre par d'autres mouvements de la membres. Certaines espèces sont activés, en particulier des tubercules ou des projections sur le palm ou unique, à escalader le haut de vieux murs. Mais le plus remarquable dans la classe des reptiles grimpeurs sont certains lézards, es])ecially ceux appelés Geckos '.' chaque pied dispose de cinq orteils, qui sont écartés de l'autre, étendu aux extrémités, et terminé par un mince sharp claw. En vertu de l'aplati

• Contributeur: The Book Worm / Alamy Banque D'Images
• ID de l’image: RDH62R
• Taille du fichier: 7,2 MB (351,1 KB Téléchargement compressé)
• Autorisations: Modèle - non | Propriété - non
• Dimensions: 983 x 2543 px | 8,3 x 21,5 cm | 3,3 x 8,5 inches | 300dpi

Informations supplémentaires

Cette image appartient au domaine public, ce qui signifie que le droit d’auteur a expiré ou que le titulaire du droit d’auteur a renoncé à ses droits. Les frais facturés par Alamy couvrent l’accès à la copie haute résolution de l’image.

Cette image peut avoir des imperfections car il s’agit d’une image historique ou de reportage.

. On the anatomy of vertebrates. Vertebrates; Anatomy, Comparative; 1866. LOCOMOTION OF LIMBED REPTILES. 263 102 Toads, with semipalmatc feet, have an awkward, l)ut not always slow, progression on land by alternate movements of tiie limbs. Some species are enabled, by peculiar tubercles or projections from the palm or sole, to clamber up old walls. But the most remarkable climbers in the reptilian class are certain lizards, es])ecially those called ' Geckos.' Each foot has five toes, which are spread wide apart, expanded at the ends, and terminated by a slender sharp claw. The flattened under surface of the toe-pad, fig. 162, is traversed by a series of transverse folds, with deep interspaces; the margins of the folds, when applied to a smooth surface, adhere thereto l)y atmos]iheric pressure, through the vacuum caused by muscular erec- tion of the folds, with concomitant exjiansion of the interspaces; thus the animal, alternately applying and releasing its suckers, climbs a vertical wall or plate of glass, or proceeds along a ceiling with its back downward. For climl^ing trees the adjustment of the toes in opposition to each other, in equal or suIj- equal groups, as already described in the Cha- meleon, pp. 175, 193, figs. 119, 123, is an eifective modification. In this reptile the limbs are short and strong, and a prehensile tail is added to the scansorial feet. Ordinary lizards, by the great length of the trunk in proportion to its breadth, and l^y the outward extension of the humerus and femur, are under unfavourable mechanical conditions for rapid course upon land. Yet such is the energy of the muscular con- tractions in some species, under the stimulus of solar heat, that they arc deservedly called ' agile, ' and ' dart' out of view in the first rush from a pursuer. They have not, however, the power of maintaining the exertion, and are soon overtaken, if they happen to be far from their retreat. The swiftest runners, e. g. the Tachy- dromi, have the fore and hi

Recherche dans la banque de photos par tags

• bookauthorowenrichard18041892
• bookcentury1800
• bookdecade1860