A handbook to the cases illustrating animal locomotion / Horniman Museum and Library.

  • Horniman Museum
Date:
1912
Catalogue details

Licence: In copyright

Credit: A handbook to the cases illustrating animal locomotion / Horniman Museum and Library. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    3^ a distinct order of mammals, the kangaroo belonging to the Marsupialia, the jerboa to the Rodentia, the jumping shrew to the Insectivora. The convergence between them is so marked that anyone unacquainted with their anatomy would at once declare them to be allied forms. It will be observed that the tail in jumping animals is long and heavy (kangaroo and jerboa) or in those forms which spring from tree to tree is long and bushy (squirrel and lemur). The heavy tail acts as a counterpoise to the rest of the body in jumping, and probably as a steering organ also in those forms which jump from tree to tree. CLIMBING. [Cases 33 to 35, and table-case.] Climbing not only enables an animal to retreat from foes upon the ground, but may also, as in the case of an arboreal form, bring within its reach the store of food, such as leaves and fruit, borne by the trees. Again, a climbing animal can make its home in rocks or on the trees, and so bring up its young with a greater measure of security than on the ground. Certain of the arboreal forms are of especial interest, as it seems probable that from animals which jumped from tree to tree or from trees to the ground, the terrestrial parachuting animals took their origin, as will be described later. The number of climbing animals is so large that only the more instructive examples can be described. VERTEBRATA AMPHIBiA.—An interesting adaptation for climbing is seen in the familiar European green tree-frog (Hyla arborea), which is so often kept as a pet in greenhouses. The under surface of the terminal joint of each toe is expanded into a flattish adhesive disc, which can be adjusted to the surface of a leaf or bough. With the aid of these discs, whose adhesive power is increased by the slimy secretion poured out from glands upon their surfaces, a tree-frog is able to walk up a vertical pane of glass. REPTILIA.—The majority of the lizards known as geckos possess structures recalling those of the tree-frogs. In the gecko (Gecko verticillalus) exhibited, it will be seen that the joints of each toe are expanded, and bear on their under surface a number of transverse folds.* Pressure * These folds can be clearly seen in the feet of a gecko preserved in spirit in the table-case. The arrangement of the folds varies in different species of gecko.
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