Animal and Vegetable Physiology Considered with Reference to Natural Theology Volume 1 (Paperback)

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. 1834 edition. Excerpt: ... activity and energy in all their movements. The. long and elastic limbs on which the body is suspended, being firmly braced by their articulations, enable the muscles to act with great mechanical advantage in accelerating the progression of the body. Hence these animals are enabled to run with great swiftness, and to spring from a considerable distance on their prey; powers which were necessary to those tribes that live altogether by the chase. The greater number of species, however, as is well known, are provided with a curious apparatus for spinning threads, and for constructing webs to entangle flies and other small insects. Every species of spider weaves its web in a manner peculiar to itself: and, besides the principal web, they often construct in the neighbourhood a smaller one, in the form of a cell, in which they conceal themselves, and lie in ambush for their prey. Between this cell and the principal web they extend a thread of communication, and by the vibrations into which this thread is thrown, on the contact of any solid body, the spider is immediately acquainted with the event, and passes quickly to the spot, by the assistance of the same thread. Some species have the power of conveying themselves to considerable distances through the air by means of threads which they dart out, and which are borne onwards by the wind, while the spider is clinging to the end of the thread which is next to it. In this manner these spiders are often carried up to a great height in the air: and it has been supposed that during their flight they often seize upon gnats and other flies; because the mutilated remains of these insects are often seen adhering to the threads: this point, however, is still open to much doubt. The Natural History of...