The Annals and Magazine of Natural History; Zoology, Botany, and Geology Volume 1

The Annals and Magazine of Natural History; Zoology, Botany, and Geology Volume 1

By (author) 

List price: US$28.01

Currently unavailable

Add to wishlist

AbeBooks may have this title (opens in new window).

Try AbeBooks

Description

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1838 edition. Excerpt: ...are not inserted into the body of the insect, but the one is confounded with the other on the opposite side; the junction of the two forming the commencement of a gutter or canal, which is prolonged along the immediate attachment of the anterior feet to the mouth, where it terminates. These five pairs of feet are in almost constant motion, even when the animal is still and at rest, and their use at such times is to communicate an undulatory motion to the water, from one pair to another; thus establishing a current which enters the shell by the anterior part, carrying the molecules, &c. in the water to the posterior part, where the gutter commences, and there being driven by the vermicular motion back again to the anterior extremity of the canal or mouth. None of these feet are used for locomotion. The first and second pairs according to Straus are used by the insect for prehension. According to Jurine, the chief action of the first pair is to direct the alimentary particles brought up by the current of water along the canal above-described, into the mouth. When the mouth is opened, says the same author, to receive the food, the motion of all the feet except this first pair ceases, but in them, on the contrary, is then accelerated. The grand use of the third and fourth pairs is for respiration, being adapted for that purpose by their branchial plates, which, as DeGeer had already observed, serve the same purpose to these insects as the gills of crabs, certain aquatic insects and larvae, fishes, &c. The second joints of these feet, which I have above described as heart-shaped vesicles, were considered by Schaeffer as pockets filled with a liquid destined for the reproduction of the shell at each moulting. This opinion, however, has never been...show more

Product details

  • Paperback | 196 pages
  • 189 x 246 x 11mm | 358g
  • Rarebooksclub.com
  • Miami Fl, United States
  • English
  • black & white illustrations
  • 1236661354
  • 9781236661357