. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. o, second thoracic ring of the Squilla; b, one of the small antennas. pendages belong especially to the function of sensation, and as we shall have to revert to these at a later period, and give an ample de- scription of their structure, we shall not enter upon this subject farther at present. Fig. 389. Third and fourth cephalic rings of the Squilla : a, carapace; b, one of the posterior antennae j c, one of the mandibles. The eleven pairs of appendages which suc- ceed are variously apportioned between the functions of d
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. o, second thoracic ring of the Squilla; b, one of the small antennas. pendages belong especially to the function of sensation, and as we shall have to revert to these at a later period, and give an ample de- scription of their structure, we shall not enter upon this subject farther at present. Fig. 389. Third and fourth cephalic rings of the Squilla : a, carapace; b, one of the posterior antennae j c, one of the mandibles. The eleven pairs of appendages which suc- ceed are variously apportioned between the functions of digestion and locomotion, to which last the five hindmost pairs are entirely dedi- cated in the Decapods. In other Crustacea, again, the first pair only is set apart in an especial manner for the office of mastication, all the others then serving for locomotion, and this pair is in consequence very generally de- scribed under the name of mandibles; very commonly one and even two other pairs are added to this first pair, and these are desig- nated jaws or maxilla. In the majority of instances, moreover, the three succeeding pairs assist the three preceding; and as they are frequently more especially apportioned to loco- motion, the two last in particular, whilst in some cases -they serve for the two functions at one and the same time, they have been de- signated by anatomists and naturalists the maxillary limbs (pieds-machoirs): these we shall describe when we come to speak of the apparatus of digestion. As to the five pairs which we have already mentioned as essentially ambulatory (see jig. 382), they present in the Brachyura no more than a simple stem, composed of six articulations; whilst in the Astacus and allied genera, we find a flabelliform appendage or whip, dedicated especially to the purposes of respiration, and in the Peneae the three sorts of appendages existing simultaneously. By- and-by, when speaking of respiration, we shall see how it happens that in a great numb
Size: 1338px × 1867px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, booksubjectanatomy, booksubjectphysiology, booksubjectzoology
