Page:Jardine Naturalist's library Entomology.djvu/199

Rh it is evident that their apparatus of muscles, on which all these acts depend, must be at once ample and powerful. Although Lyonnet's enumeration of the muscles of the cossus has been often cited, we are acquainted with no other instance which so well exemplifies their wonderful multiplicity. In that caterpillar he discovered no fewer than 4061, of which 228 belong to the head, 1647 to the body, and 2186 to the intestines, a number exceeding by 3532, the amount of those which are to be found in the human frame! In some respects the muscles of insects have a strong similarity to those of the vertebrata, but in others a notable discrepancy is observable. For the most part they consist of two portions, viz. the tendon and the muscle. The muscle properly so called, is formed of a multitude of straight fibres, and enveloped, according to Lyonnet, in a membrane composed of many parallel bands, consisting of bundles of fibres enclosed in separate membranes. At one extremity they are attached to the inside of the external crust, and the various processes connected therewith, at the other to the organ on which they are designed to operate, their attachment being either immediate or by means of a tendon. When the muscles are not provided with tendons, the shape is determined by that of the parts to which they are attached, and they are commonly cylindrical or prismatic, retaining their sides parallel throughout their whole course. Those which are furnished with tendons are more variable in form, and have been divided into several classes,