OF INSECTS. 
103 
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 ex- 
emplifies their wonderful multiplicity. In that cater- 
pillar 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, 
N 
