MUSCULAR SYSTEM. 267 



develope themselves, at least the dorsal ones, and particularly during 

 the pupa state, that they subsequently present themselves as the large 

 dorsal muscles, distended between the phragmata. The straight ventral 

 muscles, on the contrary, so contract together, that they transform them- 

 selves into the small connecting muscles of the internal sternal pro- 

 cess. The lateral muscles again enlarge, and then exhibit themselves 

 as the large lateral muscles of the thorax. 



The crossing pectoral muscles are peculiar to the thoracic segment. 

 They are the small band-shaped muscular strips on the pectoral side, 

 originating from the posterior margin of the first thoracic segment, and 

 running obliquely to the lateral parts of the following thoracic segment. 

 With their lower shanks they embrace the nervous cord, and cross each 

 other precisely over it, that coming from the left passing over to the 

 right and those from the right to the left ; each passes directly through 

 the straight ventral muscle, and affixes itself to the exterior wall of the 

 segment. In the perfect insect they exhibit themselves as the above 

 described furcate dorsal muscles. In the larvae of Coleoptera I found 

 besides transverse pectoral muscles, which originating at one side of 

 each of the three thoracic segments passed over to the opposite side, and 

 in the first and third segments covered the nervxms cord, but in the 

 second were covered by it. I have not detected its development and 

 conformable appearance in the perfected insect. 



The muscles of the legs correspond evidently with those of the per- 

 fect insect. The profoundest, or muscles of the coxae, come from the 

 lateral parts of each segment, and insert themselves at the inner 

 margin of the ring of the coxa. In larvae with long and large legs 

 there is found at the inner lateral part of each thoracic segment a pro- 

 jecting horny ridge, which passes over the cavity of the coxae, whence 

 spring all, or at least the more deeply seated, muscles of the coxae, 

 whereas the superior ones pass over this ridge, coming from higher 

 situated parts of the thoracic case. The muscles which move the 

 thighs lie in the ring of the coxse, and form three or four narrow fasci- 

 culi ; thus also in each successive joint is found the muscles of the 

 third in advance. The last joint, or claw, the preformation of the 

 subsequent tarsus, receives two muscles, which originate with several 

 heads from the several rings of the foot, both from their superior and 

 inferior sides, and all are attached to two tendons which are again 

 attached to the inferior margin of the claw. Their common contrac- 



