Page:Jardine Naturalist's library Entomology.djvu/203

Rh From the free movements of the legs, and the number of separate pieces entering into their composition, it may be presupposed that they have obtained a large supply of muscular power. The coxæ receive the greatest number of muscles, especially if of a globose form, and performing a rotatory movement upon their axis. Four extensors and a flexor, according to M. Strauss, is the complement of the anterior and posterior coxæ of the common cockchafer, and three flexors and two extensors of the middle coxæ. The muscles of the trochanter are inserted in the coxæ, and, like those of the latter, vary in number. In the insect just named there are three extensors and a flexor for those of the anterior legs, and only a single flexor and extensor for each of the others. The thigh is moved by two muscles, and the tibia by a like number, the tarsus by two general ones, and a pair appropriated to each separate articulation. The last joint has two peculiar ones which act upon the claws. The muscular apparatus of the abdomen is much more simple than that of any of the other primary divisions of the body. It consists chiefly of a series which serve to unite this part with the thorax, and of another designed to maintain the connection of the different segments with each other. They are in general broad flat ribbons, rather thin and deprived of tendons. The organs of generation, owing to the complicated movements they perform, necessarily employ a great number of muscles, which assume as great a variety of forms as the organs themselves, and of which, therefore, it would be unsatisfactory to