312 FISHES. 



muscles which move the different parts of the head, and its several 

 apparatus on each other. 



The muscles of fishes, like those of other vertebratae are composed 

 of fleshy fibres of a more or less deep red colour, and of tendinous 

 fibres of a silvery or white colour, in similar respective positions. 

 But it may be affirmed, that with the exception of certain particular 

 muscles, which are sometimes of a deep red, the flesh of fishes is paler 

 than that of quadrupeds, and especially than that of birds. There are 

 even species, whose flesh is purely white ; its odour and savour are 

 different; it exhales more infection during decomposition, an infec- 

 tion of a particular character which has been compared to that of 

 phosphuretted hydrogen gas, but which, according to M. Chevreul, 

 depends on a particular principle. 



Great lateral Muscles of the body.* 



Essentially there is but one great muscle on each side, (No. 1) 

 filling up the space from the head above, and the bones of the shoul- 

 der below, down to the sides of the base of the caudal fin. But this 

 single muscle is very complicated, and represents the three fasciculi 

 of the sacro spinal, which, as fishes have no necks, extend from the 

 tail to the head, without presenting those distinctions, which obtain in 

 other animals, between the cervical portions, and the dorsal and ca x- 

 dal portions. 



The muscle of one side is separated from the other, by the spine 

 and its apophysis, by the deep seated muscles of the interspinal small 

 bones (Nos. 3 and 4) and by the ribs which surround the abdominal 

 cavity. They separate from each other below (in a) to make room 

 for the pelvis, to which they often furnish, each a small fasciculus, and 

 for the ventral fins. Farther forwards (in 6) each is divided into 

 two, for the passage outwards of the pectoral fin, and the muscles that 

 belong to it. 



The superior portion of this anterior division, is inserted chiefly 

 into the cranium (in d, e) the bones of the shoulder (in f, g) and in 

 many species, even to that part of the humerus, which is above the 

 pectoral (in, A). A part of it stops at the first rib, and from the point 

 a fasciculus, (y) sometimes, is sent to the mastoid bone, which we 

 might compare to a scalenus. Its inferior portion is inserted into 

 the inferior part of the humeral bone (in c) and particularly to its 

 symphysis. Below, it is continued to the body or the azygous piece 

 of the hyoides (from c to d). It is this prolongation which occu- 

 pies what is called the isthmus. This inferior division of the great 

 muscle envelops the stiliform bone behind the shoulder (in a, b) 

 nearly in the same way, as the vestige of the clavicle is enveloped be- 



* The muscles of the Perch have been represented in plates IV, V, and VI of the 

 osteology of fishes : plate IV. is the external lateral layer ; plate V. the deep lateral layer. 

 In pi. VI. is represented the upper layer of the muscles situated below the head and 

 chest ; fig. II. are the muscles under the cranium and internal surface of the bran- 

 ehiostegous membrane ; in fig. III. the muscles which are proper to the branchiae ; 

 the heart is also in its situation. It is to these three plates that the references in 

 the present chapter are directed. 



