FISHES. 313 



tvveen the great pectoral and the sterno-cleido-mastoid, in carnivorous 

 quadrupeds, or at least, this bone is attached to its surface, by dense 

 cellular tissue. 



These two great muscles are divided, transversely, by aponeurotic 

 laminae into as many layers of fibres as there are vertebrae. These 

 layers, when detached by cooking (which dissolves the gelatine of the 

 tendons) gives to the flesh of fishes a foliated appearance. 



These aponeurotic laminae, and the fleshy leaves which they mark, 

 are disposed more or less obliquely to the spine, and generally curved 

 so that their superior (i k, i k) and inferior (I in, 1 m) parts are 

 directed obliquely from behind forwards, the former ascending, 

 the latter descending, and their middle portion (k I, k I) forms an 

 angle, or an arch more or less convex, with its convexity directed 

 forwards. The muscle is thus divided lengthways into three bands. 

 When we cut into the superficial layer, we find that the superior band 

 is easily separated from the middle one ; and in removing the superior 

 band from the bones at its inferior border, we observe that its deep- 

 seated and inferior part is attached to the spinous apophyses of the 

 vertebrae by tendinous threads which take a direction obliquely back- 

 wards. If we separate it superiorly from the spinous apophysis, 

 and insterspinal bones, we find that its superior deep-seated part 

 also gives oblique tendons to the spinous apophysis, but which 

 have a direction obliquely forwards. Its more superficial part sends 

 sometimes, also, in the places where there are dorsal fins, to the 

 interspinals of those fins, especially to those of the needles, straps 

 which are similarly oblique, and directed forwards. It is this band 

 which seems to us to represent the spinal muscle of the back. 



The middle band would appear to us to represent the longissimus 

 dorsi, that which is called in quadrupeds with tails, the lateral lumbo- 

 sub-caudian. As the pelvis does not here interrupt the continuity of 

 the muscles of the tail, with those of the back, there is no further dis- 

 tinction, excepting in the neck. Superiorly its deep seated portion 

 furnishes oblique slips, directed backwards to the sides of the spinous 

 apophyses of the vertebrae. Throughout the rest of its height, its 

 deep seated fibres pass from one rib to another, drawing them together 

 like the intercostals. 



The third band, appears to me to correspond in the part which is 

 under the tail, to the inferior lumbo-sub-caudal of Mammalia ; but in 

 all the part which runs along the abdomen, it performs the function 

 of the abdominal muscles, especially in the species in which the ribs 

 do not cover the entire cavity. Its union with the middle band is much 

 more intimate, than that of the superior band. 



Along each flank, in the middle of the height of the fish, and conse- 

 quently on the middle band of the great lateral muscle, there is a 

 slight furrow, in which a mucous vessel is lodged. It corresponds 

 to the extremities of the accessory ribs ; but it does not penetrate 

 deeply, nor is there in this place any separation between the muscles, 

 at least, in the majority of fishes having compressed bodies. 



This, however, is not always the case. In the eel for instance, the 

 situation of this furrow marks the principal solution of continuity, so 

 that the lamime of the superior band have the form of a V open in 



