MUSCULAR .SYSTEM OF FISHES. 163 



LECTURE VII. 



MUSCULAR SYSTEM OF FISHES, 



The modification of the muscles, or active organs of motion, and 

 their deviation from the fundamental vertebrate type, proceed conco- 

 mitantly with tlie metamorphosis of the passive organs of motion, as 

 the Myelencephala rise in the scale and gain laigher and more vai'ied 

 endoAvments : therefore, as the segments of the skeleton preserve 

 the greatest amount of uniformity in the lowest class, so does the 

 principle of vegetative repetition most prevail in the corresponding 

 segments of the muscular system. 



The chief masses of this system in ordinary Osseous Fishes are 

 disposed on each side of the trunk, in a series of vertical flakes or 

 segments, corresponding in number with the vertebrae. Each lateral 

 iiake (Mi/ocomma, jjg. 44. a, h, c) is attached by its inner border to 



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44 



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Muscular system, Perca fluviatilis. 



the osseous and aponeurotic parts of the corresponding vertically 

 extended segment of the endo-skeleton, by its outer border to the 

 skin, and by its fore and hind surfaces to an aponeurotic septum 

 common to it and the contiguous myocommata. The gelatinous 

 tissue of these septa is dissolved by boiling, and the muscular seg- 



vor.. ji. *M 2 



