. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. CETACEA. 569 ness and thinness, principally in those at- tached to the atlas and the axis, are extreme; and although those which proceed from the other cervical vertebrae may be better charac- terized, their action, nevertheless, is not much more extensive. The muscles of the back present no other important modifications than their great deve- lopment and their prolongation even upon the coccygeal vertebra. Thus the longissimus dorsi and the sacro-lumbaits are attached anteriorly to the skull, and posteriorly transmit th
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. CETACEA. 569 ness and thinness, principally in those at- tached to the atlas and the axis, are extreme; and although those which proceed from the other cervical vertebrae may be better charac- terized, their action, nevertheless, is not much more extensive. The muscles of the back present no other important modifications than their great deve- lopment and their prolongation even upon the coccygeal vertebra. Thus the longissimus dorsi and the sacro-lumbaits are attached anteriorly to the skull, and posteriorly transmit their ten- dons, the first to the end of the tail, the second to all the transverse processes of this part of the spine, associating in this way the move- ments of the back with those of the tail. As to the muscles peculiar to the tail, besides those which belong to this organ in all Mammals where it exists as a moveable organ, there are besides, in the Cetaceans, 1st, the antagonists of the sacro-lumbalis below the transverse pro- cesses ; 2nd, a levator caudte, which takes its rise above the five or six dorsal vertebrae, under the longissimus dorsi, and often in this part blends with it; it then extends freely as far as the extremity of the tail, where the two muscles unite together again by their tendons; 3rd, a depressor caudte, of great thickness, which pro- ceeds from the pectoral region, and spreads its tendinous processes upon the ribs, distributes them laterally to the transverse processes, and below to be inserted into the chevron bones along the two posterior thirds of the tail; 4th, a muscle which comes from the rudimental bones of the pelvis, and is inserted into the chevron bones of the anterior portion of the tail; 5th, the great recti muscles and the obliqui ascen- dentes, which, proceeding from the abdomen, attach themselves behind to the sides of the base of the tail. It is in consequence of this great aggre- gation of muscles, which are developed in unexampled
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