. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. 540 CEPHALOPODA. Fig. Circulating and respiratory organs—Cuttle-fish* form thin colourless pyriform sacs, extending nearly an inch from the vein. They are ar- ranged in distinct clusters, and are relatively shorter in Argonauta. In Sepioteuthis the whole extent of the superior and inferior trunks of the veins contained in the pericardium pre- sent an uniform and continuous cellular en- largement of their parietes. In Loligo the coats of the corresponding veins in like man- ner present only a spongy thickening. In S
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. 540 CEPHALOPODA. Fig. Circulating and respiratory organs—Cuttle-fish* form thin colourless pyriform sacs, extending nearly an inch from the vein. They are ar- ranged in distinct clusters, and are relatively shorter in Argonauta. In Sepioteuthis the whole extent of the superior and inferior trunks of the veins contained in the pericardium pre- sent an uniform and continuous cellular en- largement of their parietes. In Loligo the coats of the corresponding veins in like man- ner present only a spongy thickening. In Sepia the cells are more elongated, but are large, irregular, and flocculent (c, c, Jig. 225), and continued without interruption not only upon the divisions of the vena cava (a), but upon the visceral veins, two of which (b, b) present remarkable dilatations. In Loligopsis the venous follicles are in distinct groups, as in Nautilus; and Rathke describes them as presenting a laminated and glandular structure. With respect to the function of these bodies nothing is as yet definitely known. They are well supplied with blood from the neighbouring arteries, and are undoubtedly glandular; but the matter which they secrete has not yet been subjected to chemical analysis. If the spongy coats of the vena cava of a Calamary be pressed, a whitish fluid escapes, which is al- * From Home's Comparative Anat. vol. iv. See the original figure and description by Huntpr, in Descr. Catalogue of Mus. R. Coll. of Surgeons, vol. ii. pi. xxii. ways thicker and more turbid than the blood which circulates in the vein. The elongated cells of the Poulp yield in like manner an opake and yellow mucus. Some physiologists suppose that the secreted matter is not expelled by the orifices of the sacs into the veins to be mixed with the current of blood, but that the venous blood passes into the cells by those apertures, and that the matter secreted from it exudes from the parietes of the cells or follicles i
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