540 



CEPHALOPODA. 



Fig. 225. 



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 

 into the great serous cavity surrounding them. 

 Mayer, considering that the urine is secreted 

 from venous blood in the lower vertebrate 

 animals, regards these venous appendages as 

 the renal organs of the Cephalopods; the serous 

 sacs ( h, fig. 226), therefore, which Cuvier calls 

 the ' great venous cavities,' and which we have 

 termed the ' pericardium,' the German Physi- 

 ologist calls the ' urinary bladder;' and the 

 papillary orifices (i) leading into the branchial 

 or excrementory chamber, which we have com- 

 pared with the orifices leading from the peri- 

 cardium of the Ray and Sturgeon into the 

 peritoneal cavity of the abdomen,f Mayer calls 

 the urethra. It must be observed, however, 

 that this Physiologist does not advance any 

 proof from chemical analysis in support of his 

 theory. Cuvier, on the other hand, believing that 

 the water of the branchial chamber might have 

 access by the orifices to the cavities containing 

 the appendages in question, supposes that they 



t Memoir on the Nautilus, p. 33. 



