558 



CEPHALOPODA. 



same structure as in Sepia and Rossia, but the 

 single oviduct is relatively wider than in the latter 

 genus, the ova being of remarkably large size. 

 In the Calamary the ovary is more elongated, 

 and theovisacsand ova are relatively smaller than 

 in any of the above genera. In the common 

 species ( Loligo vulgar is) the oviduct is single, 

 but narrower, and more elongated than in the 

 Sepia, and, like the vas deferens in the male, 

 it is disposed in convolutions ; its terminal 

 gland is relatively larger and longer; and the 

 detached nidamental glands are correspond- 

 ingly restricted to a smaller development. 



In the great Sagittated Calamary, which is 

 not uncommon on our north-western shores, 

 we found in a large specimen taken before the 

 beginning of the breeding season, that the 

 oviducts commenced by separate apertures 

 about two inches apart from the anterior sur- 

 face of the great ovarian bag, and were imme- 

 diately disposed in sixteen short transverse 

 folds, beyond which they continued straight 

 to the terminal ovarian gland. The whole 

 length of each oviduct was two inches ; the 

 convoluted portion occupying one inch ; 

 the straight and glandular parts each half 

 an inch. Monro, in his anatomy of this 

 species of Loligo, conjectured that the glan- 

 dular appendages of the biliary ducts, of 

 which he gave a figure, were the ova : of 

 the oviducts and nidamental glands he had 

 no knowledge. The latter parts are situated 

 external to the terminations of the oviducts; 

 they are of a narrow, elongated, flattened form, 

 about one inch, and a half in length, with a 

 wide cavity for moulding the secretion of the 

 two lateral series of glandular laminae. 



The ova which are contained in the mem- 

 branous part of the oviduct of the Sepia, 

 consist of a deep yellow vitellus, inclosed, 

 first, in a very delicate vitelline membrane, 

 and, externally, in a thin, smooth, shining, 

 easily lacerable, cortical tunic, or chorion. 

 We have generally found them in great num- 

 bers, squeezed together in a mass, so that few 

 retained their true form. 



The external tunic of the ova in Rossia is 

 stronger than in Sepia, and the form of the 

 ovum, which is elliptical, is consequently bet- 

 ter preserved : the oviduct, in the specimen 

 dissected by us, contained several ova detached 

 from one another, in progress of exclusion, 

 as represented in the figure at J\ f. The ova 

 in Sepiola, as in the two preceding genera, 

 are devoid of any external reticulate markings, 

 which belong only to the ovisac or formative 

 calyx. 



The delicate ova are defended by additional 

 layers of a horny substance deposited on their 

 external surface by the terminal gland, which 

 may be compared to the shell-secreting segment 

 of the oviduct in the Fowl. When the ova 

 quit the oviduct, they are connected together 

 by, and probably receive a further covering 

 from, the secretion of the two large super- 

 added glandular bodies (g, g^fig- 239), the wide 

 ducts of which converge and open close to the 

 termination of the oviduct. 



These bodies, in the Cuttle-fish, Sepiola, 



and Rossia, are of a pyriform shape with the 

 apices, converging and turned forwards; of large 

 size, especially at the reproductive season, situ- 

 ated on the ventral aspect of the abdomen, 

 but not attached, as in the Nautilus and in- 

 ferior Mollusks, to the mantle. They are each 

 composed of a double series of transverse, 

 parallel, close-set semi-oval laminae, the 

 straight margins of which are free and turned 

 towards each other along the middle line of 

 the gland. When the gland is laid open, an 

 impacted layer of soft adhesive secreted sub- 

 stance is found occupying the interspace of 

 the two series of laminae ; in which, in Rossia, 

 it is evidently moulded into a filamentary form, 

 whence it escapes by the anterior orifice above 

 mentioned. (See h, h, fig. 239.) 



The laminae are attached by their convex 

 margins to the capsule of the gland, which is 

 thin, and probably contractile ; it is com- 

 pletely closed at every part save the anterior 

 outlet, forming a shut sac posteriorly, and 

 having no communication with the oviduct or 

 oviducts, for which these glands have some- 

 times been mistaken.* 



In the Cuttle-fish the extremities of the 

 ovarian glands rest upon a soft parenchymatous 

 body of a bright orange colour : the correspond- 

 ing part is rose-red in the Sepiola, and of a 

 bright colour in all the congeneric species. In 

 the Sepia this body is trilobate, consisting of two 

 lateral slightly compressed conical portions, 

 whose obtuse apices are directed forwards, and a 

 smaller middle portion connecting the lateral 

 ones at their posterior and internal angles. 

 The dorsal surface of the lateral lobes is flat- 

 tened, the opposite side excavated to receive 

 the superincumbent extremities of the ovarian 

 glands. To these the substance in question is 

 closely attached by a tough connecting mem- 

 brane, but has no correspondency of structure 

 nor any excretory outlet. Its texture is dense 

 and granular, with minute cells, the largest of 

 which are in the centre of the body, and are 

 filled with a yellowish brown caseous substance. 

 In Sepiola the corresponding body is single, 

 and is similarly attached to the anterior extre- 

 mities of the two nidamental glands. In the 



* In the description of the anatomy of the Loliyop- 

 sis by Dr. Grant, contained in the first volume of the 

 Zoological Transactions, it is stated that " the 

 usual large glands of the oviducts appear to be 

 wanting," p. 26 ; whence we are led to conclude 

 that the oviducts are double in that genus as in the 

 Octopods. Rathke, however, describes the oviduct 

 as being single, and states that it is continued 

 downwards to terminate at an aperture situated on 

 the ventral surface of the hinder extremity of the 

 body. This is so singular a deviation from the 

 Cephalopodous type of structure, and makes so 

 important a step towards the Vertebrate Organiza- 

 tion, that we have selected the figure (Jig. 223J 

 in which the learned author above quoted illustrates 

 this part of his observations on Loligopsis, where 

 14 represents the ovary, 15 the oviduct, and 16 its 

 posterior terminal aperture. Further dissection of 

 this remarkable genus is, however, evidently re- 

 quired, in order to reconcile the discrepancies in 

 the accounts of the anatomy of these animals which 

 have hitherto been published, both as to the ge- 

 nerative system and in reference to other important 

 structures. 



