CEPHALOPODA. 



559 



Fig. 240. 



Ova of the Argonaut. 

 Fig. 241. 



Loligines and in Rossia it is double; each 

 portion (i, i,fig. 239) in the latter genus is at- 

 tached by cellular tissue to the anterior part of its 

 corresponding nidamental gland, and is excava- 

 ted by a deep groove close to the aperture of the 

 gland : from this structure and their position it 

 would appear that they assisted in moulding 

 the nidamentum, and, perhaps, in applying it 

 to the ova. Considering the texture of these 

 singular bodies, their ordinarily bright colour, 

 and their relative position to the generative 

 apparatus, we believe ourselves justified in 

 regarding them as the analogues of the glan- 

 dule succenturiata or i supra-renal bodies' of 

 the Vertebrate animals. 



In the Octopodous Dibranchiates the ovary is 

 a spherical sac with thick parietes (\,fig. 226). 

 The ovisacs (2) are racemose or connected in 

 bunches, and attached in the Poulp to a single 

 point of the ovarian capsule, but in the Eledone 

 to about twenty separate stalks suspended from 

 the upper part of the ovary. The ova, when 

 detached from the ovisacs, escape by a single 

 large aperture (3), leading from the anterior part, 

 of the sac into a very short single passage,- 

 which then divides to form the two oviducts. 

 These tubes, in the unexcited state of the ge- 

 nerative system, are membranous, straight, and 

 of an uniform narrow diameter, except where 

 they perforate a glandular laminated enlarge- 

 ment (4), situated about one-third from their 

 commencement; but, towards the period of ovi- 

 position, the parietes of the oviducts increase 

 in thickness and extent, forming longitudinal 

 folds internally. 



The laminated glands doubtless serve to pro- 

 vide an exterior covering to the ova, and con- 

 nect them together, thus performing the func- 

 tion of the accessory external glands in the 

 preceding tribe. The oviducts ascend behind 

 the lateral hearts and venous cavities, and open 

 on each side of the mediastinal septum of the 

 branchial cavity opposite the middle of the 

 gills (5, 5). 



A glandular body surrounds each oviduct in 

 Eledone, but is situated nearer the lower end 

 of the tubes, and is of a darker colour than in 

 Octopus. 



In Argonauta the oviducts are continued by 

 a short common passage from the ovary, and 

 form several convolutions before they ascend to 

 their termination, which is the same as in Oc- 

 topus ; they differ, however, from both the 

 preceding genera in having no glandular lami- 

 nated bodies developed upon them : the minute 

 ova of this genus are, therefore, connected 

 together by the secretion of the lining mem- 

 brane of the long and tortuous oviducts. 



In correspondence with the striking differences 

 which the female organs present in the Cephalo- 

 podous class, it is found that almost every genus 

 has its own peculiar form and arrangement of 

 ova after their exclusion. Of these, therefore, 

 we proceed to give a short description of the 

 principal varieties, 



The ova of the Argonaut are invariably found 

 occupying a greater or less proportion of the 

 bottom of the shell ; they are of an oval form, 

 about half a line in length before the develop- * From Fcrussac, Monographic des Cephahpodes. 



Fig. 242. 



243. 



Ova of the Calamary, Loligo Vulgar is. 



