SOME NEW AND RARE CEPHALOPODA. 121 



The female organs of generation in the Cephalopodous class present five principal 

 modifications of structure. The ovarium is single in all, but sometimes, as in the 

 Cuttle-fish, it is divided by a septum. 



1. In the Nautilus there is one oviduct, which traverses an elongated gland at its ex- 

 tremity : there is also a superadded nidamental gland, which has no connection with the 

 oviduct, but is attached, as in the Pectinibranchiate Gastropods, to the parietes of the 

 branchial chamber. 



2. In Sepia, Sepiola, Rossia, Sepioteuthis, and some species of Loligo, there is also 

 one oviduct with a glandular termination ; but the nidamental glands are two separate 

 bodies, detached from the mantle, and having no communication with the oviduct. 



3. In Onychoteuthis, Loligo sagittata and some other Calamaries there are two distinct 

 oviducts, each terminated by a glandular organ, and also two separate nidamental glands. 



4. In the Octopi and Eledonce there are two oviducts, each of which traverses a glan- 

 dular organ, situated about the middle of its course : there are no detached nidamental 

 glands. 



5. In the Argonaut the two oviducts are convoluted, and have glandular coats 

 throughout their extent,but without partial enlargements : there are no separate nida- 

 mental glands. 



and oeconomy of the Cephalopods, gives two descriptions of the act of impregnation. In the fifth book of the 

 Historia Animalium it is stated that the Polypus (Octopus or Poulp), the Sepia {Cuttle-fish), and the Teuthis 

 (Calamary), all copulate in the same manner; the male and female having their heads turned towards one an- 

 other, and their cephalic arms being so coadapted as to adhere by the mutual apposition of the suckers. In 

 this act the Poulps are described as seeking the bottom, while the Cuttles and Calamaries are said to swim 

 freely about in the water, the individual of one sex moving forwards, the other backwards. Aristotle also observes, 

 that the ova are expelled by the funnel, which the Greeks call (j)v(7riTrjpa ; and some, he adds, assert that the 

 coitus takes place through this part. From the position of the terminal orifice of the oviduct at the base of the 

 funnel, and the inclination of the penis towards the same part, the latter supposition derives some probability, 

 especially with respect to the Sepia and Sepioteuthis, in which the male organ is well developed ; but in these, 

 as in all other Cephalopods, true intromission is physically impossible. From the dense nature of the external 

 covering which the ova derive in their course along the efferent passages, it is very improbable that they can be 

 impregnated otherwise than internally, and before the nidamental covering is laid upon the thin smooth chorion 

 which invests the ovum externally, prior to its escape from the oviduct : the descriptions of Aristotle may there- 

 fore relate to some such imperfect connexion as takes place in the Salamanders, &c. It is worthy of remark, 

 indeed, that the differences in the situation in which the coitus is said to take place in Aristotle's description 

 corresponds with the modifications of the locomotive powers in the three genera treated of. It is only, for ex- 

 ample, in the Sepia and Loligo that posterior fins exist, enabling the individuals to swim forwards. The 

 second account of the impregnation of the Malakian ova occurs in the 1 2th Chapter of the 8th Book of the 

 Historia Animalium, where the generation of fishes is treated of. " When they (fishes) bring forth, the male, 

 following the female, sprinkles the ova with his semen. The same thing happens to the Malakia, for in the 

 genus Sepia, wherever the female deposits the ova the male follows and impregnates them : this possibly hap- 

 pens in like manner to other Malakia, but hitherto it has been observed in the Sepia alone." The ova of the 

 Sepia, however, are precisely those which, of all Cephalopods, from the density and thickness of their coats, are 

 the least likely to receive the impregnating influence after having been excluded. 



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