CEPHALOPODA. 



course a round gland, and its terminal portion possesses glandular 

 walls. In addition, the so-called nidamental glands (fig. 537) are 

 present in the Decapoda and Nautilus ; they open into the mantle 

 cavity near the generative opening and secrete a cementing substance 

 which surrounds and unites together the eggs. The eggs are sur- 

 rounded either singly (Argonauta, Octopus) or in great number 

 (Sepia) by capsules with long stalks, which are united together in 

 racemose masses (so-called sea- grapes), and fastened to foreign objects 

 in the sea. In other cases the eggs are aggregated in gela- 



tinous tubes 



(Loligo, Se- 

 piola). 



The male 

 generative 

 apparatus 

 presents a 

 similar ar- 

 rangement 

 (fig. 538, a). 

 The testis (2 1 ) 

 consists of 

 an unpaired 

 gland formed 

 of long cylin- 

 drical tubes. 

 The duct of 

 the testis is 



FIG. 53Sa. Male sexual organs of Sepia offidnalis (after ^1^ ~- fl,~ 



Duvernoy), modified from C. Grobben. T, testis, with * 



a piece of peritoneum ; To, opening of the testis into the left side and F l Q 5336 



body cavity; Vd, vas deferens; O, opening of the vas j ^ Spermato- 



deferens into the body cavity; 7s, vesicula seminalis; * n g> CO phore of Spia 



Pr, prostate; Sp, spermatophore reservoir ; Oe, sexual and COmpli - (after Af Ed 



cated. The *-* 



following parts may be distinguished in it : (1) a much coiled vas 

 deferens (Vd), which opens into the body cavity, (2) a long dilated 

 vesicula seminalis (Vs) with two prostatic glands (Pr) opening into 

 its terminal portion, (3) a spacious sac, known as Needham's sac, in 

 which the spermatophores are formed, and which opens into the 

 mantle cavity at the apex of a papilla placed on the left side. 



In copulation the large spermatophores (fig. 538, b) are introduced 

 by means of the hectocotylised arm into the female sexual opening. 

 Tn some Cephalopoda (Tremoctopus violaceus, Philonexis C arena, and 



VOL., II. 5 







