CEPHALOPODA. 



629 



{g\ with thinner walls, containing the spermatophores, or moving 

 filaments of Needham* and from which pouch the short muscular 



penis Ck) is continued. Tlie 



229 



prostate, in Sepiola, com- 

 municates by a long and 

 slender duct with the vesi- 

 cula seminalis. The moving 

 filaments {li) in the terminal 

 pouch are capsules of sper- 

 matozoa and sperm -fluid, 

 with a singular associated 

 mechanism. They form one 

 of the most remarkable pecu- 

 liarities of the Cephalopoda, 

 and have been regarded as 

 parasitic worms, under the 

 names of Echinorhynchus^ 

 Scolex dibothrms, Need- 

 hamia expidsatoriay &c, ; but 

 were rightly recognised as 

 sperm-holders by Swam- 

 merdam.f 



In Octopus {fig. 229, K) 

 they are from six to eight 

 lines in length, slightly en- 

 larged at one extremity. 

 Their outer tunic or capsule 

 is elastic and transparent : this contains an elongated sac, occupying 

 the larger extremity of the sheath, and filled with the minute clavate 

 spermatozoa. This sperm-sac communicates by a short narrow canal 

 or isthmus, with a second narrower, elongated sheath, inclosing a 

 highly-elastic piston, from which a spiral filament is continued to the 

 small extremity of the outer sheath. In the Cuttle-fish, the isthmus 

 connecting the sperm-sac with the ejaculatory sac is longer, and the 

 coils of the spiral membrane are closer and more numerous. The 

 spermatophores of the Calamary are remarkable for the superior size 

 and length of the internal sac containing the spermatozoa. Under 

 every modification, the analogy of the apparatus which forms the 

 receptacle of the essential particles of the fertilising fluid, with the 

 nidamental sacs containing the ova in the opposite sex, is very 

 obvious. The spermatophores in the bursa are regularly arranged 



Male organs, Octopus. 



* CCCLXXVIII. 



t CCXXXIII. 



s s 3 



