142 VERANY AND VOGT ON THE HECTOCOTYLI 



nal mass is not included in a sac as in the other Cephalopoda, 

 but is formed by a long cord coiled upon itself and completely 

 deprived of any special envelope. The formation of these semi- 

 nal machines, whose size is enormous relatively to that of the 

 male animal, is pretty well explained by an observation we made 

 upon one of the four individuals which we examined. A 

 whitish mass (PI. III. fig. 5/) was situated in the deferent canal 

 of this individual a little beyond the pyriform enlargement by 

 which this canal commences. It presented itself under the form 

 of a pear (PI. III. fig. 9.) with an elongated tail, containing 

 internally a thousandfold coil of a fine gelatinous, very transpa- 

 rent thread, beset on all sides with motionless spermatozoa. 

 This thread became lost by degrees in the more enlarged portion 

 of the mass ; and even by pressing aside the matted spermatozoa 

 forming it, one could only distinguish here and there some traces 

 of a similar gelatinous thread ; it was however by no means well 

 marked. This mass of spermatozoa was not invested by any 

 envelope, and it still retained the form of the foot-like enlarge- 

 ment in which it had been modelled. It seemed evident to us 

 that such a seminal accumulation is moulded by passing through 

 the whole length of the deferent canal into an elongated thread, 

 and that it is in the common reservoir that this thread receives 

 at once both its envelope and the ejaculatory cord secreted by 

 the accessory gland, which thus transforms the whole into a 

 spermatophore. This, once formed, passes into the flask, whence 

 it is expelled when copulation is about to occur. 



In the great majority of individuals which we examined, the 

 right arm of the third pair was disproportionately developed, 

 and had an external organization such as we have pointed out 

 in our zoological description. In other individuals this arm was 

 replaced by a very considerable pedunculated vesicle. We shall 

 see by the anatomy of these parts that there exists a correlation 

 between them an intimate correlation and that the formation 

 of the vesicle must necessarily precede that of the hectocotyli- 

 form arm. 



As to the latter, we have been unable to discover in its struc- 

 ture any great differences beyond those we are about to point out, 

 from that of an ordinary Cephalopod-arm. The axis of this arm 

 is formed by a cylindrical muscular tube of great thickness, 



