140 VERANY AND VOGT ON THE IIECTOCOTYLI 



of a fine spiral thread. The proper coat which lies below this 

 layer becomes distended by the action of water, very much as a 

 gummy mass would be, and finally bursts to allow the passage 

 of the contents of the spermatophore. 



These contents are composed of two very dissimilar threads ; 

 the one belonging especially to the beak-like prolongation, the 

 other to the sac of the spermatophore. We call this last thread 

 the spermatic cord (PI. IV. fig. 2 c), since it is wholly made up of 

 spermatozoa united together around a fine thread-like axis. This 

 spermatic cord is entirely white, silvery to the naked eye, and 

 of an even diameter throughout, except its anterior extremity, 

 where it becomes more delicate, to attach itself finally by an ex- 

 cessively delicate thread to the posterior extremity of the ejacu- 

 latory cord. The spermatozoa are united together in the sper- 

 matic cord in such a manner that their cylindrical end, which is 

 the larger, is attached, or rather glued by a viscous liquid, to the 

 axis of the cord, whilst their very fine caudal extremity is turned 

 towards the periphery. We can compare this structure to 

 nothing better than to the elongated brushes used for cleaning 

 bottles, in which the bristles radiate upon all sides from a me- 

 dian axis formed by an iron thread. The spermatic cord becomes 

 distorted very soon when it is subjected to the action of water, 

 and it is almost impossible to unroll its coils before the comple- 

 tion of this distortion. At the very moment the spermatic cord 

 is drawn out of its envelope, all the spermatozoa appear to be 

 united by a glutinous liquid, which connects them so closely that 

 it is impossible to distinguish them. By the action of w^ater, 

 this glutinous mass at first dissolves a little ; the spermatozoa 

 become free, and appear then to be animated by slight undu- 

 latory movements. Little by little these motions cease, whilst 

 the glutinous matter congeals by the operation of the water, and 

 to such an extent that the spermatic cord soon looks like a felted 

 mass whose elements are undistinguishable. It seems probable 

 to us, that the irregularly nodulated appearance noticed by 

 Von Siebold upon the spermatic cord of the Heciocotylus Trem- 

 octopodis, proceeds from a similar alteration produced by the 

 influence of water. 



We have said that the spermatic cord ends by a more delicate 

 extremity, when, forming numerous convolutions, it approaches 



