AND THE MALES OF CERTAIN CEPHALOPODS. 135 



We have just pointed out the form of the testicle ; besides the 

 general envelope which unites this organ to the cornu, it has a 

 proper fibrous envelope which closely invests it. Invariably 

 situated upon the dorsal surface, behind the branchial heart of that 

 side, the testicle however changes its place more or less, according 

 to the state of turgescence of the different portions of the sexual 

 apparatus. The testicle itself is divided into two portions which 

 differ in appearance even to the naked eye ; the pointed extre- 

 mity being more transparent than the body of the organ which 

 is turned towards the cornu. Fine chalky lines radiate from 

 the pointed extremity in all directions towards the enlarged 

 centre of the organ, where they converge again to approach that 

 face of the testicle which is in contact with the cornu. Under 

 the microscope these chalky lines are seen at once to be the 

 seminiferous tubes which end in a cul de sac at the pointed 

 extremity of the testicle, and which begin to ramify when they 

 enter into the thick portion of this organ. These ramifications 

 however are almost parallel with one another, so that the entire 

 testicle seems to be composed of parallel seminiferous tubes, 

 which however converge both towards the point and towards the 

 base of the organ. 



The seminiferous tubes contained, in all the individuals we 

 examined, no trace of completely developed spermatozoa, but 

 only granular cells and very small free granulations, which from 

 their strongly -marked contour had the appearance of fine drops 

 of oil ; the granule-cells also exhibited among the fine granules 

 more strongly-marked little drops. All the individuals which 

 we examined being in the pairing season, the spermatozoa had 

 already passed into the ejaculatory organs, and in the semini- 

 ferous tubes of the testicle there were found only the elements 

 required for the reproduction of the semen. 



There is no direct connexion between the seminiferous tubes 

 and the efferent canal; we have assured ourselves of this cir- 

 cumstance microscopically. The special envelope of the testicle 

 (PL III. fig. 5.) is considerably narrowed at the base of that organ, 

 and is directly continued into the muscular envelope of the cornu. 

 A kind of funnel is thus formed at the place where the testicle is 

 attached to the cornu, towards which all the seminiferous tubes 

 converge to terminate by a rounded end. The contents of these 



