68 MULLER OX THE MALE OF 



vesicle which otherwise terminates the Hectocotylus Octopodis. 

 The pigmented capsule upon the back of the latter again is evi- 

 dence of a process of eversion similar to that of the Argonaut ; 

 and in the specimen of Octopus, which M. Verany had the good- 

 ness to show me, the pigmented spot upon the back of the 

 Hectocotylus-arm appeared very similar, if I do not err, to that 

 upon the back of the Hectocotylus-arm of the Argonaut when 

 just everted from its sac. Here also then the eversion of the 

 Hectocotylus from its sac precedes its separation. Whether the 

 pigmented capsule is already developed in one of Verany's spe- 

 cimens I know not. It is interesting that Cuvier describes one 

 of his Hectocotyli as the arm of the Octopus. Four out of five 

 individuals were found in the mantle of the Octopod ; " the fifth 

 had attached itself to one arm of the Poulpe, and had changed 

 it into a kind of sac in which it had imbedded its head, whilst the 

 rest of the body remained free externally (p. 150) ; " and " it has 

 almost destroyed the arm, and appears to replace it so com- 

 pletely that at first it might be taken for the arm itself " (p. 149), 

 It is hardly to be doubted that the animal " qu'un parasite devore" 

 was a male Octopus, which carried a Hectocotylus newly freed 

 from its sac, but not yet separated. The last link of the series 

 finally is formed by that Octopus, in which Verany found merely 

 a short stump in the place of the Hectocotylus-arm, which in all 

 probability had already fallen off. 



Considering the general resemblance of the Hectocotyli of the 

 Argonaut and of the Octopus, it is very remarkable, that, accord- 

 ing to Verany, in all cases the third arm of the right side is the 

 abnormally developed one in Octopus, whilst in the Argonauts 

 it always is the third arm of the left side. Cuvier does not 

 state in the place of what arm his Hectocotylus was fixed. 



It is much to be regretted that Cuvier has given no informa- 

 tion as to the sexual organs of the Octopods which carried the 

 Hectocotyli in their mantle or as an arm, and it is the more de- 

 sirable that such Octopods should be closely examined, since 

 their more considerable size will without doubt allow a more 

 easy and better determination of many points than the small 

 Argonauts permit. 



