78 MULLER ON THE MALE OF 



Nature of the Hectocotyli. 



With regard to this problem, we must consider, first, their 

 relation to the animal which lodges them in their free condition, 

 and, secondly, to that as whose arm they are developed. 



The main point as respects the former relation^ which Kolliker 

 first demonstrated for the Hectocotyli, may be safely assumed 

 to be — that each of the three forms of Hectocotylus, considered 

 as one with the animal upon which it is developed *, forms the 

 male factor with respect to a particular kind of female Cepha- 

 lopod; Argonauta, Tremoctopus and Octopus granulosus, Lamarck, 

 O. Carena f, Verany. The evidence of this consists in the fol- 

 lowing facts : — 



1. No other males of the Cephalopoda mentioned are known. 

 All Argonauts { of the ordinary form with velate arms, and all 

 individuals of Tremoctopus which have been dissected, were 

 females with ova. To the Argonauts enumerated by Kolliker I 

 can add fifty others of every size, and to the thirteen individuals 

 of Tremoctopus, thirty which I have examined with reference to 

 this matter. As has been said, nothing is known respecting the 

 Octopus. 



2. Most of the free Hectocotyli carried semen demonstrably ; 

 and it is very probable that the others had done so. To the 

 fifteen Hectocotyli Tremoctopodis fourteen others may be added 

 in which this was certain, w^hilst in four the demonstration failed 

 on account of the emptiness of the capsule. Tn Cuvier's Hec- 

 tocotylus Octopodis Dujardin found spermatozoa. To the six 

 Hectocotyli Argonautce enumerated by Kolliker, I can add thir- 

 teen which all carried the white sac under the pigmented dorsal 

 capsule, and as often as this was opened it was found to con- 

 tain spermatozoa. To these free Hectocotyli are to be added 

 the Argonauts which carried a Hectocotylus-axm inclosed in its 

 sac. All the specimens, which were carefully examined, contained 

 semen either in the sac of the Hectocotylus-arm or in the testis. 



Respecting these animals, indeed, doubts might be raised as 

 to the identity of the species with the common Argonaut, on 



• Hectocotylus Tremoctopodis questionably. 

 f If these be different, there will be four species. 



+ Verany (p. 54) cites a solitary statement of Leach that he had found a 

 male Argonaut. 



