ARGOXAUTA ARGO AND THE HECTOCOTYLI. 85 



original animal. For we know as little how long the isolated 

 Hectocotylus, as how long the seven-armed Cephalopod, lives ; 

 whether the latter produces new Hectocotyli*, or passes through 

 yet other metamorphoses. In this respect it is remarkable that 

 male individuals of only a very small size relatively to the females 

 have been observed, and that, independently of sex, they exactly 

 resemble the very young females. The circumstance also that 

 many of the small animals had a tolerably advanced mass of 

 semen in the testis, and that others already carried perfect semen 

 in the seminal sac of the Hectocotylus-arm, rather indicates that 

 these males do not grow large, for the ova of females of the 

 same size are nowise developed to the same extent. If large 

 male Argonauts occur, they have been without doubt overlooked 

 in consequence of their wanting the expanded arms and the 

 shell. The specimens of the Octopus described by Verany are 

 indeed considerably larger ; and Cuvier says nothing about the 

 size of the animals which bore the Hectocotyli either in the 

 mantle or as an arm. Yet the case of an Octopus, brought for- 

 ward by Verany, which, in the usual place, had merely the pe- 

 dicle without an arm or vesicle, is the only direct evidence for 

 the continued existence of the Cephalopod which has cast off 

 the Hectocotylus. 



Until more light is thrown upon these relations, it seems 

 unnatural to assume that all the most important organs of an 

 animal, the central organs of the circulating and nervous systems, 

 the apparatus of sense and digestion, and so forth, are thrown off 

 en bloc, and that the remainder with the semen, which is not 

 even produced in it, should continue to represent the individual. 



4. If for the present then the Hectocotylus can hardly be 

 considered to be an entire individual, it only remains to regard 

 it as a separated portion of the whole. 



Costa has expressed the view that the Hectocotylus Argonauts 

 is the spermatophore of the Argonaut (Annales des Sciences Na- 

 turelles, 1841, p. 184). The Hectocotylus might be rightly so 



* In favour of a regeneration of the cast-off flectocotylus-arm we have the 

 fact, that not uncommonly this occurs with other arms. A small conical pro- 

 cess covered with a number of small suckers sprouts forth from the torn place 

 of the arm. 



