ARGONAUTA ARGO AND THE HECTOCOTYLI. 83 



pretty closely to the quantity of ova which we often find in Trem- 

 octopus in a dilatation of the oviduct, which, on the outer side, 

 immediately follows the gland. The ova which we find in the 

 part of the oviduct before the gland, as well as in Argonauta in 

 the beginning of the oviduct, are as yet only provided with their 

 separate proper stalks, which are delicate, but already somewhat 

 long ; these become united in the outer part of the oviduct into 

 a group with a common stalk, and thence they probably remain 

 here for a considerable period. It may therefore well be, that 

 the different groups of a large bunch of eggs are attached at dif- 

 ferent times, and although the duration of the intervals is wholly 

 unknown, it may be imagined to be not very small, and perhaps 

 too considerable to allow of the fecundation of all the ova by a 

 single previous copulation. Such ova belonging to different 

 periods might be fecundated by many Hectocotyli at different 

 times. 



Inasmuch as it has been said that the Argonaut is hermaphro- 

 dite, I beg expressly to observe that nothing which I have ever 

 noticed favours this conclusion. In the male specimens the 

 testis lay where otherwise the ovary would be found, and of the 

 latter there was no trace ; whilst in a female of 3 lines long it 

 was already very perceptible, and characterized microscopically 

 by ova of 0-02 of a line in diameter. Besides, the want of the 

 velum upon the arms of the Hectocotylus-bearers shows that 

 these are quite separate individuals from the females. 



If now with regard to two kinds of Hectocotylus the anatomical 

 fact is established, that they are developed as arms of perfect 

 Cephalopods, and also that all three Hectocotyli very frequently 

 occur isolated, there is a question which promises to be one of a 

 more general interest, viz. What is the relation of the free Hec- 

 tocotylus to the animal from which it has detached itself ? 



1. That the Hectocotylus stands still less in the relation of a 

 parasite (Cuvier) to the animal as whose arm it is developed, 

 than to that in whose mantle it resides, is clear. I will only 

 call to mind, how from the very first all observers have brought 

 forward the striking similarity to a Cephalopod-arm ; they have 

 not, however, come to the readiest conclusion, that it is such an 

 arm, without many deviations. 



2. That Madame Power also wrongly imagined the Hectoco- 



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