90 MULLER ON THE MALE OF 



of other Cephalopoda; but perhaps the so-called ductus de- 

 ferens in Hectocotylus Tremoctopodis is similar to the?e. 



15. The free Hectocotyli can by no means be regarded as 

 independent animals. 



NOTE BY PROFESSOR KOLLIKER. 



I desire to take this opportunity of stating, that I have con- 

 vinced myself of the truth of the most important of the discoveries 

 made by M. Miiller, by examining the Cephalopods which he 

 has brought, and that I entirely agree with his view of the re- 

 lation of the Hectocotylus Argonauta to the male Argonaut. As 

 it now appears, I was led formerly to put too great a value 

 upon the statements of Maravigno and Madame Power, and I 

 was thence induced to consider the Hectocotyli as male Cepha- 

 lopoda which were developed as such in the ovum. It appears 

 now that I was indeed right in the main, when I claimed the 

 Hectocotyli as belonging to the Cephalopoda ; but that they are 

 not complete animals, but only parts of them, separated indeed in 

 a very strange manner, and by the great independence of their 

 organization and vital manifestations forcibly resembling inde- 

 pendent animals. 



KOLLIKER. 



EXPLANATION OF FIGURES 1 AND 2 OF PLATE I. 



(Both figures are magnified somewhat more than four times.) 



* Represents the natural size. 



Fig. 1. The perfect male Argonaut seen from the left side : the numbers in- 

 dicate the pairs of arms ; the second and fourth arms of the left side 

 are thrown back, in order to show in what manner the sac containing 

 the Hectocotylus is fixed by its pedicle in the place of the third arm. 

 Over the exterior of the sac a ridge extends longitudinally. 



Fig. 2. A male Argonaut in the same position, only the Hectocotylus has come 

 out of its sac. The sucker-bearing portion is twisted once completely 

 round upon its own axis, so that it is seen at first from one side, then 

 from above, then from the other side, then in the ascending portion 

 directly from below, and again upon the same side as at first. The 

 fixed end of the Hectocotylus is still covered by the pigmented mem- 

 brane of the sac ; further on the latter is torn longitudinally upon the 



