84 mCller on the male of 



tylus Argonaut(B to be a vermiform embryo of the common Argo- 

 nauta [vide supra) has been already shown by KolUker. 



3. Kolliker brought forward formerly the view that the Hec- 

 tocotyli as male individuals are the independent equivalents of 

 the female Cephalopods. According to the present state of 

 knowledge, this view can be tenable only under two suppositions. 

 Either, one must assume an alternation of generations in its 

 wider sense between the Hectocotylus and its previous supporter ; 

 or, after the separation of the Hectocotylus from the rest of the, 

 body, it must be regarded as the representative of the individu- 

 ality, having thrown off the remainder as so much no longer 

 useful ballast. 



Against the former view of a kind of alternation of genera- 

 tions however, too many objections at once arise ; among others^ 

 the development in the place of one of the eight typical arms ; 

 the imperfect organization as regards the other generations; 

 further, that the alternation would take place merely in the 

 males; whilst the females o^ Argonaut a and Tremoctopus are 

 known to lay eggs from which individuals similar to them pro- 

 ceed. Lastly, the presence in Argonauta of a testis with per- 

 fect semen, which probably passes thence into the Hectocotylus, 

 opposes altogether the hypothesis that the latter is a male gene- 

 ration proceeding from an asexual gemmiparous one. 



For the other supposition, that the Hectocotylus, together with 

 its producer, forms only one animal, but after its separation 

 must be regarded as a continuation of the whole, because it is 

 the means of propagation of the species, analogous cases might 

 be adduced of certain animals in which the organs of individual 

 life retrograde in relation to those of the propagation of the 

 species. 



It might be instanced that many Echinoderms, for example, 

 are produced by budding from larvae, w hich then waste away ; 

 and herewith might be compared the surprisingly great and 

 rapid development of the Hectocotylus-arm, as contrasted with 

 the small size of the other arms*. But before drawing such 

 comparisons, further observations must be obtained upon the 

 duration and mode of Hfe of the two separated moieties of the 



• In my specimens not more than six pairs of suckers are distinctly developed 

 upon three arms. 



