in Anatomy and Physiology. 261 
zoological import, what is their individual character. Are they to 
can be regarded only as distinct individuals. Moreover, he brings 
to the support of his view the observations of Madame Power, 
and of Maravigno, from which it would appear that the hecto- 
cotyli are formed within eggs, and first appear as small worms 
having two rows of suckers on their whole length, and a filiform 
appendage at one extremity, and a small enlargement at the other. 
On the other hand, other and later observers support the second 
view, the non-independent animal character of these forms. Chief 
among these are H. Miiller, and Vérany & Vogt, and incontro- 
vertible as would seem at first the ground of Kolliker’s opinion, 
they have satisfactorily shown, even to Kdlliker himself,* the 
correctness of their position. ‘The details of these researches by 
which the question seems now pretty definitely settled, the limits 
of these pages will not allow me to give. It may be remarked, 
however, that these observers have all studied these forms upon 
living specimens on the coast. It has been shown that the Argo- 
nauts on which these hectocotyli are found, have a highly de- 
veloped testicle, the situation and structure of which correspond 
to those of the common cephalopods, and which communicates 
with the hectocotyle. : 
In conclusion, | may quote H. Miiler’s own words: “It is 
then proved that the hectocotylus is formed on a male argonaut. 
and is nothing but an arm metamorphosed in a very irregular 
manner. This arm, or the hectocotylus, is detached when it has 
been filled: with the sperm which is formed in a true testicle of 
the argonaut itself, and it then plays an apparently independent 
life. In this condition, it meets the female argonauts which form 
a true copulation, it impregnates, as I have observed with the 
hectocotylus of a Tremoctopus, and it resembles in this, as also, by 
its movements, by a kind of circulation, and by the long duration 
of its life after detachment, a true male animal.” 
* See the Nachwort, by Kélliker, to the memoir by H. Miiller in the Zeitsch. far 
wissenschaftl. Zool., iv, p. 35. ; 
