OTHER FORMS OF ALTERNATION. 179 



of independent beings, rather than as integral parts of the 

 same animal suggesting a comparison to a loose confeder- 

 ation of Indian tribes, or to the feudal system of the middle 

 ages, rather than to a well-ordered polity of our own day.* 

 And though the proper organs of reproduction, from 

 their partial independence even in the higher animals, seem, 

 as we might expect, to manifest most clearly this emanci- 

 pation from the controlling influence of somatic life, yet it 

 is seen very distinctly in others also, as, for instance, in the 

 peculiarly modified tentacle of the Argonauta, which, when 

 filled with spermatic fluid, is detached from the body, and 

 finds its way spontaneously to the female for the purpose of 

 impregnation.-f- The organs of alimentation in the Poly- 

 pifera may also be considered as an illustration in point. 

 It is quite a tenable view of the compound polypes to re- 

 gard the whole polypidom as one body, of which the several 

 polypes are organs, combining the characters of mouth and 

 stomach ; yet such is their independence of each other, and 

 of the whole group of associated organs, that the play of 

 their functions is not arrested by their separation, it being 

 indeed in some cases the normal course for a polype to de- 

 tach itself from the rest and become the nucleus of a new 

 community. This relation is suggested especially by such 

 cases as that of Hydractinia, in which the various appen- 



* Some appropriate remarks on the general question here referred to 

 will be found in Professor Laycock's recent work on " Mind and Brain," 

 Vol. II., Ch. VIII. 



f The worm-like appearance led at first to its being described as a 

 parasite of this organ under the term of Hectocotylus ; and even after its 

 sexual relations were determined by Kolliker, it was still considered as 

 an integral, though rudimentary animal, and in this point of view was 

 employed by Darwin (in the first vol. of his monograph of the Cirrhi- 

 pedes) in illustration of the nature and relations of the minute parasitic 

 males occurring in certain genera of that group. The discovery of its 

 tme nature as a mere tentacle of a Cuttlefish is due to Verany and H. 

 Muller. 



