106 Prof. J. Steenstrup on IIectocotylus-/orma/ion 



ccption or transfer of the seminal mass*. But in all this we 

 have nothing but indications. I must content myself with 

 having pointed out generally all the formations and agreements 

 here described, and leaving it to those who possess richer mate- 

 rials, and especially to naturalists living on the sea-coasts, par- 

 ticularly that of the Mediterranean, who are fortunate enough 

 to observe these animals daily in a state of nature, to carry out 

 the comparison in all its details, I will only append to the above 

 scries of observations the general remarks to which they appear 

 to lead me at the moment. 



In the first place, it follows clearly, from these observations, 

 that the Hectucofij/us-fonnat'ion in Argonauta and Tremoctopus 

 is a far less paradoxical phfenomenon than it was sup[)osed to be 

 by naturalists, nor does it occur so suddenly and without trans- 

 itions, as appeared at first, and as has hitherto been stated. 

 We see rather that the peculiarity, so strange and anomalous at 

 the first glance, is here, as throughout Nature, prepared and 

 brought about by a series of transitions. It appears that it is 

 only a stronger expression, in particular spots, for that which is 

 expressed more or less distinctly in numerous other pointo in 

 the vicinity f. 



In the consideration of the Hectocoti/lus-fovmation in Argo- 

 nauta, the modification and transformation taking place here of 

 an organ originally connected with motion and nutrition, into 

 an organ of reproduction, has frequently been compared with 

 the alteration in form and function which the palpi undergo in 

 the male Spiders, by certain parts of them becoming transformed 

 into spoon-shaped organs, Avhich arc employed for the reception 



* I may, however, refer to the ainmdant and interesting literature of 

 the last few years upon the three known species of Hcctocotylus, and 

 especially to — 



KoUiker, Berichte von der k6uig;l. zootomischen Anstalt zu Wiirzburg, 

 1849. 



Veranv, Mollusques Mediterraneens, 1851, P. 41. p. 126-128. 



H. Millier, Zeitschr. fur Wiss. Zool. 1853, p. 1-35, & p. 346-358. taf. 1. 

 (See also Yerhandl. der physikalisch-mcdicinischen Gesellsch. zu Wiirz- 

 burg, 1851 ; Annales des Sciences Naturelles, torn. xvi. 1851, and Scien- 

 tific Memoirs, new series.) 



Verany and Vogt, Annales des Sciences Naturelles, torn. xvii. 1852, 

 J). 148-185. pi. 6-9 (and Scientific Memoirs, new series). 



Leuckart, Zoologische Untersuchuugen, iii. 1854, p. 91-109. taf. 2. 

 fig. 19-22. (See 11. Miiller, Vcrhandl. der phys.-med. Gesellsch. zu Wiirz- 

 burg, 1854, 1). 332.) 



t The entire developmental series in this respect in the Cuttle-fishes is 

 similar to that which I have indicated with regard to the breeding of the 

 Frogs and Toads, in which the care of the male oi Alyles ohstetricaus for the 

 eggs, evidently originates from, or is in relation with, the obstetric assist- 

 ance which all the species render to their females. 



