Miscellaneous. 93 



in its importance for reproduction in general. It is evident that 

 this peculiar structui'e, sometimes of one pair of arms, sometimes of 

 another, sometimes to the right, sometimes to the left, sometimes at 

 the summit, sometimes at the base, &c., must involve many differ- 

 ences in the mode of fixation of the spermatic masses or spermato- 

 phores on the females, and (inasmuch as the semen does not seem to 

 be poured upon the eggs by involuntary or mechanical, but by con- 

 scious movements) in the manner in which fecundation is effected. 

 What simple reflection tells us on this subject is equally confirmed 

 by observation. The spermatic masses are in reality fixed on very 

 different places and in very difterent conditions, a thing which I shall 

 explain in another memoir of which I here give only the general 

 conclusion — namely, that the genera Se2^ia, Sepioteutliis, aud Loligo 

 (consequently all those in which I have found the left ventral arm 

 hectoeotylized) fix the spermatic masses on the internal surface of 

 the buccal membrane of the females, which is specially organized for 

 that purpose ; whilst in the other Decapoda I have never fouud the ■ 

 sperm fixed in that place, but in various points of the mantle or of 

 the interior organs, in Ommatost replies for example, far back in tho 

 cavity of the mantle, towards the middle part of the back " *. 



Lastly, I show in my memoir how the apijlication of these sper- 

 matic bodies, on such extraordinary points, is effected in reality, in the 

 families of the Sepians and the Loliginians, by means of figures repre- 

 senting types of the principal groups of the Sepias. One of these 

 figures represents the buccal part of Sepia hierredda, a species closely 

 allied to Sepia qfficinaUs, and which might pass for a type of the 

 Sepias with a very strongly developed test, terminating behind in 

 the form of a beak ; another the corresponding part of Sepia inermis, 

 which, as a contrast, furnishes a good type of the Sepias with the 

 test very feebly developed and not produced behind. Lastly, Sepio- 

 teuthis sepioidea is the representative of the great group of the 

 Loliginians. In all these cephalopods the spermatici masses in their 

 cylindrical sacs are always fixed to the internal surface of the buccal 

 membrane. I have found this arrangement in many species of these 

 three genera, with only slight modifications in the different species 

 and different individuals of the same species. 



Although these characters are of very great importance in the 

 determination of the sex and age of the Cephalopoda, no very clear 

 idea is generally entertained of them. It has even been denied, of 

 late years, that the male Sepias observed in the aquarium had hecto- 

 eotylized arms, although it is so easy to prove this conformation of 

 the arms in all male individuals ; and after this it is not astonishing 

 that we should have had to wait so long for the recognition of the cor- 

 responding character on the buccal membrane of the females, although 

 Sepias exist now in many aquariums. 



To the figures just mentioned I have added the representation of 



* ' M(5moires de I'Academie Royale Danoise des Sciences/ 5th series, 

 vol. iv. p. 213, with two plates (translated in ' Wiegmann's Archiv ' for 

 1857, p. 211, and in Ann. & Mag. Nat. Hist. ser. 2, vol. xx. p. 81, with two 

 plates). 



