524 M. SANDER RANG 



the history of the poulp of the argonaut ; and the manner in 

 which the experiment has been conducted denotes, on her 

 part, great accuracy of observation, and a laudable zeal for 

 the progress of science. 



We now proceed to the second remark we have to make, 

 and which concerns the use of the elliptic lobes of two of the 

 arms of the poulp. We have watched many of these animals 

 in their shells, some at liberty in the sea, which we followed 

 by coasting along near them in a rowing boat ; others, as we 

 have already said, in a basin, where they enjoyed a seeming 

 liberty ; and after all we must confess that we have seen no- 

 thing in the habits and manoeuvres of these animals which 

 resembled the things that have been related of them; — positive 

 fables which have been preserved by some authors merely 

 through their love of the marvellous, or their too great confi- 

 dence in the observations of the ancient naturalists. 



We have on the other handmade the following discoveries. 

 In the first place we remarked that many authors have wrongly 

 represented the poulp in the shell, placing the palmated arms 

 in front, that is to say, on the outer edge of the opening ; 

 we find even in the beautiful plates of a recent work of M.M. 

 Ferrussac and d'Orbigny, a figure in which the animal is 

 turned one way, whilst in the remainder of the plates it is 

 turned another. If it were true that the mollusc is sometimes 

 situated one way and sometimes another, we might take ad- 

 vantage of this circumstance to strengthen the opinion of 

 those who maintain the poulp to be a parasite ; but as among 

 the great number of specimens we have studied, not one has 

 presented to us an anomaly of this kind, we can cite this fact 

 in support of the contrary opinion, for it naturally leads us 

 to suppose that the position of the mollusc in its protecting 

 covering, is not an accidental circumstance, but rather the 

 consequence of their mutual identity, and of an absolute ne- 

 cessity. 



The two palmated arms are always behind, that is to say 

 they lie near the retreating spire ; and we consider that part 

 of the poulp which terminates in front as being ventral, and 

 the opposite part, which includes the bag and the opening 

 leading to the branchiae, as dorsal. When the poulp creeps, 

 as we are about to shew that it does, these palmated arms 

 might still be called posterior arms, because it is they which 

 terminate behind the locomotive disc. 



We observed that these palmated arms, from the point of 

 coming out of the shell, embrace it, extending from the two 

 margins of the keel, whilst their membranous lobes spread 

 themselves over the two sides, which they carpet entirely, as 



