520 M. SANDER RANG 



manner of so many other molluscs, — lobes which would be 

 useless if the animal had not had a shell from its birth ; and 

 finally from that remarkable colouring at the base of the pal- 

 mated arms which is reproduced in so complete a manner 

 upon the corresponding part of the shell ? 



Such was the note which we remitted to the Academy of 

 Sciences, during one of the sittings of the month of March 

 1837, a note which, as we have already said, was sent to a 

 commission composed of M.M. de Blainville and Dumeril,in 

 order to make a report of it agreeably to the desire we had 

 expressed; for our object in taking the step, was simply to 

 provoke on the part of these naturalists, but more especially 

 M. de Blainville, the most decided supporter of the parasitic 

 theory, an examination of the new facts we brought into view, 

 in order to deduce from them inferences which might on one 

 side or the other, tend to the determination of the question. 



We have related in what an obliging manner this natural- 

 ist replied to our request, in undertaking to make the report 

 we desired; and how he afterwards returned to the subject 

 in a memoir in which he examined all that has hitherto been 

 said upon this interesting problem. 



It is upon the occasion of this memoir, which resumes so 

 well the past thread of the argument, that we enter into the 

 details which follow, in order to complete our note, and make 

 known in its place and order what further our researches 

 concerning the poulp of the argonaut have enabled us to dis- 

 cover. 



We are about in the first place to resume the observations 

 indicated in the note, and then to deduce from them inferences 

 which in our opinion may be drawn from them. We shall 

 then pass on to the examination of some facts or arguments 

 presented by different naturalists ; but before commencing 

 we shall divest ourselves of all personal bias as to the parasitic 

 or non-parasitic nature of the poulp ; which in conscience, 

 there is but little difficulty in doing, for it seems to us that 

 we are at this moment in the most complete uncertainty. It 

 is the truth that we wish for ; and in order to find it we 

 know no other means than to examine calmly and candidly 

 the pro and con of each argument, as well as the value of 

 the observations and hypotheses that have been presented. 



The newly detailed facts in the note in question are : — 



1st. The belief more or less generally entertained since the 

 time of Aristotle, respecting the skilful manoeuvres of the 

 poulp of the argonaut in progressing by the help of sails and 

 oars, on the surface of the water, is false. 



