398 Report of a Notice respecting 



lopod with palmated arms as the true constructor of the shell 

 which it inhabits, we cannot, like Mrs. Power, consider this 

 discovery as conclusive ; for, in reality, the part reproduced 

 is but a thin plate (lame) ; transparent, and but a mere 

 diaphragm, which has neither the texture, nor the solidity, 

 nor the whiteness, of the rest of the shell ; and having 

 an irregular form, as if it had not been secreted by the 

 same means and the same organs as the original shell. In 

 a word, according to M. Rang, it just recalls what is done 

 by snails, when their testaceous covering is broken ; and we 

 know that, in this case, the collar of the animal, which alone 

 produces the shell, has nothing to do with this work of 

 reparation. 



Thus, even supposing that the reparation of the breach 

 made in the shell of the Argonaut, whilst it inhabits it, be really 

 similar to that which takes place amongst snails, and be pro- 

 duced by means of a solid calcareous substance (which we are 

 far from thinking), and be anything else but a mucous plate 

 (lame muqueuse), the result of the solidified excretion (sueur 

 eoagulce) of the skin of the animals, we can evidently draw 

 nothing from it to sustain the theory that the Cephalopod 

 inhabiting the shell of the Argonaut is its true constructor ; 

 since, as M. Rang allows, the plate which stops up the breach 

 that has been made has neither the texture, nor the solidity, 

 nor the whiteness, of the shell itself. 



As to the new assertion of Mrs. Power, that the voung 

 animal contained in the egg offers no trace of a shell, this 

 being developed at a subsequent period, M. Rang, unfortu- 

 nately, has had no opportunity of verifying it ; the living 

 specimens which he has had in his possession being but few 

 in number, and in circumstances that were unnatural to 

 them : a great tub, or cask, filled with sea-water, in which 

 they died at the end of a few days. 



But a newer and much less questionable fact, which M. 

 Rang had an opportunity of observing, is the use made by 

 these animals of the palmated arms, with which all the species 

 of Ocythoe are provided, to hold their shells; and the man- 

 ner in which these animals propel themselves, whether float- 

 ing upon the surface, or entirely immersed, or, finally, upon 

 the solid bottom of the sea. 



In the first condition, M. Rang makes the remark, that 

 naturalists have been wrong in representing the Cephalopod in 

 the shell of the Argonaut as sometimes having its back (that 

 is to say, the side upon which are its palmated arms) turned 

 towards the back of the shell, and sometimes towards its 

 lower part (ventre). He affirms that, in reality, it is always 

 in the same position, so that the palmated arms are behind 



