102 OBSERVATIONS ON THE ARGONAUT. 



It has been a subject of much controversy amongst natu- 

 ralists, whether the poulp of the argonaut really secretes the 

 shell in which it is commonly found, or, like the Paguri, 

 forces itself in after the proper inhabitant has been either 

 driven out, devoured, or become naturally extinct. Indeed, 

 whilst Lamarck, Montfort, Ranzani, &c. supported the former 

 opinion, Blainville and others maintained as certain the lat 

 ter ; and this learned malacologist went so far as to assert that 

 the animal of the argonaut was totally unknown, — ("Animal 

 tout-a-fait inconnu." — ' Manuel de Malacologie,' p. 494"). — 

 Prior to these the enlightened Abbe Olivi had stated, although 

 he had not had the opportunity of seeing a living argonaut, 

 that he was inclined to believe that a cephalopod might ea- 

 sily form a calcareous shell like that of the argonaut, if another 

 cephalopod, according to the observations of Martini, was the 

 constructor of the heavy and chambered shell of the nautilus. 



The reasons which induced the opposers of this opinion to 

 think the shell not the work of the poulp, were that its body 

 had not a spiral conformation, and that it did not adhere to 

 the shell, which bore no resemblance to the neighbouring 

 parts of the inclosed animal, being regularly furrowed at the 

 sides, and possessing a spiral convolution something like an 

 ammonite, while nothing analogous was observed in the ani- 

 mal, whose folds, when it withdrew into the shell, presented 

 the appearance of anything but regular furrows. To these 

 objections I will now reply, because I am glad to show at 

 this time how Signor Poli, attentively scrutinizing the eggs 

 of the argonaut, assures us that he saw the young shell at- 

 tached to the mollusc, and concludes that there is no longer 

 room to doubt that the shell in which we see the argonaut is 

 generated in the egg with the mollusc, and not merely inha- 

 bited by it afterwards, as many believe. With all this, the 

 observations of Poli do not appear to have entirely removed 

 the doubts of the celebrated Baron Cuvier, who, not being 

 willing to declare the opinion of Blainville erroneous, quali- 

 fied it as exceedingly problematical. 



Such was the state of things with respect to the argonaut, 

 when it occurred to me that the absence of experiments alone 

 was the cause of such conflicting opinions, and that all must 

 be brought to light if attentive examinations were instituted 

 on so important a subject. 



Determined on this undertaking, I well considered the aim 

 of my observations, which was to assure myself of the fact 

 that the constructor of the argonaut shell was the cephalopod 

 which inhabited it. In this case to become acquainted with 

 the structure of this mollusc should be the first of my endea- 



