OBSERVATIONS ON THE ARGONAUT. 105 



Reflecting on the delicacy and fragility of the shell here 

 treated of, it seems strange to see them so rarely broken, and 

 wishing to trace the cause, I set about touching one whilst its 

 poulp was within; and taking it dexterously between my 

 fingers to learn what degree of flexibility it would admit, 

 I discovered that it was extremely pliant, so much so as to be 

 able to bring in contact the two extremities of the great curve 

 without breaking it ; and indeed, shells so fragile ought to 

 possess this flexibility, in order that they should not conti- 

 nually be liable to be broken to pieces by the restless and 

 uninterrupted movements of their poulps, as well as the shocks 

 which they would be likely to suffer in the depths during a 

 stormy sea. In this case it would prove very unfortunate for 

 them, not being capable of forming an entire new shell, as 

 will be observed afterwards. 



Having ascertained the flexibility of the above mentioned 

 shell, while the living animal was within it, I tried to assure 

 myself whether such would be the case without it, and after 

 having been exposed to the air for some time, I immersed some 

 empty ones in fresh water, and at the end of three days found 

 them as pliant and flexible as the first. 



As regards the connection between the animal and the shell 

 in which it is housed, I have not found any ligament or mus- 

 cle which connects them ; while the sac is simply held by the 

 turning of the end of the spiral, from which it may be easily 

 separated ; and it appears that the tight adhesion of the sac 

 against the internal surface of the ribs of the shell is sufficient 

 to hold it attached. Moreover the external super-position of 

 the sail-arms keeps the shell firmly upon the poulp. 



Passing on now to what it has been my fortune to observe 

 with regard to the habits of this mollusc, I shall remark that 

 in a state of natural liberty in the environs of Messina, and 

 even in the port, the argonaut is to be found almost all the 

 year, although in larger or smaller quantity. But I should 

 say their true season to be during autumn, or September, Oc- 

 tober, and November. It may be because the sea at that time 

 brings them with the current of the Faro ; or because that 

 season is more favourable to them on account of certain ma- 

 rine matters on which they feed ; or finally because it may be 

 the time of their fecundation. They are therefere seen most 

 abundantly in the muddiest parts of the port, and exactly 

 where the anchored boats are thickest among them. 



On observing any person, if they are on the surface of the 

 water, they fold the sail-arms over the shell, and the rowing 

 ones inside of it, and sink to the bottom. 



If they are under water, by means of the tube, where ter- 



