CEPHALOPODS. 497 



•Home asserts the contrary ; and no opportunity presented itself for 

 the complete solution of the question, until Poli was placed by the 

 :King of Naples in a position to solve it. The piscina of Portici was 

 placed at his disposal. He witnessed the curious mechanism by 

 which the egg is expelled from the egg cavity, and found in it the 

 rudiments of a shell, and satisfied himself, by following their develop- 

 ment day by day, that the shell existed in the embryo, and grew with 

 the animal. He satisfied himself also that the opinion enunciated by 

 Aristotle, that at no point did the animal adhere to the shell, was 

 perfectly true. 



Finally, in the curious series of experiments carried on by 

 Madame Power, in the port of Messina, the fragments of the frail 

 bark of the mollusc, which were broken off in taking it, were restored 

 in a few days, having been reproduced. It is, therefore, now quite 

 demonstrated that the Argonaut, Hke other testaceous molluscs, itself 

 secretes and constructs its shell — its diaphanous skifif. The reader, 

 .however, must not flatter himself that he can witness with his own 

 eyes from the shore, in our narrow channel, the charming picture of 

 the Argonaut painted by poets and natural historians : they never 

 come near the shore. They are timid and cautious creatures, dwelling 

 almost always in the open sea. They live in families, some hundreds 

 of miles from the shore ; and it is during the night, or at most in the 

 fading light of sunset, that they assemble together to pursue their 

 gambols on the surface of a tranquil sea. 



However reluctant we may be to destroy the marvellous fictions 

 of ancients and moderns, we are compelled to declare that there is no 

 truth in the often-repeated statement that the Argonaut uses its pal- 

 mated arms as oars or sails. In order to swim on the surface, it comports 

 itself as all other Cephalopods do. It uses neither oars nor sails, and 

 the palmate arms only serve to envelop and retain its hold on its frail 

 shell. Its principal apparatus of progression is the funnel with which 

 it is furnished, in common with all Cephalopods, and which is very 

 long in the Argonaut. Aided by this apparatus, it ejects the water 

 after it has served the purpose of respiration, and, in doing so, pro- 

 jects itself through the water. While it advances through the water 

 under this impulse, its pendent arms, elongated and united in bundles, 

 extend the whole length of the shell. Fig. 337 shows the position of 

 the different parts of the animal when it thus breasts the waves. These 

 arms are also powerful aids when the animal creeps on the ground at 

 the bottom of the sea. 



When the animal is disturbed it retires completely into its shell. 

 From that moment, the equilibrium being changed, the shell is over- 



G G 



