THE " SAILING " OF THE NA UTIL US. 27 r 



been broken in its capture, discovered that the animal 

 quickly repaired the fracture, and reproduced the portions 

 that had been broken off. Induced by this to make 

 further experiments, she kept a number of living argonauts 

 in cages sunk in the sea near the citadel of Messina, and in 

 1836 laid before the "Academy" at Catania the following 

 results of her observations of them : 



ist. That the argonaut constructs the shell which it 

 inhabits. 



2nd. That it quits the egg entirely naked, and forms the 

 shell after its birth. 



3rd. That it can repair its shell, if necessary, by a fresh 

 deposit of material having the same chemical composition 

 as its original shell. 



4th. That this material is secreted by the palmate, or 

 sail, arms, and is laid on the outside of the shell, to the 

 exterior of which these membranous arms are closely 

 applied. 



Madame Power was mistaken on two points. Firstly, 

 the construction of the shell does not commence after 

 the birth of the animal, but, as has been shown by 

 M. Duvernoy, its rudimentary form is distinctly visible by 

 the aid of the microscope in the embryo, whilst still in the 

 egg ; and secondly, she continued to believe in the use of 

 the membranous arms as sails, and of the others as oars 

 This fallacy was exploded by Captain Sander Rang, an 

 officer of the French navy, and " port-captain " at Algiers, 

 who carefully followed up Madame Power's experiments, 

 and confirmed the more important of them. Thus were 

 set at rest questions which for centuries had divided the 

 opinions of zoologists. 



" The * Paper Nautilus ' is, in fact, a female octopod 

 provided with a portable nest, in which to carry about and 



