I ON THE METHOD OF ZADIG 15 



causes other than those which are at work in 

 inorganic nature. On close examination, the 

 saucer-shaped partitions were proved to be all 

 perforated at one point, and the perforations being 

 situated exactly in the same line, the chambers 

 were seen to be traversed by a canal, or siphunde, 

 which thus connected the smallest or aphical 

 chamber with the largest. There is nothing like 

 this in the vegetable world ; but an exactly cor- 

 responding structure is met with in the shells of 

 two kinds of existing animals, the pearly Nautilus 

 and the Spirula, and only in them. These 

 animals belong to the same division the 

 Cephalopoda as the cuttle-fish, the squid, and 

 the octopus. But they are the only existing 

 members of the group which possess chambered, 

 siphunculated shells ; and it is utterly impossible 

 to trace any physiological connection between the 

 very peculiar structural characters of a cephalopod 

 and the presence of a chambered shell. In fact, 

 the squid has, instead of any such shell, a horny 

 " pen," the cuttle-fish has the so-called " cuttle- 

 bone." and the octopus has no shell, or, at most, 

 a mere rudiment of one. 



Nevertheless, seeing that there is nothing in 

 nature at all like the chambered shell of the 

 Belemnite, except the shells of the Nautilus and 

 of the Spirula t it was legitimate to prophesy that 

 the animal from which the fossil proceeded must 

 have belonged to the group of the Cephalopoda. 



