C86 



A HISTORY OF 



its prey, until, with its trunk, it has sucked 

 out all substance, or until it drops off when 

 the other begins to putrefy. 



Thus it would seem throughout nature, 

 that no animal is so well defended, but that 

 others are found capable of breaking in upon 

 its entrenchments. The garden-snail seems 

 tolerably well guarded; but the wall of its 

 shell is paper itself, in comparison with that 

 which fortifies some of the sea-snail kind. 

 Beside this thick shell, many of them are also 

 furnished with a lid, which covers the mouth 

 of the shell, and which opens and shuts at 

 the animal's pleasure. When the creature 

 hunts for food, it opens its box, gropes or 

 swims about; and, when satisfied, drops its 

 lid, and sinks to the bottom: there it might 

 besupposed to remain in perfect security; but 

 the trochus soon finds the way to break into 

 the thickest part of its enclosure, and quick- 

 ly destroys it with the most fatal industry. 



Their being liable to the attacks of the 

 trochus seems to be a calamity to which 

 most of this tribe are subject. Scarce a shell 

 is met with entirely and sound to the end of 

 its convolutions; but particularly the thinnest 

 shells are the most subject to be thus invaded. 

 As their shells are easily pierced, the preda- 

 tory shell-fish, or the sea-worm, chiefly seek 

 them for subsistence ; and of those thin, 

 paper-like shells, not one in a hundred is 

 found that has not suffered some disaster. 

 As they are lighter than other shell-fish, they 

 swim with greater ease ; and this is the chief 

 method of avoiding their heavier thick-shell- 

 ed pursuers. The food of all snails properly 

 lies at the bottom ; when, therefore, the nau- 

 tilus, or other thin-shelled fish, are seen busily 

 swimming at the surface, it may be, that, in- 

 stead of sporting or sunning themselves, as 

 some are apt to suppose, they are actually la- 

 bouring to escape their most deadly pursuers. 



Of all sea-snails, that which is most fre- 

 quently seen swimming upon the surface, and 

 whose shell is the thinnest and most easily 

 pierced, is the nauiilus. Whether, upon these 

 occasions, it is employed in escaping its nu- 

 merous enemies at the bottom, or seeking for 

 food at the surface, I will not venture to de- 

 cide. It seems most probable, that the for- 

 mer is the cause of its frequently appearing ; 

 for, upon opening the stomach, it is found to 



contain chiefly that food which it finds at 

 the bottom. This animal's industry, there- 

 fore, may be owing to its fears : and all those 

 arts of sailing which it has taught mankind, 

 may have been originally the product of 

 necessity. But the nautilus is too famous not 

 to demand a more ample description. Al- 

 though there be several species of the nauti- 

 lus, yet they all may be divided into two: 

 the one with a white shell, as thin as paper, 

 which it is often seen to quit, and again to 

 resume ; the other with a thicker shell, some- 

 times of a beautiful mother-of-pearl colour, 

 and that quits its shell but rarely. This shell 

 outwardly resembles that of a large snail, but 

 is generally six or eight inches across: with- 

 in it is divided into forty partitions, that 

 communicate with each other by doors, if I 

 may so call them, through which one could 

 not thrust a goose-quill: almost the whole 

 internal part of the shell is filled by the ani- 

 animal ; the body of which, like its habita- 

 tion, is divided into as many parts as there 

 are chambers in its shell: all the parts of its 

 body communicate with each other, through 

 the doors or openings, by a long blood-vessel, 

 which runs from the head to the tail : thus 

 the body of the animal, if taken out of the 

 shell, may be likened to a number of soft bits 

 of flesh, of which there are forty threaded 

 upon a string. From this extraordinary con- 

 formation, one would not be apt to suppose 

 that the nautilus sometimes quitted its shell, 

 and returned to it again; yet nothing, though 

 seemingly more impossible, is more certain. 

 The manner by which it contrives to disen- 

 gage every part of its body from so intricate 

 a habitation ; by which it makes a substance 

 to appearance as thick as one's wrist, pass 

 through forty doors, each of which Avould 

 scarcely admit a goose-quill, is not yet dis- 

 covered ; but the fact it is certain ; for the 

 animal is often found without its shell ; and 

 the shell more frequently destitute of the ani- 

 mal. It is most probable, that it has a power 

 of making the substance of one section of its 

 body remove up into that which is next; and 

 thus, by multiplied removals, it gets free. 



But this, though very strange, is not the 

 peculiarity for which the nautilus has been the 

 most distinguished. Its " spreading the thin 

 oar," and " catching the flying gale," to use the 



