364 



HISTORY OF FISHES. 



seems to be a calamity to which most of 

 tins tribe are subject. Scarce a shell is met 

 with entire and sound to the end of its convo- 

 lutions ; but particularly the thinnest shells 

 are the most subject to be thus invaded. As 

 their shells are easily pierced, the predatory 

 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-shelled pursuers. The 

 food of all snails properly lies at the bottom; 

 when, therefore, the nautilus, or other thin- 

 shelled fish, are seen busily swimming at the 

 surface, it may be that, instead of sporting or 

 sunning themselves, as some are apt to sup- 

 pose, they are actually labouring 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 nautilus. 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 former 

 is the cause of its frequently appearing ; for, 

 upon opening the stomach, it is found to con- 

 tain chiefly that food which it finds at the 

 bottom. This animal's industry, therefore, 

 may be owing to its fears ; arid all those arts 

 of sailing which it has taught mankind, may 

 have been originally the product of neces- 

 sity. But the nautilus is too famous not to 

 demand a more ample description. Although 

 there be several species of the nautilus, yet 

 they all may be divided into two: the one 

 with a white shell, as thin as paper, which it 

 often is seen to quit, and again to resume; the 

 other with a thicker shell, sometimes of a beau- 

 tiful mother-of-pearl colour, and that quits its 

 shell but rarely. This shell, outwardly, re- 

 sembles that of a large snail, but is generally 

 six or eight inches across ; within 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 animal ; the body of 

 which, like its habitation, 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 ex- 

 traordinary conformation, 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 disengage 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 would scarcely admit a goose-quill, is 

 not yet discovered : but the fact is certain ; for 

 the animal is often found without its shell ; 

 and the shell more frequently destitute of the 

 animal. 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. 1 

 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 poet's description of it, has chiefly ex- 

 cited human curiosity. These animals, par- 

 ticularly those of the white light kind, are 

 chiefly found in the Mediterranean ; and 

 scarcely any who have sailed on that sea, but 

 must often have seen them. When the sea 

 is calm, they are observed floating on the 

 surface ; some spreading their little sail ; 

 some rowing with their feet, as if for life and 

 death ; and others still, floating upon their 

 mouths, like a ship with the keel upward. 

 If taken while thus employed, and examined, 

 the extraordinary mechanism of their limbs 

 for sailing will appear more manifest. The 

 nautilus is furnished with eight feet, which 

 issue near the mouth, and may as properly be 

 called barbs: these are connected to each 

 other by a thin skin, like that between the 

 toes of a duck, but much thinner and more 

 transparent. Of these eight feet thus con- 

 nected, six are short, and these are held up 

 as sails to catch the wind in sailing ; the two 

 others are longer, and are kept in the water, 



1 Goldsmith has confounded two shells very different 

 in their characters. The one is an Argonauta, and the 

 other a Nautilus. The paper argonaut is extremely 

 thin, spiral, involute, membraneous, and unilocular, or 

 consisting of a single apartment or cell. It has a narrow 

 keel, bordered on each side by a row of conical sharp 

 tubercles ; its sides are nearly fiat, with numerous 

 angular waved ridges ; its colour is white, with the keel 

 often brown. The shell is very thin and brittle ; from 

 which circumstance it has obtained the name of paper 

 nautilus. This shell is the nautilus of the ancients, 

 mentioned in the writings of Pliny and others. It is 

 supposed, that, in the early ages of society, the art of 

 navigation owed its origin to the expert management of 

 this instinctive sailor. 



Learn of the little Nautilus to sail, 



Spread the thin oar, and catch the driving gale. Pope. 



It swims on the surface of the sea, on the back of its 

 shell, which exactly resembles the hull of a ship ; it 

 raises two feet like masts, and extends a membrane 

 between, which serves as a sail ; the other two feet are 

 employed as oars. This fish is usually found in the 

 Mediterranean. 



