106 STUDIES IN LIFE AND SENSE. 



credited with being that of maintaining a low vitality in the disused 

 chambers of the shell. 



All other living cuttlefishes possess, on the contrary, two gills, 

 never more than ten arms provided with suckers, an ink-sac, un- 

 stalked eyes, a completely tubular funnel, and an internal shell. If, 

 however, the nautilus represents in its solitary self the four-gilled 

 cuttlefishes of to-day, it likewise, like " the last of the Mohicans," 

 appears as the descendant of a long line of famous ancestors. In 

 its distribution, the nautilus is limited to the southern seas. It is 

 still the rarest of animals in our museums, although its shells are 

 common enough. The scarcity of living nautili appears difficult to 

 account for, when we find Dr. Bennett informing us that the natives 

 of the New Hebrides dive for one species, and likewise capture it in 

 fish falls; the Fijians capturing Nautilus Pompilius with lobster-bait. 

 Mr. Moseley tells us that the " Challenger " expedition obtained but 

 a single specimen of the nautilus. It " swam round and round a 

 shallow tub in which it was placed, moving after the manner of all 

 cephalopods backwards, that is, with the shell foremost. It floated 

 at the surface, with a small portion of the top of the shell just out 

 of the water, as observed by Rumphius." Remarking on the scarcity 

 of the living animal, as compared with the abundance of the shells, 

 Mr. Moseley says, " The circumstance is no doubt due to the fact 

 that the animal is mostly an inhabitant of deep water. The shells of 

 Spirula (fig. n) similarly occur in countless numbers on tropical 

 beaches, yet the animal has only been procured two or three times. 

 We obtained one specimen during our cruise, which had evidently 

 been vomited from the stomach of a fish." 



Mr. Moseley further expresses his opinion that " both Nautilus 

 and Spirula might be obtained in some numbers if traps, constructed 

 like lobster-pots, and baited, were set in deep water off the coasts 

 where they abound in from 100 to 200 fathoms." He adds, "The 

 fact that the living Nautilus was obtained from 320 fathoms shows 

 that it occurs at great depths. It is probably a mistake to suppose 

 that it ever comes to the surface voluntarily to swim about. It is 

 probably only washed up by storms, when injured perhaps by the 

 waves." 



It is thus the pearly nautilus floats under certain circumstances 

 on the surface of the water. The argonaut (fig. 9), credited in 

 poetry and fiction with this power, never floats on the surface, as was 

 of old believed. It is simply a mundane cuttlefish, whose two ex- 

 panded arms are never used as sails, after the popularly supposed 

 fashion, but are employed solely to secrete and attach to the body 

 the false shell (fig. 9, A) with which it is provided. Pope's advice- 

 Learn of the little nautilus to sail, 

 Spread the thin oar and catch the driving gale 



