124 THE BOTTOM OF THE SEA. 



seems to us brown, lustreless, and uniformly dull when 

 we observe it by the light of day, acquires in the 

 abysses of the Ocean tliose rich tints and phospho- 

 rescent gleams with which the Arab story-tellers 

 liave glorified their dreams of fairyland — and you 

 will have a faint idea of the wonderful spectacle 

 presented by the Ocean to the diver who dares to 

 brave the innumerable dangers of a submarine ex- 

 cursion ! 



2. Migration of Marine Animals — Nests at the Bottom of the Sea — 

 Fisheries. 



In all ages man has derived instruction from the 

 observation of nature. The sea above all has sharp- 

 ened his intelligence, and therefore we are not sur- 

 prised to l-e told that the nautilus or argonaut, one 

 of the oldest-known of marine animals, has the 

 credit of having taught him navigation. The species 

 which inhabits the Mediterranean {Argonauta Argo) 

 must in former days have been more widely diffused 

 than at present. It is now found only in tlie better 

 sheltered latitudes — the Archipelago, the Adriatic, 

 and the Straits of Messina. On a beautifully fine day, 

 when the air is serene and the sea tranquil, the 

 elegant shell of the argonaut may be seen floating 

 on the water, which it navigates by means of a 

 locomotive tube, and by spreading to the wind two 



