HISTORICAL SKETCH OF DEEP-SEA WORK. -tl 



These results were abundantly confirmed subsequently by the 

 rich collections made by Professor Giglioli in the " Washington" 

 (Captain Magnaghi), sent out by the Italian Government to ex- 

 plore the depths of the Mediterranean. While the deep-water 

 species of the Mediterranean are, without exception, also found 

 in the abyssal region of the Atlantic, it is also true that the 

 Mediterranean contains only such deep-water species as can bear 

 a somewhat high temperature. We may consider that all en- 

 closed seas like the Sidu Sea, or inland seas like the Mediter- 

 ranean, the Red Sea, the Caribbean, and Gulf of Mexico, have 

 received their fauna from the adjoining oceans. When from 

 some cause or other the colder water of the great depths was 

 shut out from a free circulation, only such species as were capa- 

 ble of living in a comparatively high temperature survived. 

 The fact that in the Mediterranean we find fossil Arctic forms, 

 such as occur in the glacial deposits of England and Sweden, 

 and are still found in the Italian pliocene deposits, shows plainly 

 that the temperature of the Mediterranean must have been dif- 

 ferent in former geological times from what it is now. 



While naturalists were discussing- the absence of animal life 

 below three hundred fathoms, Portuguese fishermen were taking 

 deep-sea sharks from nearly five hundred fathoms, and bringing 

 up occasionally a glass sponge (Holtenia) on their lines. Japan- 

 ese fishermen had also been catching a very similar shark in 

 three hundred fathoms, often drawing up with it a Hyalonema 

 which found its way to Europe as a great curiosity of Japanese 

 art. No attention was paid to the existence of the many ani- 

 mals which from the end of the last century were shown to live 

 at great depths. Indeed, the occurrence of animal life in the 

 deeper waters of the ocean seemed to produce no impression on 

 scientific men, although in deep water on the two sides of the 

 northern part of the Atlantic, a number of species of fishes, 

 which could only subsist on animal life, were constantly caught, 

 thus plainly proving the existence of a varied animal fauna at 

 those depths. No attention was paid to the early observations 

 of Sir John Ross (1818) in Baffin's Bay where, at the depth of 

 between 800 and 1,000 fathoms, a fine Astrophyton was brought 

 up on the sounding line. The extensive collections made by 



