LIFE IN THE OCEAN CLARK 393 



ing distance from the shores is that the nutritive material brought 

 to the sea by rivers and washed from the land by rain upon which 

 the plants subsist is most abundant here. On very precipitous 

 coasts the detritus from the seaweeds falls into deep water and adds 

 to the food supply of the deep-sea creatures, which elsewhere is 

 derived only from the remains of oceanic organisms. 



The ocean's deepest spot is 40 miles east of Mindanao, in the 

 Philippines, where a depth of 6.08 miles (32,113 feet, or 5,352 

 fathoms) has been determined. 1 



No animal life is known from such a depth as this. The animal 

 from the greatest depth so far recorded is a fish (Grimaldichthys 

 profondissimus) which was brought up from 19,806 feet, or 3% 

 miles, beneath the surface in the north Atlantic by the late Prince of 

 Monaco. Many other things, of course, must live at this depth also 

 for this fish to feed upon. It is perhaps worthy of remark that a 

 fish of the same type, a so-called brotulid, lives in fresh water in 

 the caves of Cuba. 



It was once thought that the abysses would contain many relics 

 of past ages which had become extinct along the shores. But sur- 

 prisingly few such relic types have come to light, and there are not 

 nearly so many of them in the deep seas as are to be found along the 

 shores and in fresh water. 



Of all the animals of the ocean floors the mud-swallowing echino- 

 derms are perhaps the most abundant and diversified and the most 

 generally distributed; but all the groups represented also occur 

 in shallow water except for a small number of minor types. The 

 most conspicuous of these echinoderms, because most strange to us, 

 are bizarre sea-cucumbers and starfish, and soft and flexible shelled 

 urchins. Stalked crinoids rooted in the ooze or firmly attached 

 to stones or other objects are characteristic of the deeps, but all the 

 groups represented, like all of those to which the more abundant un- 

 stalked forms belong, come up into shallow water, with possibly one 

 exception. The crinoids most important from the paleontological 

 viewpoint, the Pentaorinus of our textbooks, and the curious Holo- 

 pus, so far from being deep-sea animals, live, at Barbados, in 30 

 feet or less, so that they can be seen from the surface with a water 

 glass. 



Sponges with silicious skeletons are often very abundant in the 

 deeps, especially near land. One of the chief trials of a deep-sea 

 naturalist is sorting over a catch with these things in the mud. Their 

 spicules are sharp as needles, glassy, and transparent, and scattered 

 everywhere, so that the sight of sponges always means sore hands. 



1 On September 1, 1924, a new " deep " was reported 145 miles southeast of Tokyo. A 

 sounding here by the Japanese steamer Manshu gave 6.18 miles (32,636 feet, or 5,430 

 fathoms) . 



