LIFE S BORDERLANDS 249 



in very deep water, bringing up the bottom animals living on the 

 sea floor 17,400 feet, or three and a third miles, below the sur- 

 face in a perpetual winter night where the unchanging tem- 

 perature was 35.3° F. At this depth the pressure is about 535 

 atmospheres, or roughly four tons to the square inch; which 

 means that if you could put your hand into this water it would 

 be instantly crushed by a pressure of over 100 tons, the weight 

 of a good sized locomotive; or that if you fell overboard here 

 and sank to the bottom, escaping the attentions of the sharks 

 on the way, you would finally come to rest under a pressure of 

 7,490 tons. 



Exclusive of the minute animals called protozoans there were 

 found in the net over 70 specimens of fishes and invertebrates, 

 representing 32 different kinds, including 5 kinds of bivalve mol- 

 luscs, 4 of sea-anemones, 3 of star-fishes, 3 of worms, 3 of sea- 

 cucumbers, a shrimp-like animal, a sea-urchin, a sea-lily, a coral, 

 a brachiopod, an antipatharian, and a hydroid, all of which 

 there is not the slightest doubt were living on the bottom. 



Rivers and most lakes are fresh and the sea is salt, and we all 

 know that in both salt and fresh water fishes and numerous 

 other living things abound. There are, however, certain lakes, 

 like the Dead Sea, the Great Salt Lake, and Mono and Owen's 

 Lakes in California in which the water contains much more 

 solid matter in solution than does the water in the sea. In the 

 shallow artificial ponds called brine pans where salt is extracted 

 from sea water by natural evaporation the density of the brine 

 of course is very high. 



Can anything live in water so saturated with salt that the 

 salt is crystallizing out? The brine-shrimps are happy nowhere 

 else. These dainty and delicate little creatures are exceedingly 

 abundant in Mono and Owen's Lakes, in the Great Salt Lake, 

 in the Dead Sea, and in many brine pans all over the world. 

 They will thrive in water with a salt content of 271 grammes 

 per liter and with the color and consistency of beer. They will 

 also live at rather high temperatures, and are found abundantly 

 in water of 80° and over. In the Great Salt Lake their food 



