life's borderlands 251 



consists of the smaller fragments of brownish simple plants 

 called algae which are very common in this salt-laden water. 



In our western saline lakes, at least in Mono and Owen's 

 Lakes, the only other visible inhabitants are the young of the 

 Ephydra Ihes which, as already described, are so greatly es- 

 teemed by Indians as food. It is these brine-shrimps and the 

 Ephydras that attract the myriads of gulls and other water 

 birds so often seen about these salt lakes and ponds. 



In the spring time in our woods and on our plains we often 

 see more or less extensive pools and ponds which disappear 

 later in the season. In such ponds the fairy shrimps, close 

 relatives of the brine-shrimps, are often abundant, swimming 

 slowly about back downward. Here in these isolated temporary 

 ponds they are quite safe from fish or other water creatures, 

 though not from birds. Their life is short and they soon disap- 

 pear, but not before sowing the bottom with great numbers of 

 their eggs. When the pools dry up these eggs mingle with the 

 dust and by the summer winds are blown about. In winter 

 they are frozen in the snow and ice. But in spite of the drying 

 and the freezing and the rough treatment by the summer winds 

 when spring comes once more they hatch and for a few weeks 

 we see again the fairy shrimps. 



Other kinds of fairy shrimps are abundant in the Arctic re- 

 gions ever>^here in the ponds and tundra pools, swimming 

 about for a few weeks in the short Arctic summer, but spending 

 most of the year as eggs in the frozen ground. 



Caves, far underground, often contain pools and ponds and 

 sometimes streams of considerable size. In such waters, always 

 beautifully clear and quiet, there live many strange creatures 

 as uncanny as their surroundings. The most conspicuous of 

 these are ghastly white or slightly pinkish fishes without eyes, 

 of several kinds, and similarly ghostly salamanders. In our 

 American caves there are found half a dozen or more crayfish or 

 crayfish-like things, all without eyes but with the eye stalks 

 remaining. About half of our fresh water amphipods or Sand 

 fleas live in caves or wells or springs, and many of them are 



