414 



THE POPULAR SCIENCE MONTHLY 



Saltorn at Bottom of Salton Sink in the Cahuilla Basin, February, 1903. 



the pools around San Francisco Bay, 

 with a view to anticipating events in 

 the slower concentration of the Salton, 

 which has now reached a stage of 

 slightly more than one per cent, brine. 

 It is eloquent of the arid conditions 

 of the Cahuilla that the sink, or the re- 

 gion formerly occupied by Blake Sea, 

 with an area of over two thousand 

 square miles, bears only 8 species of 

 trees, 33 shrubs and woody plants, and 

 81 herbs, or a total of 122 species, about 

 the number that might be expected in a 

 square mile in the Mississippi Valley, 

 or on the eastern sea-board. Small as 

 this number may be, the stage seems + o 



le set for the appearance of new ones, 

 as evidenced by the number of endemic 

 forms. Striplex Saltonensis, Sphceral- 

 cea orcuttii, Crypt anthe costata, As- 

 tragalus limatus, A. aridus and Clue- 

 mctisyce Saltonensis occur so far as 

 known in this sink, which must have 

 been occupied by Blake Sea within four 

 or five centuries. That they have ever 

 lived elsewhere or before this can not 

 be demonstrated, and their occurrence 

 suggests most strongly a recent local- 

 ized origination. The modifications in 

 Aster exilis, Prosopis glandulosa, Stri- 

 plex canescens, and Scirpua paludosus 

 shown by individuals on emerged 







.»•'** 



• 



Rank of Vegetation at Upper Margin of Terrace Formed by Recession of Salton 



Lake During 1911. 



