16 BOOKS AND CURRENT LITERATURE 



cal activity seems to depend upon the presence of certain bacteria, 

 some of which were isolated. Jones confirm this conclusion by show- 

 ing that both now and in the past the Salton tufas have been deposited 

 only in the presence of algae. The presence of minute organism, is 

 probably of much more importance chemically than has commonly 

 been realized. In this respect and in other ways this monograph on 

 The Salton Sea is likely to prove of great value in stimulating new 

 lines of thought. — Ellsworth Huntington. 



The Salton Sea: Floristics and Ecology. — The papers of Parish 

 and MacDougal occupy more than half of the Salton Sink volume. 

 They give, detailed and in broad lines, answers to many questions of 

 great interest concerning desert vegetation as a whole, the biology, 

 dispersal and wandering of its plants, the relation of a sink to sur- 

 rounding elevated land masses and especially concerning revegetation 

 of bared land, the means which enable plants to get a foothold and the 

 causes which make them again disappear. The latter part of the book, 

 MacDougal's treatment of the revegetation of the beaches, is the prin- 

 cipal one, giving as it does a vivid picture of movement and activity 

 in nature under almost unique conditions. 



The paper of Parish shows us, as it were, the stage upon which the 

 play is performed, or the ordinary order of things undisturbed. So 

 we learn that the Salton Sink with its Atriplex vegetation is bordered 

 on both sides by zones of more or less related vegetations of which 

 the Opuntia zone is especially interesting, showing the curious feature 

 of cacti living on the rim of the Sink without entering it. 



The Sink flora of which a very careful list is given, numbering 200 

 species, including sporophytes, is a part of the Colorado desert flora 

 which is the western fringe of the arid lower Sonoran flora; from the 

 southeast to the northwest species drop out successively, so we under- 

 stand that the conditions of the Sink are very exclusive; only 122 

 species are indigenous. These are tabulated with regard to ecological 

 classes, 51 are annuals, 30 perennial herbs, 23 shrubs, etc., numbers 

 which indicate desert conditions, as emphasized elsewhere by the pres- 

 ent writer. 



The factors in control of distribution are the chemical and physical 

 character of the soil and especially its water content; of the formations 

 accordingly established by Parish the xerophytic formation occupies 

 an area exceeding the combined areas of all the other formations; its 

 main plants are: shrubby Atriplices, Prosopis, Cercidium, Parasela, 



