860 



SCIENCE 



LN. S. Vol. XL. No. 1041 



not be most wisely studied first, as they can be, 

 without extended reference to other parts of 

 the subject; and then knowing the raw mater- 

 ials with which forces and processes deal, the 

 student can most intelligently follow out the 

 various modifications produced upon them by 

 the geological agents. 



Professor Park does not take up rocks as ob- 

 jects in and of themselves, but views them as 

 products of geological processes. Thus, sedi- 

 mentary rocks are first outlined following the 

 introductory chapters already mentioned, and 

 even after joints, faults and cleavages have 

 been described. Igneous rocks are introduced 

 by a preliminary chapter on volcanoes and 

 volcanic action. Before the individual rocks 

 are taken up we find the topics — alteration, 

 magmatic differentiation and Atlantic and 

 Pacific types discussed, inevitably with the 

 use of rock names with whose significance the 

 student can not yet be familiar. In these par- 

 ticulars it seems to the reviewer that the nat- 

 ural order of treatment is reversed. 



A chapter on fossils and a following one on 

 conformity and unconformity lead up to the 

 great subject of stratigraphical geology which 

 forms Part II., and to which fifteen chapters 

 or more than one third the work are devoted. 

 One hails with satisfaction this recognition of 

 the great stratigraphical part of the subject, 

 by one who writes primarily for mining 

 schools. The tendency to minimize this enor- 

 mously important branch of the subject in 

 favor of purely structural and dynamic por- 

 tions has become pronounced in later days, and 

 yet mistakenly. The great conceptions of 

 older and younger strata, of succession in 

 time, of recognition by organic remains; of 

 the growth of land masses, are all fundamental 

 to the applications of the subject as well as to 

 its proper understanding. The treatment is 

 well balanced and the succession of living 

 forms is brought out by reasonably full num- 

 bers of illustrations. Sections are given for all 

 the better explored portions of the globe. 



Part III., Economic Geology, embraces two 

 very condensed chapters, one relating to min- 

 eral deposits of all kinds and one on the meth- 

 ods of field work and geological surveying. Be- 



sides two brief appendices on special field 

 methods, a condensed bibliography of geolog- 

 ical works, classified by subjects, is given at 

 the close of the work. All in all. Professor 

 Park's work is well written, interesting, and 

 will prove a serviceable text-book. 



J. P. Kemp 



BOTANICAL NOTES 



A STUDY OF A DESERT BASIN 



Several months ago there appeared from 

 the Carnegie Institution of Washington, as 

 " Publication No. 193 " an interesting paper 

 entitled " The Salton Sea," by Dr. D. T. Mac- 

 Dougal and his collaborators. It fills a 

 quarto volume of nearly two hundred pages, 

 and is illustrated by thirty-two full-page 

 plates, and four text figures. 



The whole book is full of interest to the 

 scientific reader, and especially to the geolo- 

 gist and geographer, as shown by the titles of 

 the chapters, " The Cahuilla Basin and Desert 

 of the Colorado " ; " Geographical Features of 

 the Cahuilla Basin " ; " Sketch of the Geology 

 and Soils of the Cahuilla Basin " ; " Chemical 

 Composition of the Water of Salton Sea. and 

 its Annual Variation in Concentration," etc. 

 Several of the chapters, including the major 

 part of the volume, are devoted to botanical 

 aspects connected with the formation and re- 

 cession of the limits of the Salton Sea. And 

 here it may be remarked that this sea is in 

 southern California, and occupies a portion of 

 a great desert depression of the earth's surface 

 below sea level. The sea was formed a few 

 years ago by an inrush of water from the Col- 

 orado River which flooded an area of over 

 four hundred square miles of the lower por- 

 tions of the Cahuilla Valley. Since then the 

 sea has been subsiding, and this fact has en- 

 abled the botanists to study the incoming veg- 

 etation under the peculiar conditions here 

 found. 



The distinctly botanical chapters are those 

 on the " Behavior of Certain Microorganisms 

 in Brine " ; " The Action of Salton Sea Water 

 on Vegetable Tissues " ; " Plant Ecology and 

 Floristics of Salton Sink"; "Movements of 



