Auausr 20, 1909] 



SCIENCE 



245 



fined gold of royalty. But a man so generally 

 popular as Dr. Gill gets all the praise that is 

 good for him, anyway; so it may be observed 

 that there are some things in which this book 

 may yet be improved. The illustrations are 

 better than none, but not much ; and the direc- 

 tions for using flash-test apparatus are not 

 quite as complete as a beginner ought to have. 

 It should always be remembered that a metal- 

 lurgical or cement chemist, for example, 

 skilled in using ordinary apparatus, may 

 know nothing at all about a flash-test; and it 

 is in little details that the manipulation of 

 the expert excels and has its greatest value. 

 In most cases the directions given in this book 

 are full and clear. 



The inclusion of refractive indices would 

 probably be generally approved, since the re- 

 fractometer has come into general use. In 

 general, the book would be better if there were 

 more of it; and while its value is partly due 

 to leaving out information not useful to the 

 analyst, some further remarks as to the nature 

 of the varioiis oils, as well as to changes pro- 

 duced by reagents, from one so experienced 

 as the author, would be of much use to the 

 student. 



Somewhat more than half of the book is 

 given to physical and chemical tests; then 

 there are descriptions, including preparation, 

 uses, tests and constants for the chief petro- 

 leum products, for seventeen vegetable and 

 nine animal oils, and certain waste fats and 

 greases. There is an appendix of tables and 

 other information. The book has been largely 

 rewritten and has a good index; it appears to 

 be free from typographical errors. 



A. H. Sabin 



SCIENTIFIC JOURNALS AND ARTICLES 

 The American Naturalist for May presents 

 two papers, and notes : " The Categories of 

 Variation," by S. J. Holmes, in which the 

 author discusses the differences between fluc- 

 tuating variations and mutations; going to 

 some length in the analysis of elementary 

 species, retrograde varieties and fluctuations, 

 as distinguished by De Vries ; with the general 

 conclusion that the evidences, so far presented. 



do not sufficiently distinguish between un- 

 stable mutations and fluctuations. " The Gen- 

 eral Entomological Ecology of the Indian Corn 

 Plant," by S. A. Forbes. " Notes on Some 

 Kecent Studies on Growth," by Eaymond 

 Pearl ; " Cuenot on the Honey-bee," by T. H. 

 Morgan; "Poulton and Plate on Evolution," 

 by V. L. E:[ellogg]. 



The American Naturalist for June presents 

 four papers, and notes: "Heredity and Varia- 

 tion in the Simplest Organisms," by H. S. 

 Jennings. " The Color Sense of the Honey- 

 bee: is Conspicuousness an Advantage to 

 Flowers " ? by John H. Lovell ; with the ad- 

 duced evidence that the query is to be an- 

 swered affirmatively. " Variation in the Num- 

 ber of Seeds per Pod in the Broom, Cytisus 

 scoparius," by J. Arthur Harris. His con- 

 clusion is that for this species variability due 

 to habitat is not more noticeable where it is 

 introduced than where it is native. " Present 

 Problems in Plant Ecology." These are pre- 

 sented in two articles read before the Bot- 

 anical Society of America at the Baltimore 

 meeting, 1908: (1) "The Trend of Ecology," 

 by Henry C. Cowles, and (2) " Present Prob- 

 lems of Physiological Plant Ecology," by Bur- 

 ton E. Livingston. Under " Notes and Lit- 

 erature " V. L. K. makes note, under the head- 

 ing of Evolution, on the retirement of Ernst 

 Haeckel from his chair in the University of 

 Jena, with emphasis upon the establishment 

 and care of his new Phyletic Museum. He 

 also notes the recent German discussion of 

 mechanical versus vital basis for explaining 

 phenomena of nature. George H. Shull notes 

 the literal translation into French of Hugo 

 De Vries's " Species and Varieties : their Or- 

 igin by Mutation." J. F. McClendon presents 

 a note on " The Totipotence of the First Two 

 Blastomeres of the Frog's Egg." 



SPECIAL ARTICLES 



ON THE CONNECTION BETWEEN STIMULATION 



AND CHANGES IN THE PERMEABILITY OF 



THE PLASMA MEMBRANES OF THE 



IRRITABLE ELEMENTS 



EwDENCE of a varied and highly conclusive 

 kind now exists that the phenomena of stimu- 



