BOOKS AND CURRENT LITERATURE 



Experimental Results in Plant Physiology. — A recent book^ 

 offers to "senior students and investigators" some of the results of 

 experimentation ''in a few of those branches of plant physiology which 

 are at present attracting attention." The subjects included are: Car- 

 bohydrates in the plant kingdom in relation to photosynthesis, respira- 

 tion and translocation; Pectic substances; Osmotic pressure and per- 

 meability of organic septa, including protoplasm; Electrical conductiv- 

 ity of plant tissues; Functions of wood; Plant oxidases and their 

 relation to pigmentation, pathology and technolog3^ The number of 

 titles included in the bibliography totals nearly four hundred and "a 

 small amount of hitherto unpublished work has also been included." 



Turning first to the selection of material, it should be noted that the 

 author does not present these subjects from a conviction that they 

 are the most important of the recent work in plant physiology. He has 

 restricted himself to those enumerated "on account of his first-hand 

 knowledge of many of the processes employed." The purpose is 

 excellent *and, although the lack of unity evident in the table of contents 

 might perhaps be adjudged undesirable, the readers for whom the 

 book is intended will undoubtedly not consider this as a serious fault. 



It is difficult, however, to see the value of that portion of Chapter V 

 that deals with the quantitative laws of osmotic pressure. Its presence 

 is not in keeping with the author's general purpose and is not to be 

 expected after reading that "matter already to be found in text books 

 has been almost entirely excluded." It is not an instructive discussion 

 of the quantitative laws of osmotic pressure because it is limited to the 

 statement of but one expression (applicable only to ideal solutions) 

 and to the enumeration of the assumptions necessary to derive the 

 van't Hoff equation from it. Even in this narrow field it is incomplete 

 and misleading. The reasoning upon which the equation is based is 

 omitted and with it the educational value of the expression itself. The 

 equation is stated to be "the most generally applicable," whereas it can 

 only apply to an ideal case, and is accordingly of so exceedingly re- 



1 Atkins, W. R. G. Some Recent Researches in Plant Physiology, pp. 328 

 figs. 28. London, Whittaker and Company, 1916 ($2.40). 



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