Botany. 91 



1. An Amateur 's Introduction to CrystallograpJiy ; by Sir 

 William Phipson Beale. Pp. vi, 220, figs. 126. London, 

 1915 (Longmans, Green and Co.). — This book, as its title indi- 

 cates, is intended for the use of the non-scientific reader but is 

 nevertheless quite scientific in its treatment. By a somewhat 

 novel method the subjects of crystal axes, indices and symmetry 

 are introduced and illustrated. A brief discussion of the differ- 

 ent crystal classes follows. In appendices more detailed descrip- 

 tions of the methods of crystal calculation and drawing are given. 

 The book is well illustrated. w. e. f. 



8. Die 82 kristallographischen Symmetriehlassen und ihre 

 einfachen Formen ; by E. A. Wolfing. Pp. 48, figs. 260, pis. 

 viii. Berlin, 1914 (Gebriider Borntraeger). — This is a second 

 edition of the work, the first having been issued in 1895. The 

 text, now added to the original work, includes brief discussions of 

 crystal symmetry, the division of crystal forms into the thirty- 

 two classes and of the simple forms characteristic of thtse classes. 

 The tables, which are bound up separately in a small atlas, illus- 

 trate diagrammatically the matter of the text. w. e. f. 



9. Annual Tables of Constants and Numerical Data. Chem- 

 ical, Physical and Technological. Vol. iii. Chapter on Crystal- 

 lography and Mineralogy, pp. 425-446 ; by L. J. Spencer. Pub- 

 lished by Gauthier-Villars et Cie, Paris and the University of 

 Chicago Press, Chicago, 1914. — This is a single chapter of an 

 important scientific publication designed to summarize yearly 

 the new data of physical science. The present volume, No. 

 Ill, covers the year 1912. The mineralogical chapter gives 

 in brief form new mineral analyses, new crystal forms and axial 

 ratios, new determinations of optical constants, of specific gravi- 

 ties, etc. It summarizes also the crystallographic and optical 

 work done on artificial inorganic and organic compounds. 



"W. E. F. 



II[. Botany. 



1. Transpiration and the Ascent of Sap in Plant; by 

 Hexry H. Dixon. Pp. viii, 216, :J0 figs. London, 1914 (Mac- 

 millan and Co.). — The valuable and original researches of Professor 

 Dixon on the complex phenomena connected with the movement 

 of sap in plants are here brought together in connected form. 

 He looks upon transpiration as something more than a mere phys- 

 ical process and considers that an active excretion of water by 

 the green cells is involved. In this way a high osmotic pressure 

 is developed in the cells, sometimes amounting to over 20 atmos- 

 pheres. He considers further that a continuity is maintained 

 between the liquids in the green cells and those in the absorbing 

 cells of the root by means of the liquids in the tracheids and 

 other conducting elements of the stem and root ; and he lays a 

 great deal of emphasis on the cohesive or tensile strength of this 



