June 17, 1922] 



NATURE 



in 



a student to acquire a first-hand knowledge of minerals 

 and their distinguishing characters and ultimately a 

 facility in identifying the commoner species at sight. 

 There is a general classification occupying more than 130 

 octavo pages based on physical characters, especially 

 streak, colour, and hardness, in the order named. 

 After a rather full account of blow-pipe and other 

 convenient chemical tests, including some which are 



lot commonly employed in this country, there is 

 ; mother classificatory table of 70 pages constructed to 

 assist in the identification of minerals by this means. 

 This is followed by a third table based on the crystalline 

 system and hardness. Perhaps greater stress might 

 have been laid on specific gravity, the determination 

 '^{ which is frequently one of the most rapid means 



if "running down" a doubtful mineral. Also no 

 iiiention is made of the use of a permanent horseshoe 

 magnet with special adjustable poles by the help of 

 which the comparatively weak magnetic character of 

 minerals like monazite can be easily recognised even in 

 the field. J. W. E. 



(1) Botany j 07 Students of Medicine and Pharmacy. By 

 Prof. F. E. Fritch and Dr. E. J. Salisbury. Pp. 

 xiv + 357. (London : G. Bell and Sons, Ltd., 1921.) 

 10s. 6d. net. 



(2) Junior Botany. By T. W. Woodhead. Pp. 210. 

 (Oxford : Clarendon Press, 1922.) 3^. 6d. net. 



(3) The Elements of Vegetable Histology. By Prof. C. W. 

 Ballard. Pp. xiv + 246. (New York: John Wiley 

 and Sons, Inc. ; London : Chapman and Hall, Ltd., 

 1921.) i8s. net. 



(i) Prof. Fritch and Dr. Salisbury have prepared 

 an elementary text-book, which is stated in the 

 preface to be for the use of students of medicine 

 and pharmacy. A large number of new figures of 

 plant structures are produced, and many of them 

 will form a useful addition to botanical illustration. 

 A few, however, such as Figs. 69 and 71, are too 

 diagrammatic, sketchy, or ragged to be desirable for 

 elementary students, and of course they are of no 

 use for any other purpose. The book begins with the 

 plant as a whole, using the Shepherd 's-purse as type. 

 It goes on with several chapters on the various plant 

 organs and their functions. The chapter on plant cells 

 concludes with an account of protoplasm in colloidal 

 terms. Growing points, tissues, cell contents, and the 

 structure of roots, stems, and leaves are then carefully 

 treated, followed by physiology and the study of types. 

 The book ends with a chapter on heredity and evolu- 

 tion, and an appendix dealing with reagents and 

 methods. It covers adequately the syllabus for medical 

 students and is one of the best we have seen for this 

 purpose, but it is questionable if a somewhat more 

 biological and scientifically imaginative treatment of 

 the subject would not be to the advantage of elementary 

 liotanical teaching. 



(2) The second volume under notice is a neatly pro- 

 duced little book of more elementary character, and 

 well illustrated, the 140 figures being new with one 

 exception. It begins with a chapter on the garden 

 stock, followed by condensed treatment of seeds and 

 germination, roots and their function, the shoot and 

 its physiology, hibernation and movement in plants. 

 The second part deals with the structure and biology 



NO. 2746, VOL. 109] 



of the flower, including pollination, fruits, dispersal, etc. 

 Every beginning student would find it useful, particu- 

 larly for its studies of flowers and fruits, and the price 

 is very moderate. 



(3) The only features we can recommend in Prof. 

 Ballard's book are the paper and binding, and the first 

 and the last chapters, dealing with the structure and 

 use of the microscope and its accessories. The body 

 of the work is too crude, even for the pharmacy students 

 for which it is intended, to deserve the name of botany. 

 A single quotation from p. 122 will be sufficient to 

 indicate how many errors can be packed into one 

 sentence. " Communication between the various cells 

 forming a tracheid is effected by means of pores in the 

 vessel walls." The illustrations can only be character- 

 ised as for the most part very poor. Fig. 29 is intended 

 to illustrate mitosis, and is stated to be " modified " 

 from Strasburger's text-book. The drawings are almost 

 caricatures. They show centrosomes where none exist, 

 and the name " polar bodies " is given to them ! It is 

 a disservice to botanical science to publish a book of 

 this character. R. R. G. 



The Autonomic Nervous System. By Prof. J. N. 



Langley. Part 1. Pp. viii + 80. (Cambridge : W. 



tleffer and Sons, Ltd., 1921.) 55. net. 



The present small volume gives a very useful summary, 

 clearly and concisely written, of the present position 

 of our knowledge of the subject of which it treats. 

 The author divides the peripheral nerves into somatic 

 and autonomic, and the latter into sympathetic 

 (thoracico-lumbar, to all regions of the body), enteric 

 (plexuses of Auerbach and Meissner), and para- 

 sympathetic, which is again divided into tectal (or 

 ocular, supplying the sphincter of the iris and the 

 ciliary muscle), bulbar (alimentary canal from nose 

 and mouth to large intestine, with appendages, in- 

 cluding the lungs), and sacral (lower part of large 

 intestine, bladder, and external genitals). The several 

 chapters deal with the divisions of the autonomic 

 system and nomenclature ; the general plan of origin 

 and of peripheral distribution ; the nerve fibres of the 

 autonomic system ; the specific action of drugs on 

 the sympathetic and parasympathetic systems ; and 

 the tissues innervated. Each chapter is followed by a 

 bibliography of important papers and by a series of 

 notes. 



First Course in the Theory of Equations. By Prof. 

 L.E.Dickson. Pp. vi+i68. (New York : J.Wiley 

 and Sons, Inc. ; London : Chapman and Hall, 

 Ltd., 1922.) 2>s. 6d. net. 

 The introduction to the Theory of Equations contained 

 in this volume is wide enough to cover the needs of 

 all except those who aspire to become mathematical 

 specialists. The methods throughout are strictly 

 elementary, the treatment reaching the algebraic 

 solution of cubic and biquadratic equations without 

 any reference to substitutions or group-theory. Useful 

 chapters on determinants and elimination are in- 

 cluded, while another one deals with elementary 

 properties of symmetric functions. The book contains 

 a severe course of computation within the scope of 

 its subject-matter, and a considerable proportion of 

 the abundant examples are numerical in character. 

 Two subjects avoided by most writers of elementary 



