REVIEWS 513 



The book is divided into two parts — the first dealing with the morphology and 

 physiology of the flowering plant, the second with the different types of plants 

 met with throughout the vegetable kingdom. Questions of classification and 

 genetics are included in the second part. 



It is usual to commence a treatment of the general morphology and physiology 

 of the flowering plant either with a description of the seed or with that of the 

 adult sporophyte. Our author, however, commences with the flower. As this is 

 in many respects the most complex of plant organs, one feels a certain prejudice 

 against commencing the study of the plant at this point in the life cycle, though 

 there is no logical reason why any particular point in the life cycle of the plant 

 should not be used as a starting-point for its study. 



The book is not by any means overloaded with anatomy, emphasis being 

 rather laid on the biological and physiological sides of the subject. This is all 

 to the good in an elementary text-book on botany, especially one that is intended 

 for the use of agricultural students. 



A few of the statements on physiological matters are not altogether satisfactory, 

 as for instance the statement that " There are various kinds of sugar, but there 

 is considerable evidence that grape sugar, having the formula CeH^Oe, is the 

 chief one formed in leaves. From this sugar as a basis other kinds of sugar, of 

 which cane sugar (Ci 2 H 22 0ii) is a common one, can be formed by minor chemical 

 changes." 



The wealth of illustrations, of which there are 488, adds to the value of the 

 book. If these illustrations are not in all cases of high technical quality they 

 are nearly always clear. The insertion of some of them seems scarcely necessary, 

 as for instance that of a chickadee carrying a fruit in its beak and that of a cow's 

 tail loaded with weeds. Even a first-year student in agricultural botany ought to 

 be capable of visualising these without the aid of illustrations. 



W. S. 



The Preparation of Substances important in Agriculture : A Laboratory 

 Manual of Synthetic Agricultural Chemistry. By Charles A. Peters, 

 Ph.D. Third Edition. [Pp. vi + 81.] (London: Chapman & Hall; 

 New York : John Wiley & Sons, 1919. 4s. net.) 



A KNOWLEDGE of the composition of the more important substances employed 

 in agriculture and of their modes of preparation is almost essential both to their 

 intelligent use and a proper recognition of their qualities and commercial value. 

 The volume before us aims at supplying this information to the agricultural 

 student by means of a series of laboratory exercises in the preparation of super- 

 phosphate, sulphate of ammonia, potassium salts, lead salts, Bordeaux mixture, 

 etc. For each substance the chemical nature of the steps involved is explained, 

 together with notes on special points and the practical applications. 



Questions are added which should help to impress the salient facts upon the 

 student, whilst the practical* work itself is so arranged as to furnish an exercise 

 in some of the more important chemical principles. 



To English and many American readers the use of simplified spelling will 

 prove a hindrance rather than a help ; but the fact that Prof. Peters' work has 

 already reached a third edition is a testimony to its practical utility. 



E. J. S. 



