REVIEWS 349 



In the chapter on Nutrition, it is a pity that the only method mentioned for the 

 measurement of photosynthesis should be the " bubbling method," for, in spite of 

 the obvious usefulness of this method as a demonstration, it is the most unreliable 

 of a number of methods which it is possible to employ. The statement (p. 104) 

 that the first step in photosynthesis is the breaking-up of the carbon dioxide 

 molecule and the separation from it of free oxygen is not founded on any reliable 

 experimental evidence ; it is simply a view which forms the basis of one group of 

 the hundred and more theories of carbon assimilation. The statement (p. no) 

 that glucose is probably the first product of photosynthesis is also only an 

 expression of personal opinion ; the experimental evidence on the point is not 

 clear, and the conclusions drawn by the experimenters themselves are con- 

 tradictory. And why does the author say that the process which he calls 

 " Photo-Synthesis " (an unusual way of writing the word) was formerly called 

 Assimilation ? The two recent workers who between them have been responsible 

 for the greater part of the work in this field are F. F. Blackman and R. Willstatter. 

 The former uses the term "Vegetable Assimilation" in the general title of all his 

 papers, and the latter invariably employs the term " Kohlensaureassimilation," and 

 this as recently as last year ! And why discard the modern word " protein " in 

 favour of the obsolescent " proteid " ? 



The book contains no more phylogeny than is necessary for a proper appre- 

 ciation of the problems of the plant, and a minimum amount of chemistry, although 

 there is an appendix dealing with vegetable foodstuffs. The absence of chemistry 

 is an advantage to the lay reader and to the elementary student who is also an 

 elementary student in physics and chemistry, but it should be understood that 

 no very deep appreciation of the life of the plant is possible without an adequate 

 acquaintance with those fundamental sciences. W. S. 



A Laboratory Guide for General Botany. By C. Stuart Gager, Director of 

 the Brooklyn Botanic Garden. [Pp. x + 206.] (Philadelphia : P. Blakiston's 

 Son & Co., second edition, 1919. Price $1 net.) 



THIS book contains directions for students taking their first course of botany in a 

 University. It is divided into two parts — one comprising Anatomy and Physiology, 

 the other Morphology and Life History. The directions are rather full, and 

 should train the student in powers of observation, and not merely in the acquisition 

 of a number of botanical facts. As in the author's Fundamentals of Botany, the 

 fact that the plant is a living organism solving the problems of existence in a 

 certain environment is never lost sight of. The book is for this reason, and for 

 the fullness of the directions, one of the best laboratory guides in general 

 botany that has ever appeared, and it is satisfactory that appreciation of it has 

 been sufficient to necessitate the appearance of a new edition. 



In the second part of the book, where the morphology and life history of types 

 rom different parts of the plant kingdom form the subject of study, more space 

 might be given to a consideration of algas. Thus, whereas one brown alga 

 (Fucus) and three green algae ( Vancheria, Spirogyra, and Pleurococcus) are 

 studied, no less than nine fungal types are dealt with. The reasons for the 

 arrangement adopted in this part of the book are not obvious ; for instance, why 

 should Pteridophyta follow Fungi, when the first type studied is one of the former? 

 This is, however, a very minor point, for the teacher can vary the order of study 

 of the different types without any trouble. 



W. S. 



