132 THE JOURNAL OF BOTANY 



continual motion, its entrances and its exits, and its consequent 

 influence on the habit of plants — here suffers in a similar way. 

 So, again, with photosynthesis ; the immense part played by the 

 green plant as the entrance-door of the sun's radiant energy into 

 the organic world is unrevealed. 



The cliapter on Ecology has been added, doubtless to meet the 

 requirements of the examinee. In this difficult field, where broad, 

 vital, scientific principles are essential to the appreciation of the 

 barest rudiments of the subject, we look vainly in chapter xviii. 

 for any boldness in the display of those principles. Test questions 

 129 and 130, beginning respectively " Enumerate the . . . plants 

 . . ." and " Write a list . . ." are significant: we should regret to 

 find such in a public examination. The reader gains either a very 

 misty idea, or none at all, of the plant association, that funda- 

 mental consideration which lies at the very root of truly scientific 

 ecology ; plant societies are named, but left undefined ; the 

 formation, the expression of the organic succession of associations 

 within a uniform habitat, is not even mentioned. In this section 

 the tutor, with whom we found that we could dispense in the 

 study of morphology, will be needed sorely. 



The systematic botany is dealt with in two portions isolated 

 from each other and from the account of floral morphology ; this 

 is in keeping with the tendency to mechanical treatment which 

 is to be deplored throughout the book. The description of the 

 "horizontal" floral diagram is clearly portrayed; but the all- 

 important longitudinal section of the flower, showing the relation 

 of floral parts to the receptacle, that great factor in classification, 

 is left practically unnoticed. 



This text-book will teach the student many facts, but it will 

 not make him think : if public examinations are to be memory- 

 tests, the author will have rendered great service to a large and 

 growing public — the examinee. HEW 



Contrihiizioni Diatoniologiche, ix-xi. Achille Forti. Venezia, 

 1910. Atti del Eeale Istituto Veneto di Scienze, Lettere ed 

 Arti. Anno acad. 1909-10, tom. Ixix., parte seconda. 

 This publication is a continuation of the excellent series of 

 contributions on Diatoms which have emanated from Dr. Achille 

 Eorti during the past few years. No. ix. is. a most exhaustive 

 account of the genus Cerataulus, in which the author summarizes, 

 with copious critical notes, all that is known concerning the 

 systematics and geographical distribution of this rare genus. No. 

 X. is an account of a number of recent and subfossil Diatoms from 

 Abyssinia. No. xi. is an extensive list of Diatoms found in certain 

 calcareous tertiary deposits at Bergonzano and Marmorito, in 

 Italy. The three contributions are illustrated by nine photo- 

 graphic plates of very great merit, which add materially to the 

 value of the work. All scientific students of Diatoms will welcome 

 further contributions from the same author. ^ q Wparp 



