58 NATURAL SCIENCE. j AN ., 



those with joined petals (Gamopetalae) to an apetalous division. 

 This is not the most scientific classification ; but, as the author's 

 aim is especially to spread a knowledge of those plants which 

 are useful from a horticultural or economic point of view, it 

 may answer the purpose. The brief introduction to the flower- 

 ing plants with which the first number opens gives a good idea 

 of the scope of the book. Characteristics which are evident or easily 

 to be understood by the fairly intelligent general reader are alone 

 put forward, though it is stated that these do not comprise the whole 

 story. It is accurate as far as it goes, and may very well 

 serve to excite an interest in plants where a more strictly scientific 

 account would only repel. The statement, however, that the stem of 

 the Rolang palm may reach a length of 300 metres needs, we believe, 

 confirmation. 



In the systematic portion the author gives, under each genus, a 

 good account of those species which are of general interest, either as 

 cultivated plants or otherwise. This account includes the characters 

 by which the plant can be distinguished from allied species, its geo- 

 graphical distribution, and its uses. Considerable help is afforded by 

 the illustrations, which are numerous and good and form a notable 

 feature on the whole. It is just the sort of book for people who take 

 an interest in plants and want to know a little about them without 

 going deeply into the scientific aspect of things. 



Plant Physiology. 



Practical Physiology of Plants. By F. Darwin, M.A., F.R.S., and E. H. 

 Acton, M.A. 8vo. Pp. xviii., 321, with illustrations in the text. Cambridge : 

 Published at the University Press, 1894. Price 6s. 



Mr. Shipley has been fortunate in securing so sorely needed and 

 excellent a practical manual for the biological series which the 

 syndics of the Cambridge Press are issuing under his supervision. 

 In olden times the botanical student gathered plants, learned to 

 examine their floral structure, and to determine their position in a 

 systematic classification. In more modern times he learned to cut 

 sections and study the internal structure of plants which he usually 

 did not gather, but found embalmed in spirit on the laboratory 

 shelves. Within the last few years he has, here and there at well- 

 equipped scientific centres, learnt to investigate the processes under- 

 lying the actual life of a plant, and of which life is but the expression. 



The little manual now to hand will be welcomed by all exponents 

 of the last-mentioned phase of botanical study and investigation. It 

 is an extension and elaboration of the written instructions prepared 

 by the authors for use in their respective classes, and contains, 

 therefore, such a selection of experimental and analytical work as can 

 be carried out by botanical students under the supervision of a 

 competent demonstrator. The latter will be found a necessity, as 

 the directions for experiments frequently assume a certain knowledge 

 of manipulation and method which the student will in many cases not 

 possess. The unpretending but clear illustrations will afford no little 

 assistance in the arrangement of apparatus. 



The book is divided into two parts. Part i., which deals with 

 general physiology and occupies two-thirds of the whole, recalls 

 Mr. Darwin's elaborate lecture demonstrations. It includes direc- 

 tions for an exhaustive series of experiments, 265 in number, on 

 respiration, assimilation, nutrition, transpiration, growth, and move- 

 ment. Part ii., on the chemistry of metabolism, is a practical study 



