TEXT-BOOK OF BOTANY. 279 



some respects unique. Morphology, physiology or the principles of 

 classification, are each one man's work, and the subdivision of 

 labour on these lines is the most important characteristic of the 

 book. The name of Strasburger is a household word among 

 botanical students ; in the opinion of many, what was left undone 

 by Sachs was done by Strasburger, and his name on the title-page 

 will be a great attraction. He is responsible for the section on 

 morphology, which is the best introduction to this branch of the 

 science, or to botany as a whole, which could be put before an 

 advanced student. The account, for instance, of the leaf (pp. 28, 29) 

 is remarkably concise and free from technical terms, but never- 

 theless conveys just the right idea of what a leaf really is. The 

 stelar hypothesis is lucidly explained and at sufficient length 

 relative to its importance, but no mention is made of the polystely 

 which has been found to exist in roots of certain palms. The 

 references to phylogeuy and ontogeny and the concluding paragraph 

 on structural deviations, with the salutary warning against accepting 

 malformations as evidence in morphology, are of interest, and help 

 to vivify the oftentimes dry facts of form-study. 



Dr. Noll's contribution, the section on Physiology, comes next, 

 and is a very fair general account of the life-processes in plants and 

 the relation between the individual and its inorganic environment. 

 It leans rather to the biological than the chemical side, the latter 

 being weak. The equation on page 200, which describes assimi- 

 lation as the union of carbon dioxide and water to form starch with 

 oxygen as a by-product, conveys an idea which is now known to be 

 incorrect. The importance of sugars as a stage in assimilation is 

 scarcely suggested till we come to the next stage, where it figures 

 as a precursor of the proteids. The ascent of water in trees might 

 have been treated at greater length, and in connection therewith is 

 one of those mistakes which seem to be unavoidable : on p. 188 

 it is stated that "the sap of a Begonia ascends 60-100 metres"; 

 the original reads Wellingtonia. Another instance occurs a little 

 further on (p. 214): the "gall- wasp of the figure" refers to the Fig 

 (Ficus), not a diagram. 



The portion on Special Botany is the work of Dr. Schenck, who 

 deals with Cryptogams, and Prof. Schimper, who does the Seed- 

 plants. In view of their importance in phylogeny, and the facilities 

 for their study, more space might have been given to the vascular 

 cryptogams and we should have welcomed a wider reference to 

 extinct forms, and the condition of the group in past ages. Prof. 

 Schimper supplies an account of the principal families of seed- 

 plants, which is clear and well arranged on the usual lines. It is 

 based on Eichler's system, which approaches more nearly to a 

 natural arrangement than the one generally adopted in English 

 text-books. A chapter on plant-geography would have been a 

 useful addition, and we should have been glad to see more about 

 the distribution of plants in space in the accounts of the individual 

 famihes. As in the original, some poisonous species are honoured 

 with coloured figures. The selection is somewhat arbitrary, and 

 the pictures are not by any means a success. APR 



