228 THE JOURNAL OF BOTANY 



each. The factors which appear to be of importance in account- 

 ing for the presence and also of the differential distribution of the 

 various associations in the district are given at length. 



Of great interest is the chapter on woodland association, where 

 the differentiating factors seem to be the chemical nature of the 

 soil, the depth of the soil, and the altitude of the woodland site. 

 The account given of the conversion of woodland into scrub, and 

 of scrub into grassland, heath, or moor, is clear and convincing. 



In the case of moorland associations, in particular, much has 

 been added to our knowledge. Factors related to the distribution 

 of the associations are clearly stated, and the transitional associa- 

 tions, so puzzling to beginners in ecology, are fully worked out. 



Many interesting facts are given by the way, e. g. the comple- 

 mentary plant community of the calcareous heath (Calluna and 

 Potcriiun), and that of the dry places in ash woods (Mercurialis 

 and Adoxa), the nunatak nature of the Peak, &c. 



The book is full of useful tables and diagrams. Appendices 

 are given of " Summary and Eelations of the Plant Communities 

 of the Peak District," " Summary of British Plant Formations and 

 Associations," and " List of Works referred to in the Text." 



The text is interspersed with numerous references to related 

 literature ; there is also a useful index. The book is well got up, 

 illustrated by many good and appropriate photographs, and written 

 in an exceptionally clear and attractive style. 



J. Eamsbottom. 



Sporeplanterne (Kryptogamerne) med 513 i teksten trykte figurer 

 eller figurgrupper af L. Kolderup Eosenvinge. Kjobenhavn 

 og Kristiania : Gyldendalske Boghandel, Nordisk Forlag : 

 1913. Large 8vo, 388 pp. 

 The text of this work is in Danish. The author states in the 

 introduction that when Prof. Warming was contemplating the 

 publication of a new edition of his Systematiske Botanik, he 

 proposed that Dr. Eosenvinge should prepare the Cryptogamic 

 section and publish it as an independent volume co-ordinate 

 with the Phanerogamic section, which was to be elaborated 

 by Prof. Warming himself. Dr. Eosenvinge willingly undertook 

 the task ; but instead of merely remodelling the text of the 

 older work, he has given an entirely new presentation of the sub- 

 ject. This was necessary, owing to the great increase of knowledge 

 which has arisen in such branches as developmental history and 

 cytology. The extent of the book is accordingly larger ; and the 

 value to the student is correspondingly increased. 



This latest text-book of cryptogamic botany comprises the 

 following: — (i) Thallophyta with eleven classes — Bacteria, Cyano- 

 phyceae, Myxomycetes, Flagellata, Dinoflagellata, Diatomeae, 

 Chlorophyceae, Phaeophyceae, Ehodophyceae, Phycomycetes, Myco- 

 mycetes, with the Fungi Imperfecti and the Lichenes as unclassed 

 groups; (ii) Archegoniatae with two classes — Bryophyta and 

 Pteridophyta (ending with the Cycadofilices). It is to be hoped 



