476 Forestry Quarterly 



from that of the botanist. Jolyet reviews the various types of 

 forests formed by the different species and the methods by which 

 each may be exploited and regenerated. These chapters include 

 special notes on sub-alpine forests and special stands characteristic 

 of the various regions of France. Due emphasis is placed upon 

 cleanings and thinnings. 



The second part forms more than half the work and includes 

 data on the forestation of forests and the restocking of denuded 

 ground. Information is also given on the establishment of under- 

 stories in oak high forests and in the pineries, as well as the intro- 

 duction of coniferous species into coppice-under-standards. The 

 results of practical experience of introducing exotics are given at 

 some length. The collection and storage of seed and the estab- 

 lishment of nurseries is described. Under protection, Jolyet 

 describes at length the protection of forests against fires, rodents, 

 insects, tree diseases, etc. 



According to Vivier, this book on silviculture has been written 

 in a very clear style and is based on the result of professional 

 practice. It is said to be a book that every forester should consult. 



T. S. W., Jr. 



Transpiration and the Ascent of Sap in Plants. By H. H. Dixon. 

 MacMillan's Scientific Monographs. 1914. Pp. 213. 



Prof. Dixon and his associates at Trinity College, Dublin, 

 have been studying the problem of the ascent of sap in plants for 

 the past twenty years. The results of these researches have been 

 published from time to time in various scientific journals. Now, 

 we have them gathered together and presented in one voltmie of 

 the above title. Not since the 1100-page voltune of Strasburger 

 on this subject has anything as complete and conclusive appeared. 



The first chapter of the book is concerned with the nature of 

 transpiration in plants. The two following chapters are criti- 

 cisms of the physical theories and the vital theories, respectively, 

 regarding the ascent of sap in stems. The subject matter of the 

 remaining eight chapters bears directly or indirectly upon the 

 elaboration of Dixon's own theory of the phenomenon. 



The first chapter presents an interesting possibility in regard 

 to the nature of transpiration. We know from the brilliant 

 investigations of Brown and Escombe that the flow of water vapor 



