SECTIONAL TRANSACTIONS.— K. 389 



Saturday, September 3. 



Excursion to Newtondale, Beck Dale, etc. 



Sunday, September 4. 



Excursion to Lake Gormire and Sutton Bank. 



Monday, September 5. 



Presidential Address by Prof. J. H. Priestley on The growing Tree. 

 (Seep. 185.) 



Dr. R. N. Aldrich Blake. — The influence of nutrition on the relative root 

 and shoot development of forest tree seedlings. 



The majority of plants, among them seedlings of five representative 

 conifers and of Casuarina equisetifolia, respond to increase of the supply of 

 nitrogenous salts by a decrease of relative root weight. There are indica- 

 tions that this generalisation may be extended and that relative root weight 

 is depressed by an increase of the supply of all nutrients normally obtained 

 from the soil. American work shows that plants with a high carbohydrate/ 

 nitrogen ratio have relatively heavy roots, and vice versa. Root-branching 

 of Corsican pine seedlings is less dense the greater the supply of arrunonium 

 nitrate. 



This response of the plant to nutrition can be explained readily on 

 teleological grounds, but as yet there has been advanced no satisfactory 

 analysis of the reaction along causal lines. 



For the forester this reaction of the tree seedling to nutrition may be of 

 considerable importance in connection with problems of manuring in forest 

 nurseries. 



Dr. L. Chalk. — Multiperforate end-walls of vessel segments. 



Scalar if orm perforations are common among the less advanced woods, 

 and are associated with long vessel segments and oblique end-walls. Reti- 

 culate-scalariform and foraminate perforations may be regarded as variations 

 of the scalariform type. 



Amongst the more highly specialised woods — e.g. in the Bignoniaceae — 

 there occurs a type of perforation which is superficially very similar and for 

 which the term pseudo-reticulate is suggested. These perforations occur 

 in only a few of the vessels, the others having simple perforations ; the 

 segments are very short and the end-walls are horizontal. Their reactions 

 with stains are unusual. Two types can be distinguished. Their origin 

 and function are discussed, and some suggestions made for revising the 

 terminology applied to perforations. 



Mr. B.J. Rendle. — The study of wood anatomy as a link between botany 

 and forestry. 



The paper deals briefly with the development of wood anatomy along 

 various lines, following the early descriptive period which culminated in 

 Solereder's Systematic Anatomy of the Dicotyledons. 



In studying the anatomical structure of wood, whether from the point 

 of view of systematic botany, plant physiology, silviculture or timber- 

 utilisation, it is necessary to distinguish clearly between characters which 



