NOTES OX RECENT RESEARCH. 



715 



scope of this paper from its first paragraph, we may be content to take 

 the convenient summary (of part of the work) which is given at the end, 

 in the following table : — 



The pore opens by — 



1. A change of shape, rather than by stretching the walls, in which 

 the change is — 



(a) An increase in the depth of the guard cell, in which there is 

 chiefly concerned — 



The entire wall (except the dorsal) . Medeola (Equisetum). 



The inner half Milium. 



The outer half Funaria. 



The dorsal half Lycoj)odium. 



The ends Osmunda. 



(b) An increase in the width of the 



slender stoma Sagittaria. 



2. Stretching the thin dorsal wall . . Amaryllis. 



3. A change in shape, with or without much stretching, at the ends of 

 the guard-cells which forces the dorsal wall, with the passive middle part 

 of the cell — 



Directly backward .... The Graminea. 

 Upward and backward . . . The Coniferce. 



4. Combinations of the types of — 



Amaryllis and Milium . . . Helleborus. 

 Amaryllis and the Graminece . . Achillea. 



It should be added that in the fifty-seven figures of the plate we have 

 a valuable exposition of stomata structure. — R. I. L. 



Decay of Timber. 



Timber, The Decay of. By Hermann von Schrenk (U.S.A. Dep. 

 Agr., Bur. PI. Ind. Bull. No. 14 : 1902 ; numerous photos and figures in 

 text). — The investigations into this subject were set on foot in consequence 

 of the annual destruction by decay of forest timber and of timber used for 

 construction purposes, such as railroad ties, posts, bridge timber, &c, being 

 almost beyond computation. The treatise deals with the following- 

 matters : — After the introduction, giving the scope of the report, there 

 follow the structure of timber, the factors which cause the decay of wood, 

 timber preservation, results of timber impregnation, ties, poles, &c, ballast, 

 tie-plates, fastening, methods of impregnation and creosoting. It concludes 

 with a summary. 



In the introduction the author speaks of the marvellous amount of 

 timber consumed annually, with the corresponding drain upon the forest 

 supply. For thirty years there has been a constant appreciation in the 

 prices of timber in certain classes. 



Timber removed from the forests decays sooner or later. By increasing 

 the length of service of timber, not only does it become cheaper, but less 

 is used. The object, therefore, is to increase the length of life of timber. 



