176 TRANSACTIONS OF ROVAL SCOTTISH AKBORICULTURAL SOCIETY. 



Stems that will form the mature crop, and thus to 

 increase their girth as rapidly as possible. Here 

 again, the dead, moribund, badly-grown, and sickly 

 individuals are those first of all thinned out, and 

 sound healthy trees should only be removed to such 

 an extent as is actually necessary. 

 4. The above rules apply to crops containing a fair pro- 

 portion of shade-enduring broad-leaved trees (and to 

 silver fir). But in spruce woods it is not advisable 

 to retain suppressed poles or trees that may still be 

 fairly healthy, as this only increases the danger from 

 insects, although some of the dominated stems may 

 be left to form part of the main crop in older woods. 



Among the reviews of books, letters to the editor, and casual 

 notes, there is also much of interest that might well be mentioned 

 if space here permitted. 



In the Zeiischn/tfiir Forst- tind Jagdtuesen there is also a great 

 deal of exceedingly interesting and instructive matter, though 

 comparatively little of it can be said to be of direct practical 

 use for British conditions. The keen desire for information 

 about the forests of other countries is evinced by long articles 

 on "Forestry in the Dutch Indies," and "A Journey through 

 the Forests of Roumania and the Eastern Carpathians." The 

 work of forest conservancy in the United States and in other 

 countries is also duly recorded, while of course specially German 

 questions are dealt with, such as timber import duties and 

 railway rates, etc. Among the scientific dissertations, along 

 with the more useful papers on the large cambial beetle 

 {Hylesinus micans), the pine-looper [Fidonia piniaria), the pine 

 fungus {Trametes pint), and other enemies of conifers, there is the 

 never-failing bitter controversy. This time it is about the dying 

 off of the tops of young spruce, said by Professor v. Tubeuf 

 (Munich) to be due to electricity (electric exchanges between the 

 tree-tops and the clouds during the period of vegetative rest), but 

 asserted by Professor Moller (Eberswalde) to be due to the small 

 moth Grapholitha pinicolana. It is among the shorter articles 

 and the notes, however, that matters of particular interest to 

 British foresters are more usually to be found. 



During the last ten to twelve years the pine-looper moth {Fidonia 

 piniaria), which also does damage here and there in British 



