192 FOBESTAL NOTES. [Jajsi., 



continuous masses of Oak, as being more valuable. The Oak, 

 unable with its light cover to kill off secondary vegetation under it, 

 gradually fell off and died out, and foresters are now obliged to 

 carry out the regeneration of the districts thus ruined by means of 

 Scotch Pine. 



As for vitrification in the soil, it may be more slowly effected by 

 tree-agency alone than by that of the growth of grasses ; but the trees, 

 when sole possessors of the soil, get the benefit of all the nitrates 

 formed ; and we may suppose that pure forest can always develop 

 the amount of these salts necessary for its requirements, which, as 

 E. H. observes, are so much more modest as regards chemical ele- 

 ments than those of cultivated plants. This seems evident from the 

 fact that, wherever trees are not overcrowded, their growth is finest 

 where the leaf canopy is continuous and the humus furnished by it 

 most abundant. 



I can, there fore,'see no reason suggested by the interesting researches 

 in question for departing from the good old rule of keeping forest 

 soil as clean as possible, and utilising all secondary growth by killing 

 it and converting it into humus as soon as we can, by making our 

 leaf -canopy continuous. 



Of course secondary growth must not be proscribed everywhere, being 

 invaluable to the artist and the naturalist, and for the pleasure of the 

 general public. I have treated the subject from the forester's point 

 of view exclusively. 



David Cannon. 



Erratum. — In the hurry of going to press with our December number the 

 woodcut on page 101 representing a group of white willows {salix alba) was 

 inserted with the erroneous description of " Lombardy Poplars " in Mr. Bonlger's 

 article on "Beauties of British Trees." The description referred to the 

 cut on page 99, which was simply named " Poplars," instead of " Ijombardy 

 Poplars." 



" Guide to Methods of Insect Life." — Miss Ormerod has courteously sent us 

 the advance sheets of her new book on Insect Life. It is published by Simpkin, 

 Marshall, & Co., is fully illustrated, and its price is to be only 2s. We shall 

 probably return to its subject shortly. Meanwhile, let us add that the authoress 

 in a note to us says : — " I hope the book may in some degree serve as the 

 plainly worded introduction to a practical knowledge of insect life that I am 

 often asked for ; but also I have endeavoured to make it a kind of pictorial 

 guide, so that the practical reader may see the figure before he has time to get 

 puzzled." 



