80 FOREST CULTURE AND 
tree itself giving but partial shade. The soil, more- 
over, remains no longer porous and permeable to 
moisture—it gets hardened, bare and consolidated by 
traffic and heat; the necessary moisture is wanting 
to keep the bark pliable, and to maintain the circula- 
tion of the sap active or normal; bark and wood are 
getting fissured and partly lifelesss ; and now places 
of seclusion, as well as a wood fit for their ready at- 
tack, are given to numerous kinds of coleopterous and 
other insects, which, by boring the ligneous tissue, are 
sure to complete the destruction of the trees. Pict- 
ures of absolute misery of this kind may be noticed 
around our city in all directions. I have succeeded 
in saving many a venerable tree on the ground under 
my control, and in arresting the incipient decay by 
merely surrounding the base of the stem with earth 
turfed over, serving as seats ; or by removing the end- 
less quantity of mistletoe, which sucks the life-sap 
out of the branches, the invader perishing with its 
victim, there being no longer a multitude of native 
birds in populous localities to devour the mistle-berries. 
In many low localities, again, the ground, indurat- 
ed by traffic, collects a superabundance of moisture, 
which becomes stagnant, and detrimental to the trees 
of such spots. Various other peculiar causes tend to 
the decay of our trees: to allude to all is beyond our 
present object. 
How to provide, therefore, in time, the wood 
necessary for our mines, railways, buildings, fences, 
and as well as for the ordinary domestic and other 
purposes, becomes a question which from year to year 
presses with increased urgency on our attention, the 
consideration of which we have already far too long 
