220 
ON TREES. 
nest of the carrion crow ? Brittle are the living 
branches of the ash and sycamore ; while, on the 
contrary, those which are dead on the Scotch pine 
are tough, and will support your weight. The arms 
of the oak may safely be relied on ; but, I pray you, 
trust with extreme caution those of the quick- 
growing alder. Neither press heavily on the linden 
tree ; though you may ascend the beech and the 
elm, v/ithout any fear of danger. But let us stop 
here for the present. On some future day, should 
I be in a right frame for it, I may pen down a few^ 
remarks, which will possibly be useful to the natu- 
ralist, when roving in quest of ornithological know- 
ledge. I will now confine myself to the misfortunes 
and diseases of trees ; and I will show, that neither 
the titmouse nor the woodpecker ever bore into the 
hard and live wood. 
Trees, in general, are exposed to decay by two 
different processes, independent of old age. 
The first is that of a broken branch, which, when 
neglected, or not cut off close to the parent stem, 
will, in the course of time, bring utter ruin on the 
tree. The new wood, which is annually formed, 
cannot grow over the jutting and fractured part, 
into which the rain enters, and gradually eats deeper 
and deeper, till at last it reaches the trunk itself. 
There it makes sad havoc ; and the tree, no longer 
able to resist the fury of the tempest, is split asunder, 
and falls in ponderous ruins. But ere it comes to 
this, the titmouse will enter the cavity in a dry 
spring, and rear its young ones here. Now, if the 
diseased or fractured branches were carefully cut 
