1SS Mr W. S, Macleay on the State of the Klvi-Trecs 
of the young elms which have lately been planted in different 
parts of them. The other species of trees, in these places of 
public resort, seem, on the whole, to be very free from disease; 
but in planting, and particularly in ornamental planting, it may 
be well to bear in mind, that indigenous trees are much more 
subject to the attacks of our indigenous insects, than those which 
are not natives of this country. 
With respect to those trees which are in an unsound state, 
it is very difficult to point out a cure for them. When the in- 
sects attack the branches, these ought obviously to be examined, 
and if infected, ought, as soon as possible, to be lopped off, and 
burnt. I scarcely know, however, what to propose, for the pre- 
servation of those trees, of which the trunks are infected. Per- 
haps it may be of use to cover over, in the month of March, with 
a mixture of tar and train oil, to a certain height from the ground, 
all such trees as it may be thought proper to attempt to save. 
I venture to recommend this coating of tar, not only by way of 
experiment, as protecting the trunks from the access of the per- 
fect insects, but for the purpose of filling those little round holes, 
which, it is easy in summer for an accurate observer to perceive, 
afford* peculiar facilities for the communication of the disease. 
To those persons who, being unacquainted with natural his- 
tory, may therefore be disposed to neglect the power of these 
insects, because they are individually minute, and who totally 
overlook the consequences of their being almost infinite in num- 
ber, I have only to remark, that they may judge from what 
these animals have already done in the Parks, how much mis- 
chief they are capable of effecting. In the year 1780, an in- 
sect *, of the same natural family as the Hylesinus destructor , 
made its appearance in the pine-forests of the Hartz, and was 
neglected. In the year 1783, whole forests had disappeared, 
and, for want of fuel, an end was nearly put to the mining ope- 
rations of that extensive range of country. At the present mo- 
ment, also, the French Government is in alarm at the devasta- 
tion committed in their arsenals, by an insect w r ell known to na- 
turalists, under the name of Lymexylon navale. About ten 
years ago, the principal naval engineer at Toulon, M. de Ceri- 
* Bostrichus typographus. Fab. 
