78 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
Another important publication recently is the third edition of 
Professor Sorauer’s Handbook of Flant-Diseases. Of special 
interest in this regard is what he has to say about the 
predisposition of the larch to infection by the canker-fungus. 
Basing his remarks on Weber’s researches into the influence of 
soil and situation on the chemical composition of the ash of larch 
timber, he points out that the transference of the larch from its 
indigenous mountains to the plains has, in many cases, occasioned 
a change in the manner of growth, whereby its immunity against 
diseases has been destroyed. In the comparatively mild and 
damp autumns on the plains the close of the vegetative period 
is delayed, and therewith the entrance into the period of winter 
rest that is necessary for its normal development—much in the 
same way, to give a homely example, as late hours are bad for 
young children. One frequent result of this is that it becomes 
less hardy against frost; and with the formation of any sort of 
wound caused by frost the door is, of course, opened for the 
entrance of wound-parasitic fungi. Hence Sorauer urges the 
importance of in future considering, more than has hitherto been 
done, the suitability of soil and situation for any particular 
kind of tree brought from mountain tracts into low-lying 
localities, and to avoid the mistake of being misled by the belief 
that cach kind of tree can thrive wherever plenty of food-material ts 
available for tt. And, of course, this just comes to the practical 
common-sense opinion, based on everyday observation and ex- 
perience, that not only the larch, but also every other kind of tree, 
will thrive most vigorously and be least liable to disease of any 
sort when it is grown on a soil and situation suited to its normal 
requirements—and also that the more the soil and situation vary 
from such normal standard for any tree, the less will be its 
power of withstanding climatic influences, diseases of all sorts, 
or the attacks of noxious insects. 
A scheme for carrying out manuring experiments in connection 
with the German Forest Experimental Establishments has been 
drawn up, so that in the near future interesting results are likely 
to be ascertained and published. This question is now under- 
going careful investigation at various centres, and is certain to 
be well threshed out. Exhausted nurseries, of course, need 
rehabilitation, and nurseries on poor soil require to be improved 
and brought up to proper fertility; but the methods hitherto 
adopted are now going to be examined very critically. Professor 
