136 TSUGA, OR HEMLOCK SPRUCE FIRS 
pests that visit them and the cankers that would 
destroy them. 
Interwoven with these questions, the collective 
wisdom of scientific and practical man has been 
brought to bear on the various systems of planting 
that have been devised for their successful propagation. 
Questions have been asked, raised, and considered, as 
to whether Larch should be planted pure. Collective 
experience seems strongly against this, unless with 
the exception of only upon the very best of forest 
soils. Whether they should be planted with Spruce, 
with the knowledge before us that Spruce is the host 
plant of their mutual enemy, the Chermes; whether 
they should be planted with Douglas Beech, or other 
hard-woods (N.B.—Larch with Pine—two light-de- 
manding trees—is the latest Swedish recipe for a 
mixture) ; whether Larch should succeed Larch, and 
‘how to deal with it in oak coppice ; or how long a 
time should elapse before replanting after felling ; 
what visitations of sun, air, and wind, it best bears ; 
the respective merits of the Scottish and Silesian seeds, 
and the comparative demerits of seed from the Tyrol, 
—all these are long questions, and burning questions, 
and they have been treated capably by those most 
capable of treating them, in many books and writings, 
in arboricultural journals, andin Board of Agriculture 
leaflets. Upon one point are all agreed, that Larch 
should not be planted in low-lying damp situations. 
Whether the last word has been said on the subject, 
whether any of the systems advised will become 
subject to variation, are questions for the experience 
of another generation to decide upon. It has always 
been held as a golden rule among musicians that 
composers should know all the rules of harmony, 
modulations, and progressions, before they presume 
to break them. In like manner, let all planters of 
trees study ¢he rules of the game of their cult before 
