142 FORESTS, WOODS, AND TREES 
trees to the acre, 125 to 135 feet in height (the tallest on 
record in England), with a total volume of 6430 cubic feet 
(quarter-girth measurement), equivalent to an average annual 
increment of 52 cubic feet per acre. If the thinnings, which 
are unknown, were added, the total yield would be enormous. 
(See Quarterly Journal of Forestry, iii. 357 (1909).) 
No ordinary plantation would give a yield over its 
whole area comparable to those recorded above for selected 
plots. We can count, however, safely on yields of 40 to 
70 cubic feet per annum per acre in successful plantations. 
Japanese Larch.—This. species is remarkable for its 
extraordinary rapidity of growth when young. Owing to 
this excessive vigour, it resists the attacks of Peziza, which 
are most liable to occur between the fifth and fifteenth year. 
In fact, Japanese larch may be considered to be practically 
immune from canker disease. It is also, for the same 
reason, free from serious attacks of insects, ike Chermes, 
Coleophora, and Argyresthia, which injure the common 
larch. These great advantages, vigour of growth and 
freedom from disease, are counterbalanced by the fact that 
Japanese larch tends to grow crooked, and does not develop 
the beautiful cylindrical stems which characterise well- 
srown European larch. Plantations of Japanese larch in 
Scotland over twenty years old show coarse, curved, and 
crooked stems. The timber is also not so strong as that 
of the common species; and when young trees are cut for 
pitwood the props are not so valuable. 
Japanese larch bears considerably more shade than the 
European larch; and when planted four feet apart, it 
quickly covers the ground, killing the grass very soon and 
producing an excellent layer of humus. As the stems can 
be kept close together, this is one of the factors contributing 
to the great volume of timber produced during youth by 
this species. Japanese larch is also a very hardy tree, 
resisting spring frost better than the common species. It 
also grows fairly well in exposed situations, where European 
larch would fail completely. It makes, however, only 
