ELXXVIII GUNNAR SCHOTTE 
sible as early as the age of 15, and necessary at the age of 20; and at 
this time a number of growing b. trees may suitably be removed and also 
trees in the third and fourth tree-strata, which at this period begin to fall 
off. If these are allowed to remain in the wood, they are easily attacked 
by larch-canker and may increase the danger of infection for their neigh- 
bours. In quality III the first thinning can most appropriately take place at 
the age of five, when 15—20 2 of the timber is thinned out. The same 
holds good of mixed woods containing larch; but here the Siberian larch 
should, as a rule, be favoured at the expense of the other trees in the first 
tree-stratum and possibly in the second, while in the third and fourth strata 
the reverse is the case. In quaiity V the Siberian larch has not closed up 
at the age of 25, and therefore thinning in those woods should be postponed 
till itherage of 30 0 Over 
It has often been maintamed in the literature of the subject that the 
Siberian larch is less exposed to diseases and injuries than the European larch. 
This is scarcely the case, however, at least not in the southern and central 
parts of Sweden. The present writer has come across larch-canker, for 
instance, in almost all stands of Siberian larch in Sweden. As a rule, trees 
in the lower tree-strata have been attacked, while the dominant trees have 
gone free, as is shown by the figures collected on pp. 667 and 668. 
As regards insects, the Siberian larch is injured in Sweden by Chermes 
and Coleophora Laricella, and moreover the squirrel is fond of attacking it. 
The properties of the Siberian larch timber are extremely good. As 
examples of the durability of the timber there is shown on p. 671 (Fig. 96) 
a sleeper which had lain for 17 years in the ground at Sundsvall in northern 
Sweden without being in the least damaged; and it may be calculated that 
it will last even longer. 
Chap. V. The Japanese Larch. 
Section A. gives short reports of the distribution of this species of larch in 
Japan; after which in section B is given a short historical account of 
the introduction of the Japanese larch into Sweden and other 
European countries. 
As early as 1879 ROSSANDER (266) mentions that he had tried this larch 
on Värmdö, outside Stockholm. A rather large specimen of this larch is found 
at Alnarp in Skåne (see Fig. 97). It was not until the end of the nineties 
that it was cultivated as a forest tree. Influenced by the experiments in 
cultivation that had been made in Prussia, the head of the zevi7 caused 
experiments to be carried out with it in 1898 on Visingsö in Lake Vättern. 
A detailed description of this stand is given on pp. 760—761 and in Table 
XVI. (Sample plot 313.) Sample plots 342 and 315 give examples of other 
younger plantations in the South of Sweden (see Table 16). 
In section D. the variation and races of the Japanese larch are treated. 
After some mention on p. 763 of the described forms of this species there is an 
account of the supposed hybrid in England between curopaea and Jleptolepis. 
That the Japanese larch, when cultivated in Sweden, is distinguished by a 
great percentage of Eloge trees appears from Table 17. 
Under section FE. is given an accountofthe sylvicultural properties of 
