60 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



remarkable case of vigour enabling a Douglas plantation to 

 throw off a fungus attack, but as I have already mentioned 

 it in a, previous number of the Transactions I will not 

 repeat it. 



Snow-break is much worse in a pure conifer wood, as close- 

 grown stems with persistent leaves hold up the snow like a roof 

 till it collects into a mass of enormous weight. 



Assuming that 100,000 hectares have to be afforested, and 

 that 5000 plants are used per hectare, 500 million plants, at a 

 low estimate, will be required. Can such great quantities be 

 found quickly in Europe ? If not, would it not be worth while 

 to experiment with many exotic species growing in similar 

 climatic conditions, and in the northern hemisphere? We may 

 remember that when the latitude is lower altitude in such 

 latitude will give us the necessary correction. Thus the field for 

 obtaining seed will be greatly extended. 



One great point — not generally considered — is that when a 

 conifer has a relatively large space to grow in, the wood becomes 

 heart-wood more quickly. It is of course true, on the other 

 hand, that the quick-grown conifer is less valuable than the 

 slow-grown, but one may reflect that if quality suffers quantity 

 increases, and when all is said and done coniferous wood is 

 generally used under cover and there quality is not of great 

 importance. It may be noted in passing that M. Jolyet states, 

 as an interesting exception, that quick growth in a Douglas does 

 not militate against quality, inasmuch as unusual widening of 

 an annual ring is found to occur more in the summer than in 

 the spring. 



By introducing deciduous species between the conifers the 

 decomposition of the needles of the latter is more rapidly 

 effected by the addition of the leaves of the former. M. Jolyet 

 says : " I suppose it is the case that the resin in the needles is a 

 preservative, and that slow decomposition has the drawback 

 of producing swampiness." 



In any case it is common knowledge that the best conifers 

 are to be found in a crop of beech, provided their heads are 

 free, and is it not the case that the best soil-enrichers are 

 deciduous? 



V. — M. Jolyet, in considering the great danger from insect 

 invasions in the forests damaged by the war, mentions an 



