28 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



planting only in northern and mountain climates where 

 it could probably withstand severe winter frosts." 



There seem to be no records of the Caesia variety having 

 been intentionally planted in Scotland, although occasionally 

 single trees may be seen that are at least as old as those at Kew. 

 There are sufficient trees at Craibstone to form a small plot, 

 which, so far as I am aware, will be the third of its kind in the 

 British Isles. 



Coast Variety. — The Oregon or Coast Douglas fir scarcely 

 requires to be referred to here since its good qualities, its great 

 vigour of growth, and the enormous quantity of timber the tree 

 produces per acre, have been one of the favourite themes of 

 most writers on forestry during the past half-century. The rate 

 of the growth of the tree is remarkable, an average growth of 

 3 to 4 feet per annum being no unusual occurrence, with the 

 addition of a second shoot 5-6 inches in the autumn. The 

 production of this after-shoot is a feature that enables the Coast 

 variety to be distinguished from the Glauca and Caesia forms, 

 in which there is no second growth. 



The transference of the Douglas fir from the Pacific Coast to 

 the British Isles seems to be attended with certain changes in 

 the characteristics of the tree, the explanation of which is 

 probably to be sought for in a difference in the amount of 

 sunshine, or is due to some other factors which react on the 

 constitution of the tree in such a way as to stimulate growth 

 in diameter. I have been led to entertain this idea from 

 comparing the habits of the tree in its native habitat and in 

 this country, although owing to the impossibility of making an 

 exhaustive study of the subject, it is hardly possible to indulge 

 in anything but vague surmises. In the first place, the shedding 

 of the branches and the production of clean timber takes place 

 more readily in Pacific Coast forests than in Great Britain. 

 This applies both to trees growing in the open and in closed 

 woods. In its native habitat, even moderately sized trees 

 growing in the open are generally bare of branches in the lower 

 portion of the trunk, and it is seldom, if ever, that one sees trees 

 of say 3 feet in diameter clothed with branches, densely foliaged 

 to the ground, a by no means uncommon occurrence in Britain. 

 A Douglas fir wood on the Pacific Coast at forty years of age 

 has much the same appearance as a fairly dense plantation of 

 Scots pine in this country. Age for age, the number of trees 



