156 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



Professor Henry's article in vol. xxix., part i. Time only can 

 settle this question for the " hybrid larch." 



In conclusion, I may mention that cross fertilisation experi- 

 ments in larch were commenced at Murthly last year. In these 

 the crossing was done both ways, viz., L. enropcea ? x Z. kptolepis $, 

 and L. leptolepis 9 x Z. europcBa $. The resulting seeds have 

 been sown recently, but so far only some half-dozen plants have 

 been got. These are all from the Z. europcea 5 and Z. leptolepis $ 

 cross. It is hoped that some of the others will yet germinate. 



I might suggest here that these experiments might be tried 

 elsewhere, and further that branches bearing male and female 

 Japanese larch flowers be also enclosed in bags so that pollination 

 is only possible with pollen of the same species. In this way it 

 may be possible to arrive at some definite conclusion as to the 

 nature of the plants. 



26. North American Forest Trees in Britain.^ 



( With Plates) 

 By Prof. A. Henry. 



Many North American species of trees are cultivated in this 

 country, but most of them are only of ornamental or botanic 

 interest. Those which are of value as producers of timber are 

 few in number, but of immense importance, and it is to this 

 class that I shall confine my remarks. 



Exotic trees are absolutely necessary for the economic 

 production of timber in the British Isles. This is admitted in 

 practice, and is sound in theory. Our native species are few 

 in number, all being late immigrants from the continent of 

 Europe after the glacial epoch, and are by no means those that 

 are most suitable to the climate conditions of the present day, 

 or that are most fit for producing, as quickly as possible, 

 valuable timber. 



The Scots pine, our solitary forestry conifer,- was widely 



^ Reprinted from the Gardeners' Chronicle, March 1915. We are indebted 

 to the editor for the loan of the accompanying blocks. 



- Our other indigenous conifers, the yew and juniper, are not used in 

 modern planting. The spruce is not a native of the present epoch ; but 

 cones of Picea ohoi'ata have been found in preglacial beds at Cromer, 

 Mundesley, Bacton, and Happisburg in Norfolk, and near Cappard in 

 Galway. Picea ohovata is the species now existing in Northern Scandinavia, 

 Finland, Northern Russia and Siberia. 



