42 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



subject in a most erudite discourse to the members of one of the 

 French forest societies. It appears that the spruce comes down 

 from exceedingly remote geological periods, and that it has been 

 driven slowly southwards. The varieties most like the earliest 

 spruce are now to be found in the Himalayas, in Picea 

 morinda and P. alba. The European spruce has a great 

 number of varieties, of which Picea excelsa pouiula and P. excelsa 

 columuaris stand at the extremes. The former takes the lower 

 station, the latter the higher, and M. Mathey gives tables 

 showing how much smaller is the projection of the crown of the 

 columnar variety compared with that of the other, the ordinary 

 spruce. This, he says, is due to adaptation to environment, 

 enabling the tree growing in the high station to present as small 

 a surface as possible to the strong winds of the mountain tops ; 

 also, the downward trend of the branches allows the snow to 

 slip off easily. Whereas the spruce of the lower station grows 

 densely and is a great shade-bearer, it is not so in the case of the 

 other. But formerly, according to M. Mathey and others, there 

 were broad-leaved species (especially the sycamore) on these 

 heights, and their disappearance is leading to that of the spruce, 

 which is receding downwards. The reason for the disappearance 

 of the broad-leaved species is a contested point ; M. Mathey says 

 it is due to man and his flocks. Once the broad-leaved species 

 are gone the struggle with the grasses and weeds is too much for 

 the spruce. Also the lack of shade means the drying up of the 

 soil, which kills the spruce seedlings. M. Mathey does not 

 appear to agree altogether with M. Moreillon that the want of 

 seedling growth is due to heavy and persistent snow. The 

 spots where regeneration is found are those where there is a 

 suitable germination bed, where the radicle can reach the 

 mineral soil, and where the young plant is free from excessive 

 competition with weeds and grass. 



II. In the course of an article by M. Emile Mer upon quite a 

 different subject we find mention of the extraordinary drying 

 effect that spruce has upon the soil, and this is a very important 

 point, for it must affect the growth of other species mixed with it 

 if it occupies a large proportion of the space. It may be that 

 species drawing their moisture from a deeper stratum than the 

 surface stratum wherein the roots of the spruce are found could 

 stand the mixture, but even so the spruce must be harmful to 

 some extent, and in fact we know that the oak must not be 



