382 METEOROLOGY. [March 



increase of the yews was nearly divided between the first and 

 second parts of the season. 



The absence of sunshine in the spring and summer of 1879 

 caused a deficiency in wood-growth, which was greatest in the 

 deciduous class, and, so far as Sir Eobert observed, least of all in 

 oaks. In 1880, though the spring and summer were characterized 

 by absence of severe frosts, and liy their average character, there 

 was rich and abundant foliage, but a decrease in the growth of 

 deciduous roots. This, Sir Eobert accounted for by the extraordinary 

 low temperatures of the previous December, succeeding an autumn 

 unfavourable to the ripening of wood and formation of buds. Dr. 

 Christison inclines to attribute the escape of the evergreens to their 

 earlier activity of growth in spring : their early buds would come 

 under the influence of the genial March and April, the later buds 

 of the leaf-shedding trees encountering a rather inclement May. 

 The readings at the Botanic Garden showed a greater cold in 

 January 1881 than in the previous year; but though this pre- 

 vailed through the spring, the deciduous trees made a remarkable 

 rally of an increase of nearly one-third in growth. This may be 

 accounted for by the favourable character of the preceding 

 autumn, which allowed the growth of wood in 1880 to be fully 

 matured. On the other hand, the evergreens, possibly because their 

 comparatively early growth exposed their buds to a severe spring, 

 declined in growth. In the winter of 1881-82, one of the mildest 

 on record, a sycamore and a Hungary oak among the marked trees 

 of the Botanic Garden began to expand their leaves on the 27th 

 March. But the sycamore was attacked by frost and insects, as 

 indeed were most of the horse chestnuts near Edinliurgh. But 

 deciduous trees, as a whole, did not suffer, though they only main- 

 tained their improvement of the previous year, not coming up to the 

 standard of growth of 1878. 



Great damage might have been expected from the great gale of 

 1881, yet Sir Eobert remarked the richness and abundance of foliage 

 in June. And in that summer of twelve gales, with a previous 

 winter of unprecedented severity, the growth of deciduous wood 

 made a remarkable rail}'. An excessive rainfall seems to be favour- 

 able to the increase of wood, particularly in evergreen trees. A great 

 excess of rain in August 1881 apparently stimulated the growth of 

 wood in these to a remarkable degree, although the temperature of 

 the month was decidedly low. 



This research of Dr. Christison's seems a model of forestal 

 observation. Why should not work of this kind be inidertaken in 

 half-a-dozen districts of Britain ? Here is room and scope for 

 local scientific societies. A comparison of their returns would 

 bring to light undiscovered truths respecting tree-growth. 



