58 



SIR ROBERT CHRISTISON AND DR CHRISTISON ON THE 



and after the wonderfully mild winter of 1882 one of them was beginning to 

 expand its leaves on the 27th of March. Their growth was more evenly dis- 

 tributed over the four growing months than that of any others of the deciduous 

 group, and among the evergreens the yews alone rivalled it in that respect. 

 The Turkish and American oaks seem also to be early growers. The propor- 

 tion of their May growth was not much less than that of the Hungary oaks, 

 still in both the first and last months of the growing season they were less active 

 than the latter. The British oak grows poorly in this district, and besides, 

 from the roughness of its bark, it is not suitable for minute measurements. 

 The only one experimented upon showed no appreciable increment in May. 



The beeches made only 12 per cent, of their annual increment in May, about 

 half the proportion of the foreign oaks, and as this was in an unusually early 

 season it is probable that in ordinary years their May growth must be very trifling. 



Table VIII.— Monthly Percentage of Increase in Girth of Seven Species of 



Trees in 1882. 





Till 31st 

 May. 



June. 



July. 



August. 



3 Hungary oaks, .... 



25 



21 



31 



23 



2 Turkish and 1 American oak, . 



22 



22 



38 



18 



9 Beeches, ...... 



12 



26 



37 



25 



4 Sequoias, ..... 



3G 



39 



18 



7 



3 Araucarias, ..... 



48 



22 



15 



15 



2 Deodars, 



6 



24 



37 



33 



4 Yews, 



33 



20 



25 



22 



Among other deciduous species, which being less reliable do not find a 

 place in this Table, the ash and the hornbeam alone showed an appreciable 

 growth in May. It is fair to state however, that in the Edinburgh district the 

 horse chestnut leaves were almost universally destroyed in 1882 by early frost 

 and the ravages of insects. It is no wonder therefore that the specimen 

 measured in the Botanic Garden grew only a tenth of an inch in the year. 



The Sequoias were remarkable, even among evergreens, for the early vigour 

 of their growth. No less than 75 per cent, of their annual growth was finished 

 by the end of June. But they ceased to increase earlier than any of the other 

 species, their growth in August being only 7 per cent. 



The Araucarias also grew rapidly in the early part of the season, accomplish- 

 ing very nearly one half of their annual increment by the end of May, and 70 

 per cent, by the end of June. 



With the Deodars it was exactly the reverse, 70 per cent, of their increment 

 taking place after June. If the observations for a single year on two trees may 

 be trusted, the Deodar is an exception to the general rule of early growth in 

 evergreens 



