248 A LIFE'S WORK IN IRELAND. 



sheltered places, will not do well. Peach-trees 

 continue growing throughout the autumn. I have 

 often seen them as full of leaves at Christmas as at 

 Midsummer. Of course the wood does not ripen, 

 and any frost kills this gi'een wood, and often reduces 

 the tree in the following summer to bare branches, 

 with a tuft of green leaves at the end of each. 

 Apricots hardly ever bear fruit. 



Such a climate as this plainly must have a very 

 great influence on farming ; a greater influence prob- 

 ably than any other natural cause. 



Mr. Buchan, President of the Botanical Society 

 of Edinburgh, in hi^ address to the society, November 

 9, 1871, thus speaks on the subject of the effects of 

 climate on the distribution of plants : — 



" Bousingault examined the distribution of wheat 

 on the continent of Europe, and arrived at the con- 

 clusion that it required 8248° Fahr., from the time 

 it begins to grow in spring, for the proper ripening 

 of the seed ; and, moreover, that this heat must be 

 partitioned so as to secure a mean summer tempera- 

 ture of 58° during the development and maturation 

 of the seed. This minimum amount of heat 

 required for the maturing of the seeds is a vital 

 consideration. We have proved in Scotland that a 

 mean temperature of 56° during the critical period, 

 with the average sunshine and rainfall of the 

 Scottish summer, is sufficient to ripen wheat pro- 

 perly. Not only so, but it was found that the 



