71 



often possesses a very practical value, namely, 

 that you may sow and plant all kinds of 

 seeds and plants wherever you like and chance 

 with what results. 



As regards statistics on the subject of resis- 

 tance to frost, all these may be averaged, 

 because, for instance, hardiness against a late 

 frost not only depends on the beginning of 

 growing period of the tree, but also on the 

 occurrence of a frosty night. In a given year, 

 for example, in which frost appeared early 

 in May the same species of trees are liable 

 to and suffer from frost, which develop their 

 buds at the beginning of May, while in another 

 year the late frost only appears in June, and 

 those species are liable to and suffer from frost 

 whose vegetation begins early in June, whereas 

 those which began growing a month earlier 

 have proved less susceptible. Much the same 

 applies to the effect of the lowest temperatures 

 on trees, as the localities in which these occur 

 are liable to variations so that the idea of estab- 

 lishing a zone of cultivation on the basis of the 

 lowest temperature of winter, as has been sug- 

 gested quite recently, is not sound. 



I. Acer dasycarpum. 

 This very rapid growing tree which is said 



