CHAPTER VI. 



CONDITIONS AFFECTING THE GEOGRAPHICAL DISTRIBU 

 TION OF PLANTS AND TREES IN NORWAY. 



IN Norway, as is the case everywhere, the distribution of 

 forests, and of different kinds of forest trees, is effected, and 

 I may say determined, by conditions varying in different 

 districts, predominant amongst which are heat and mois- 

 ture, and wind and soil. 



From a knowledge of the natural history of different 

 kinds of trees there may be learned much in regard to 

 these conditions in the several localities in which they grow, 

 much more than can be stated and proved in a few words, 

 for it is not simply the sum of different measurements 

 such as are applicable to these conditions, but the reflex 

 and complicated influence of one and another of these upon 

 one and another of them, upon which the ultimate result 

 depends, and on variations in some of them at different 

 periods, embracing, amongst others, the periods of the 

 germination of the seed, of the expansion of the leaf, of 

 the formation of the flower, of the casting of the pollen, 

 and of the maturing, and the falling of the fruit. By 

 stating, however, the characteristics of different localities 

 in connection with these conditions, there may be made a 

 contribution towards a collection of facts which may be 

 interesting to the general reader, and not without value 

 to some youthful student of forest science ; and this I 

 shall attempt, citing and translating facts embodied in the 

 report by Dr. Broch, to which I am indebted for much of 

 what I have advanced in regard to the geographical dis- 

 tribution of the trees. 



' Speaking generally/ says Dr. Broch, ' the Norwegian 

 flora presents little variety. The gneiss, granite, and 



