Periodical Literature. 515 



ant species early an inquiry of similar character, while knowledge 

 of the field of original distribution is still alive. 



Die ursprilngliche natiirliche Verbreitungsgrenze der Tanne. Naturwis- 

 senschaftliche Zeitschrift fiir Forstund Landwirtschraft. April-May, 1912, 

 pp. 200-267. 



Two articles based on investigations, are de- 

 Periodicity voted to a discussion of the periodicity of 



in the taking up of mineral salts and the forma- 



Life tion of food materials in trees. Kuebler 



Processes used two-year-old beech, some grown with 



mineral fertilizer, others without fertilizer. 

 He describes his method of analysis and the weather conditions. 

 During the month of April a loss of dry substance amounting to 

 from 15 to 32% of the various salts in the unfertilized, and from 

 O to 30% in the fertilized material. This shows that while out- 

 wardly still at rest the chemical processes are by no means stopped, 

 respiration using up reserve materials, sugar and water being 

 the end product. It is suggested that this water may go from the 

 root into the soil. Other chemical processes take place and are 

 explained. After the period of vegetation is ended similar pro- 

 cesses take place. During the budding forth of the foliage a 

 further loss from the perennial issues of stem and root is re- 

 corded, the roots not being able to supply all the consumption. 

 Hence this part of the growth depends upon the growth conditions 

 of the previous period of vegetation. 



Here the difference between unfertilized and fertilized plants 

 appears. Soon after leafing the former are entirely dependent 

 on the soil, having exhausted their reserve material in the forma- 

 tion of foliage, while the fertilized plants, with a considerably 

 larger store of reserve material, produce first a larger amount of 

 foliage and thew supply the same with more materials. The for- 

 mer made only 1.8 of foliage per 100 plants, the later 93.4 g, 

 and in addition increased their dry weight by 4%. On unferti- 

 lized soil the foliage of the plants represented 16% of the total 

 weight, on fertilized soil 2>2>%^ ^ great advantage for assimilartory 

 activity. From middle of May to middle of July the analyses 

 show relatively little difference in the percentic increase of dry 

 substance, but a noticeable difference in nitrogen contents, the 

 unfertilized plants showing considerably less; and most of it in 



33 



