5i6 Forestry Quarterly. 



the leaves, the stem retaining 33%, the root, nothing. The 

 fertilized plants also take up less nitrogen than other salts, half 

 of it in the leaves, and little in the roots. 



Only from the middle of July does the fertiliser become effec- 

 tive, a remarkable difference between the two sets of plants being 

 exhibited, the difference in dry substance formed or absorbed in 

 1000 parts, being as follows : 



Whole Plant. Stem. Root. Foliage. 



Fertilized, 683 685 525 328 



Unfertilized, 164 147 158 59 



Here the practical suggestion as to use of fertilizer suggests 

 itself. A comparison of the two sets of plants showed at the be- 

 ginning for the unfertilized plants ii8g, for the fertilized, 335. 5g, 

 the difference of 2i7.5g being the effect of two years fertilizer. 

 During the year of investigation the following changes took place 

 setting the unfertilized equal to 100: 



Before leafing out 100 : 297. 

 After leafing 100 : 259 '( — 38). 

 Middle of July 100 : 317 ( + 58). 

 Middle of September 100 : 683 (4-366). 

 End of vegetation 100 : 485 ( — 198). 



It is only after the middle of July that the beech utilizes the 

 fertilizer, and by middle of September it has attained six times the 

 weight of the unfertilized. The greater leaf fall brings about the 

 greater loss of the fertilized specimens. Ample tabulations and 

 diagrams illustrate the detail. 



A similar inquiry is made by Bauer on the oak, except that 

 only one set of nursery grown material was analyzed, in addition 

 to his former investigations on Ash, Alder, Maple, Elm, Larch, 

 Spruce. In all these species as long as loss by respiration was 

 demonstrable this loss was supplied by the root much more than 

 by the stem, so that this may be assumed as a law. The root 

 respires, but does not assimilate, hence this loss. The same 

 progress of changes in substance as in beech is noticeable, except 

 in those oaks which have August shoots. These produce a sec- 

 ondary annual ring as is well known, and also a repetition of the 



