564 Forestry Quarterly 



the same time thickest-walled fibres were present in the strongest 

 specimens. 



The general range of variation in fibre length was not found to 

 be greater within the species than in the individual tree. From 

 ITOO measurements of 15 specimens of Longleaf pine {Piniis 

 palustris), and 900 measurements of Douglas fir (Pseudotsuga 

 tasi folia) it was found that the largest fibres occurred in the 

 earliest spring wood ; the length then decreased gradually and the 

 shortest fibres were present in the last formed layers of the 

 ring. 



The root fibres of Longleaf pine and White pine were found to 

 have a fibre length as long as, or even longer than, that of the 

 trunk fibres. This may enable the pulpmill to utilize stumps 

 obtained where land is being cleared, or the chips from which 

 resin has been extracted, for a strong craft pulp. 



In general, the hardwoods or angiosperms have a shorter fibre 

 than the softwoods or gymnosperms. All other things being 

 equal, the strength of a pulp varies with the length of the fibres 

 composing it. 



The early or spring-wood fibres are always longer than the 

 late or summer-wood fibres. The data obtained from about 80 

 specimens indicated that less than one-fourth of the fibres found 

 in every hundred macerated fibres were sum'mer-wood. In two 

 cases the summer-wood fibres made up about one-third of this 

 amount; in both cases this large number of fibres was found in 

 wood from very low down in the tree. The percentage and char- 

 acter of the summer-wood fibres are significant factors in de- 

 termining the character of a wood to be used for pulp. 



R. Z. 



Science, Vol. XLI, No. 1043, p. 179. 



STATISTICS AND HISTORY 



From the 7,500,000 acres under forest 



Prussian management in Prussia there is expected 



Forest Budget for the year 1915 an annual yield of 53 



cubic feet per acre. Ninety per cent of the 



total area is devoted to forest production. The gross income is 



estimated to be $5.15 per acre and the expenses $2.32, so that the 



