Water-Conductivity of the Wood in Trees and Shrubs. 223 



variation in an individual species is far narrower than in the deciduous forms. 

 The Holly affords a good example of this character. The specimens used for 

 the experiments were cut from trees and bushes of the juost diverse habitat, 

 some growing in wet soil near a brook, others in woodland shade, others again 

 were hedgerow trees on well-drained sandy soil, fully exposed to wind and 

 sun. No constant difference was observed between shoots bearing prickly 

 leaves, and those with laurel-like foliage. The subjoined Table will illustrate 

 the points just mentioned, and it also shows that the uniformity of the wood 

 is independent of its cross-sectional area and the age of the twig. Of course, 

 in this, as in all the other examples, only the. sap wood is under consideration. 

 No branches with functionless heart wood were used. Naturally also, 

 properly ripened wood must be taken. Young or immature wood always 

 gives a relatively low reading and of quite uncertain value. 



Table II. — Twenty-eight Twigs of Holly from Different Trees Growing in 



Diverse Situations. 



Age in years. 



Area of wood in inclies 



Absolute vol. in c.e. 

 per i hour. 



Specific Tol. in c.c. 

 per i hour. 



( X 10). 



2 



2 

 2 

 1 

 2 

 2 

 2 

 2 



1 

 1 

 1 

 1 

 2 

 2 

 2 

 2 

 3 

 2 

 1 

 3 

 1 

 1 

 1 

 1 

 2 

 2 

 2 



1 

 1 

 1 

 1 



2 

 3 

 6 

 4 

 6 

 1 

 2 

 3 

 2 

 1 

 1 

 1 

 4 

 3 

 3 

 2 

 1 

 2 

 2 

 1 

 4 

 4 

 4 

 2 



•60 

 •45 

 •19 



•36 

 •74 

 •48 

 •19 

 •84 

 •36 

 ■93 

 ■56 

 •74 

 ■49 

 •59 

 ■77 

 ■24 

 ■76 

 ■30 

 ■28 

 ■60 

 ■98 

 •47 

 •49 

 ■52 

 ■73 

 •23 

 •34 

 •72 



1 1 

 10 

 0-6 



0- 7 



1- 6 



1- 7 

 3-0 



2- 6 

 5-0 

 1-4 

 1-5 

 1^9 

 1-3 

 1-2 

 0-9 



0- 7 



3- 3 



1- 8 



2- 

 16 

 1-2 

 1-4 



1- 2 



0- 8 



2- 3 

 2-7 

 2-2 



1- 9 



7 "5 



7- 

 12-2 

 11 3 



8 9 

 7^8 



8- 1 



9- 8 



7- 9 

 8^6 



8- 6 

 7-4 



9- 4 



7- 9 

 9-4 



8- 6 

 7-9 



6- 8 



7- 6 

 10-0 



7- 8 



8- 6 



10 ^8 

 10 -5 

 7^8 

 8^0 

 9-0 

 7-7 



82 ^94 



46 •e 



242-4 



(=5 ^35 sq. cm.; 

 actual size) 



ATerage = 8 ^7 



