232 Prof. J. B. Farmer. On the Quantitative Differences in the 



observations on some of the other plants, e.g., Plum " Belgian Purple." On 

 the other hand, many species of both evergreen and deciduous plants do not 

 admit of the water conductivity results being grouped in so satisfactory a 

 frequency curve as that of the Privet. 



The Evergreen Oak [Quercus Eex) also stands high, at about 28. Its wood 

 is far less close than that of most evergreens, and contains wide vessels 

 resembling those of the common Oak. It shares with the latter species a 

 considerable degree of plasticity, and in this respect it also departs from the 

 evergreen type. 



The relatively freely transpiring evergreen Portugal Laurel (Frunus 

 lusitanica) has a specific conductivity of about 18'5 ; of 14 specimens 

 examined 10 were within +4 of this amount. The Common Laurel (P. Lauro- 

 cerasus), as might have been expected, ranks much lower, and of 9 speci- 

 mens 6 fell within the limits of 10 + 2. 



A number of other evergreens were examined, but thos^ here mentioned 

 will suffice to indicate the general character of the group. The preceding 

 Table will, however, sufficiently indicate the range of the investigation on 

 evergreens; it will be more fully referred to in a second paper dealing witli 

 the deciduous species of trees and shrubs. 



On the Quantitative Differences in the Water- Conductivity of the 

 Wood in Trees and Shrubs. Part II. — The Deciduous Plants. 



By J. Bretland Farmee, F.E.S., Professor of Botany in the Imperial 

 College of Science and Technology. 



(Received January 23, 1918.) 



If the broad-leaved deciduous trees and shrubs be contrasted with the 

 evergreens, it is found that they are marked by a specific conductivity 

 which in the free-growing and foliage-bearing shoots is far greater than in 

 the class hitherto considered. 



This is well brought out by contrasting the results obtained on comparing 

 an evergreen with a deciduous species of the same genus. The subjoined 

 Table (I) for Euonymus japonica (evergreen) and E. europoeus (deciduous) 

 will serve to illustrate the point. It will presently become apparent, 

 however, that there are certain exceptions to be reckoned with amongst 

 the deciduous trees, especially in the case of young sapling trees and 

 coppice stool-shoots (e.g. of ash or hazel). 



