.342 Journal of Agriculture, Victoria. [11 June, 1917. 



Fig. 2 is also Jonathan wood, but two years old, and its natural size 

 was 5-inch in diameter. The pith (a), which has practically ceased to 

 act -as a sap channel, is narrower than that in Fig. 1. This is due 

 mostly to the pressure exercised on it by the ring of two-year-old wood. 

 The sap wood (c), cambium (d), and the bark (e) correspond with 

 those marked (b), (c) and (d) respectively in Fig. 1. 



Plate 99. — Skeleton of upper surface of an Emperor Alexander leaf. 



The gradual outward movement of the cambium enables it to retain 

 its connexion with the channels through which it is essential the return- 

 ing elaborated sap should flow, and this facilitates its even distribution 

 through the tree. 



Plate 94, Figs. 1 and 2, are longitudinal sections of one-year-old and 

 two-year-old Jonathan wood respectively. These show the various 

 strands and tissues of the stem in the direction of their length. 



