PLATE XVI. 



A TYPICAL GUM BARK. 



Eucalyptus saligna, Sm. 



The largest group of all, having a smooth, pinkish, yellowish tint, or whitish bark. 



powdery on the outside. 



The principal constituent in oils of most species having barks of this character is 

 cineol, the terpene being pinene. This is so with those of E. globulus, E. goniocalyx, &c. 

 On the other hand some " Gums " also yield phellandrene oils in which little cineol occurs 

 as for instance E. arcades, E. coriacea, &c. A greater variety of oils is thus found in 

 this division than obtains in anv of the others. 



