(a) From Naturally Growing Trees

The most profitable species of Eucalyptus for oil production, considered from a commercial point of view, will be those which, both for yields and quality of oil, can stand the test of competition, so that naturally the continuity of supply enters very prominently into the question, particularly when a permanent plant has been erected.

In virgin forest country where the growth of Eucalyptus species has had free play, many of them, useful for oil production, acquire large dimensions, particularly species like E. globulus, E. dealbata, E. Smithii, E. Macarthuri, E. citriodora, etc. As only the leaves and terminal branchlets are required by the distiller, such large trees are naturally a disadvantage, the material having to be collected either by lopping off the branches or by felling the trees.*

Opinion is divided as to which of the two methods is the most advantageous, and at one time considerable lopping of the branches from big trees was carried out. Lopping, however, is dangerous, and men are adverse to climbing tall trees for the purpose, although in Queensland the method is still adopted with E. citriodora.

More easy collection would naturally be obtained from the "coppice" growth which springs from the short remaining stems of the felled trees, and with many species this is rapidly produced and abundant.

* The bark of E. Macarthuri has, however, been employed for oil production.