122 R. T. BAKER AND H. G. SMITH. 



while eucalyptol is almost if not entirely absent. It may thus be 

 assumed that organic differences are present and indicated by the 

 venation of the leaves, and we conclude that like differences will 

 be eventually detected in many other species of Eucalypts when 

 the investigation shall have been carried more deeply by systematic 

 research. 



The oil of E. striata contains a little aromadendral but no- 

 peppermint and it is one of the richest in eucalyptol that we have 

 investigated. The matter thus becomes of technical importance, 

 because if the two trees are not systematically separated, then the 

 products would be different, and if worked, disappointment and 

 perhaps loss would necessarily follow. We thus propose to make 

 the Berrima form distinct, and to give it specific rank under the 

 name of Eucalyptus apiculata. 



In summarising the results there appears every reason to sup- 

 pose that with the Eucalypts a gradual deviation from a type has 

 taken place, and that the formation of characteristic constituents 

 in these oils has been contemporaneous with the characteristic 

 alteration or deviation of the venation of their leaves. That the 

 constituents have been fixed and constant in the oils of the several 

 Eucalypts for a very long period of time is demonstrated by the 

 fact that whenever a species occurs over a large area of country 

 the constituents of the oil are practically identical also, only differ- 

 ing in about the same amount as is to be expected with the oils 

 from trees of the same species growing together in close proximity 

 to each other. The venation of the leaves of individual species 

 is comparatively similar throughout their geographical distribution, 

 and their botanical characters show also a marked constancy. All 

 this comparative constancy is probably accounted for by the long 

 period of time that must have elapsed before a particular species 

 could have established itself as such over so extensive a range 

 as we find species to-day. 



The chemical and botanical peculiarities must also have been 

 fixed primarily, because we do not find the differences in characters. 



