Comparative Constancy of Specific Characters 

 of Eucalyptus Species. 



The reputed or supposed greal variation oi individual Eucalyptus species has 

 arisen probably by the attempts oi botanists to found -pirns on morpholo 

 characters alone ; and Bentham, when working on this system, experienced great 

 difficulty in finding any constant feature upon which even to establish groups, 

 and had to discard such differences as opposite or alternate leaves, comparative 

 length oi the operculum, length oi calj \ tube &c. He finally sele< ted the shape 

 ol the anthers as a means oi classification, but even this has since been found 

 to be defective and is open to objections. Bentham evidently fell thai even 

 this was not such a natural classification as he would wish, be< ause m his remarks, 

 B. FL, iii. p. 186), he expresses a hope thai a " truly natural arrangemeril 

 may be founded on a knowledge oi the 'Gum ' trees in a living slate, upmi the 

 proposed cortical or on any other system which experience may suggest." However, 

 ire quite in accord with him when he states, concerning his classification, 

 thai ' the groups pass very gradually into each other through intermedial 

 forms," and our results confirm this gradation of groups; bu1 i1 is the individual 

 species that shows a comparative constancy of specific characters throughout 

 iis known geographical distribution. Not only is this the case with the 

 botanical characters, but also in their chemical constituents, a conclusion fully 

 confirmed by the mass of evidence we are now able to submit in connection with 

 the species here enumerated, and as the resnlt of a research extending over a 

 period of thirty years. 



Tire most serious objections to Bemham's antheral system are:— 

 i. That of placing in the same group, and hi juxtaposition, species which 

 to those familiar with the trees in the field, are perfectly distinct from 

 each other ; and 

 2. Thai of separating under various sections trees which bj hark, wood, 

 habit, general characters, chemical properties of their oils, kinos, dyes, 

 &c, ought to stand near to each other. 

 For instance, in the former case, with the smooth barked " Mountain 

 Gum" (E. goniocalyx), the " Bundy Box" (E. elceophora), was confounded or 

 associated. The " Apple " of Victoria, with its red timber and stringy bark, 

 was placed with the " Apple " or ' Woollybutt " ol New South Wales I 

 Bridgesiana) , a tree with a pale coloured timber, and a " Box " hark; numerous 

 othei examples could also be given, and similar associations will no doubt o< 

 uv student oi the Eucalypts 



The second case could be illustrated by the " Ironbark " trees, which 



might be grouped together, hut \ I tand apart; whilst with them were 



included tie " Scribbly Gum" (/:'. hcemastoma), "Tallow wood" (E. microcorys) , 



and others nee- which have quite distinctive characters and should he 



iarated. 



Probably it has been the effort to utilise this and similar systems that 

 has led to the acceptance oi the idea oi great variability oi Eucalyptus species, 

 I. ut from the results ol this extensive study we consider that only in exceptional 

 -l- in h nuani es exist, even under ,i natural ' lassification. 



