340 J. H. MAIDEN. 



yield different oils, botanists will (as I have already done) still 

 further examine them to see if they possess morphological 

 differences that are at present not obvious to our own eyes. 

 When any differences are detected surely it will be then 

 time enough for a new name to be proposed, for at present 

 it is obviously impossible for the botanist, unless he subjects 

 the plant to distillation, to say whether he has collected 

 E. stricta, Sieb. or E. apiculata, Baker and Smith. 



Messrs. Baker and Smith's statement that there is no 

 morphological difference between the plants and yet the 

 oils vary, may surely be interpreted as evidence in favour 

 of the view that the oils in plants vary according to environ- 

 ment. It is a matter of common experience in Europe 

 that the same plant, cultivated in different soils and situa- 

 tions, yields oils varying much in quantity and character. 

 Acting on that experience cultivators only attempt to grow 

 oils of certain grades in special soils and situations. I think 

 I have shown, beyond doubt, that all other characters of 

 Eucalyptus vary. There seems to be no evidence why the 

 oil should present a remarkable exception to the general rule. 



It seems strange to me that with evidence (as I contend), 

 simply inexhaustible, of variation in Eucalyptus, both as 

 regards spontaneous and cultivated plants, where it is 

 sometimes necessary (I believe) to name a plant with the 

 qualifying note that another botanist may have good 

 grounds for placing it in an allied species, this doctrine of 

 variation apparently does not command universal accept- 

 ance. It seems to me that the "non- variation" theory 

 ruis counter to some of the most generally accepted sets 

 of practical observations on which the doctrine of evolution 

 of species is based, and there is just a little danger of what 

 Darwin terms "arguing in a circle" in presenting the 

 observations that are interpreted to destroy the dogma 

 which many of us look upon as built on unassailable facts. 



