BY J. H. MAIDEN. 21 



iiouncement modified, although direct reference to it in the 

 present paper is but scant. Speaking of E. globulus, 

 Labill., the authors remark, "Its botanical and chemical 

 "characters never seem to alter, v/hatever hemisphere it 

 "may be planted in" (p. 154). 



In another place (") I have pointed out that mannas, 

 kinos, oils, etc., are non-essential but accessory or adaptive 

 (;haracters, and examination of them can simply be looked 

 upon as aid to diagnosis. 



One of the functions of volatile oils is assumed to be 

 protection of the plant against the attacks of animals. This 

 is certainly not operative against opossums and native 

 bears, but it certainly is as regards herbivora introduced 

 by the wdiite man. 



Every grower of plants for the distiller of essential oils, 

 e.g., those of Mitcham, England, knows that there may be 

 variation in the crop in two adjoining fields. The cham- 

 pagne grower also knows this well. Different parts of the 

 Orange tree (leaves, flowers, fruit) produce oils with differ- 

 ent odours. I have elsewhere dwelt on these points, (^) 

 giving numerous additional instances of the variation of 

 accessory characters, and these need not be repeated here. 



The Gardeners' Chronicle recalls that Comes has stated 

 that if a plant, which in its wild state was of therapeutic 

 value, be cultivated for several generations on manured or 

 in-igated soil, it becomes in time quite useless, owing to 

 the disappearance of the active principles. (^) 



The inteipretation of qualitative and quantitative re- 

 sults of oil distillations is of great value to enable us to 

 Tinderstand the relations of the species of this complex 

 genus, and also to check, if necessary, detei-minations ar- 

 rived at on taxonomic evidence. The present writer was 

 the first to lay down a plant for the distillation of Eucalyp- 

 tus leaves, in order that the products of each species might 

 be rigorously kept apart, and also the fir,st to insist, at least 

 as regards this genus, that every product of it, leaves, 

 flowers, fruits, oils, mannas, kinos, barks, timbers, should 

 be considered in all their interrelations, so that the relative 

 values of the differing entities we at present record as 

 species, might be appraised. 



The only thing fixed in Eucalyptus is the taxonomic 

 type of each species, and, unfortunately, since Australia 

 and Tasmania were in the early days looked upon as mere 



(3) Proc. Roy. Soe. N.S.W. xxxvi., 336 (1902). 



(4) Critical Revision genus Eucalyptus, i., 248. 



(5) Phann. Journ., p. 5S7, 4th Novembei', lail. 



