THE EUCALYPTUS IN THE FUTURE. 667 



inches long, in the specimen from which this was sketched. Alluding 

 to the difficulty in denning the species, Woolls says, " Botanists, from 

 Robert Brown to Baron Muller, have endeavored to reduce the vary- 

 ing forms to systematic arrangement," but without success. And a 

 vast amount of acumen and ingenuity has been brought to the task; 

 such as the consideration of the operculum or cap of the flower-bud, 

 and the length of the pistil. Compare the long pistil in the seed-ves- 

 sel of E. Preissiana, left side of Fig. 1, with the short one in the 



Fig. 2. Eucalyptus Macrocarpa. 



flower of E. Globulus, in Fig. 3. The form of the anthers and the 

 seed-vessels, and the texture of the bark, have all been taken as fac- 

 tors of the problem. 



Owing to the bluish-green of its leaves, E. globulus is popularly 

 known as the blue-gum tree. Abroad it is most known outside of its 

 systematic name as the Tasmanian gum-tree, and Australian fever-tree. 

 Among the settlers, gum-tree is the general name of the eucalypts. 

 But, as might be expected of a genus so numerous in species, there are 

 many trivial names, such as blue-gum, brown-gum, the red and the 

 white mahogany, stringy-bark, and iron-bark, etc. The botanists 

 reckon 150 varieties. These all belong to the great order Myr- 

 tacece, or myrtle-blooms. And a decidedly respectable relationship 

 have these trees which shed " their medicinal gum," for they are close 

 cousins to the well-known myrtle, the pomegranate, pimento, or all- 

 spice, cajeput, and clove. The flowers of this order are known in 

 their structure as calycifloral. Perhaps this curious blending, or con- 

 fusion, of the calyx and the corolla, is shown most interestingly in the 

 flowers of these eucalypts. The calyx is really in two distinct parts, 

 a woody cup below with an operculum or lid above. (See middle fig- 

 ure, bottom of cut 3.) When the flower is ready to open it pushes 



