lo2 KEV. \V. AYOOLLS, ril.l)., F.L.S.^ ON THE 



there is something incongruous in fixing some name of little 

 meaning on any of Nature's gems, or of subjecting them 

 arbitrarily to a generic association unsuitable to them. 



And then again there is a difhcnlty to be overcome in the 

 formation of sub-genera, or the grouping of species in the 

 hirger genera. From the days of Brown to those of 

 Bentham and von Mueller this has been felt especially 

 in Eucalyptus and in a less degree of Acacia. Before the 

 conception of the cortical or anthereal systems, species 

 were thrown together without any suitable arrangement ; 

 but in tJie Flora Australunsis and the Baron's Census, the 

 latter system has rendered the grouping of species of 

 Eucal^^ptus possible. Still, however, there are objections to 

 both systems, for whilst the one is useful in the field and 

 the other in the cabinet, they are both liable to exceptional 

 anomalies, and there is inconsistency in placing in close prox- 

 imity to each other species which differ materially. Here 

 then is a problem yet to be solved. Whilst therefore thanking- 

 those great men for what they have done to remove past 

 errors, and render the identification of many species an easy 

 task, thus affording the means of grouping trees in some 

 respects similar, men of observation can regard the present 

 arrangement of the genus as provisional only, and an 

 instalment towards better things to come. With regard to 

 the genus Acacia, in the describing of which ]\Ir. Bentham ex- 

 perienced so much trouble. Baron von Mueller has furnished 

 a series of figures whereby the character of many species will 

 be clearly seen, and when his work is completed the 

 grouping of the species Avill be comparatively easy. As in 

 Eucalyptus, the flowers of very different trees or sln-ubs are 

 very similar, and IMr. Bentham when dealing with dried 

 specimens, remarked that he found "species with the most 

 discrepant ]K)ds sometimes almost identical in foliage, and on 

 the other hand pods apparently identical sometimes belonging 

 to species widely different in foliage and even in flower." In 

 Acacia therefore the groupijig of the species must be regarded 

 as only provisionally settled until the pods of all the species 

 have been collected and carefully examined, and a system 

 devised founded on the shape and nature of the fruit. 



The arrangement of the natural orders is the last difliculty 

 Avhich 1 propose to consider — a difliculty rendered liighly 

 perplexing by the fact that our most eminent botanists have 

 entertained different opinions on the subject. Passing over 

 some of the minor difterences, it may be sufiicient to notice 



