30 president's address. 



the typical micro-organism. Evidence has also been obtained 

 to show that the failure to ferment glucose is associated with tlie 

 absence (or diminution) of the reducing ferments in the cell. In 

 this way, the intermediate substance from which formic acid, 

 acetic acid, and alcohol is formed, is not decomposed. The 

 selection by the sodium mono-chloracetate can thus be explained 

 on a rational chemical basis, since those microbes endowed with 

 reducing qualities would liberate hydrochloric acid, and thus 

 occasion their extinction. Only microbes in which the reductase 

 is absent or diminished, would survive. 



The study of these micro-organisms has made it evident that 

 the characters of these plants are determined by the conditions 

 of the environment. The question remains as to whether such 

 a conception can be applied to higher forms. Have soil and 

 climate any influence on the structure and functions of highei- 

 plants? There is much to suggest that the forms of plants are 

 dependent on the interaction with the environment. Before 

 this problem can be considered, it is necessary to obtain a better 

 knowledge of the plants which occur together in any district. 

 Owing to the small aboriginal population and their low state of 

 civilization, there has been little interference with the flora of 

 this Continent. Studies can be made upon areas in which plants 

 have grown together with little, if any, human selection. These 

 areas are, however, being settled by the white population. 

 Before these areas have been destroyed, it behoves our naturalists 

 to make their survey. In this vast continent, we can travel 

 from Cape Otway, in the south, to Cape York, in the north, 

 without losing sight of one or other species of Eucalyptus. It 

 is possible to go from Sydney, in the east, to the western shores 

 of Australia without missing anywhere the familiar Eucalyptus. 

 Is it not possible to determine what characters have enabled 

 these trees to extend over such a vast area"? May I suggest to 

 you that the members of our Linnean Society consider the sys- 

 tematic study of the distribution of our plants and the factors 

 w^hich determine their association. Such a labour would be a 

 worthy memorial of the work of this generation, and would 

 remain a testimony of our appreciation of the benefaction of our 

 revered founder. Sir William Macleav. 



