INFLUENCE OF BUSH FIRES ON DISTRIBUTION OF SPECIES. 105 



Australiensis " of Benthara and Mueller. The doctrine of the 

 '" survival of the fittest " has been generally accepted by scientific 

 men, but there are certain modifications which must be always 

 laken into account. 



The few species of scrub bushes already referred to in the early 

 part of the paper had no difficulty in holding their own until the 

 fire destroyed them, and then they disappear for a time at least, 

 and a few of their nearest relatives took possession of the ground, 

 along with a much feebler but more beautiful species of plants. 

 The wild flowers in Australia had not much to contend with until 

 the arrival of the white man. Then commenced a general 

 destruction against forest trees, shrubs, and wild flowers, and this 

 has continued down to the present day. Bush fires I have no 

 doubt, were common enough when the Aborigines had possession 

 of the country, and the effects then would be the same as they are 

 now. When we read of a bush fire, we generally think of so many 

 square miles of trees and shrubs destroyed, perhaps half a mile of 

 fencing and a selector's barn burnt. We may visit the scene 

 immediately after, and all that we see is scorched gum-trees, burnt 

 shrubs, and the grass and wild flowers completely destroyed. If 

 we should visit the district a few years later, the scene will be 

 completely changed. The grass is richer and more abundant, the 

 wild flowers more numerous, and new shrubs and trees have taken 

 the place of those destroyed by the fire. Bush fires must have 

 had a most important influence in the distribution of species in 

 Australia. Many of them were of great extent ; hundreds of 

 square miles of country laid waste in one sense, and yet in another 

 hundreds of square miles prepared for the perpetuation of humbler 

 forms of plant life. We read of the influence of water in the 

 distribution of species, of the influence of the wind, of the agency 

 of birds, and many other operations at work fulfilling the same 

 ends ; but I am not aware that any one has called attention to 

 what is going on before our eyes every summer in Australia, when 

 at the expense of a certain number of forest trees, and scrub 

 bushes, space is given for a hundred species of plants and flowers, 

 which gladden our hearts as we walk abroad and make our lives 

 all the happier because of their existence. 



List of plants collected and arranged according to the " Flora 

 Australiensis " : — 



DlLLENIACE^E. DltOSEEACEiE. 



Hibbertia stricta Drosera spathulata 



,, fasciculata „ binata 



„ dentata 



„ virgata m 



° Teemandre^;. 



ViOLAftiEiE. Tetratheca juncea 



Viola hederacea ,, ericifolia 



