Aug.,"! Kelly, Plant Distribution in the Healesville District. 65 



1914 J -' 



repatriation for a long period, yet the same burnt soil is 

 sanctuary for Cassinia, Acacia, Eucalyptus, and the harder- 

 seeded leguminous and myrtaceous plants, as also for the 

 extremes — mosses, ferns, fungi, and Marchantia — particularly 

 the latter. Fire thus accounts for the total or partial elimina- 

 tion of some species and the predominance of others. It has 

 also another mode of causing a change in the relative pro- 

 portion of trees by its effect on mature forms, for, whilst it 

 destroys absolutely most other individuals that it attacks at 

 all badly, of the eucalypts the smooth and finer-barked 

 ones rarely recover ; those with fibrous barks, such as E. 

 ohliqua and E. Stiiartiana, not only recover but send out strong 

 side shoots, which, though spoiling the trees for timber 

 purposes, produce abundant fruit. The protective feature of 

 the smooth, white-barked eucalypts is that they do not readily 

 catch fire, and in a swift blaze escape altogether. 



On the southern face of Mount Monda is a patch of some 

 acres in extent which has been completely divested of the 

 upper story of vegetation (eucalyptian) and of the lower 

 stratum (sclerophyllous bush). The soil was apparently 

 shallow, and rain falling and running down the steep hillside 

 exposed the rock, which subsequently gradually became covered 

 with lithophytes ; these, supplemented by soil washed from 

 higher parts, the growth of moss, and banking on lower edges 

 by talus, have formed a distinct field of special vegetation 

 selected from the environs — a pteridetum interspersed with 

 xerophytes, mostly of leguminous genera. Ground not rid of 

 soil, often, after fire, rehabilitates itself — first by fungus and 

 soon after by strong growths of Marchantia, both the common 

 M. polymorphia and the rarer M. tahularis. In close associa- 

 tion with these follows Polytricha commune, and they are the 

 forerunners of a new but long-deferred vegetation, often 

 heralded by introduced weeds. The associations of Pteris 

 aquilina are noteworthy. Sometimes they are spread in open 

 formation right through an extensive area of timber country, 

 at others scattered individuals only are found ; but the usual 

 habit is in large clumps. These last close formations are to 

 be attributed to drifts of wind-blown spores rather than any 

 congenial character of soil, feature of situation, or light. This 

 is exemplified by patches in older cleared paddocks, which have 

 been more or less cultivated and generally used for grazing. 

 Clumps of bracken may be seen growing against fallen logs 

 and around trunks or stumps of trees — not that there is any 

 virtue in these to attract the plant, but they have formed 

 breaks against which the spores have piled, and, retaining 

 moisture, have sheltered growing young and formed at each 

 spot a pteridetum. These features are not peculiar to this 



