68 J. H. MAIDEN. 
ledge, been yet attempted. The ascertainment of the rate of 
growth of exotic trees in various districts is also of great practical 
importance, and the data are often more readily available than is 
the case with indigenous trees, as, since as a rule they have been 
planted by man, approximate dates of planting are often ascer- 
tainable. 
Natural Re-afforestation.—A_ phase of the forest question that 
is not often enquired into is the conversion of grazing land into 
forest growth since European settlement. It isa well ascertained 
fact that, since the advent of the white man, a growth of trees, 
more or less dense, has, without artificial planting, taken possess- 
ion of grass land. Enquiry might be made into the circumstances 
of each case, for opinions are by no means unanimous as to the 
cause of these forest growths. The reason of this change is 
attributed to the overstocking of country, the stock eating down 
the grass, so that bush-fires, (which formerly consumed the seedlings 
of forest-trees), are now less frequent, and devastate smaller areas 
of country, than they used todo. In some cases there is no doubt 
that stock aid in the propagation of trees by trampling the seeds 
into the ground, and even manuring the ground, thus preventing 
the seed being washed away by rain. At the same time one 
must not lose sight of the fact that stock have important influence 
on the formation of natural forest growths, as they eat out (par- 
ticnlarly when grass is scarce), many young trees. 
d. Horticultwre.—Many of our plants are well worthy of culti- 
vation for ornamental and other purposes. The merits of but few 
are known to horticulturists, so that there is room for much 
enquiry.' Some desirable’ plants are sparingly distributed ; in 
regard to these we require full data as to localities, with particulars 
as to soil, aspect, etc., and particularly the season for maturing 
8. 
1 See “ Some New South Wales Plants Worth Cultivating for Shade, 
Ornamental, and other Purposes.” —Agric. Gazette N.S.W., vi1., 341, (June 
1896). 
