54 QUEENSLAND AGRICULTURAL JOURNAL. [1 Jaw., 1900. © 
short, so will be the kauri; if, on the other hand, the surrounding timber be” 
tall, then the kauri will be taller. The tree, by the time it is 12 inches in 
diameter, has done all its upward growth. It has reached the free air, and 18 
now at liberty to devote its energies to lateral expansion. Each year sees 
from 5 to 9 inches added to its cireumference—even as much as 123 inches 
have been noted. his rate of increase is continued until the tree has attained | 
50 inches in diameter, when the lateral growth slackens off, but does not cease. 
In the case of the hoop pine, it is drawn up through the dense scrub towards | 
the free air until it reaches it, and has attained a diameter of 10 inches, 80 
following the example of the kauri in seeking the light before increasing i 
diameter, which it does at the rate of from #-inch to 1 inch annually. 
The red cedar makes three growths per annum after topping the scrub, | 
equivalent to an increase in diameter of 2 inches in three years. 
To appply the lesson, let us suppose that one pine-tree is planted at the 
bottom of a gully in the scrub, and another of equal size on the ridge above. 
What happens? The first tree will be drawn up towards the light in a tall, 
straight stem of almost equal diameter at the ground and at the head. - The 
growth will be rapid, given reasonably moist and warm weather, because 00) 
portion of the sapling’s strength is wasted on lateral growth or in throwing” 
out lateral branches. The tree on the ridge will certainly grow quickly till it 
has topped the scrub, when it will taper off, and expend its strength on increasing | 
its circumference and in producing an umbrageous head. This is easily exempli- 
fied in the growth of lowlier plants. Let us take as an example Sida retusa and” 
the jute plant. If either of these be planted singly in the open, they will attain 
no great height. but will throw out a number of branches when the stem is but 
1 foot or so high. Now sow the seeds thickly in some shady spot. It will be 
found that the stems are drawn up till the jute will have attained a height of from 
6 to 8 feet before branching ; the Sida retusa will reach from 4 to 5 feet before | 
doing so. It is the same with many plants. Now the plain inference is that if 
we want to produce tall branchless timber, we must follow the teachings 0 
Nature and plant up the ravines and gullies. Even comparatively shallow 
depressions in the surface of the soil will have a marked effect on increasing the» 
height of the trunk before it branches. I have seen this in a pine forest (the - 
Black Forest) in Germany, where the science of forestry is carried to great 
perfection. 
There the trees are allowed to grow thickly together, that they may be 
drawn up to a suitable height before the forests are thinned; and then by the 
ume the rotation period has arrived, they expand laterally and form fine thick 
oles. 
This growth or “drawing up” of trees is what the Germans call “height: 
growth,” and in an article written by Mr. J. Simpson in the Gardeners 
Chronicle that gentleman defines the term very accurately, and points out those 
advantages of height-growth which any observant traveller in the bush can se?” 
quite plainly. | 
He says:—Theterm “height-growth” in forestryisderivedfrom the German. _ 
Neither the words nor their meaning have ever had any significance in British 
forestry practice, and the importance of height-growth as a factor in the pro-— 
duction of timber does not appear to have ever been so much as thought of | 
On the Continent, on the ates hand, height-growth is the first thing the- 
forester concerns himself about after he has planted his trees. Get height- 
growth, he says, and the rest will come. Height-growth has the same 
significance as “drawn up,” an expression well known to gardeners. ‘The 
editor may perhaps remember me writing to him a year or two back on this 
subject, and asking for explanations of a puzzle that physiologists have not 
yet solved—viz., how trees in crowded woods, dells, and ravines get pulled up 
at such an extraordinarily rapid rate compared to isolated trees in the open 
and how more timber is produced toa given area in that way than when the 
