1 AvG., 1901.] QUEENSLAND AGRICULTURAL JOURNAL. 2929 
own. increase; they serve for the formation of woody fibre and all the solid 
matter of similar composition. The leaves now produce sugar, amylin or 
starch, and acids.” ray 
As soon as the cane is fully developed, the nourishment obtained by the 
organs of assimilation from the atmosphere is converted by the leaves into sugar 
and sent down into the cane for its future development. At this period in the 
growth of the cane, every green leaf is of especial value, as it constitutes both 
a mouth and a stomach. Nature has given plants leaves not to merely decorate 
them, but they are a part of a wondrous system of life quite as perfect as that 
of the animal kingdom. Seeing, then, how indispensable are a healthy foliage 
and a free circulation of air about it, to enable the leaves to assimilate the 
elements of the atmosphere to be converted into sugar by the performance of 
the special functions destined by Nature to the leaves, therefore, to enable the 
cane plant to give a maximum return for a minimum of outlay, it is quite 
evident that a different system of culture from that in vogue at the present 
time will have to be adopted. It is difficult to promulgate a system that would 
be entirely satisfactory, but, instead of the present aim to produce as much 
cane as possible per acre irrespective of sugar, a more rational practice would 
be to select only the best varieties of cane and to plant and cultivate them in 
such a manner as to enable the plant to absorb and assimilate from the soil and 
atmosphere the elements, so bountifully supplied by Nature, to their fullest 
extent. By thus producing less cane and more saccharine matter, 5 to 10 per 
cent. more sugar per acre would be obtained than at present with less labour. 
What mode of planting would ultimately prove to be the best must be decided 
by practical experience ; but, looking at the subject from a vegetable physio- 
logist’s point of view, the following method of planting and culture promises 
excellent results. Sets planted in treble rows thus :— 
5 dike Gg. dba 
5 feet by 4 feet between the sets; the distance between the rows to be 
regulated by the variety of cane and by the fertility of the soil, but probably 
from 12 feet to 20 feet would enable the plants to develop strong and healthy 
foliage and the air to circulate freely among them. Every breeze that blew 
would convey the required nutriment to the growing plant, the air would pass 
freely between the rows, and the leaves would do their work by extracting from 
it the elements necessary to the full development of the plants. All the 
experiments in vegetable physiology carried out by scientific men, from 
Priestly to Saussure and Boussingault, must satisfy everyone that the leaves do 
assimilate carbon from the atmosphere in the form of carbonic acid. 
Boussingault found that by passing air over a vine branch in full leaf the 
leaves actually deprived the air of three-fourths of the whole quantity of 
‘carbonic acid it contained. As soon as the sun goes down the plants absorb 
carbonic acid from the atmosphere, and this goes on all night; but when the 
sun rises the plants commence to decompose the carbonic acid, exhaling the 
oxygen, and retaining the carbon, which, while the plant is growing, goes to 
buildit up. But as soon as the plant has finished its growth, a change takes place; 
it no longer requires the carbon, which thencombines with the other elements, and 
is converted into sugar by the leaves and sent down into the stem to be stored 
‘for the future use of the plant. The office of the cane is to convey fluid 
obtained by the roots from the soil, and called sap, into the leaves for elabora- 
tion and then to receive it back again. No matter how much sunshine may be 
let in on to the canes themselves, it gives them no power to produce sugar ; 
they are only the medium between roots and leaves, and this goes on until the 
growth of the plant is complete for the season, after which the cane is used by 
the plant as a storehouse for the sugar. 
Cane grown on the above lines would require no trashing, so far as the 
production of sugar is concerned; the wide spaces between the rows could be 
cultivated by horse labour during the entire season, thereby producing more 
sugar per acre with a minimum of labour. 
