April 1. 1904 
SCIENCE NOTES. » 
The student is inclined to ask why the 
modified system of Jussien, now generally 
used, should be called ‘natural.’ An 
auswer is that it is less “artificial” than 
that of Linnaeus. - Under the latter sys- 
tem the number of stamens and pistils is 
the first guide to the classification of 
plants. This is so simple that even now 
it is not unfrequently used, the natural 
system being taken up later on just as 
Linnaeus himself looked forward to. But 
this mechanical method of sorting is little 
better than indexing a library by the color 
of the binding of the books, or by their 
size. In both cases the artificial system 
brings together individuals absolutely 
diverse. A natural system seeks to estab- 
lish affinities amongst the things grouped. 
It is evident that with so complex a struc- 
Apples at the Adelaide Show. 
ture as a plant several parts might have 
been chosen as starting points; for 
example, the leaves. But that part which 
has the most permanence is the most suit- 
able, and the organs of reproduction. have 
been found to have the highest claim. The 
natural system, then, takes into primary 
account the stamens and pistils, but also 
their arrangement, and the form and ar- 
rangement of the including petals and 
sepals; the seed, too, with its enclosure 
and its internal structure, is also brought 
into account. As secondary characteris- 
tics the leaves, and, in ‘fact, every other 
part of the plant, are duly considered. 
Thus in the large group of Acacias the 
flowers are often so similar that the leaves 
are important guides. The natural sys- 
tem claims to establish affinities, but. that 
by no means,applies to size or even general 
THE AUSTRALIAN GARDENER. 
appearance. Thus the apple, Rose, and 
strawberry belong to the same order, but 
for any similarity of appearance they musti 
also belong to the same tribe or. sub-order. 
Nor must the student be discouraged if he 
finds ‘exceptions’ to the general descrip- 
tions of *the orders; Nature will not be 
bound by rigid definitions. He will even 
find differences of opinion as to which order 
certain plants best fit in, just as certain 
animals are either goat-like sheep or sheep- 
like goats. If, however, he is wise he will 
not at first trouble himself about’ excep- 
tional cases, but will seek to acquire a 
knowledge of the broad characteristics of 
each order, and its differences from and 
agreements with, adjoining orders. He 
can then for himself test the claims of the 
‘natural’? system: the Labiates will do 
well for a commencement. 
The Orchard. 
OPERATIONS FOR APRIL. 
By W. J. ALLEN. 
In case the grower intends giving his 
orchard two ploughings, the first should be 
completed at as early a date as possible. 
Outside of this, the land should have as 
complete a rest as possible until the winter 
ploughing, when all weeds which may have 
grown will be turned under while still 
green, and before they seed. It is now 
rather late to sow seeds for green crops, 
as there are very few crops which will 
make much of a growth between now and 
August, which month in most instances is 
quite late enough to do the winter plough- 
ing. * Sted 
5 : 
ie 
Planting of citrus trees may be con-- 
tinued this month. When autumn plant= 
ing 1s practised, care should be taken im 
handiing such trees not to expose the roots 
to either wind or sun for any time. 
Codlin moth bandages must still be kepis 
on the trees, as, even after all the fruit is 
removed, an occasional grub finds its way 
to the bandage. ain 
Trees badly disfigured by the ravages of 
woolly aphis, are a source of danger in the 
orchard, as are also rough-barked varieties: 
of cither apples or pears, as in the ruptures 
caused by the woolly aphis will be found 
numerous grubs, as also underneath the 
rough bark, and it is a question whether it 
would not pay to cut all trees well back or 
down, which are in very bad condition, as 
I feel sure it will be impossible to eradi- 
cate the moth while the trees offer suclr 
Kindly lent: by the Proptietors of the “ Adelaide Observer.” 
excellent harbor for the grubs. _ It is very 
noticeable when removing bandages that 
those trees which are badly disfigured with 
woolly aphis are rarely found to have many 
moths under the bandages, but on a close: 
inspection of the knobs grubs may be found 
in all of them, and where this is the case, 
there is 4but slight hope of ridding the 
orchards or districts of this pest. 
All dormant bud ties may be removed 
this month. ; 
The stones and pits of the different fruits 
required for stock-raising may be planted 
this month. 
Trees required for refills or for planting 
new orchards should be secured as early a= 
possible, and all land which is to ve planted 
should be prepared without delay. 
In. purchasing trees deal with nursery~_ 
men who are known to have a good reputa- 
tion, and who are raising their own trees, 
