74 
mustard as a catqhcrop for rubber. 
A correspondent writes to the local papers under the initials ■ 
S. W. H. to recommend the planting of mustard as an ideal not 
remunerative crop among rubber as giving that nitrogen to the soil in 
which it is so rich and abundant. It also, ihe says, is “ a vermicide 
and has weed killing properties.” The ordinary mustard plants 
cultivated in cold or dry climates naturally will not grow in our wet 
and hot one. The Chinese, it is true, grow a variety of which the 
leaves are eaten, but it is hardly worth while to recommend this plant 
which requires heavy manuring here. What does he mean by its 
nitragenous qualities? Not being a leguminous plant it is not pro- 
vided with the well known nitragenous galls that Tephrosia, Clitorta , 
etc., have/ and is of no use in that direction. What is meant by its 
weed killing properties? Does not a mustard plot require as much 
weeding as any other plant and is it itself not a weed? 
Its vermicidal properties would seem to be an allusion to the 
practice of evicting earth worms from flower pots by the use of 
powdered mustard seed, as often practised in Europe. I he plant 
itself has no such effect, and if it did it would be a good argument 
against its use, as one of the greatest defects in the soils of this region 
is the absence of the earth-worms which if abundant would immensely 
improve the soil. 
It is really regrettable that people should publish such nonsense 
as this recommendation. We have had a number of such pieces of 
advice given by people really not at all qualified to give any, recom- 
mending the use of quite unsuitable and useless plants for cultivation 
in stron^ language. Such plants in late years we Combretum sundai- 
cum, the so called anti-opium drug, Ocimum viride, the anti-mosquito 
plant Commdina nudi flora, Lucerne, Comfrey as weed killers or 
valuable forage plants, the Manicoba rubbers which have proved com- 
plete failure etc. 
These recommendations reprinted in all kinds of papers mislead 
people into investing money and wasting time in attempting to glow 
them only to discover they are useless and that the adviser had not 
experimented with them and was only guessing that they might prove 
useful.- Ed. 
SPANGLE— SCALE ON SOURSOP. 
A correspondent from Ipoh sends some leaves of sour-sop 
muricata bearing the pretty silver spangle scale know " “ in 
expmsum var metallic!, m. This scale is common on “eg trees. 
Singapore and Penang. I have not previously seen on&>ur-s 
and the correspondent says he has not seen it on any 
the garden. The insect is never so far as I have seen abundant a 
many scale insects are, one sees but one or two on a leaf. It is 
