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thus increase the amount of plant food available in the soil where 
they are growing. This property of leguminous plants has been 
the subject of a large number of practical experiments which 
have definitely shown the improvement of soils where bacteria- 
bearing leguminous plants are growing. 
The introduction of a leguminous plant in rubber estates to 
take' the place of the weeds which grow so vigorously and are so 
expensive means therefor an automatic manuring of the soil, and 
a conservation of surface soil which will otherwise be frequently 
washed away. . 
The best plant for this purpose is one which is sufficiently 
vigorous under all conditions to spread and hold its own against 
other weeds when once introduced. A plant which needs careful 
attention in order to make it cover the ground is unsuitable and 
might be as costly to maintain as weeding. 
During the past year I have been carrying on observations 
and experiments with a view to the discovery of a suitable plant 
and believe that sensitive plant Mimosa pudica fulfils to a much 
greater degree than any other the required conditions. I have 
examined a large number of plants on different soils, in the open 
and under partial shade, and have found in nearly all cases that 
their roots contain' nitrogenous nodules. It grows vigorously, 
and is one of the very few plants which can compete with “ lalang ” 
( Imperata arundinacea) with any chance of victory. In size it is 
suitable as it seldom grows to a greater height than 18 in. to 2 ft. 
It is peculiarly free from attacks of fungi and insects, a character 
which is of importance in any plant which it is proposed to introduce 
in large quantities among cultivated plants. It’s fruits are not 
eaten by animals or insects, and therefore it cannot prove 
attractive to rats or other undersirable animals as are ground-nuts 
or other leguminous plants with edible fruifs. 
It is a native of Brazil, and like Lantana, Tithonia , and 
Hevea braziliensis itself is an interesting instance of an exotic 
plant, finding here, in the country to which it has been introduced, 
conditions as favourable, and probably more so, than those in its 
native land, and consequently growing and spreading with 
great energy. 
The only point against this plant is the presence of sharp, 
hard thorns which make walking bare-legged through it unpleasant, 
but this is unimportant during the earlier years of a plantation 
before tapping. A plot of Mimosa has been laid out at the 
experiment station for seed purposes, asd this will be used for 
sowing or planting down an experimental plot of rubber, and a 
field of rubber has been laid down with this plant. During the 
year X have been searching with not much success for some 
individual plants which possess fewer or smaller thorns, or if 
