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 sufncieiith 

 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 It. 

 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 noi 

 eaten by animals or insects, and therefore it cannot pro\ 

 attractive to rats or other undersirable animals as are ground-nui> 

 or other leguminous plants with edible fruits. 



It is a native of Brazil, and like Lantana, Tithonia, and 

 Hevea braziliensis itself is an interesting instance of an e\< 

 plant, finding here, in the country to which it has been introduce* 

 conditions as favourable, and probably more so, than those in i 

 native land, and consequently growing and spreading w«n 

 great energy. 



The only point against this plant is the presence of sharp, 

 |™rdthorn S whichmakew 



but this is unimportant during the earlier years of a p lantan 

 before tapping. A plot of Mimosa has been laid out « 

 experiment station for seed purposes, asd this will be useu 

 mowing or planting down an experimental plot of rubber, a 

 held of rubber has been laid down with this plant. During 



I have been searching with not much success for so jf 

 -ndividual plants which possess fewer or smaller thorns, 



