RUBBER PLANTING 103 



be recommended which is scarcely practicable on in- 

 dividual estates. This is the method of selection by 

 progeny which has been practised with great success 

 in the case of many annual crops. The method con- 

 sists in planting a number of definite areas, each of 

 an acre or less, with seed taken from the best yielding 

 individual trees selected over as wide an area as possible. 

 If practicable the seed of at least fifty trees should be 

 separately planted in this way. When the different 

 plots come into bearing their yields should be compared, 

 and a few of the best plots retained for seed bearing. 

 On the selected plots a comparison of individuals should 

 again be made by the only reliable test, namely indi- 

 vidual tapping, and the best yielding trees only should 

 be allowed to stand. The analogy of cinchona would 

 lead us to believe that if this method is carried far 

 enough a very marked increase in the average yield 

 of latex may be obtained. In Java the proportion of 

 alkaloid in the bark of the introduced cinchona plants 

 has been very nearly doubled by careful selection. 

 There is good evidence to show that the variation in 

 the yielding capacity of Hevea trees is considerably 

 greater than the normal variation in richness of cin- 

 chona bark. 



Draining, Irrigation, Roads, etc. 



Nurseries having been properly established, attention 

 may next be turned to the preparation of the fields for 

 planting. In the first place some kind of draining will 



