201 



feet, in rows twelve feet apart. This method of planting, 

 appears at first sight decidedly wrong as the plants stand too 

 close. A planter of Para rubber naturally thinks of the price of 

 every seed he puts in the ground, but this is a minor consideration 

 in the case of the small and rather cheap Castilla seeds. On 

 Zacualpa we have the seeds for the picking, and any quantity of 

 them. 



In planting in the manner described we allow for a high per- 

 centage of failures in germination, we are prepared to give ants, 

 lizards and field rats their due amount, and we still have plants in 

 abundance. This is no theory but has been practised for several 

 years with success. There are no complete failures in any hill, 

 except where planting has been done in ground which is too sour. 

 In such places we may have to replant in small patches after 

 proper draining has been prepared for, and in such cases we use 

 excess plants growing in the neighbourhood. During the firot 

 few months seedlings if backward, misshaped, or where crowding 

 is observed, are cut out at the time of each weeding. Generally 

 we cut at least 50 per cent, of all the seedlings during the first six 

 months. Detailed rules have been worked out for this first thinning 

 and they will be applied in the field by the assistants in charge. 

 Great care is exercised in the selection of the plants allowed to 

 remain, and many points have to be attended to. Thus if a 

 plant branches in a way that does not promise regularity, or if it 

 has grown twisted or bent it is cut out. In selection those plants 

 that show a tapering shape with thick stem are preferred to plants 

 growing mainly in height, and plants with large dark green leaves 

 are preferred to those with small leaves of a lighter or yellowish 

 colour. 



ADVANTAGE OF CLOSE PLANTING. 

 One of the great advantages of this system of close planting 

 and successive thinning is the opportunity for selection, a matter 

 which is generally overlooked, but which, no doubt, will be found 

 to be a most profitable policy. In Castilla cultivation we often 

 get trees which produce very little or sometimes no rubber. It is 

 evident that such trees are an unnecessary expense on the plan- 

 tation. Why should we waste time on valueless trees ? Can this 

 in any way be avoided ? With our present limited knowledge of 

 the nature of the tree we cannot say with absolute certainty 

 whether a seedling will become a good "milker" or not. But in 

 the course of my physiological investigations of Castilla, I have 

 already been able to draw some conclusions, which give us certain 

 indications on which we can judge in this matter. That is to say, 

 we can in some instances say definitely that a seedling, which 

 shows certain characters, will never produce a large amount of 

 latex. On the other hand, we cannot guarantee that a number of 

 non-producing trees would not be passed during the selection 

 time. But we have found a way to reduce their number, and I 

 hope that further investigation will considerably improve the 

 method. There is, however, another important point which can 



