Gums, Resins, 



411 



[November, 100S. 



thods used in Ceylon for Hevea, have 

 given unsatisfactory results with Fuu- 

 tumia. The lactiferous system of the 

 two trees cannot be compared. The 

 milk-bearing tubes or cells of the Hevea 

 are divided into well-defined compart- 

 ments, running vertically, with very 

 little, if any, lateral communication, so 

 that, a vertical cut produces very little 

 latex. In the Fnntumia, however, the 

 tubes are longer and not divided to the 

 extent that the milk tubes of the Hevea 

 are. One vertical groove produces 

 more latex than the same length of 

 diagonal grooves, distributed over a 

 wide surface. This points to there 

 being horizontal, or secondary tubes, in 

 Fnntumia, connecting the vertical or 

 primary ones, and this is clearly proved 

 by the microscope. 



A series of vertical grooves made at 

 intervals, say of two months, would 

 at a distance of 4 in. completely tap one 

 tree in the course of a year without 

 inflicting the damage that the spiral and 

 herring-bone systems undoubtedly do. 

 A knife, made on the principle of the Cey- 

 lon V-kuife, would be the best one to 

 use. I find, however, that a slightly 

 rounded apex cuts better and does less 

 damage to the bark of the Fnntumia. 



In preparing an estimate for any 

 forest or plantation venture on the 

 Western Coast of Africa, it is quite use- 

 less and incorrect to count on any rubber 

 coming from untapped trees on the 

 property. A few untapped trees may 

 exist, but they are very few and far 

 between. The native rubber collector 

 knows the value of an untapped rubber 

 tree just as well as a man does, and has 

 greater facilities to seek it out. — Tropical 

 Life, Vol. IV., No. 8, August 1908. 



HEVEA BRASILIENS1S. 

 Experiments in Germination, etc. 



By. T. Petch. 



The latest contribution to our know- 

 ledge of the seeds of Hevea brasiliensis 

 is furnished by Mr. G. Vernet, of 

 Annam. A comparison of his results 

 with the figures obtained in Ceylon is 

 interesting, more especially as the 

 Annam trees, now ten years old, weie 

 grown from Ceylon seeds. 



Mr. Vernet gives illustrations of the 

 seed and details of its analysis. He 

 states that the oil content of the dry 

 kernel varies from 28-3 to 80-32 %. 

 This is considerably less than the value 

 found at the Imperial Institute, viz., 

 42 - 3 %, but the difference may be 

 accounted for, if we suppose that the 

 Annam .figures refer to " air dry " ker- 



nels; the kernels, " air dry " in England, 

 would be drier than in Annam. 



The weight of a seed (just gathered ?) 

 is said to vary from T02 grammes to 

 9 55 grammes ; and for selecting seed 

 for experimental plantations Mr. Vernet 

 rejects all which do not weigh more 

 than 5 grammes. We have no recorded 

 variation of this extent in Ceylon, 

 though it is probable that some seeds 

 may be found which approach the 

 lower limit. Carruthers gives 3*14 

 grammes to 5*14 grammes, but only deals 

 with twelve seeds; and the figures 

 obtained by Macmillan and myself are 

 only averages. But it may confidently 

 be stated that the application of the 

 "5 grammes'' rule to the seeds sent 

 from Ceylon would have led to the 

 rejection of almost all of them. Car- 

 ruthers onl> found one seed in twelve 

 to weigh more than 5 grammes ; and as 

 the weight of one hundred fresh Ceylon 

 seed has been found to vary from 336 

 grammes to 424 grames, it is evident 

 that only a very small percentage can 

 weigh more than five grammes, Tlie 

 samples were fairly uniform, and 

 certainly did not include a large pro- 

 portion of small seeds. 



If the results of experiments are to 

 be comparable, the conditions must be 

 the same in each case. The Ceylon seeds 

 were gathered on the ground each 

 morning, and therefore had ripened 

 and fallen daring the previous twenty- 

 four hours. Mr, Vernet states that in 

 order to reduce the error due to loss 

 of weight on drying, the seeds were 

 obtained by gathering the fruits as 

 soon as the capsule had turned com- 

 pletely brown. This procedure would 

 seem to be impossible in Ceylon, for 

 many fruits, at least, split when they 

 are some shade of green. It might be 

 thought that this method would account 

 for some of the difference between 

 the weights of Ceylon and Annam 

 seeds, as the latter might contain 

 more water, but this explanation is 

 contradicted by Mr. Vernet's figures 

 which show that the Annam seeds left 

 to dry in the laboratory lose a similar 

 prcentage of their weight in ten days 

 than the Ceylon seeds lose in a week 

 under similar conditions. We must 

 conclude, therefore, that the Annam 

 seeds are heavier than the Ceylon 

 seeds. The recorded weights per 100 

 seeds (Annam) vary from 381 grammesto 

 630 grammes, 2,900 seeds being weighed; 

 Peradeniya seeds vary from 330 to 434 

 grammes per 100 seeds, 2,000 seeds 

 being weighed. 



Mr. Vernet quotes the alleged opinion 

 of the planters of Ceylon and Malaya 

 that trees less than eight years old 



