limtLS, tiesms, 



224 



[Sept. 1906, 



Mr. Wright :— After expressing the oil there is a residual cake which can 

 be used as food for cattle. 



THE EFFECT OF OVERLAPPING ON SEED BEARING. 



Mr. Watt :— If a tree is tapped to the fullest extent, would it not prevent 

 the seed from forming at a later period ? 



Mr. Wright:— Will over-tapping affect the seed? That is what your 

 question really amounts to. There are some people who believe it will, and others 

 believe it will not, and consequently they are always disputing whether they should 

 select seeds from trees which have or have not been tapped ; or whether tapping 

 operations should be suspended while the fruits are forming. I do not know any 

 one who can give a definite opinion on the matter. My private opinion is tha^ 

 provided the trees are not harshly dealt with, the tapping operation has very little 

 effect on the seeds. If, on the other hand, you badly damage the tree, the 

 effects will naturally be obvious on other parts including the seeds. Personally I 

 should like to select my seeds from trees that had been tapped and proved 

 to yield latex. There are some Para trees which, when tapped, did not give 

 latex ; if you select seeds from trees that have not been tapped, you may be select- 

 ion seed from trees that will never give you the required quantity and quality of 

 latex. It is a very complicated matter. Provided the trees have not been roughly 

 handled, I see no reason why we should not have the seed taken from big trees that 

 have been tapped and have given a fair quantity of latex. 



VARIATIONS IN THE QUANTITY OF SEED PRODUCED, 



Mr. Thornhill :— Last year we got 80,000 seeds from tapped trees. This year 

 we did not tap and we got 280,000. 



Mr. WRIGHT : — Do you ascribe that to not having tapped ? 



Mr. Thornhill :— I do ascribe it to that. They only gave 60,000 before, and 

 they never had been tapped then- 



Mr. Wright : — You can tap in a way to threaten the life of the tree ; and if 

 you do that, the tree immediately shows a disposition to produce a large quantity of 

 flowers and seeds. Take a cacao tree and ring it; the upper parts will simul- 

 taneously burst into blossom. There are other plants which behave in a similar 

 way ; check or cut off their water-supply and seed-like structures will appear 

 in an interval of a day or so, as a last effort to propagate their kind. In the 

 same way if you overtap a tree you may lead to the production of a large blossom 

 and seed crop. I hope that was not the case here ? 



Mr. Thornhill:— I do not think that was the reason here. It certainly 

 Was not over-tapped. The bark was renewed and we had started to tap again. 



Mr. Wright : — What was the average yield per tree each year? 



Mr. Thornhill 300 seeds per tree I got, but there is a vast difference 

 between this year and last. 



Mr. Wright.-— There is nothing abnormal in that. The trees ought to 

 mature and give a larger number until they yield an average of about 500 seeds 

 per year, judging from the number of seeds we have distributed from Heuaratgoda. 



rubber substitutes. 



Mr. John Hill :— With reference to Mr. ThorrihiU's " sweet future " and Mr. 

 Clark's " glut," can you tell us if they are likely to get a substitute for rubber in the 

 future. 



Mr. Wright : — Ask an easier one, please. It is necessary to distinguish 

 between substitutes and artificial rubber produced synthetically by the chemist. 

 (Laughter.) We are trying to arrange for an exhibition of rubber substitutes 



