I 



June 1907.] 341 Saps and Exudations. 



never more than one heavy crop ; (II) that the Autumn is the more uniform crop of 

 the two, as the Spring has only exceeded the Autumn crop twice in 10 years ; and 

 (III) that the Autumn fruit periodicity represents the true normal condition 

 of the tree. 



FRUIT PERIODS IN BRAZIL. 



Mr. Ridley does not consider that there are any signs to indicate that Hevea 

 brasiliensis in Malaya differs in its characteristics from the indigenous trees in the 

 Amazons ; or that it is in a state of transition in the East. He quotes Mr. Consul 

 Temple, and Ule regarding the flowering periods in Brazil ; the latter authority 

 says the flowering season is July-August, the fruits falling in January-February, and 

 this would agree with a statement in a recent letter to us from Mr. H. A. Wickham 

 regarding his collecting of the seeds in Brazil which produced the original plants 

 in the East. 



THE RESULTS OP TAPPING. 



We now come to the tapping experiments themselves. These are admirably 

 arranged and tabulated in the report ; but we cannot refer to them here at at all 

 in detail for want of space. We refer to the general conclusions drawn. 



Full details of the trees, girths, methods and periods of tapping, yields in 

 latex and caoutchouc, etc., are given for each experiment. For instance, we note, 

 in experiment IV., during 1906, groups of 40 trees were tapped, mornings only, on 

 single and full herring-bone methods during 25 days. In 2 groups of single cuts 1,216, 

 and 1,823 fluid oz. of latex were obtained ; in the full herring bones, 1,703, 2,816 and 

 3,385 oz. latex were obtained, giving a total for the 5 groups of 154 lb. dry rubber. 

 The trees averaged 37| inches and 38| inches. There was a period of rest of 4 months 

 given the trees, and the average gross yield per tree was 2 lb. 4f oz. In experiment 

 VI, herring-bone tapping, daily tapping shewed a better result than alternate days. 



TWO TAPPINGS A YEAR. 



The result of a year's working " clearly shows that morning are better than 

 evening tappings, the trees can be tapped twice within the period of a year but 

 the interval of rest should not be less than 5 months ; that the dormant months 

 December, January, February yield a smaller percentage of caoutchouc, and that 

 the best season for tapping is from April to November, We have not found any 

 advantage in respect of yield by the spiral over the herriug-bone, and considering 

 the small advantage of the double over the single incisions we think the single cut 

 with small trees would best economise the bark," 



These authorities have come to the conclusion that the Para rubber tree 

 responds to shock, and that the tapping instrument capable of making the cleanest 

 and quickest incision is the ideal one. 



RUBBER PRODUCTION IN PROPORTION TO YIELD OP LATEX. 



An important result of the experiments is that concerning the production 

 of caoutchouc in proportion to the yield of latex. A falling off in the proportion 

 of caoutchouc to latex in Ceylon trees has already been notified. The latex in the 

 bark is quickly renewed after a period of tapping but the production of rubber is 

 very much slower. In a trial of spiral tapping on a tree girthing 112 inches, from 

 the first period tapping 531 fluid oz. of latex (half added water, or 265i oz. pure 

 latex) was obtained giving 9 lb. rubber ; from the second period tapping, one month 

 later, 433 oz. latex gave only 4 lb. 15 oz. rubber— a remarkable difference. 



This phenomenon is one which cannot be overlooked. It has already been 

 observed in Ceylon, and at the Ceylon Rubber Exhibition (September, 1906) Mr. 

 Kelway Bamber, Ceylon Government Analytical Chemist, brought the matter up in. 



