APRIL, 1909.] 



321 



Saps and Exudations. 



for planting. The leaves have red ribs 

 especially wheu looking up through the 

 leaves with sunlight shining through. 

 Those obtained at the Kew Gardeus 

 had whitish green ribs which it has 

 been suggested might be due to arti- 

 ficial cultivation there, or may mean 

 two such varieties have been described. 

 Both are of about the same value how- 

 ever. I intend to try watering some of 

 these trees very heavily, and letting 

 others have only the rainfall, which if 

 this dry weather keeps up will be a 

 slight test as to whether it will thrive 

 best in a dry or wet locality here in 

 the islands. 



So far I have watered all the young 

 seedlings and they have done very well. 

 Seeds of this variety are the only ones 

 so far obtained. But it is doing very 

 well when we remember that not even 

 the Kew Gardens nor the Gardens in 

 Ceylon, Singapore, etc., have been able 

 to obtain these other two varieties, 

 though they have been seeking to do so 

 for two years. The Peradeniya Gardens 

 of Geylon have 100 seedlings of Manihoi 

 dichotoma growing, also the Singapore 

 and Penang Botanic Gardens. The Pera- 

 deniya Gardens are constantly asked for 

 seed, they cannot as yet supply for 

 planting in the dry lands in Geylon, 

 where the Hevea cannot be grown. We 

 must not, however, forget that the rest 

 of the tropical world always thinks of 

 these varieties as well as the Geara in 

 connection with a dry region, and it 

 was only because we found trees of the 

 Ceara variety growing and yielding so 

 well in our wettest localities, as in 

 Nahiku and Puna, and so much better 

 than in the drier localities, as in and 

 around Honolulu, etc., that we decided, 

 what subsequent plantings have all 

 tended to confirm, that the wetter local- 

 ities, if not too cold, are better for the 

 Ceara than the drier ones here in the 

 Hawaiian Islands. Still it would be a 

 wise thing to plant some of these 

 Manihot dichotoma in some dry places 

 for experiment. Dr. Ule says : — 



' ' If, as is probable, the cultivation of 

 Hevea brasiliensis will undoubtedly ob- 

 tain the greatest importance for the pro- 

 duction of rubber in luxuriant tropical 

 regions, the future has to look to Manihot 

 Jieptaphylla and Manihot piauhyensis 

 as the rubber plants for the dry and 

 less fertile areas. " Of course, it is only 

 fair to say that other observers speak 

 as highly of Manihot dichotoma, which 

 he has left out in this statement. 



To sum up, then, there are several 

 reasons why the planters of Hawaii 

 should direct their attention to these 

 varieties. 



51 



1. In the first place the industry in 

 these islands is in its infancy, and we 

 should endeavour to test all the different 

 varieties of rubber-yielding trees which 

 seem to promise well. For we do not 

 yet know which species will prove the 

 best in the long run, all things consi- 

 dered, such as early yield, cheapness of 

 installation, length of yield with con- 

 stant tapping, amount of yield, cheap- 

 ness of collection, quality of the rub- 

 ber obtained, etc, etc., a balancing of 

 all of which will give us finally the 

 best species to cultivate most largely. 

 The present plantations must necessa- 

 rily do a great deal of pioneer work in 

 this regard, if we have regard to the 

 industry for the islands as a whole. 

 After the present companies have 

 shown what can or cannot be done 

 commercially with the different species, 

 no doubt many plantations will follow 

 this lead, 



2. These varieties in their habitat 

 yield considerably larger quantities than 

 the Ceara and yet thrive under very 

 much similar conditions to those in 

 which the Ceara thrives, the variety 

 which so far has proved to grow the 

 best here. 



3. Most important of all, here are 

 varieties which promise the lowest cost 

 of collection which, quality being equal, 

 is as I have said the pivotal point in 

 regard to the whole industry in Hawaii.— 

 Hawaiin Forester and Agriculturist, 

 Vol. V., No. 12, December, 1908. 



METHOD OP TAPPING ASSAM 

 RUBBER. 



The Experiment Station Record (No. 

 11, 1908) furnishes the following account 

 of an improved method of tapping Assam 

 rubber {Ficus elastica), together with 

 the results of some tapping experiments 

 carried out in India, in which this 

 method was used :— 



The tapping instrument consists of an 

 ordinary carpenter's chisel from i-inch to 

 |-inch wide. This is driven into the bark 

 vertically in a series of cuts, each the 

 width of the chisel, across the direction 

 of the trunk or branch being tapped, 

 and with at least i-inch space between 

 each incision. The" rows of incisions are 

 made about 6 inches apart on the stems 

 and branches of the tree. Thin strips of 

 lead are secured to the stem underneath 

 each row, by which the latex is con- 

 ducted into cups. By this method of 

 tapping about two-thirds of the latex 

 is said to find its way into the cups, 

 while one-third coagulates on the cuts. 



