Gums, Resins, 



512 



[December, 1908. 



day for its operation being a matter 

 of rather fine judgment. Hot, sunny- 

 weather, with a light breeze, is best ; high 

 winds naturally render the work very 

 risky. As soon as the ground has cooled 

 off sufficiently to permit of its being 

 walked over, it is lined and staked for 

 planting, which commences with the 

 advent of the first rains in June, when 

 about 4 inches have fallen. Five or six 

 seeds are sown at stake, in a circle 8 or 

 10 in. from the same, the lines being 

 1\ ft, square, representing about 800 

 trees to the acre. Maize is frequently 

 sown as a catch crop between the rows 

 of rubber. Periodic complete cleanings 

 are given to the ground during the first 

 year to afford the young plant air and 

 space for development ; and formerly 

 such complete cleanings were continued 

 at regularly extended intervals. The 

 present general practice, however, is to 

 clean only along the rows of rubber 

 trees, after they have attained a height 

 of 5 ft, or 6 ft., leaving the natural 

 "soft "growth to come up between 

 them, with the two-fold object of pro- 

 tecting the elongating trunks of the 

 rubber trees — as they begin to cast 

 their disarticulating branches — against 

 scorching by the sun, and of providing 

 shade over the surrounding surface of 

 the ground, the effect being to limit, if 

 not to wholly prevent, the spread of 

 pernicious grasses, and tending towards 

 a restoration of what is technically 

 known as the "forest floor," in the form 

 of an accumulation of leaf mould, which 

 is an essential requisite to the per- 

 manence of the lateral root system of 

 Castilloa. Subject to such modifications 

 as local conditions may suggest, this 

 appears now to be accepted as the best 

 treatment for Castilioa plantings, while 

 having, in addition, the advantage of 

 considerable economy over the older 

 method of complete cleaning. Such 

 planting may then be properly charac- 

 terized as one of a Sylvan culture, and 

 it may be assumed that the application 

 of the same to Castilloa would favour 

 the theory of equilibrium in Nature, 

 and thus minimize the chances of attack 

 upon wounded trees by parasites, &c. 

 In this connection it is interesting to 

 note that Dr. Warburg, of Berlin, in his 

 work "Die Kautschukpflanzen und ihre 

 Kultur," makes reference to the fact 

 that Mr. Millson, a former Government 

 official in British Honduras, early pointed 

 out the desirability of the sylvan system 

 of culture for Castilloa, recommending 

 just such procedure as is now being 

 adopted. 



The writer recently had the oppor- 

 tunity of witnessing a series of experi- 

 mental tappings made upon Castilloa 



trees of six, seven and eight years 

 old, on an estate on the Isthmus 

 of Tehuantepec. The crude method of 

 tapping as practised by the native 

 Indian, by cutting the trees with 

 a " machete " has, of course, been 

 superseded by the employment of 

 specially designed tools. The knife used 

 in the experiments here dealt with was 

 one invented by Mr. V. S. Smith, an 

 American planter in the State of Chia- 

 pas. The incisions were made in V form, 

 but, instead of making a complete V, the 

 cut on one side was stopped short of the 

 other, to avoid introducing a possible 

 focus of infection or rot at the meeting 

 point, where moisture might be retained. 

 A drip cup was attached to the base of 

 the tree, by means of an upward cut 

 made in the bark, the bottom of the cup 

 resting on the ground. (The object of 

 the upward cut was, of course, to convey 

 the latex into the receptacle without 

 waste.) In earlier tapping experiments 

 a straight incision was also made 

 between the centres of the \'s, forming 

 a regular herring-bone arrangement; this 

 was, however, found to be a useless 

 mutilation of cortex, increasing the 

 risk of rot, as the mere drawing of a 

 finger on the bark from V to V sufficed 

 to establish a route for the flow of the 

 latex down into the drip cup. The 

 central cut, moreover, added little or 

 nothing to the actual flow of latex, 

 owing to the verticle structure of the 

 lactiferous cells in the Castilloa tree. 



The latex collected in a fluid state in 

 the drip cups was emptied into a large 

 vessel at the expiration of the day's 

 work and carried to the coagulating 

 shed, where it was first run through a 

 fine wire mesh, to free it from mechan- 

 ical impurities, such as bits of bark, 

 lichen, moss, &c. It was then poured 

 into upright, open-toppeJ wooden 

 barrels, and mixed with clean water in 

 the proportion of one part of latex to 

 four parts of water ; thoroughly agitated 

 for a few moments, covered with a lid, 

 aud allowed to stand over-night. The 

 following morning the latex was found 

 to have risen to the surface in the form 

 of a thick, almost pure, white cream. 

 The barrels being provided with taps on 

 the side at the bottom, the separated 

 black water was drawn off until nothing 

 remained but the washed latex, which 

 was then ready for coagulation. A primi- 

 tive method was here adopted in the use 

 of a juice of a wild vine, known locally as 

 ' ' Jamole " (Ipomaia bona nox), a mem ber 

 of the Convolvulacece, which grows 

 in great abundance along the margins 

 of the streams and rivers of this part 

 of the country. Pieces of the riper 

 stems of this vine were ci: about a yard 



