259 



ward. Moreover it is scarcely reasonable to expect the interested 

 public to adopt what may appear to be a radical view of Castilloa 

 culture without understanding the basis of the current opinion that 

 continuously humid regions are required for the production of 

 rubber. 



The report on the Caoutchouc of Commerce, written by James 

 Collins, and published in 1872 under the auspices of the British 

 Government remained for many years the most complete and 

 authoritative statement of the subject. It was very frequently 

 quoted by subsequent writers, and has probably done most to 

 establish the idea that continuous humidity is required by Castilloa. 

 Collins says : 



The species of Castilloa seem t . like best and thrive in thick, humid, warm 

 forests. They abound in Nicaragua ; and as I have, through the kindness of my 

 friend Dr. Bureau, of Paris, received from M. Paul Levy, a botanical collector in 

 Nicaragua, a good account of their history there, it will serve to give a correct idea 

 of their habits. . 



The basin of the Rio San Juan is where the ule tree grows to perfection, ihis 

 river is the natural vent of the two vast basins of the lakes of Nicaragua and 

 Managua, receiving numerous tributaries, which have all their sources m the 

 innumerable tract hitherto virgin and unfrequented, and wheie the trees abound. 

 The gr. und is very fertile. The district is very unhialthy ; it rains for eight or 

 nine°months in the year, and the climate is very warm and humid. The trees 

 prefer humid and warm soils, but not marshy, clayey, or gravelly ground, and the 

 presence of these trees is looked upon as an indication of a fertile soil. . . 

 The ule is often near water-courses, and nearly always on the banks.* 



CASTILLOA IN COSTA RICA. 



The most extensive recent publication on Castilloa is by Herr 

 Th F. Koschny, a resident of Costa Rica, whose opinion on the 

 subject of climate appear to be nearly opposite to those stated 

 above. He says : 



The safest and most productive rubber plant i^ the Castilloa elastica of Central 

 America. Its tenacity of life and adaptability to soil and climate are seldom 

 exceeded by other trees ; the same is also true of the quantity and quality of the 

 rubber. 



It requires a humid, warm climate, and with respect to rainfall less depends upon 

 the amount of precipitation than upon the distribution of it. The shorter the dry 

 season and the more the rain extends over the entire year the better will a locality 

 be adapted for rubber culture ; regions with a long, absolutely dry season are 

 unsuitable for this culture In the valley of San Carlos, Costa Rica, upon the 

 Atlantic slope, it rains occasionally also in the dry season, and even in the two 

 driest months, March and April. The Pacihc slope of Central America has, on 

 the contrary, a completely dry season of four months, and tw.> months at the 

 beginning and end with little rain. Both the wild and the planted rubber trees 

 die there at the third tapping at the latest, in case this takes place in the dry 

 season, t 



If the above statement represents a general fact in Costa Rica 

 it can only be said at present that either the climate, or the rubber 

 trees, or both, are different from those of southern Mexico. In 

 spite of six months of dry weather the rubber trees at La Zacualpa 



♦ Collins' Report on Caoutchouc, p. 14. 



t Beiheftezum Tropeupflauiier, 2: 111), 19U1. 



