26o 



have reached maturity in the open sun, and have survived many 

 and severe tappings. 



It may not be without significance that the conditions with 

 which Herr Koschny is most familiar and which he considers 

 favourable for rubber production are not those of continuous 

 humidity, for there is a dry season of two or three months. In 

 eastern Guatemala, an interesting example of the rapidity with 

 which the tropical sun can dry out the vegetation was observed. 

 Our party arrived at Panzos during a heavy rain, and rode the 

 next day toward Senahu over muddy roads through the dripping 

 leaves of a luxuriant tropical growth. Three weeks later the 

 same region was dry and parched, and even the leaves of the 

 undergrowth of the forest were shrivelled. 



CASTILLOA ON THE ISTHMUS OF PANAMA. 



The idea that the Castilloa sent from the Isthmus of Panama 

 to British India came from a continuously humid district seems not 

 to be justified by the statements of Mr. Cross, who secured seeds 

 and cuttings in the vicinity of Colon. He says : 



The interior of the Darien forests would frighten most people. The under- 

 growth is c )ttiposed of boundless thickets of a prickly leaved species of Bromelia 

 often 8 to 10 feet high, the ground swarms with millions of ancs, and the snakes 

 raise themselves to strike at anyone « ho approaches. 



The Caucho tree grows not in inundated lands or marshes, but in moist, undula- 

 ting, or flat situations, often by the banks of streamlets and on hillsides and 

 summits where is any loose stone and a little soil. It is adapted for the hottest 

 parts of Tndia, where the temperature does not fall much below 74° F. The tree 

 is of rapid growth, and attains to a great size, and I am convinced that, when 

 cultivated in India, it will answer the most sanguine expectations that may have 

 been formed noncerning it. I have been up the Chagres and Gatun rivers. I came 

 out on the railway about 7 miles from CoIdu. I go back to the same place (the 

 village of Gatun), from which place by the river the India-rubber forests are 

 reached.* 



The undergrowth of Bromelia indicates a relatively barren, open 

 forest with a severe dry season, and this supposition is strengthened 

 by the allusion to the ants, snakes, " loose stones," and " little soil.'* 



ANALOGY or THE ASSAM RUBBER TREE. 



The fact that the production of rubber may fail under conditions 



which permit the luxuriant growth of the trees is not new, since it 



was recorded with reference to Assam rubber tree as early as 1875, 



as shown in the following extract : 



The production of different kinds of caoutchouc in India continues to engage 

 the attention of the India Ofl&ce and of this establishment. One fact in connection 

 with it which seems to require very careful consideration has been pointed out by 

 Mr. Mann in his report on the caoutchouc plantations in Assam. It is found that 

 although the Ficus elastita will grow with undimiuiahed rapidity and luxuriance 

 in situations remote from the hills, it fails to yield caoutchouc. Mr. Mann con- 

 cludes that no greater mistake could be made than to start plantations of Ficus 

 elastica in any part of Bengal. It appears, therefore, judging from this case, that 

 conditions which may insure the successful growth of caoutchouc-yielding trees 

 may not be sufficient 10 determine their producing caoutchouc. f 



* Trans. Linn. Soc, London 2d ser.. 2: 213. 



t Report on the Progress and Condition of the Royal Gardens at Kew dudng the year 

 1875, p. 7. 



{To be continued.) 



