VARIOUS FARM PRODUCTS 595 



vation of rubber on a wholesale scale. Rubber is practically the only 

 staple crop the supply of which has always come from what may 

 be called natural sources. Even with the increase in the number 

 of plantations during the last ten years 99 per cent of all of the 

 rubber of commerce has been procured by the most wasteful and 

 destructive methods from natural rubber forests. The rubber gath- 

 erer has preceded the tax collector in searching the unexplored and 

 unknown forests in the interior of South America and all over the 

 African Continent. He has destroyed forests and exterminated 

 species in a relentless effort to secure enormous returns without the 

 investment of proportionate capital. Wherever the rubber collector 

 has gone no other need follow. 



The cause of this frantic search for rubber-producing trees is 

 to be found in the multitudinous uses to which this valuable ma- 

 terial may be put. Because of its increasing scope of usefulness 

 the rubber consumers have never been able to procure enough of 

 the raw material to satisfy the yearly demands, so that the end of 

 every decade has witnessed a marked increase in its value. 



By January, 1908, 400,000 rubber trees had been planted in 

 Hawaii, upwards of 90 per cent being Manihot glaziovii. The re- 

 mainder are Castilloa elastica and Hevea brasiliensis in about equal 

 proportions. There are now five large plantations in operation, and 

 ruboer trees are being planted by many independent farmers and 

 planters. The oldest plantation is one of those at Nahiku. A first 

 tapping was made on some of the trees of this plantation during the 

 summer of 1908. Tappings begin when the trees have reached a 

 circumference of 20 inches, which is considered to be the smallest 

 size at which it is safe or convenient to tap. 



The natural home of the Ceara rubber tree (Manihot glaaziovii) 

 is in the dry regions of Brazil. In former years it was very abun- 

 dant in the State of Ceara and derives its name from this fact. It is 

 also known as the Manicoba rubber, this having been its native 

 name. 



This tree is closely related to the cassava (Manihot utilissima) . 

 It belongs to the spurge family, which also includes the Para rub- 

 ber (Hevea brasiliensis) and many other rubber-producing plants. 

 Most of the members of this group, the Euphorbiacese, have milky 

 sap. (Hawaii Sta. B. 16.) 



Guava. The guava (Psidium guajavd) is most peculiar in that 

 when ripe its odor is usually very offensive to the uninitiated, but 

 after a considerable familiarity with it the odor is no longer dis- 

 agreeable and most people like it. Not a few, especially those who 

 are familiar with a variety of odors, consider it pleasant from the 

 first. 



Commercially, the guava is the leader of the jelly fruits. The 

 fact, however, that it decays soon after ripening makes it impos- 

 sible to keep it on the market, as is done with ordinary fruits. 

 Jelly factories have to be established near the place where the fruit 

 is grown, but with good railway service guavas may be transported 

 300 miles without danger of loss. For immediate home use largo 



