TREE PRODUCTS 137 



mere accident that this juice has the property of 

 coagulating to form the substance called rubber 

 which we now find so important. But this sub- 

 stance, obviously, as man uses it, has small place 

 in the economy of the plant. Coagulated latex 

 would serve no better purpose in the tissues of 

 the rubber tree than would coagulated blood in 

 the veins of a human being. 



Oils and Resins 



Of course the latex of the rubber tree might 

 exude when the tree received an accidental in- 

 jury, as from a falling limb, and in such case it 

 would be advantageous to the tree to have the 

 juice coagulate, just as coagulated blood is use- 

 ful to a wounded man. In each case coagulation 

 prevents excessive hemorrhage. 



Possibly this may explain the quality of the 

 latex, its capacity to coagulate having been de- 

 veloped through natural selection. But under 

 normal conditions, at least, the latex is always 

 fluid, and its properties are little more like those 

 of rubber than are the properties of the maple 

 tree like those of sugar. 



Of course the same thing is true of the plant 

 juices that when dried or partially evaporated 

 constitute the various gums and resins. As 

 manufactured in the tree they are transformed 



