i8 THE RUBBER TREE BOOK 



For many years after their discovery in the seventeenth 

 century bacteria were regarded as minute animal organisms 

 interesting to observe through the microscope but of no par- 

 ticular importance in the economy of nature. By the middle 

 of the nineteenth century, however, their scientific importance 

 was recognized; but it was the detrimental members of the 

 family which were taken into account, and they were studied 

 only in connection with diseases, and at first more especially 

 those diseases affecting animals. This general reputation given 

 to them was, however, scarcely just, for, fortunately for 

 humanity, the beneficial bacteria far outnumber those which 

 are detrimental in their action. They are intimately associated 

 with processes going on in the soil and water which are abso- 

 lutely essential to the existence of horticulture. Their function 

 is most important. These micro-organisms play a funda- 

 mental part in the processes of nature. Without these micro- 

 scopic plants these processes would cease, and the culture of 

 rubber trees would become utterly impossible. 



During the last thirty years much study has been devoted 

 to them, and it is recognized that they are closely related to 

 the yeasts. They have, therefore, been relegated by scientists 

 from the animal to the vegetable kingdom. The reason, at 

 first sight, may not seem comprehensible, many of them being 

 apparently endowed with the power of motion from place to 

 place. A frequent method of their reproduction, namely, 

 by means of spores, which can survive dried for very long 

 periods, is that of plants rather than that of animals. Their 

 rapidity of multiplication is quite extraordinary. If the rate 

 were continued without interference, one of these bacteria in 

 twenty-four hours would produce 17,000,000 descendants, 

 in forty-eight hours 281,000,000, while the oceans might be 

 filled up with a solid mass of these bacteria in the course of five 

 days, if the rate of increase was permitted to continue without 

 check. 



The soil, then, is by no means a dead, inert mass of material, 

 but should rather be viewed as an immense factory in which 

 the most interesting and complex chemical transformations 

 are being incessantly carried on by minute organisms. One 

 can scarcely imagine the labyrinth of minute winding passages 

 and cavities which are always contained in the soil. It has 



