10 TROPICAL AGRICULTURE 



branch may show flowers and green and ripe apples at the 

 same time. 



The effect of temperature, so far at least as it is felt by 

 plants and animals, seems to be a relative matter. Plants suf- 

 fer in the Tropics at times from the low temperatures which 

 prevail, although these temperatures may not be below 65° F. 

 -—-The effect of temperature upon plants appears to be almost 

 entirely a matter of adaptation on the part of the plants. On 

 the high plateaus in the Rocky Mountains of the mainland one 

 may see certain spring flowers which have actually forced 

 their way through an inch or more of ice to bloom above the 

 surface of the ice and snow. These plants are frozen as stiff 

 as icicles every night and yet are not affected by such tem- 

 perature conditions. In tropical conditions, on the other hand, 

 a temperature of 65° F. at night, especially if accompanied 

 with a rather high wind, may injuriously check the growth of 

 many plants and may even turn the leaves of cotton brown as 

 if from the effects of frost. Similarly with man and animals, 

 the lowest temperatures which occur in the Tropics seem to 

 be felt as cold, and a certain amount of discomfort is experi- 

 enced by both man and animals when the temperature descends 

 ^ as low as 65° F. 



In tropical countries nearly all animals can find food for 

 themselves the year round, and if they escape from domestica- 

 tion on farms they may run wild. We have therefore in nearly 

 all tropical countries wild cattle, horses, asses, sheep, goats, 

 chickens, turkeys, pea fowl, dogs, cats, etc. In some of the 

 rough mountain districts of Hawaii wild goats which are de- 

 scended from goats escaped from domestication on the farms 

 have become a veritable scourge requiring organized expedi- 

 tions of hunters for their destruction. Similarly, pigs, cattle, 

 and sheep after escaping from restraint have multiplied rapidly 

 and occupied the rougher mountain regions, destroying much 

 of the grazing which is required for the more improved strains 

 of domestic animals. The common breeds of poultry, after 



