32 



THE COCO-NUT 



CHAP. 



old trees inevitably become less productive, and at 

 the same time the expense of harvesting the nuts and 

 the danger of their breaking as they fall increase. The 

 time comes when they are no longer worth taking care 

 of and they should then be destroyed. 



The effect of inadequate or improper nutrition may 

 be shown by the same symptoms as old age, or in 

 other ways. A tree growing without enough light 

 will for some time bear at least as large leaves as 

 any other plant, but the production of fruit will not 

 continue long, because the shade makes the proper 

 supply of the plant in both carbohydrate and mineral 

 food impossible. Malnutrition may be with regard to 

 the total food or to a single kind of food. The remedies 

 in the former case are thinning the trees, cultivation, 

 and irrigation or drainage. When the absence of only 

 one or two of the food-elements is responsible for the 

 bad condition, the want can usually best be remedied 

 by the use of fertilizers. Unless the cause of weakness 

 is very clear, or the need of action is much more urgent 

 than it usually is, any proposed remedy (as drainage, 

 irrigation, cultivation, thinning, or the use of various 

 fertilizers) should be tested on a few trees before it is 

 tried on a whole plantation. 



In all cases, then, in which coco-nuts are in poor 

 condition but no living enemy is to be found, the 

 treatment consists in invigorating them "by sanitary 

 measures and better nutrition. 



B. Pests. — General Considerations. — If a small 

 community of men lives by itself, never seeing or 

 having anything to do with other men, its members 

 are in no danger from smallpox or syphilis. If, 

 however, they had rats, and the rats came and went 

 and associated with other rats, the community might 

 be attacked by plague. With the growth of cities 

 and nations, the opportunity for the spread of disease, 

 and consequently the danger to each individual, and 

 the necessity for strict sanitation, quarantine, and skill 

 in medicine, are manifolded. Commerce and general 



