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General Biology 



in purchasing- food for himself and family. In the silk industry Pebrine 

 — a very serious silk-worm disease — reduces the annual production of 

 silk to the extent of thousands of yards and, thereby, raises silk prices. 



To make this clear, suppose a man is employed for a certain num- 

 ber of days each week and a certain number of weeks in the year, and 

 is paid $5 a day for such work. It follows that his employer must re- 

 ceive enough money, when selling the product produced, to pay the 

 worker $5 each day, plus a proportionate amount of the rent, taxes, 

 bookkeeping, salesmen's salaries, and traveling expenses, as well as 

 allowing interest on his investment. That is, what the worker gets $5 

 for, will cost the ultimate user at least $10, for, it is just as difficult 

 to sell and to deliver goods as it is to make them. But now suppose 

 a storm comes up and destroys the plant, and the workman still works, 



Fig. 216. Head and Foot of Fly. 

 The Foot shows hooks, hairs and pads. (Head after Herms.) 



receiving $5 each day, the traveling salesman still works, the book- 

 keeper, stenographer, foreman, engineer, fireman, night watchman, are 

 still all kept on the job, and receive their stated pay, but the work 

 is all put into clearing away the debris and in rebuilding. It follows 

 that all of this expense of keeping these men employed must be added 

 to the cost of the article. This loss may be spread over a great many 

 years, it is true, only a cent or two being added to the selling price of 

 the article, but it must nevertheless be paid. 



Now, suppose for a moment, that such a fire takes place regularly 

 every year, and that, therefore, one must work one-tenth of the entire 

 year without producing anything. This is equivalent to taking the 

 workman's salary away for this tenth of the year though still obliging 

 him to do the work. 



Here is a parallel to the financial loss caused by insect pests alone, 

 to each of us. For this is our loss. We must work an extra five weeks 

 each year to pay for the fact that men at large rank so low in the intel- 



