5 SECOND REPORT ON ECONOMIC BIOLOGY. 



The first effort of such an organization should be to enlist the 

 sympathy and co-operation of the health authorities of the community. 

 This gained, every possible effort should be made to induce the con- 

 trollers of the appropriations for the health officials to realize the 

 importance of this work. Health officers without funds at their 

 disposal for the employment of inspectors and for the carrying out of 

 regulations are hopeless, and therefore the first step, after the health 

 officials themselves are convinced of the desirability of the work, is to 

 secure the funds. In some cases this has been done by private sub- 

 scription, the money to be expended under the supervision of 

 the health officers. In other cases private individuals with sufficient 

 leisure have had themselves appointed as health inspectors without 

 salary, but by virtue of the appointment they are armed with the legal 

 authority which the health board has. Continuous and successful 

 voluntary work of this kind, however, is not to be relied upon, and 

 the campaign for funds, and preferably for regularly appropriated 

 funds, must be a strenuous one." 



A most important point to remember is to commence this crusade 

 early. The flies destroyed in April and May mean a lessening of the 

 summer plague by many millions. 



Quoting again from Dr. Howard (torn, cit., p. 38), he says a 

 singly over-wintering fly which on April i5th lays 120 eggs gives 

 rise ultimately to the following progeny : 



April 1 5th. The over-wintering female fly lays 120 eggs. 



May i st. 1 20 adults issue, of which 60 are females. 



May loth. 60 females lay 120 eggs each. 



May 28th. 7,200 adults issue, of which 3,600 are females. 



June 8th. 3,600 females lay 120 eggs each. 



June 2oth. 432,000 adults issue, of which 216,000 are females. 



June 3oth. 216,000 females lay 120 eggs each. 



July loth. 25,920,000 adults issue, of which 12,960,000 are 

 females. 



July igth. 12,960,000 females lay 120 eggs each. 



July 29th. 1,555,200,000 adults issue, of which 777,600,000 

 are females. 



