196 



MASSACHUSETTS AGRICULTUEE. 



women and children, and brings in large revenues to the coun- 

 try. Insects we must thank for honey, — the sweetest of sweets. 

 The air we breathe and the water we drink are kept pure and 

 wholesome by the agency of myriads of little creatures which 

 draw sustenance from the impurities of the elements. It is 

 not, then, that insects are to be exterminated, even if it were 

 possible, but only kept in check. 



RELATIVE FERTILITY OF BIRDS AND INSECTS. 



The majority 

 of our native 

 birds have but 

 one brood of 

 young in the 

 course of the 

 year, a few have 

 two or three. 

 In the case of 

 the smaller in- 

 sect-eating 

 birds the num- 



ber of eggs to a 

 brood is on an 

 average not 

 more than five. 

 Some of the 

 larger birds, as 

 the various Gal- 

 linse, lay from 

 five or six to 

 twenty eggs to 

 a brood. On 

 the other hand 

 the reproduc- 

 tive energy of 

 insects is truly 

 marvellous. It 

 is said that a 



single pair of grain-weevils have produced six thousand young 

 between April and August. The common varieties of aphides 



Fig. 6. — Upper fig. Wood-Pewee. Contopus vire7is. Lower fig. King- 

 bird. T. carolinensis. (Insessores.) 



