444 STATE BOARD OF AGRICULTURE. 



pioneer work has been attended with more difficulty than if it had been an 

 old and well beaten field. It may well be doubted also whether it would be 

 best to investigate the whole subject in a single season; by continuing the 

 investigation through a series of years, even though but few specimens were 

 examined each year many accidental errors would be eliminated and a much 

 broader basis for generalization obtained. 



But although the data here given may not be sufficient to justify any very 

 general conclusions they at least point to such. Before we have a right to 

 say that any bird must go, careful investigations must be made, through a 

 long series of years, of its food, not only under the normal conditions of 

 insect and plant life, but also under the many abnormal conditions that annu- 

 ally arise. Not only must this be done in one locality but also in several 

 localities, for a bird may during its sojourn in one place where exceptional 

 conditions exist do great injury, while in another place where the conditions 

 of life are different it may do only good and vice versa. So many points 

 arise in grappling with Nature's problems that the greatest care is required 

 before any safe conclusion can be arrived at ; and before the question of the 

 relations of birds to agriculture can be intelligently discussed, a more general 

 knowledge must be obtained not only of the food of birds, at all ages and 

 under all conditions, but also of the relations of the different classes of 

 insects to each other and to agriculture. 



II. The Food of Fkogs. 



The investigations which are here recorded were undertaken to determine 

 the economic status of two of our common frogs, namely : the spotted frog, 

 Rana halecina, and the green frog, Mcma clamitans. On account of the 

 abundance and general distribution of these two species, they must exert a 

 very appreciable influence upon the agricultural interests of our country. So 

 far as can be learned but very little has hitherto been known of the food of 

 either of these species. 



