UTILITY OF BIRDS. 67 



it out even to the bark. From the report of the naturalists it 

 was made apparent that the extraordinary increase of this insect 

 was Giving" to the entire disappearance of several species of 

 ivoodpecker and titmouse, which had not for some years been 

 seen in the forest." 



Doctor Lettsom, an English physician, remarks that he was 

 assured by an intelligent farmer, that, notwithstanding the 

 power of severe frost to kill insects, they are always most 

 numerous after a cold winter, because the birds are prevented 

 from jfinding them by the hardness of the soil. When a hard 

 frost binds the surface of the ground it protects the dormant 

 insects from the birds no less than it exposes the insects to 

 injury from the cold. It would seem, therefore, that nature, 

 while providing checks to the over-multiplication of insects, has 

 carefully guarded them from extermination, by taking care that 

 when they are more than usually exposed to one agent of their 

 destruction, they shall at the same time be less exposed to 

 another. 



Buffon relates the following anecdote of a certain species of 

 grackle, resembling our crow blackbird, which is so injudiciously 

 destroyed by the farmers in the vicinity of Boston : " The 

 Isle of Bourbon, where the grackle was unknown, was overrun 

 with locusts, which had been accidentally introduced from 

 Madagascar ; the eggs having been imported in the soil with 

 some plants which were brought from that island. The 

 governor-general and the intendant deliberated seriously on 

 the means of extirpating these noxious insects, and for this 

 purpose caused several pairs of the Indian grackle to be intro- 

 duced into the island. This plan promised to succeed ; but 

 unfortunately, some of the colonists seeing the birds eagerly 

 thrust their bills into the earth of the newly sowed fields, 

 imagined they were in quest of grain, and reported that the 

 birds, instead of proving beneficial, would be highly detrimental 

 to the country. On the part of the birds it was argued, that they 

 raked in new-ploughed grounds, not for the sake of the grain, but 

 for the insects, and were, therefore, beneficial. They were, how- 

 ever, proscribed by the council ; and in the space of two hours 

 after the sentence was pronounced against them, not a grackle 

 was found in the island. This prompt execution was followed by 

 a speedy repentance. The locusts gained the ascendancy, and 



