FOOD OF BIRDS. 
17 
tial judgment we may be willing that a single wasp should live if it 
causes the death of a dozen spiders. The spider, however, lives upon 
other insects, and we must discover, if possible, whether these are in- 
jurious or not before we are competent to pass judgment upon the merits 
of the Martin which destroyed the wasp. In fact, the forms of insect life 
seem to be about equally divided into those which are injurious, and 
those which are beneficial by arresting the too rapid multiplication of 
injurious species. Some of the latter effect this by devouring adult in- 
sects, others the larvae or eggs, and still others are external or internal 
parasites. When we view the relations which one portion of the class 
sustains to the other in this respect, the destruction of insects by birds 
sinks into comparative insignificance. Many more grasshoppers, in all 
probability, are destroyed by spiders alone than by all species of birds, 
while still more are destroyed by parasitic animals than by spiders. 
The consideration of this portion of the subject belongs to the ento- 
mologist, and it is to be regretted that our legislators, who have shown 
sufficient zeal in protecting birds for their good qualities, have not deemed 
the determination of what are and what are not beneficial insects worthy 
of their consideration. In my opinion, the benefit derived would amply 
compensate for any outlay of money, time and skill employed for this 
purpose. Other States have their State Entomologist, and upon them 
Ohio is dependent for all she possesses of useful knowledge on this sub- 
ject. 
Having thus traced the influence of insectivorous birds to the only 
conclusion which we can consider legitimate at present, it will not sur- 
prise the reader that a similar conclusion awaits us respecting those 
which are gramnivorous — simply that they are useful so far as they de- 
stroy the seeds of weeds and noxious plants, and injurious only in their 
destruction of cultivated seeds. 
In the consideration of this subject the influence of agriculture upon 
birds must be taken into the account. The clearing and cultivation of 
laud, and the draining of swamps and marshes, have produced some 
changes in the bird-fauna of the State worthy of notice. The Carrion 
Crow, Swallow-tailed Hawk and Carolina Parrot have apparently ceased 
to visit us. The Pileated Woodpecker, Turkey Buzzard, Wild Pigeon, 
Turkey, Pinnated and Puffed Grouse are much less common than formeily 
throughout the State. To these might be added several other species 
which are rarely seen in localities wbaro thej were once common. In the 
vicinity of Columbus the Marsh and other Hawks (except the Sparrow 
Hawk) the Owls, Herons, and in fact nearly all the larger birds, have 
greatly diminished in number. Even the Pewee is much less numerous 
