"Hence will appear the 'loving kindness' of the Almighty, in setting such bounds, and keeping them within such limits as best answers the purpose for which He created them; and hence appears the necessity of their becoming food to other animals. Birds, fishes, and the smaller kinds of beasts, are at eternal war with them; but as all these would be insufficient of themselves to restrain and prevent them from multiplying too fast, other kinds of beings are instituted for this end, whose existence depends on their destruction. Of these, the species of insect I am describing, is the most singular, of which (genus) there are several sorts, differing greatly in size and shape. Some are furnished with three setæ or bristles at the extremity of their bodies, the middle one being a hollow tube, secured or fenced by the outer ones, through which they eject their eggs, after they have penetrated the body of the caterpillar they settle on. Some appear to have no bristles, others have them bent close under their bodies, and are not to be seen, unless closely examined. As their whole business appears to be the destroying the caterpillars of the butterfly and moth tribes, they are indefatigable in the pursuit of them; but as this is confined to the pregnant females, they are observed ranging about continually in search of the proper subjects to lay their eggs on; flying on every bush, and running with unwearied diligence on every twig, till they have arrived to the place where the scent of the caterpillar soon furnishes them with the certainty of its being there. Having thus discovered the animal it was in quest of, the Ichneumon immediately settles on it, with an intent to discharge its eggs; but the caterpillar being sensible, from a natural instinct, of its enemy's assault, bends its head backwards to the place where it feels itself attacked, and endeavours by various means, either by striking its head violently against the part, falling to the ground, or by some sudden contortion, to disengage itself: but this seldom happens, unless the Ichneumon is feeble, and unable to withstand the shocks of the caterpillar; in which case they will frequently relinquish their attack, and seek out some other subject, whose resistance they are more capable of encountering. On the other hand, if the Ichneumon is strong enough to withstand the efforts of the caterpillar, it either lays its eggs on the outside of the skin, as is the nature of some to do, or else perforates the body with the bristle before described, and immediately discharges an egg. Some of these Ichneumons quit the caterpillar upon the emission of an egg, but others {95}continue thereon till they have emitted them all; which sometimes is more than an hundred. It is necessary to observe, that many caterpillars of moths and butterflies (the former more especially) are infested by a particular species of these Ichneumons, that confine themselves entirely to