_Field-Boxes._--In collecting butterflies it is often possible to kill, or half kill, the specimens contained in the net by a smart pinch administered to the insect by the thumb and the first finger, the pressure being applied from without the net (Fig. 48). This mode of procedure, however, unless the operator is careful, is apt to somewhat damage the specimens. The writer prefers to hold the insect firmly between the thumb and the first finger, and apply a drop or two of chloroform from a vial which should be carried in the upper left-hand vest-pocket. The application of the chloroform will cause the insect to cease its struggles immediately, and it may then be placed in the poisoning-jar, or it may be pinned into the field-box. The field-box, which should be worn at the side, securely held in its place by a strap going over the shoulder and by another strap around the waist, may be provided with the poisoning apparatus or may be without it. In the former case the box should be of tin, and should have securely fastened in one corner some lumps of cyanide, tied in gauze. The box should be very tight, so that when it is closed the fumes of the cyanide may be retained. The bottom should be covered with cork, upon which the specimens, as they are withdrawn from the poisoning-jar, should be pinned. It is well to bear strictly in mind that it is a mistake to continue to put one specimen after another into the poisoning-jar until it is half filled or quite filled with specimens. In walking about the field, if there are several insects in the jar at a time, they are likely to become rubbed and their beauty partially destroyed by being tossed about as the collector moves from place to place; and a large insect placed in a jar in which there are one or two smaller insects will in its death-struggles possibly injure the latter. So, as fast as the insects are partially asphyxiated, or deprived of the power of motion, they should be removed from the poisoning-jar to the poisoning-box, where they are pinned in place and prevented from rubbing one against the other. Some collectors prefer simply to stun the insects, and then pin them into the field-box, where they are left, in whole or in part, to recover their vitality, to be subsequently put to death upon the return of the collector from the field. This mode of procedure, while undoubtedly it yields in the hands of a skilful operator the most beautiful specimens, appears to the writer to be somewhat cruel, and he does not therefore approve of it.