Instead of setting-boards, setting-blocks (see Figs. 100 and 101), may be advantageously employed in setting smaller specimens, especially of the Hesperidæ and the Noctuidæ, the wings of which are refractory, and refuse to be treated in the method that has just been described. Instead of using strips of tracing muslin it is necessary, in the case of setting-blocks, to use threads or cords, which may be adjusted, as is shown in the figure. Care should, however, be taken not to draw the thread or cord so tightly about the wings of the specimens as to cut into their vestiture and thus leave marks.
[a]Fig. 100.]—Setting-Block. A, Groove for body of insect; B, nick for holding thread; C, cork to receive point of pin passing through holes in bottom of A.
[a]Fig. 101.]—Butterfly Expanded upon Setting-Block.
The insects having been adjusted upon the board, care being taken that the pin is set perpendicularly, the next step is to
[a]Fig. 102.]—Setting-Needle.
draw out the wings in the position which they are to maintain when the specimen is thoroughly dry. This is accomplished by means of what are known as "setting-needles" (see Fig. 102). They can easily be made by inserting ordinary needles into handles, which may be made of some soft wood. The writer generally employs as handles for his setting-needles matches, from which the sulphur tip has been removed. In drawing the wings into position care should be taken to plant the setting-needle immediately behind the strong nervure of the costal margin of the wing. Otherwise the wings are likely to be torn and disfigured. The rule in setting lepidoptera is to draw the anterior wings forward in such a way that their posterior margins form a right angle with the axis of the body, which rests in the groove in the middle of the setting-board. The posterior wings are then drawn forward in such a way as fully to expose their outline. The next step is to firmly fix the wings in position, as they have been placed. Some writers recommend for this purpose using short strips of paper over the wings, others recommend placing upon the wings pieces of glass, of a size sufficient to cover the entire wing. A far better plan is to employ strips of tracing muslin, such as is used by draughtsmen and engineers. These strips may be secured at the ends of the setting-board by thumb-tacks, and may be drawn down over the wings of the specimen and securely held by pins in place. Care should be always taken to nicely turn up the edge of the strips nearest to the body, so that a crease or depression may not be left upon the scales covering the wings of the insects when the specimen has been thoroughly dried. The wings having been arranged, the antennæ and the feet may be brought forward and displayed in a natural position. Care should be always taken to lower the antennæ so that they do not stand erect above the head. In the latter position they are very apt to become broken. A number of such boards may be conveniently arranged in a box, as shown in Fig. 103, and if strips of muslin are used, and are firmly held in place by pins, such a box may be transported from place to place, upon the backs of men or beasts, and the process of drying the insects may go on en route, while the naturalist is conducting his investigations. In this manner the writer carried four or five large boxes with him through the interior of Japan (Plate XXIII., Fig. 2), and succeeded in bringing home with him nearly six thousand specimens, dried and ready to place in the cabinet. The length of time which is required for drying, varies of course a little with the temperature, and the amount of humidity in the atmosphere. In some climates it is almost impossible to absolutely dry the specimens, in others they dry very quickly. In the United States a week or ten days will generally suffice to secure that rigidity which is necessary in a cabinet specimen.
