Now for the setting of the butterfly. Drying-boards can be bought of any length, made either of soft deal, or, better still, of cork, covered with white paper. They have a groove down the centre to receive the insect’s body. Different widths are required for different-sized insects. Place the row of butterflies to be set down the board, their bodies pinned in the groove. Cut strips of writing paper an eighth of an inch wide. Pin a strip of paper on each side of the groove, about the centre. Secure it additionally by a pin between each butterfly. With the point of a pin arrange the wings equally under the strips ([Fig. 1]). These drying-boards should be kept out of the dust, or ants or flies may damage the specimens. Some people have a box with a perforated zinc door, into which they slide the boards. I called such an one my meat safe!
In the case of dried specimens preserved in envelopes and which need relaxing before setting, there are two ways of going to work. The first is to float a piece of cork in hot water, and to pin the specimen on to the cork. The wings should not touch the water. A saucepan is a good thing to use, as the lid can be put on. The cork should float high in the water.
But the best plan is to steam them in a tin box with cork in the lid. Pin the insects to the cork and half fill the box with boiling water, and close it. If the boiling water as it cools is renewed two or three times, in an hour or so the insects will be perfectly relaxed. They should then be set at once, after shaking off the drops from the wings, and placed near enough to the fire to feel the heat and to dry quickly, but not too near. The outer margins of the wings should be covered with the setting braces (the paper strips), or they will curl up with the heat. The wings should, if possible, not be allowed to touch the cork when being relaxed, as they suck up the moisture.
A butterfly cabinet with drawers is very expensive, and beyond the means of most boys. Cases to hold the butterflies should be uniform in size, made of mahogany, seasoned deal, or cedar, and lined with cork, to be procured at any shoemaker’s, and fitted with a glass lid on hinges. These can be hung as ornaments against the wall. In one corner should be fixed a little perforated tin match box containing a lump of camphor. The appearance of a collection is much improved by having a piece of black cotton stretched from two pins down the box, between the lines of butterflies. Cases for travelling should on no account be glazed, but be shaped like a book, with a hinge in the centre, that the butterflies may be put on either side.
The pins used had better be the headless taxidermist pins, sold for the purpose, which being so much slighter than the ordinary pins, do not spoil the specimens.
Should the larger butterflies show signs of decay in their bodies, paint them with a little solution of carbolic acid, equal parts of acid and water.
It is unnecessary to catch more than four or five good specimens of each class. First, the male (which is much smaller than the female), secondly, the female, can be set out. Then two butterflies, which have been set with their wings closed to show the undermarkings, can be placed body to body to economise space. The fifth specimen may be some abnormal one of the same class, if such has been caught.
All valuable collections are kept away from the light, which deteriorates them. In the British Museum but few specimens are shown to the general public, and even the cases containing these are covered with a square of American cloth, which the public are asked to replace after looking at them. The real collection is kept downstairs, and can only be seen by applying for an order.
Some of the best specimens in England have been bred for collection from the caterpillar. This accounts, to my mind, for the occasional appearance of some brilliant foreign specimen in this country. It has probably escaped from some one’s menagerie. I caught last year, on the southern coast, a beautiful specimen of the North American linea plexippus in such perfect condition that it could not possibly have been wafted across the Atlantic.
No creature in Nature goes through such marvellous evolutionary changes as the butterfly. It emerges from the chrysalis hanging on the bough, the male appearing fifteen days earlier than the female. This latter lays her eggs, as it were, on her death-bed, and they are hatched the following year into the minutest of larvæ. Each kind of butterfly lays its eggs in a spot where the caterpillar can procure the food peculiar to it. Thus caterpillars kept in confinement require each kind a different sort of leaf. Some caterpillars hibernate and do not turn into a chrysalis till the second year.