air and sunshine, may die without cleaning themselves properly.
If it is desired to preserve the specimens, they should be killed either with cyanide of potassium, ether, or chloroform. If the first of these agents is used, a piece of about the size of a small hazel nut should be put at the bottom of a bottle (for collecting purposes, an ordinary "Coleoptera bottle", which can be obtained from any naturalist's shop, is the most convenient) and should be kept down by a wad of blotting paper, well pressed down upon it; this prevents the cyanide, as it liquifies, from wetting the hairs, etc., of the insects. Over this a piece of white paper should be placed; this will get stained at once when there is much damp, and should then be changed. The objections to cyanide are its very poisonous nature, and the stiffness which is caused by its use to the specimens killed by it, and also its tendency to turn yellow colours red. I always use it myself as I think it is preferable to the other insecticides, notwithstanding its demerits, but then I do not extend the legs and wings of my specimens, but simply leave them in whatever position they happen to
die. Ether is a very favourite method of killing with many; a few drops in a bottle with some paper in it is sufficient to last for some hours; it however soon evaporates in hot weather, and it is necessary to carry a small phial of it in one's pocket to replenish the supply when exhausted; this makes one smell of ether perpetually, which is more than I can stand. But the insects killed in this way are beautifully supple, and, for those who wish to set their captures as they would Lepidoptera, it is an excellent medium, i.e. if they don't mind its smell; it has also the benefit of not affecting colour. Chloroform acts much as ether does. When killed, I strongly recommend collectors to pin their specimens through the thorax with a very fine pin (those used for micro-lepidoptera are the best), and then to pin this through a narrow strip of card, mounted on a long stout pin; in this way the insect can be moved about by the strong pin, and the thorax of the insect itself is not destroyed, as it often is in the case of the smaller species by the use of thicker pins. The cards should be cut as small as possible; they need not be more than a quarter of an inch long. The insect
should be pinned at right angles to the long axis of the card, and the long pin should be inserted on the right-hand side of the insect so as not quite to touch it. In this way the insects look quite as neat as if they were pinned direct. Locality labels, etc., should be affixed to the long pin, and the insects should be stored in cabinets or boxes.
ON COLOUR
There is but little tendency towards brilliant coloration amongst our native aculeates. No doubt our comparatively high latitude accounts for this to some extent, as also the fact that the aculeates do not, as a rule, elsewhere assume great brilliancy. Even in the tropics and other warm regions, where bright green, blue or coppery coloured species occur, they are comparatively few in number. In this country metallic colours are to be found in less than a dozen species, and in most of these it exists only as a tinge. Amongst our ants and wasps it does not exist at all, unless the slight bronziness of the typical form of Formica fusca be so considered. The fossors can exhibit only a bluish tint in Mutilla Europæa ([pl. A], 4, 5), and a slight bronzy tinge in two of quite the smallest species, Miscophus maritimus and the ♂ of Crabro albilabris. The bees can do a little better; five species of Halictus have a distinctly
bronzy head and thorax, and in three the bronzy colour extends to the abdomen; there is also another with a very dull green tinge on the thorax; besides these there is a little bright blue bee, Ceratina (unfortunately a great rarity in this country) and two or three species of Osmia, showing more or less tendency to bronziness, and one which is distinctly bluish; but, considering our indigenous species number nearly 400, this is a very small, and compared with other countries I should think an abnormally small, proportion.
Species with bodies banded like a wasp's are much more abundant—no less than eighty of our native kinds having this style of coloration. The bands may be reduced to lateral spots, but such cases, I think, are only modifications of the banded scheme.