A rather convenient and inexpensive method of storing vials is that used by Dr. Marx. In this method the vials are stored in a wooden frame, shown at Fig. 113. The top piece of the tray into which the vials are thrust has a cork center, in which holes corresponding to the size of the vials are made with a gun-wad punch. The outer end of the tray bears a label or labels describing the material in the tray. The vials used by Dr. Marx are of thinner glass than those which I recommend and flare slightly at the top, as shown in the accompanying illustrations. They are made in various sizes to accommodate larger and smaller specimens. A vial thrust into the hole punched in the cork rests on the bottom piece of the tray, the flange or neck preventing it from sliding through. These trays are arranged on shallow shelves in a case or cabinet, especially constructed for the purpose and a large quantity of material may be stored by their use in small compass. The use of the cork center piece in the upper part of the tray is not a necessity, and a wooden piece may be used in which holes are bored with a bit of proper size. [Illustration: FIG. 114.--Vials used in the Marx tray (original.)] _Preserving Micro-larvae in Alcohol._--The following is quoted from Packard's "Entomology for Beginners," for which it was translated from the "_Deutsche Ent. Zeitg._," 1887, Heft I: "Dr. H. Dewitz mounts the larvae and pupae of Microlepidoptera, and also the early stages of other small insects, in the following way: The insects are put into a bottle with 95 per cent alcohol. Many larvae turn black in alcohol, but boiling them in alcohol in a test tube will bleach them. They may then be finally placed in glass tubes as small and thin as possible, varying from 0.003 to 0.006 meter in diameter, according to the size of the insects. About 0.07 meter's length of a tube is melted over a spirit lamp, and the tube filled three-quarters full with 95 per cent alcohol, the insects placed within and the contents of the tube heated at the end still open, and then closed by being pulled out with another piece of glass tubing. After the glass has been held a few minutes in the hand until it is slightly cooled off, the end closed last is once more held over the lamp so that the points may be melted together, and this end of the glass may be finished. During the whole time from the closure of the tube until the complete cooling of the glass it should be held obliquely in the hand, so that the alcohol may not wet the upper end, for if the tube is too full it is difficult to melt it, as the steam quickly expanding breaks through the softened mass of glass. The tube may be mounted by boring a hole through a cork stopper of the same diameter as the glass. The stopper is cut into the shape of a cube, a strong insect pin put through it, and the glass tube inserted into the hole. It can then be pinned in the insect box or