In the use of the rubber stopper the novice may find some difficulty in inserting it in a vial filled with alcohol. The compression of the alcohol, or alcohol and air when the vial is not completely filled, forces the stopper out, and this is true whether of rubber or cork. If a fine insect pin is placed beside the cork when this is thrust into the bottle, the air or liquid displaced by the cork will escape along the pin and the latter may then be removed and the cork remains securely in position. If cork stoppers have been used the vials may be stored in large quantities together in jars filled with alcohol. This will prevent evaporation of the alcohol from the vials, and the specimens may be preserved indefinitely. This is only desirable in the storage of duplicate specimens and unarranged material and is not recommended as a substitute for the use of the rubber stopper. With cork stoppers evaporation can be in a measure prevented if the cork is first anointed with the petroleum preparation known as vaseline. This substance is practically unaffected at ordinary temperature and is sparingly soluble in cold alcohol. Experiments with it have shown that at ordinary spring and summer temperatures there is no appreciable loss of alcohol from vials and jars. My old method of keeping alcoholic specimens, which I abandoned for the method outlined above, was fairly serviceable, inexpensive, and warrants description. I had special folding boxes constructed resembling in exterior appearance a large insect box. The bottom of the box was solid and was made by gluing together two 11/2-inch planks. Holes extending nearly through the lower plank and of various sizes to accommodate vials of different diameters were bored as closely together as the wood justified without splitting or breaking. The holes were numbered consecutively and the vials when placed in them were numbered to correspond; the box also had its number, and in the notes the vial was referred to by number of box and vial thus, 3/73 (box 3, vial 73). The vial should project one-half to 1 inch above the hole, and should be loose enough to provide for the swelling of the wood in moist weather. To protect the vials a cover having a depth of about 11/2 inch was hinged to the back and secured in front by hook-and-eye fastenings. This method of storing vials is satisfactory enough for private collections, but for larger public collections is not so suitable. [Illustration: FIG. 113.--The Marx tray for alcoholic specimens (original.)]