storing slides I have found very convenient the box shown at Fig. 111. It is constructed of strong pasteboard and is arranged for holding twenty-six slides. The cover bears numbers from 1 to 26, opposite which the name of each insect mounted, or the label on the slide, may be written. This box when not in use is kept in a pasteboard case, on which may be placed the number of the box. These slide cases may be stored in drawers or on shelves made for the purpose. In mounting specimens taken from alcohol it is advisable to put a drop of oil of cloves upon them, which unites with the balsam and ultimately evaporates. The occurrence of minute air bubbles under the cover-glass need occasion no uneasiness, for these will disappear on the drying of the balsam. [Illustration: FIG. 110.--Balsam mount, showing method of labeling, etc. (original).] [Illustration: FIG. 111.--Slide case, showing method of labeling case and of numbering and labeling slides (original).] In mounting minute Acarids or mites it has been found best to kill the insects in hot water, which causes them to expand their legs, so that when mounted these appendages can readily be studied. If mounted living, the legs are almost invariably curled up under the body and can not be seen. This method may also be used in the case of other minute insects. Some insects, such as minute Diptera, are injured by the use of hot water, and for these dipping in hot spirits is recommended. In the mounting of Aphides the same difficulty is avoided in a measure by Mr. G. B. Buckton, author of "A Monograph of the British Aphides," by first placing a few dots of balsam on the glass slide, to which the insect is transferred by means of a moistened camel's-hair brush. The efforts of the insect to escape will cause it to spread out its legs in a natural position and a cover glass may then be placed in position and a drop of the balsam placed at the side, when, by capillarity, it will fill the space between the slide and cover glass and the limbs will be found to have remained extended. If three or four drops of the balsam are put on the glass the wings may also be brought down and caught to them so that they will remain expanded in shape for examination. _Preparing and Mounting the Wings of Lepidoptera._--The student of Lepidoptera will frequently find it necessary in the study of the venation of wings to bleach them or denude them of their scales in some way. Various methods of bleaching and mounting the wings of these insects have been given, and a few of them may be briefly outlined.