In endeavoring to prepare mounts of mosquitos with especial reference to use with opaque projection or lantern slides, and especially for facilitating photography, and which would avoid the objectionable shadow caused by the usual mounts the following methods have been developed.

1. Place in the center of a clean glass slide a drop of Canada balsam, and in it stand on end a slender clear glass bead about 1 centimeter long, so that it forms a small pillar. Place the preparation on a level surface until the balsam is sufficiently hardened to retain the bead in position.

The commercial bead often is not broken at right angles to its axis, so that at least one end is irregular, and if used as a base tends to let the bead fall to a horizontal. For this reason it is necessary to select the beads and use the square cut end as a base, watching the preparation and keeping the bead perpendicular, otherwise, the result will be quite unsatisfactory.