_Arrangement of Specimens._--Specimens are best arranged in rows. The males should be pinned in first in the series, after them the females. Varieties should follow the species. After these should be placed any aberrations or monstrosities which the collector may possess. The name of the genus should precede all the species contained in the collection, and after each species the specific name should be placed =Fig. 71= shows the manner of arrangement. [Illustration FIG. 71.--Manner of arranging specimens in cabinet.] _Insect Pests._--In order to preserve collections, great care must be taken to exclude the various forms of insect pests, which are likely, unless destroyed and kept from attacking the specimens, to ruin them utterly in comparatively a short time. The pests which are most to be feared are beetles belonging to the genera _Dermestes_ and _Anthrenus_. In addition to these beetles, which commit their ravages in the larval stage, moths and mites prey upon collections. Moths are very infrequently, however, found in collections of insects, and in a long experience the writer has known only one or two instances in which any damage was inflicted upon specimens by the larvæ of moths. Mites are much more to be dreaded. [Illustration FIG. 72.--Naphthaline cone.] In order to prevent the ravages of insects, all specimens, before putting them away into the boxes or drawers of the cabinet in which they are to be preserved, should be placed in a tight box in which chloroform, or, better, carbon bisulphide, in a small pan is put, and they should be left here for at least twenty-four hours, until it is certain that all life is extinct. Then they should be transferred to the tight boxes or drawers in which they are to be kept. The presence of insect pests in a collection is generally first indicated by fine dust under the specimen, this dust being the excrement of the larva which is committing depredations upon the specimen. In case the presence of the larva is detected, a liberal dose of chloroform should at once be administered to the box or tray in which the specimen is contained. The specimen itself ought to be removed, and may be dipped into benzine. Naphthaline crystals or camphor is generally employed to keep out insect pests from boxes. They are very useful to deter the entrance of pests, but when they have once been introduced into a collection neither naphthaline nor camphor will kill them. Naphthaline is prepared in the form of cones attached to a pin, and these cones may be placed in one corner of the box. They are made by Blake & Co. of Philadelphia, and are in vogue among entomologists. However, a good substitute for the cones may very easily be made by taking the ordinary moth-balls which are sold everywhere. By heating a pin red-hot in the flame of an alcohol-lamp it may be thrust into the moth-ball; as it enters it melts the naphthaline, which immediately afterward cools and holds the pin securely fixed in the moth-ball.