97 



pin the specimens. A slight slanl from the middle upward most be 

 provided for in stretching boards in order to counteract the tendency 

 of the wings, however well dried, to drop utter the insect is placed in 



the cabinet. 



779. SPREADING CASE. 



This is designed for use where a good deal of work is to be done. 



Five or six spreading boards are made together, forming a shelf, and 

 a number of these shelves are arranged as slide drawers in a suitable 

 case, which is compact and prevents the specimens from being injured 

 by other insects while they are being dried. 



780. DRYING OVEN. 



For the inflation of the larvae of Lepidoptera a tin diving oven, 

 placed over an alcohol lamp, is used. The sides are of glass or mica. 

 so that the larva is constantly in view, and the oven is furnished with 

 suitable sliding or hinged doors and with a brass screen on the lower 

 side to regulate and distribute the heat. 



781. MICROSCOPIC SLIDE CASE. 



This is made of strong pasteboard and is arranged to hold twenty- 

 six slides, the cover bearing numbers from 1 to 26, opposite which may 

 be written the name of each insect mounted and labeled on the re- 

 spective slides, 



782. BALSAM SLIDE MOUNTS. 



An exhibit is made of a number of slides showing the method fol- 

 lowed in the work of the entomologist m mounting and labeling 

 specimens. 



The preservation of* aleoliolie specimens. 



Very much of the biologic material in entomology will be kept in 

 alcohol or other preservative fluids. There are a number of methods 

 of storing tln^ vials, two of the most satisfactory being illustrated, 



783. THE RILEY VIAL-HOLDER. 



This consists of a small block of wood, in the upper side of which 

 are fastened two curved clamps <»i music wire, each forming about two- 

 thirds of a circle, and on the back arc set four pointed nails which 

 project about one-fourth of an inch, and serve to hold the block to the 

 cork lining of the case or drawer. The advantages of these h<>ldrr> 

 are the ease with which the block can be removed tor study or for re- 

 arrangement, and the facility of removing the vial itself from the 

 holder. 



n:;4s;;_N,,. 31 7 



