Februar}', '12] O'lvANE: INSECT PHOTOGRAPHY 67 



of them is 4 1-2 inches in diameter; the other 6 3-4 inches. The small- 

 est concave mirror used was taken from a compound microscope and 

 attached to the end of a mounting designed to carry an ordinary small 

 bulls-eye condenser. 



When used with the photo-micrographic camera the Nernst lamp is 

 mounted on a lower stand, so as to bring it better within the field of 

 action. The general scheme of manipulation, however, is the same. 

 Ordinarily, use is here made of the smallest concave mirror of short 

 focus, giving an extremely concentrated beam of light, and often one 

 of the larger mirrors in addition, to soften shadows. 



This camera with the lighting arrangements slightly altered is used 

 for photographing small, semi-translucent objects by transmitted 

 instead of reflected light; such, for example, as aphids or thrips mounted 

 on slides. In this case -a ground glass is interposed between the lamp 

 and the mirror beneath the microscope stage. 



Posing the Object. When a picture is desired for purposes of illus- 

 tration the writer believes in the plan of posing a given insect in as 

 life-like a position as possible, wherever this can be managed. This 

 is not with intention of deceiving the lay reader, but because such 

 posing usually gives a better idea of the real appearance of the insect 

 ^s it is found in nature. If the insect can be posed on a natural 

 background without merging into the background so as to be obscure, 

 so much the better. Thus, larvse and adults of the potato beetle 

 carefully posed on a half-eaten potato leaf convey a truer idea to 

 the ordinary reader than does a single beetle standing in space with 

 each leg extended with mathematical accuracy. 



Often it is quite impossible to use such backgrounds. Plain white, 

 solid black or a neutral gray may then be used. Oftenest a white 

 background is best. To make the proper start toward this, we have 

 made frequent use of a simple piece of plate glass fastened at one end 

 to the top of a common dissecting stand in such way that most of the 

 glass has nothing beneath it. On this glass is placed the object to be 

 photographed, and beneath it a clear white paper or cardboard, far 

 enough away if possible that the shadow of the object will not be 

 included in the negative. If the object is small this may be done 

 succes.sfully. If it is large, it may not. Pinned butterflies and the 

 like may be posed above the plate glass by glueing to the latter a tiny 

 piece of cork into which the pin may be inserted. 



For the photomicrographic camera a similar glass stand was made 

 by setting four pins in the corners of a one by tw^o inch block of wood, 

 and cementing on the top of these slender posts a small piece of 

 plate glass. 



When it is necessary to photograph larvae that have been preserved 



