26 



HOW TO PHOTOGRAPH 



cian. The insect, or part of one, is re- 

 moved from the turpentine and drained, 

 placed in position on a slide, a cover-glass 

 placed over it, and a small quantity of the 

 balsam solution applied to the side, when it 

 will be drawn under by capillary attraction. 

 By a little care, air-bubbles may be entire- 

 ly avoided. The slide is then put aside 

 until the balsam has become quite ! ard, 

 when it may be cleaned for the cabinet, 

 and ornamented with rings of colored var- 

 nish, as the mounter's taste may dictate. 



Of late years many microscopists have 

 objected to the "squashing" process usu- 

 ally employed in mounting insects, as, in 

 many cases, it deforms and distorts the 

 preparation almost beyond recognition ; 

 and now many amateur and professional 

 preparers mount insects without pressure, 

 first gaining the necessary transparency by 

 prolonged immersion in turpentine, and 

 finally mounting with balsam in a cell. 

 Objects thus mounted are very beautiful, 

 especially when illuminated with the para- 

 boloid or spot-lens, but are somewhat diffi- 

 cult subjects for photography, unless a very 

 low power, such as a five- inch, four-inch, or 

 three-inch be employed, as great penetra- 

 tion is required. 



It is best, when engaged in mounting in- 

 sects, specially for photography, not to 

 mount indiscriminately any pretty object, 

 but to set up a type series, to illustrate the 

 class Insecta, which, when photographed, 

 would have a real scientific value. Some- 

 thing after the following style might be 

 attempted : 



1. Coleoptera. — Many of the smaller 

 species can be set up whole, after bleach- 

 ing in the chlorate of potash mixture. A 

 few feet may also be mounted ; the paddle- 

 foot of Dyticus, the broad-padded foot of 

 Tiniarchus, and the type-foot of Carabus. 

 Some of the antennte, as those of Melolon- 

 tka, are also well worth mounting and pho- 

 tographing. 



2. Dermaptera (the earwigs). — A speci- 

 men may be mounted whole for a five- 

 inch objective ; if possible, with the wings 

 expanded. This subject will not require 

 more than a few hours' treatment with pot- 

 ash. 



3. Orthoptera (the cockroach). — Blatta 

 Orientalis is a good type, although not a 

 true English insect. Almost colorless spec- 

 imens may be found in kitchens which these 

 creatures haunt. These will require no pre- 

 Jfminary bleaching. 



4. Tkysanoptera. — The diminutive in- 

 sects so abundant and so troublesome in 

 hot snmmers— insects which will persist in 

 crawling over one's face, and into one's 

 mouth and eyes, which swarm everywhere 

 and on ever) thing — constitute this order. 

 One of the largest, Phlaeothrips coriacea, 

 measuiing about /-^ of an inch in length 

 may be set up whole in balsam 



5. Neuroptera. — A portion of the large 

 facetted eye of the dragon-fly may be 

 mounted flat on a slide in balsam, and will 

 form a very instructive photograph. 



6. Trichoptera. — The larva of the cad- 

 dis-fly may easily be prepared. The inter- 

 nal parts must be removed, when, after wash- 

 ing and treatment with turpentine, it is 

 ready for mounting. The mature caddis- 

 fly may be set up whole. 



7. Hynienoptera (bees and wasps). — The 

 wings, showing attaching booklets, may be 

 mounted dry or in balsam. The feet will 

 require to be bleached strongly, as most 

 of the Hymenoptera are strongly colored. 

 The modified ovipositor, called a "sting," 

 should be cut from the insect carefully, so 

 as to have the poison bag attached. The 

 stings — for there are two — lie enveloped in 

 a case of brown chitine, from which they 

 may be dislodged with a fine needle The 

 poison-bag, owing to its extreme transpar- 

 ency, must be stained — not with blue, as in 

 many professional preparations, but with 

 brown. Bismarck brown is, perhaps, as 

 good as any. Sufficient stain should be 

 used to give this part as nearly as possible 

 the same color as the stings. 



The saw-flies show another modification 

 of — or, rather, addition to — the real ovipos- 

 itor. This consists of a sawing apparatus, 

 composed of four saws — two small and two 

 large ones, the former fitting into the latter. 

 This object is rather difficult to photo- 

 graph when set up in balsam, as it becomes 

 too transparent. A well-mounted ^/ry spec- 

 imen will give more satisfaction. 



