The Capture, Preparation, and Preservation of Specimens 



same as when setting-boards are used, with the simple difference 

 that, instead of pinning strips of paper or tracing-muslin over the 

 wings, the wings are held in place by threads or very narrow 

 tapes, which are wound around the block. When the wings are not 

 covered with a very deep and velvety covering of scales the threads 

 or tapes maybe used alone; but when the wings are thus clothed 

 it becomes necessary to put bits of paper or cardboard over the 

 wings before wrapping with the threads. Unless this is done 

 the marks of the threads will be left upon the wings. Some 

 little skill, which is easily acquired by practice, is necessary in order 

 to employ setting-blocks to advantage, but in the case of small 

 species and species which have refractory wings they are much 

 to be preferred to the boards. 



The Preparation and Preservation of Eggs.— The eggs of but- 

 terflies may be preserved by simply putting them into tubes con- 

 taining alcohol, or they may be placed in vials containing dilute 

 glycerine or a solution of common salt. The vials should be kept 

 tightly corked and should be marked by a label written with a 

 lead-pencil and placed within the bottle, upon which the name 

 of the species and the date of collection should be noted, or a 

 reference made to the collector's note-book. Unless the eggs of 

 insects are preserved in fluid they are apt in many cases to dry up 

 and become distorted, because, on account of their small size, it 

 is impossible to void them of their contents. The larvae escaping 

 from eggs often void the shell very neatly, leaving, however, a 

 large orifice. Such remnants of shells may be preserved, as they 

 often are useful in showing some of the details of marking; but 

 great vigilance in securing them should be exercised, for almost 

 all the larvse of butterflies have the curious habit of whetting thei 

 appetites for future repasts by turning around and either wholly 

 or partially devouring the shell of the egg which they have quitted. 

 Eggs are most neatly mounted in the form of microscopic slides 

 in glycerine jelly contained in cells of appropriate depth and diam- 

 eter. It is best, if possible, to mount several specimens upon the 

 same slide, showing the side of the egg as well as the end. A 

 cabinet filled with the eggs of butterflies thus mounted is valu- 

 able and curious. 



The Preservation of Cbrysalids.— Chrysalids may be deprived 

 of their vitality by simply immersing them in alcohol, or they 

 may be killed by means of chloroform, and they may then be 



43 



