230 Journal of Applied Microscopy. 



this amount can be used for twelve or fifteen specimens, or used until the Cu SO4 

 becomes blue, when it must be changed. One end of a thread is attached to the 

 stopper and the other end supports a bent pin, the thread being of such length as 

 to permit of the pin resting just below the surface of the alcohol. The tissue is 

 hung on this pin, and the whole dropped into the alcohol — the bottle being 

 tightly corked. 



By preference the benzol-cedarwood oil mixture should consist of one and 

 one-half parts of tliick cedarwood oil-and two and one-half parts of pure benzol. 



If thin cedar oil is used the mixture then should consist of equal parts. The 

 thin oil does not give as good results, however. 



I have used this method for four years, and in my hands it has been much 

 more satisfactory than the freezing methods. The entire process can be carried 

 through in from three and one-half to four hours. 



S. H. Champlin, M. D. 



Chicago. 



Methods of Mounting Small Coleoptera and Other 



Small Insects. 



In response to the request appearing in the November number of this jour- 

 nal, for a method of mounting small Coleoptera and parts of insects, I will give 

 the methods in use in the laboratory of the Ohio State University. 



The method giving best results for general work is as follows : drop speci- 

 mens in absolute alcohol and leave for an hour or more to dehydrate, then trans- 

 fer to xylol or other clearing agent for a few minutes, from which they are taken 

 and mounted in balsam. If it is desired to make opaque objects transparent, 

 they should be boiled for a moment in caustic potash and then treated as above 

 described. 



If it is desired to clear and mount small and fragile specimens with little 

 handling, this may be accomplished by dropping them in water-free carbolic 

 acid to kill, dehydrate, and clear. After remaining in this an hour or more they 

 are mounted in balsam. 



The smaller beetles, after being chloroformed, are often mounted directly in 

 balsam. They are cloudy for a time when mounted in this manner, but in the 

 course of four or five weeks they become clear, so that this simple method may 

 be used to advantage with small insects and their parts if they may be given 

 time to clear up perfectly before being studied. 



In working with scale insects (Coccida-) the insects are first picked out of 

 the scales and placed upon a slide where it is desired to mount them. A few 

 drops of a five per cent, solution of caustic potash are applied, and the specimens 

 boiled in this for two or three minutes by holding the slide over a bunsen burner. 

 The specimens are then worked two or three times by being covered with a few 

 drops of absolute alcohol, after which they are cleared and balsam applied. 



E. L. Fullmer. 

 Ohio State University. 



