132 ENTOMOLOGICAL NEWS. [May, 



unable to obtain other desirable species in numbers sufficient to 

 test the methods. I would suggest that similar experiments on 

 some species of Sympetrum and some ^Kschna or Anax might 

 yield something of interest in the way of color preservation. 



More than two hundred males of Enallagma civile were 

 caught one forenoon, and the following conclusions result from 

 treating these specimens in various ways. Mr. D. A. Atkin- 

 son, of Pittsburg, has had good results in the preservation of 

 herpetological material by thoroughly hardening in formalin 

 solution and then using a solution of zinc sulphate (ZN 

 SO 4 , i pound; H 2 O, 3 gals.) for the permanent preserv- 

 ing fluid. This will not do, however, for dragonflies. Thor- 

 oughly hardened in 95 per cent, alcohol or 6 per cent, forma- 

 lin and then placed in zinc sulphate solution the} 7 slowly 

 blackened and spoiled. They spoiled more rapidly if placed in 

 the zinc sulphate without previous hardening. Specimens pre- 

 served in 6 per cent, formalin, in a few days turned dark 

 obscure reddish. Formalin is, at the best, an unsafe perma- 

 nent preservative for material of any kind. In glass stoppered 

 jars, sealed w r ith vaseline, it disappears, not, as often stated, by 

 evaporation, but by decomposition. It is valuable in fixing 

 the colors of fishes, salamanders, etc., but even in strong solu- 

 tion does not seem able to set the colors of Enallagmas. 



Specimens were placed in 95 per cent, alcohol. In this, 

 colors are natural after three months. Specimens were papered 

 after being in alcohol eight days. Color preservation good, 

 shrinkage bad. Specimens papered after one month in 

 alcohol did not shrink any more than those of eight 

 days, but there was some whitening of postocular spots 

 and blue of thorax. Specimens were papered after four hours 

 in benzine. Color preservation good, but the blue of thorax 

 took on a slight violet tinge. After a few hours in benzine 

 specimens soften and the abdominal segments fall apart easily. 

 Specimens hardened in alcohol, then placed two days in ben- 

 zine, and finally papered had the colors almost perfectly pre- 

 served, but with the hint of a white line on either side of the 

 black mid-dorsal stripe. Specimens placed four hours in ace- 

 tone and then papered also had the colors well preserved, but 



