Collecting and Preserving Dragonelies 15 



penetration of the fluid into the body cavity and the organs lying in it. In 

 passing such material through alcohols of increasing strength as directed 

 above, the transfer should be carried to 90 or 95% strength. 



Permanent preservation of material for dissection should be in 70% 

 alcohol, for histological purposes 85-95% alcohol. 



Strickland (Biol. Bull, XXI, 191 1, 306), has recommended Kahle's fluid 

 (30 parts water, 15 parts 96% alcohol, 6 parts 40% formalin, i part glacial 

 acetic acid) as superior to Gilson's mixture for fixing larvse of Simulium and 

 it may perhaps be superior for Odonata. 



Schulze (Deut. ent. Zeitschr., 204, 191 5) suggests a mixture of 200 cc. 

 glycerine. 200 cc. distilled water and i g'ram crystallized carbolic acid for 

 preservation of larvae for dissection, especially in the tropics. 



Further directions for preparation of histological material must be sought 

 in such works as Bolles Lee's "Microscopists Vade IMecum," 7th edition, 

 Philadelphia, Blakiston, 191 3. 



COLLECTING MANUALS. 



For suggestions and directions on collecting and preserving dragon- 

 flies see: 



I. Directions for collecting and rearing dragonflies, stone flies and May 

 flies, by James G. Needham. Part O of Bulletin No. 39, U. S. Nat. Mus., 1899. 

 2. Directions for collecting and preserving insects, by Nathan Banks. 

 Bulletin 67, U. S. Nat. Mus., 1909. 



