148 Psyche [Oct.-Dec, 



presence of one or more organic acids. . . . Having tested for 

 valerianic acid in the usual way with neutralized soda solution 

 upon sesquichloride of iron, no red precipitate of valerianate of 

 iron was formed, nor have I obtained a bluish-white opalescent 

 liquid of butyrate of copper on adding acetate of copper. Uric 

 acid was also found to be absent, on treating with nitric acid and 

 ammonia in the usual way; neither could I detect formic or acetic 

 acid, nor did boiling with caustic soda liberate anuuonia. A few 

 drops of the secretion, put on a piece. of dry caustic soda, turned 

 at first dark green, became in a few seconds dirty brown, and 

 cleared up to a Ijrownish red after several hours." 



It was interesting to note that the quantity of the secretion voided 

 varies noticeably with the different species under observation, both 

 under field and under laboratory conditions, and some of the spe- 

 cies, notably Eleodes tricostata Say, imdoubtedly have the habit 

 of erecting the abdomen in a threatening manner when approached, 

 though no secretion may be voided. Such species undoubtedly find 

 protection through imitation of the threatening movements of their 

 more formidable associates. Two of the characteristics of the 

 Eleodes are their slowness of movement, and their habit of coming 

 out of their hiding places about sunset for feeding purposes, and 

 their presence is readily noticed on the bare sandy plains by birds, 

 skunks, and other enemies, hence their protective secretion, or, in 

 the absence of this, their threatening maneuvers are no doubt of 

 highest value to them. 



References. 



1839. Westivood, J. 0. Modern classification of insects. Vol. 1, 

 pp. 75-76. 



1879. Gissler, C. F. On the Eepugnatorial Glands of Eleodes. 

 Psyche, Vol. 2, pp. 209-210, inc. 



1882. Dimmoch, G. On some glands which open externally on 

 insects. Psyche, Vol. Ill, pp. 387-401. 



1884. Williston, S. W. Protective Secretions of species of Ele- 

 odes. Psyche, Vol. IV, pp. 168-169 inc. 



189 5-. Pacl-ard, A. S. The Eversible repugnatorial Scent Glands 

 of Insects. Jour. N. Y. Ent. Soc, Vol. Ill, pp. 110-127. 



