APRIL, IDOl). THE CHEMICAL NATURE OF SOME INSECT SECRETIONS. 25 



The myriapod "Petascrpcs rosalbns secretes a considerable 

 quantity of a milky substance which has the perfume of gum 

 camphor." (Cope '70) (see also Banks, Science, '00. p. 649) 

 Cook ('90) noted camphor also in Polyzoninm, a closely related 

 form. These seem to be the only recorded occurrences of cam- 

 phor in the animal kingdom, but in the absence of chemical evi- 

 dence must of course remain doubtful. The occurrence of canthar- 

 idine in members of the ]\Ieloid?e may be mentioned in this connec- 

 tion. 



MISCELLANEOUS. 



Finally, the assertion that free iodine in present is the gaseous 

 secretion of the Paussid Beetle, Ccraptcnis qnadrimacidatus must 

 be noticed. (Loman "^y). The close similarity between the purely 

 organic secretion of the Spirobolus described in the sequel and 

 the physical characteristics of free iodine in solution cause us to 

 doubt Loman's observation. 



ACID. 



A small leaf beetle {Xotodoiita) is stated to secrete hydro- 

 chloric acid. (Denham '88). Another leaf beetle, (Liiia) suppos- 

 edly secretes Hydrocaynic acid according to Candeze ('74). It 

 has long been known that ants produce formic acid in great quan- 

 tity, while this acid is probably present in the poison of all wasps 

 (Forel '78). The relative amoimt in various species of ants will 

 be tabulated in the special part of this paper. Butyric acid as well 

 as formic occurs in nearly all the Carabida; associated with other 

 substances. The whip scorpion (TJiclyphoiius) secretes acetic 

 acid (Marx. '86) in such quantity tliat a stream is ejected from 

 each side of the body which fact has earned its ^Mexican name of 

 "vinagron". According to Claus {'Sy) the myriapod Fontaria 

 secretes a fluid which contains free hydrocyanic acid. Cope ('70) 

 and Wheeler ('90) have both demonstrated that the allied Poly- 

 dcsnins lirginiensis secretes free hydrocyanic acid. 



ALKALINE. 



The only recorded case of a strong alkali being found in the 

 animal kingdom is in Dicraiiura, and some other moths, wdiich 

 produce potassium hydroxide at the last moult in order to soften 

 the silk of the cocoon ( Latter '92 and '95). Strangely enough the 

 larva of this same insect produces formic acid in quantity (Mel- 

 dola '92), 



