the Excrement of Insects. 29 



the solution yielded crystalline forms, rhomboidal plates, resem- 

 bling those of nitrate of urea. 



46. A moth (^Cercqotei-yx gravunis) voided no excrement in 

 confinement. After its death, the anal portion of its abdomen was 

 detached and digested for a few minutes in dilute nitric acid; the 

 solution, evaporated and exposed to a graduated heat, afforded a 

 faint but clear trace of lithic acid. 



47. A fly {Anthomijia platura), in confinement, voided a minute 

 portion of excrement; which, on examination, was found to con- 

 sist principally of lithate of ammonia. 



48. Another ^y (CaU'qjhora vo7nitor in), in confinement, voided 

 a very little excrement, which was ascertained to be like the 

 last. 



49. A butterfly {Pontia Napi) yielded in confinement some ex- 

 crement; found to consist chiefly of lithate of ammonia. 



50. Two cow-dung flies {Scataphaga stercoraria), in confine- 

 ment, voided a little excrement in reddish patches, which, under 

 the microscope, exhibited the usual granular appearance of lithate 

 of ammonia, the granules about yo^og of an inch in diameter, and 

 was similarly acted on by nitric acid and heat. 



51. Several small flies (^Musca rudis), in confinement two or 

 three days, voided pretty much greyish excrement deposited in 

 patches. Under the microscope, after being diluted witli water, 

 it exhibited, in addition to granules, some prismatic slender crys- 

 tals, as of phosphate of lime, and some scales, as of epithelium. 

 Acted on by nitric acid and heat, proof was obtained of the pre- 

 sence of lithic acid. 



52. A honey bee {Apis mellijica) died in confinement without 

 voiding any excrement. On pressing its abdomen a colorless 

 drop of fluid was obtained, in which a trace of lithic acid was 

 detected. 



5S. Three bees, taken from their hive in October, presently 

 died at a temperature of about 40° Fahrenheit. The anal portion 

 of the abdomen of each was separated and digested in dilute nitric 

 acid ; on evaporating the solution at a graduated heat, a trace of 

 lithic acid was detected. 



54. A wasp — the common English wasp — which in confinement 

 voided no excrement, yielded after death, the abdomen being 

 pressed, a drop of fluid, in which, under the microscope, a few 

 granules were seen, as of lithate of ammonia, and in which a trace 

 of lithic acid was found by the ordinary means. 



55. A beetle {Geotrupes syloaticus), in confinement, during one 

 night voided many small cylindrical masses of a brown color, with 



