26 Dr. John Davy's Observations on 



ment, after having voided some excrement, in which lithic acid 

 was detected by the ordinary test. During the first two or three 

 days it was remarked that they fed on their comb. 



The cells of the comb contained larvae nearly in a state to pass 

 into the perfect form. One taken out and killed was examined. 

 Its intestine, the lower portion, was found full of a chalk-like 

 matter, which on examination proved to be lithate of ammonia. 



The comb, freed from the old wasps, was placed on a clean 

 plate and covered with a glass shade. In a few hours a young 

 wasp made its appearance, having broken down the lateral portion 

 of its cell. It soon voided some excrement, which was of two 

 kinds, one almost black, of an offensive smell, a kind of meconium ; 

 the other of a light fawn color. This, the latter, had what appeared 

 mucous covering, within which was a fluid, and in that a little 

 mass of soft consistence, about the size of a barleycorn. The 

 fluid was brownish and transparent ; w ith nitric acid it emitted a 

 smell like that from impure urea or hiunan urine similarly acted 

 on. The included little mass was found to consist principally of 

 lithate of ammonia. 



33. Several flies, such as are common in Barbados within doors, 

 somewhat smaller than the common English house-fly, voided in 

 confinement a little semifluid excrement. By the ordinary 

 means a distinct trace of lithic acid was detected in it. The liquid 

 part afforded indications of urea, yielding a honey smell on the 

 addition of nitric acid, and minute crystalline plates on evapora- 

 tion in sunshine, which deliquesced in moist air. 



34. Musquitos. These insects, averse to light, harbour in dark 

 places ; the case of my microscope was a favourite place of 

 resort : its brass stand became spotted with their minute drop- 

 pings, so minute, indeed, as hardly to be distinguishable without a 

 magnifying glass. The specks were nearly of the same size and 

 appearance, except that some were darker than others. A good 

 many of each color were collected ; heated apart with nitric acid, 

 both proved rich in lithic acid, judging from the purple color 

 produced. 



A single musquitoe was confined under a wine glass, inverted 

 on a porcelain plate. Shortly after, on careful examination with 

 a magnifying glass, a speck of excrement was detected of a light 

 color and semi-globular form, as if voided in a semifluid state. 

 Removed carefully to a slip of thin glass, and nitric acid added, it 

 dissolved completely, and cautiously evaporated and heated, a dis- 

 tinct mark of the presence of lithic acid was obtained ; there was 

 a circular patch of a bright rose-hue, which was dissolved by 



