The Glow-Worm and Other Beetles 



charging little gaseous bubbles. The process 

 of solution is a slow one, requiring several 

 hours for a tiny fragment. Everything is 

 dissolved, except a few yellowish flocks, 

 which appear to be of an organic nature. As 

 a matter of fact, a piece of the lid, when 

 subjected to heat, blackens, which proves the 

 presence of an organic glue cementing the 

 mineral matter. The solution becomes 

 muddy if oxalate of ammonia be added and 

 deposits a copious white precipitate. These 

 signs indicate calcium carbonate. I look for 

 urate of ammonia, that constantly-recurring 

 product of the various stages of the meta- 

 morphoses. It is not there: I find not the 

 least trace of murexide. The lid, therefore, 

 is composed solely of carbonate of lime and 

 of an organic cement, no doubt of an al- 

 buminous character, which gives consistency 

 to the chalky paste. 



Had circumstances served me better, I 

 should have tried to discover in which of the 

 worm's organs the stony deposit dwells. I 

 am, however, convinced : it is the stomach, 

 the chylific ventricle, that supplies the chalk. 

 It keeps it separate from the food, either as 

 original matter or as a derivative of the 

 ammonium urate ; it purges it of all foreign 

 bodies, when the larval period comes to an 



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