THE CAPRICORN 55 



fibers, broken into minute shreds. The velvety matter, 

 as ind when obtained, is appHed to the wall in a continu- 

 ous felt at least a millimeter thick. ^ The chamber is 

 thus padded throughout with a fine swan's-down, a deli- 

 cate precaution taken by the rough worm on behalf of the 

 tender pupa. 



Let us hark back to the most curious part of the 

 furnishing, the mineral hatch or inner door of the en- 

 trance. It is an elliptical skull-cap, white and hard as 

 chalk, smooth within and knotted without, resembling 

 more or less closely an acorn-cup. The knots show that 

 the matter is supplied in small, pasty mouthfuls, solidify- 

 ing outside in slight projections which the insect does 

 not remove, being unable to get at them, and polished on 

 the inside surface, which is within the worm's reach. 

 What can be the nature of that singtilar lid whereof the 

 Cerambyx furnishes me with the first specimen? It is 

 as hard and brittle as a flake of lime-stone. It can be 

 dissolved cold in nitric acid, discharging little gaseous 

 bubbles. The process of solution is a slow one, requir- 

 ing 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 hatch, when subjected to heat, blackens, proving the 

 presence of an organic glue cementing the mineral mat- 

 ter. The solution becomes muddy if oxalate of ammonia 

 be added; it then deposits a copious white precipitate. 

 These signs indicate calcium carbonate. I look for urate 

 of ammonia, that constantly recurring product of the 



1 .039 inch. — Translator's Note. 



