FABRE'S BOOK OF INSECTS 



First, it requires space for the purpose. So it retreats 

 some distance down its gallery, and in the side of the 

 passage digs itself a trairsformation-chamber more sump- 

 tuously furnished and barricaded than any I have ever 

 seen. It is a riximy hollow with curved walls, three to 

 four inches in length and wider than it is high. The 

 width of the cell gives the insect a certain degree of 

 freedom of movement when the time comes for forcing 

 the barricade, which is more than a close-fitting case 

 would do. 



The barricade — a door which the larva builds as a 

 protection from danger — is twofold, and often three- 

 fold. Outside, it is a stack of woody refuse, of particles 

 of chopped timber; inside, a mineral lid, a concave cover, 

 all in one piece, of a chalky white. Pretty often, but 

 not always, there is added to these two layers an inner 

 casing of shavings. 



Behind this threefold door the larva makes its arrange- 

 ments for its transformation. The sides of the chamber 

 are scraped, thus providing a sort of down formed of 

 ravelled woody fibres, broken into tiny shreds. This 

 velvety stuff is fixed on the wall, in a thick coating, as 

 fast as it is made. The chamber is thus padded through- 

 out with a fine swan's-down, a delicate precaution taken 

 by the rough grub out of kindness for the tender creature 

 it will become when it has cast its skin. 



Let us now go back to the most curious part ot the 



[220] 



