202 



INSECT ARCHITECTURE. 



Nesis, &c , cf an Earth-mmon Caterpillar. 



earthern structures were formed by a very rude and 

 unskilful process — the caterpillar, according to them, 

 doing nothing more than roll itself round, while the 

 mould adhered to the gluey perspiration with which 

 they describe its body to be covered. This is a 

 process as far from the truth, as Aristotle's account 

 of the spider spinning its web from wool taken from 

 its body. Did the caterpillar do nothing more than 

 roll itself in the earth, the cavity would be a long 

 tube fitted exactly to its body {fig. c) : it is essentially 

 different. 



It does not indeed require very minute observation 

 to perceive, that every grain of earth in the structure 

 is united to the contiguous grains by threads of silk; 

 and that consequently, instead of the whole having been 

 done at once, it must have required very considerable 



