220 Insect Architecture. 



open, always exhibits a cavity, smooth, polished, and regular, 

 ia which the cocoon or the chrysalis lies secure (Fig. B, 

 p. 221). The polish of the interior is precisely such as 

 might be given to soft earth by moistening and kneading it 

 with great care. But beside this, it is usually lined with a 

 tapestry of silk, more or less thick, though this cannot 

 always be discovered without the aid of a magnifying glass. 

 This species of caterpillars, as soon as they have completed 

 their growth, go into the earth, scoop out, as the cossus does 

 in wood, a hollow cell of an oblong form, and line it with 

 pellets of earth, from the size of a grain of sand to that of a 

 pea united, by silk or gluten, into a fabric more or less 

 compact, according to the species, but all of them fitted for 

 protecting the inhabitant, during its winter sleep, against 

 cold and moisture. 





Outside view of Nests of Earth-mason Caterpillars. 



One of the examples of this occurs in the ghost-moth 

 (Hepialus humuti), which, before it retires into the earth, 

 feeds upon the roots of the hop or the burdock. Like 

 other insects which construct cells under ground, it lines 

 the cemented earthen walls of its cell with a smooth 

 tapestry of silk, as closely woven as the web of the house- 

 spider. 



Inaccurate observers have inferred that these earthen 

 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 



