INTRODUCTION. 79 



are the coverings of the caterpillars of the Clothes- 

 moths, in the fabrication of which they show a 

 degree of diligence and ingenuity, which it would 

 be more pleasing to contemplate if less frequently 

 exercised to our disadvantage. Their mantle con- 

 sists of a small somewhat cylindrical tube, open at 

 both ends, and rather widest in the middle. The 

 exterior of this tube is a tissue of wool and silk, but 

 the interior is lined with pure silk, for the greater 

 comfort of the little tenant, whose body is soft and 

 tender. So indispensable to its welfare is a fabric 

 of this kind, that the worm begins to weave it soon 

 after it issues from the egg. The growth of its 

 body, however, renders it necessary that the do- 

 micile should be frequently enlarged both in length 

 and width. The former it readily accomplishes by 

 putting out its head from one end, cutting the 

 filaments of the wool with its scissor-like mandibles, 

 and then, by turning its head backwards, incorpo- 

 rating them with the rest of the tissue; it then 

 turns itself in the opposite direction, which the 

 wideness of its tube in the centre enables it do with 

 facility, and repeats the same operation at the other 

 extremity. The widening of the tube is a more 

 difficult task, and the plan which it adopts to ac- 

 complish it is as ingenious as if it were the result 

 of a process of reasoning. The most obvious me- 

 thod, and that which we would probably adopt in 

 such a case, would be to make a rent the whole 

 length of the garment, and again fill it up by in- 

 serting a new piece sufficient to afford the extension 



