INTBODUCTION. 
79 
are tlie coverings of the caterpillars of the Clothes- 
nioths, in the fabrication of which they show a 
degree of diligence and ingenuity, which it would 
he more pleasing to contemplate if less frequently 
exercised to otit 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 luied Avith 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 tliis kind, that the AA'orm 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 AA-idth. The former it readily accomplishes by 
putting out its head fi-om one end, cutting the 
filaments of the aa'ooI AAnth its scissor-like mandibles, 
and then, by turning its head backAA'ards, incoi-po- 
rating them Avith the rest of the tissue; it then 
turns itself in the opposite direction, Avhich the 
AAndeness of its tube in tlie centre enables it do Avith 
facility, and repeats the same operation at the other 
extremity. The AAidcning of the tube is a more 
difficult task, and the plan aaIucIi it adopts to ac- 
complish it is as ingenious as if it AA’ere the result 
of a process of reasoning. The most obvious me- 
thod, and that which we would probably adopt in 
such a case, Avould be to malce a rent the AA-hole 
length of the garment, and again fill it up by in- 
serting a ncAV piece sufficient to afford the extension 
