280 THE INSECT WOELD. 



carries it to the end of the tube, against which it attaches it. It 

 repeats many times in succession a similar manoeuvre, sometimes 

 coming partly out of its tube, and then again re-entering it to fix 

 against one of its sides a new piece of wool." 



After having worked for about a minute at one end of its tube, 

 it thinks of lengthening the other. It turns itself round in its 

 tube with such quickness, that you would imagine it could not 

 have had time to do so, and would think that its tail was formed 

 in the same way as its head, and possessed the same address in 

 choosing and tearing out the bits of wool. 



Furthermore, when the moth 

 which is working at elongating its 

 case does not find the threads or 

 hairs of wool to its taste within 



Fig. 295.-La of a Tinema walking. ^^ Q{ ^ j^ ^ cbmges its 



place. Re'aumur saw this insect walking, at some speed even, carry- 

 ing with it its case. It walks on its six front legs (Fig. 295). 

 With the middle and hind legs it clings to the interior of its case. 



At the same time that the larva becomes longer it becomes 

 stouter. Yery soon its garment will be too narrow for it. Will 

 it cast off its old coat, or will it make itself a new one ? Eeaumur 

 discovered that it preferred to widen its old coat. 



This is what our naturalist saw when he placed larvae with blue 

 cases, for instance, upon stuff of a red colour. The bands, which 

 extended in straight lines from one end of the case to the other, 

 showed the part that had been added. 



"From watching them at different times," says this admirable 

 observer, " I find that the means which they employ is precisely 

 that to which we should have had recourse in a similar case. We 

 know of no other way of widening a sheath, a case of any stuff that 

 we find too narrow, than to split it right up and to let in a piece 

 of the proper size between the parts which we have thus divided ; 

 we should let in a piece on each side if the shape of the tube seemed 

 to require it. This is also exactly what our larvae do, with an 

 extra, and which with them is a necessary, precaution, so as not to 

 remain exposed whilst they are working at the enlargement of 

 their garment. Instead of two pieces, which should each be as long 

 as their case, they let in four, each of which is not longer than half 



