THE LARVA 37 



this alone would hardly be safe, for when it casts its skin, as it is 

 shortly about to do, its claspers will all disappear ; and although it 

 afterwards secures itself by the ' tail,' it would be dangling in such 

 a manner as to swing with every breeze a very unsatisfactory 

 state of affairs, especially with those that pupate late in the summer 

 and remain in the pupal state throughout the winter storms. 



Its next procedure, then, is to make a strong silk band round the 

 middle of its body, so as to keep it close to the surface against which 

 it rests. But how is this to be done ? It bends its head round till 

 the spinning organ can be applied to a point close beside the middle 

 of its body. Here it fixes one end of a thread ; and then, gradually 

 twisting its body, brings its head round to the other side, still keep- 

 ing it close to the same segment, and fastens the other end of the 

 thread exactly opposite the point at which it started. 



The head is now brought back to its former position, thus 

 adding another thread to the band ; and the process is repeated 

 several times, till at last the caterpillar is satisfied with the thick- 

 ness and strength of the cord formed. 



Now it straightens out its body as if to rest from its labours ; 

 but the work is not yet complete. Soon it exhibits much restless- 

 ness. Its foremost segments are seen to shorten, and consequently 

 become thicker. Then the skin splits, and the last moult of the 

 caterpillar commences. The movements that follow are exactly 

 similar to those we have already described in connection with one 

 of the earlier moults : the alternate and successive contractions of 

 all the segments gradually force back the old coat, and this is 

 finally thrown entirely off by a somewhat vigorous wriggling of the 

 ' tail.' 



Then, for a moment, the creature is supported only by its silken 

 cord. But this lasts only for a moment. For, as soon as it is 

 quite free from the old garment, it applies its tail to the densest 

 part of the carpet it had prepared at the start, and secures its hinder 

 extremity by means of little hooks. 



But what a change has now come over the creature ! It is no 

 longer a caterpillar. Its head is no longer distinct, although we 

 can readily make out the positions of the eyes. Its mouth and 

 jaws have quite disappeared, and the legs and claspers are apparently 

 gone. The three segments that bore the legs are no longer distinctly 

 separable, though in reality they still exist. The head and thorax 

 are peculiarly shaped ; and, instead of being cylindrical, are angled 

 and ridged ; but, beneath the soft greenish skin the new garment 



