658 POPULAR SCIENCE MONTHLY. 



sticks from one to four inches long, in the center of which the lower 

 end of the silken bag protrudes, free from sticks and very flexible; 

 it has a charming silky softness, and is of a gray, ash, or mouse 

 color; of this beautiful tissue the upper or head extremity is also 

 composed, forming a tube half an inch wide. 



As a larva grows, needing more accommodation, it splits the 

 habitation at the sides, weaving into the opening portions of the 

 vegetable substances selected, and adding to the exterior fresh 

 pieces of stick, straw, or leaves, as it requires. So with Saunders's 

 case moth, when any accident happens to the nest, the caterpillar, 

 with incredible expedition, repairs the damage received, employing 

 the same silky stuff to fill up the hole, and with a nicety so perfect 

 that the severest scrutiny can not detect what was the extent of the 

 injury. 



Under the protection, then, of the substantial and somewhat 

 formidable case the larva lives. At each end there is an opening, 

 and through the anterior one it emerges to feed and change its 

 position. Commonly it only protrudes the head and the first three 

 or four segments of the body, or sufficient to use its six 

 true legs for locomotion when feeding; and if wishful 

 to remain quiet, it usually takes the precaution of fasten- 

 ing a portion of the edge of the aperture by fibers of silk 

 temporarily to the branch upon which it is, that, if 

 alarmed, it can suddenly recede completely into the case, 

 very rapidly drawing in the flexible part after it, by 

 means of its mandibles and fore legs, and contracting the 

 aperture, so as to exclude all enemies; thus hid, it stays 

 in security, suspended only by a few threads. Were 

 the nature of the hanging, tight-closed, strong, tough 

 sack unknown, it would never be suspected of containing an active, 

 voracious larva. Exceedingly wary and timid are these insects in 

 retreating at the approach of danger. On a desire for removal the 

 suspending threads are bitten off close to the case. 



As long as the caterpillar is small, and the house of no great 

 weight, it is borne nearly erect; but soon, as a rule, the incumbent 

 mass lies flat, owing to increased weight, and is dragged along in that 

 attitude. The abdominal and anal legs of the larva are furnished 

 with a series of small points or hooks, with which it moves in the 

 tube, laying hold of the interior of the lining, to which it can adhere 

 with great pertinacity; so firm the hold retained, it is impossible to 

 remove the creature without injury. 



Having attained full growth, and being about to change to pupa, 

 the larva of Metura Saundersii firmly fijses itself, by means of 

 silken fibers spun for the purpose, to a branch or trunk of a tree, or 



