i6 SECTION OF COCOON 



bark of the tree itself looks exactly like a 

 natural excrescence which only the practised 

 eye of the entomologist can detect. By-and-by 

 the larva pupates, an operation that involves 

 the shedding of its skin together with the 

 cutting mandibles. How, then, is it possible 

 for the soft woolly moth, due to emerge the 

 following spring, to break through the walls 

 of its prison ? Save for a short proboscis 

 and antennae it has then no tools to work 

 with. 



To understand how the moth escapes and 

 the modus operandi, we must carefuUy cut out 

 a cocoon with a chisel and extract the chrysa- 

 lis ; then by holding to the light the empty 

 shell, which looks like the half of an almond 

 shell, it will be seen that the interior is opaque 

 with the exception of a small circular cap at 

 the top end ; this, it will be noted, has less 

 bark and is transparent, otherwise as hard as 

 the rest of the structure. This glazy " sky- 

 light " is pure consolidated gum (liquid silk) 

 which is spread by the larva as it finishes work. 

 The consistency of the cement is such as to be 

 unaffected by moisture, but is solvent to an 

 alkaline fluid with which the moth is provided 

 and which it exudes when breaking through 

 the chrysalis case ; thus the gum gives way 

 and the insect struggles through the aperture. 



