282 IXSECT ARCHITECTURE. 



the clirysalis. But what is niiost remarkable, it is impos- 

 sible by the naked eye to tell which of these two has been 

 opened by the moth, so neatly has the joining been finished. 

 (J.E.) 



Some species of moths spin a very slight silken tissue for 

 their cocoons, being apparently intended more to retain 

 them from falling than to afford protection from other acci- 

 dents. The gipsy-moth (^Hypogymna dispar), rare in most 

 parts of Britain, is one of these. It selects for its retreat a 

 crack in the bark of the tree upon which it feeds, and over 

 this spins only a few straggling threads. We found last 

 summer (1829), in the hole of an elm-tree in the Park at 

 Brussels, a group of half a dozen of these, that did not 

 seem to have spun any covering at all, but tnisted to a 

 curtain of moss (^Hypna) which margined the entrance. 

 (J. K.) In a species nearly allied to this, the yellow- 

 tussock (^Dasycliira pudihunda, Stephens), the cocoon, one of 

 which we have now before us, is of a pretty close texture, 

 and interwoven with the long hairs of the caterpillar itself 

 (see figure b, page 17), which it plucks out piece-meal 



Cocoon of Avctia villica. 



Xet-work cocoon. 



during the process of building, — as is also done by the 

 vapourer (Orgyia antiqua, Hubts^er), and many others. 

 These are additional instances of the remarks we for- 



