272 STRANGE DWELLINGS. 



me. It was found in a hedge, about two feet from the 

 ground, and is rather a compHcated structure. The scaffolding, 

 so to speak, of the nest is formed by a horizontal spray of 

 three small twigs, and it is strengthened by the long hedge- 

 grass which crossed the spray. Seeds of different kinds are 

 woven into the walls, so that a comparatively small portion of 

 the silk is exposed to view. 



When cut open, it shows a singularly beautiful structure 

 within. There are several sheets of silken tissue, each be- 

 coming more delicate, and the innermost being white, shining 

 like satin ; whereas the outer covering is dull- white, and very 

 tough, clinging to the scissors so that a straight cut is almost 

 impossible. Delicate walls divide the interior into several 

 compartments, in all of which are evidences that the caterpillars 

 must have resided for some time. The reason why the crea- 

 tures make this nest is, that they are hatched towards the end 

 of summer, and in consequence are forced to pass the winter in 

 the larval condition, so that some warm residence is needful 

 for them. It is well known that air is a very bad conductor of 

 heat, and, in consequence, the successive sheets of silk which 

 cover the nest, and which inclose layers of air between them, 

 form a protection which is far warmer than would be obtamed 

 by a solid mass of silk measuring twice the thickness of the 

 three walls, together with their intervening spaces. 



There is an allied insect, popularly called the Brown-tailed 

 Moth {Porthesia aurifiud)^ which spins a social nest that in 

 many respects resembles that of the Gold-tailed Moth. The 

 nest, however, is scarcely so elegant, nor is the silken web so 

 beautifully delicate. Much, however, depends upon surrounding 

 conditions, such as the disposition of the twig on which the nest 

 is placed, and the presence or absence of leaves, whether those 

 of the tree or of other plants that happen to grow in close 

 proximity. 



