ORDER IV. MOTHS AND BUTTERFLIES. 159 



mucli heavier than those of the Silk-worm, and will yield a 

 greater quantity of silk ; and as the insects remain un- 

 changed in the chrysalis state fi'om September to June, the 

 cocoons may be kept for unwinding at any leisure time 

 during the winter. The Luna, Polypheme, Cecropia, and 

 Promethea Moths are the only native insects belonging to 

 the genus Attacus laiown to me. Their large cocoons, con- 

 sisting entirely of silk, the fibres of which far surpass those 

 of the Silk- worm in strength, might be employed in the 

 formation of fabrics similar to those manufactured in India 

 from the cocoons of the Tusseh and Arindi Silk-worms, the 

 durability of which is such that a garment of Tusseh-silk 

 is scarcely worn out in the lifetime of one person, but often 

 descends from mother to daughter ; and even the covers of 

 palanquins made of it, though exposed to the influence of 

 the weather, last many years. Experiments have been 

 made with the silk of the Cecropia, which has been carded 

 and spun, and woven into stockings that wash like linen." 



"With all these facts before us, however, the raising of 

 Silk-worms for the production of silk in this country has 

 never yet been a flourishing branch of industry, nor are we 

 able to foresee the time when it will become so. 



Another large silk-producing Moth is the Poi.TPHEiiE 

 MoTii {Attacus Polyphemus), Fig. 35. Its name, derived 

 from one of the giants of mythology, Linnaeus gave to this 

 Moth probably on account of the large size of its wings, 

 which, like those of the Cecropia, expand from three to six 

 inches. They are of an ochre-yellow color, clouded witlf 

 black, and each wing is ornamented with a transparent spot 

 resembling an eye. The caterpillar of this Moth is found 

 in July or August, according to the geographical latitude, 

 on oak, elm, and lime trees, and is from two to three inches 

 long, and nearly as thick as a man's thumb. Its body is 

 pale, bluish green, covered with orange-colored and purple 

 warts. Its head and feet are black. When full grown, it 



