STATES OF INSECTS. 221 



quercifolia ; others almost fusiform a (Odenesis potaioria). 

 Reaumur received one from Arabia which was nearly 

 cylindrical b . Those of T. prasinana before noticed, and 

 many other Tortrices, are shaped like a reversed boat c ; 

 that of Saturnia Pavonia and others of the same tribe, 

 like a Florence flask with a wide and short neck. The 

 cocoon of Lygcena Filipendula: resembles a grain of bar- 

 ley. Another cocoon in my cabinet, of very slight net- 

 work, is shaped something like an air-balloon. But the 

 most remarkable one for its form and characters, is one 

 that I received from the rich cabinet above quoted. This, 

 which is of an unusually close texture, is suspended by 

 a thread more than two inches long from the point of a 

 leaf; it then swells into a perfect cone, at the base about 

 four-fifths of an inch in diameter and half an inch in 

 length, and covered with scattered setiform appendages : 

 from the centre of the base projects a large hemispherical 

 protuberance, which terminates in a long stalk, much 

 thicker than the thread that suspends the cocoon. There 

 is commonly no difference between the shape of cocoons 

 spun by larvae which are to give birth to different sexes of 

 the same species. The silk-worm cocoons, however, 

 which will produce male moths, have more silk at the 

 ends, and consequently are more round than those which 

 are to produce females : but the difference is not strik- 

 ing;. 



The most usual colour of silken cocoons is white, yel- 

 low, or brown, or the intermediate shades. The whites 

 are very pure in the general envelope of some species 

 of Ichneumonidce, and yellows often very brilliant. But 



a Sepp. iv. t. viii./. 5. b Reaum, i. t. xliv./. 2. 



c Plate XVII. Fig. 7. 



