OF NATURAL HISTORY. 29T 



from its feemingly inanimate condition, and appears in the 

 form of a winged infe<5l. Thus the fame animals pafs the 

 firft and longeft period of their exiftence in the water, anoth- 

 er under the earth, and the third and laft in the air. Some 

 caterpillars, when about to change into a chryfalis ftate, 

 cover their bodies with a mixture of earth and filk, and con- 

 ceal themfelves in the loofe foil. Others incruft themfelves 

 with a filky or glutinous matter, which they pufh out from 

 their mouths, without fpinning it into threads. Others re- 

 tire into the holes of walls or of decayed trees. Others fuf- 

 pend themfelves to the twigs of trees, or to other elevated 

 bodies, with their heads undermoft. Some attach them- 

 felves .to walls, with their heads higher than their bodies, 

 but in various inclinations ; and others choofe a horizontal 

 pofition. Some fix themfelves by a gluten, and fpin a rope 

 round their middle to prevent them from falling. Thofe. 

 which feed upon trees attach themfelves to the branches, in- 

 flead of the leaves, which are lefs durable, and fubject to a 

 greater variety of accidents. The colours of the caterpillars 

 give no idea of thofe of the future flies. 



In general, the figure of chryfalids approaches to that of a 

 cone, efpecially in their pofterior part. When under this 

 form, the infecl feems to have neither legs nor wings. It is 

 incapable either of walking or of crawling. It takes no 

 nourifhment, becaufe it has no organs fuited to that purpofe 5 

 yet, in fome fpecies, life is continued for feveral months be- 

 fore their laft metamorphofis takes place. In a word, it 

 feems to be a lifelefs mafs. But, upon a more attentive ob- 

 fervation, it pofiefTes the power of bending upwards and 

 downwards the pofterior part of its body. The fkin, or ex- 

 terior covering, of thofe which do not fpin cods, feems to be 

 of a cartilaginous nature. It is commonly fmooth and fliin- 

 ing. In fome fpecies, however, the fkin of the chryfalis is 

 more or Icfs covered with hair, and other rugofities. Though 



