OF NATURAL HISTORY. 301 



fubes or cafes, and the animal retires from thefe cafes, becaufe they 

 have become too ftrait. The reahty of thefe encafements has been 

 demonftrated by a fimple experiment. When about to molt or 

 caft its ikin, if the foremoft legs of a caterpillar are cut off, the ani- 

 mal comes out of the old ikin deprived of thefe legs. From this 

 fad, Reaumur conjedured, that the chryfalis might be thus encafed, 

 and concealed under the laft ikin of the caterpillar. He difcovered 

 that the chryfalis, or rather the butterfly itfelf, was inclofed in the 

 bodv of the caterpillar. The probofcis, the antennae, the limbs, and 

 the wings, of the fly are fo nicely folded up, that they occupy a 

 fmall fpace only under the two firfl: rings of the caterpillar. In the 

 firft fix limbs of the caterpillar are encafed the fix limbs of the but- 

 terfly. Even the eggs of the butterfly have been difcovered in the 

 caterpillar long before its transformation. 



From thefe fads it appears, that the transformation of infedls is 

 only the throwing off external and temporary coverings, and not aa 

 alteration of the original form. Caterpillars may be confidered as 

 analogous to the foetufes of men and of quadrupeds. They live 

 and receive nourifhment in envelopes till they acquire fuch a degree 

 of perfedion as enables them to fupport the fituation to which they 

 are ultimately deftined by Nature. 



One would not readily believe that the excretnents of a butterfly 

 fhould be capable of exciting confternation in the minds of the people. 

 But this event has frequently happened in different places and na- 

 tions. Among many other prodigies which have terrified nations, 

 Jhoivers of blood have been enumerated by hiftorians. Thefe fliowers 

 of blood were fuppofed to portend great and calamitous events, as 

 wars, the defl:rudtton of cities, and the overthrow of empires. About 

 the beginning of July, in the year 1608, one of thefe pretended 

 fhowers of blood fell in the fuburbs of Aix^ and for feveral miles 



round* 



