296 THEPHILOSOPHY 



denominated from its figure, affords an example of a fimilar prodi- 

 gy. This fly adually lays an egg, from which a new fly is hatched 

 that is as large and as perfe£l as its mother. This egg is roundilli, 

 is at firft white, and afterwards aflumes a fhining black colour. 

 Upon a more accurate examination, however, this produdlion was 

 found to be an egg only in appearance. When the envelope is 

 removed, inftead of a gelatinous fubftance, the new infed, furnifhed 

 with all its members, is difcovered. But this difcovery does not 

 render the fad the lefs wonderful. All winged infedts undergo their 

 diflerent transformations after being expelled from the bodies of 

 their mothers, and receive great augmentations of fize before their 

 metamorphofis into the nymph or chryfalis ftate, after which their 

 growth fl:ops. But the fpider-fly affords an inftance of an infe(3: 

 transformed in the belly of its mother, and which grows no more 

 after it efcapes from its envelope. This fa£t is fully authenticated 

 by Reaumur *, Bonnet f, and other naturalifts. 



The worm from which the tipula or crane-fly is produced is 

 perfedlly fmooth. Immediately before its firfl transformation it re- 

 tires under ground. After this metamorphofis, the furface of the 

 nymph is furnifhed with a number of prickles. By means of thefe 

 prickles, the nymph, when about to be transformed into a fly, raifes 

 Itfelf in its hole till the cheft of the infeft is above ground. The 

 fly then burfls its prifon, mounts into the air, and leaves its former 

 covering behind in the earth. 



Many fpecies of flies depofit their eggs in the leaves and different 

 parts of plants. Soon after the egg is inferted into the leaf, a fmall 

 tubercle begins to appear, which gradually increafes in magnitude 



till 



* Reaumur, vol. 12. p. 412. edit. izmo. 



t Oeuvres de Bonnet, vol. 4. p. 28. edit. 8vo. 



