Micro scop i c ai 



E'SS&YSc 



Of the different Orders of Muscles, by which the 

 Caterpillar is enabled to move all the various 

 Parts of the Body. 



Thefe mufcles have neither the exterior Form, nor the colour of 

 thofe of larger animals. In their natural ftate they are foft, and 

 have the appearance of a jelly ; they are of agreyifh blue, and the 

 filver-coloured appearance of the aerial or pulmonary veffels, 

 which creep over and penetrate their fubftance, exhibits under 

 the microfcope a mod beautiful fpe&acle. When the caterpillar 

 has heen foaked for fome time in fpirit of wine, they lofe their 

 elafticity and tranfparency, and become firm, opake, and white j 

 the aerial veffels difappear. At firft fight they might be taken for 

 tendons, as they are of the fame colour, and poffefs almoft the 

 fame luftre. They are generally flat, and of an • equal iize 

 throughout ; the middle feldom differs either in colour, fub- 

 ftance, or iize, from the extremities. 



The ends are fixed to the fkin ; the reft of the mufcle is gene- 

 Tally free and floating ; feveral of them branch out confiderably ; 

 the branches extend fometimes fo far, that it is not always eafy 

 to difcover whether they are diftinct and feparate 'mufcles, or 

 parts of another. They are of a moderate ftrength ; thofe that 

 have been foaked in fpirit of wine, when examined by the 

 mrciofcope, will "be found to be covered with a membrane, which 

 may *be feparated from them, they then appear to corifirt of 

 feveral parallel bands, directed according to the length of the 

 mufcle. Thefe, when divided by the afliftance of very fine 

 needles, appear to be com po fed of frill fmaller fafcicles of fibres-, 

 in the lame direction, which, when examined with a very deep 



'magnifies 



