Microscopical Essays. 203 



traced out, and it's wings, legs, antennae, Sec. may be opened 

 and difplayed by an accurate obferver. 



The parts of the moth, or butterfly, are not difpofed exaclly 

 in the fame manner in the body of the caterpillar, as when left 

 naked in the chryfalis. The wings are longer and narrower, 

 being wound up into the form of a cord, and the antennas are 

 rolled up on the head ; the tongue is alfo twilled up and laid 

 upon the head, but in a very different manner from what it is in 

 the perfect animal, and different from that which it lies in 

 within the chryfalis ; fo that it is by a progreffive and gradual 

 change, that the interior parts are prepared for the moth and 

 pupa ftate. The eggs, hereafter to be depofited by the 

 moth, are alfo to be found not only in the chryfalis, but in the 

 caterpillar itfelf, arranged in their natural and regular order. 



The time which the moth, or butterfly, remains in the pupa 

 ftate is not always the fame, varying in different fpecies, and de- 

 pending alfo upon the warmth of the weather, and other adven- 

 titious circumflances • fome remain in that fituation for a few 

 weeks ; others do not attain their perfecl form for eight, nine, or 

 eleven months : this often depends on the feafon in which they 

 alfume the pupa form, or rather on the time of their birth. 

 Some irregularities are alfo occafioned by the different tem- 

 perature of the air, by which they are retarded or accelerated, fo 

 us to be brought forward in the feafon beft fuited to their nature 

 and the ends of their exiftence. I have heard of an inftance, 

 where the pupa produced from caterpillars of the fame eggs, nou- 

 rimed in the fame manner, 2nd which all fpun up within a few days 

 of each other in the autumn, came into the fly ftate at three different 



Bb 2 and 



