302 Mr. ClARkV Obfervaiiom on the Genus Oejlrus. 



The lips at the obtnfe end of the bot feem dcfigned to prevent 

 the gaftrick and other iecretions of the ftomach, afllfted by its heat 

 and adion, from injuring the cartilaginous plate ; for we do not 

 difcover any apparatus of this nature to cover thefe plates in the 

 G2. Oi-'ts or 5oivj-, which, though allied in all other refpecls, arc not 

 expofed to thefe circumftances. 



Thefe lips are found, on opening them, to be mere membranous 

 bags, filled with a watery fluid ; a convincing proof they do not form 

 any part in the future infect, and are merely for the convenience of 

 the larva. 



Refpiration appears to be the office of thefe air canals, which are 

 the lungs of the larva ; and, confidered in this point of view, they 

 are much larger than the refpiratory organs of any other animal : 

 which is the more extraordinary, if the purpofe of refpiration in 

 animals be the produdion of animal heat, as the later chemifts 

 fuppofe, this being altogether unneceffary to /^r-y^;' that are fupplied 

 fo abundantly with it from the high temperature of their refidence 

 in the living ftomach, and have a greater fhare of it than is pro- 

 bably pleafant to them; nor can thefe organs be formed for the 

 purpofes of the future infea.fmce they cannot be detefted in either 

 the chryfalis or fly. 



I have fince found that air veflels of a fimilar ftrufture may be 

 detefted in the larvce of moft infers, as well in thofe that are not 

 expofed to any extraordinary temperature as thofe that are; they are 

 therefore not conftrudled with any view to thefe fingular fituations. 



From the fuperior magnitude of the refpiratory organs in moft 

 of the larva of infers, one ihould be almoft led to imagine that the 

 refpiration in all animals was more intimately connedted with the 

 reception of food, and the converting it into living matter, than any- 

 other defign. 4 



In 



