OF MANDIBULATA. 449 



ing : " Larva alimento propria nutrit imaginem latentem in 

 adult iorem (elatem." And indeed when we trace the natural 

 history of a Libellula from the egg to its perfect state, no 

 clear idea of the truth can be formed, except by con- 

 ceiving one animal to be so inclosed in another, that the 

 imago is in some measure distinct from the larva, and is 

 only declared to view by the death of the latter. Hence 

 a system unconnected with metamorphosis may be reckoned 

 to take no more notice of half the number of true insects, 

 than if they never had existed. It is the defect both of the 

 artificial system in Entomology, and of the sexual system 

 in Botany, that they become useless, except when the ob- 

 jects of the respective sciences are before us in one parti- 

 cular state, which is often the most transitory of their life. 

 Unless this condition be fulfilled, such systems lose their 

 sole and peculiar merit of being dictionaries by which na- 

 tural objects may be named. There are thousands of or- 

 ganized beings, to the history and knowledge of which 

 the disciple of Linnaeus or Fabricius has no clue what- 

 ever ; although perhaps they are in that state of their ex- 

 istence which most directly affects the interests of man. 

 Plants not in flower, and insects not in their declared 

 state, constitute an ocean of difficulties in which the most 

 skilled in Linnaean nomenclature will founder, unless he 

 have other beacons than such momentary considerations 

 as are afforded by the number of stamina or the form of 

 antennae. 



There is surely, therefore, reason to think that it would 

 be an immense improvement on a Species Insect or urn, and 

 would, as much as any thing whatever, benefit the philo- 

 sophy of the science, if larvae were classed on artificial 

 principles. Rather than that they should be totally neg- 



<2 G 



