HYMENOPTERA : CHARACTERS. 383 



observed killing, wounding, or dragging along other insects, 

 caterpillars, or spiders, have been ascertained to be employed, 

 not in providing for their own support, but for that of their 

 offspring. The elongation of the parts of the mouth of the 

 Coleoptera has been regarded as a character indicating car- 

 nivorous appetites ; and hence the same idea has been applied 

 to those Hymenoptera which have the trophi, especially the 

 jaws, elongated; but observation has proved that these species 

 are destined to carry heavier burthens than the others ; their 

 prey destined for their progeny is more weighty ; and they 

 consequently need more powerful tools for its transport. 

 Now the Coleoptera have no work of this kind to perform, 

 and consequently the analogy cannot be supported : and this 

 observation, as it appears to me, oifers an interesting clue to 

 the solution of the oft-debated question, why it should be 

 requisite to employ characters derived from so many distinct 

 organs in the natural classification of any extensive group of 

 animals, instead of deriving them throughout the group from 

 a single organ. 



In one order of insects, for instance, we find the primary 

 divisions founded upon variations in the construction of the 

 tarsi, whilst in other orders the structure of these parts is 

 uniform. Thus it is only by acquiring a perfect knowledge, 

 not only of the structure, but of the habits of animals, that 

 we can ever hope to be made acquainted with the relative 

 value of this or that character, so as to be able to affirm, with 

 any thing like precision, that the one or the other is of the 

 greater importance ; and this happens to be a question of 

 considerable moment in respect to the order at present under 

 consideration, in which some authors have distributed the 

 families according to their general structure, whilst others, 

 and more especially the Count de St. Fargeau, in the work 

 above mentioned, have regarded the various instincts of the 

 insects, as exhibited in their social, solitary, or parasitic 

 qualities, as of the highest value, although these qualities 



