THE HABITS OF INSECTS AS A FACTOR IN 

 CLASSIFICATION.* 



Herbert Osborn. 



There is, I presume, at the present time a very general agree- 

 ment among systematists that our systems of classification should 

 represent something more than a convenient placing of groups in 

 divisions in which they may be discovered by some key. Cer- 

 tainly all naturalists who look into the significance of relationship 

 must wish to see their classification represent what they can 

 discover in the way of natural affinity or the lines of derivation of 

 the respective groups. It is also, I presume, a common if not 

 universal experience that in every piece of systematic work there 

 remains at the end some unsolved problem or some remnant of un- 

 certain species that cannot be placed to the satisfaction of the 

 worker. It is not my expectation that I can solve these perplexi- 

 ties in a short discussion of the criteria for taxonomic work, but 

 it appears to me that we may secure some assistance and reach, 

 perhaps, more satisfactory results if we bring to our assistance in 

 this difficult field as many as possible of the factors which have 

 been concerned in the differentiation of species, and, therefore, 

 a recognition of the characters by which species and the larger 

 taxonomic groups may be separated. Of these different factors 

 the habits associated with the life of insects is one which should 

 doubtless be given much greater attention than has been our prac- 

 tice in most of our systematic work. In large part, of course, 

 this is due to the fact that we have been compelled to work with 

 collected material of which we knew practically nothing as to 

 environment or habit, or sometimes, even as to the more general 

 ecologic conditions. Such data ought to be considered more and 

 more an essential part of the basis of classification. 



Insects doubtless serve as well as any of the great groups of 

 animals for the illustration of any biological principle, and it is 

 my belief that almost ever}^ important principle in biology 

 may be studied and elucidated within the group. What is said 

 here about insects may, therefore, in large part be applied to other 



* Annual address delivered at the Chicago meeting, January 3, 190S. The 

 address was illustrated and amplified by a series of lantern slides. 



