GRADES IN THE EVOLUTION AND CLASSIFICATION OF INSECTS

Abstract

Grades of organization, of the kind recognized in vertebrates by de Beer and J. S. Huxley, are a conspicuous feature of the insects also. Four can be distinguished by well‐defined anagenetic gaps: apterygote; palaeopterous and exopterygote; neopterous and exopterygote; neopterous and endopterygote. As grades can be defined more clearly than phylogeny at higher taxonomic levels and the reverse is true at lower levels, it is suggested that a classification can be made to reflect both without confusing the user. Copyright © 1967, Wiley Blackwell. All rights reserved