ABSTRACT
Systematics, which might be defined as 'the ordering of genera' in Bergson's sense of the term is characteristically a pre-occupation of natural historians. In all branches of natural history—Astronomy, Geology, Meteorology, Botany and Zoology—classification, whether it is of stellar spectra, of igneous rocks, of pressure-distributions, of algae or of worms has always occupied a central position, comparable perhaps to that which natural philosophers accord to mathematics. The words classification, systematics and taxonomy are now commonly treated as synonyms, an example of the confusion and carelessness in the use of words which is prevalent in so much modern scientific writing. Classification is essentially a cumulative subject; in general, the systematist can only hope to improve on the systems of his predecessors by first understanding and appreciating what they did. The value of a classification is more or less proportional to the number and variety of the characters used in constructing it.
