For further classificatory details, reference must be made to the special articles on the various orders.
Most of the elements combine with oxygen in several proportions, for example nitrogen has five oxides: N 2 0, NO, N 2 0 3, NO 2, N205; for classificatory purposes, however, it is advantageous to assign a typical oxide to each element, which, in general, is the highest having a basic or acid character.
Xenocrates indeed, identifying ideal and mathematical numbers, sought to ' That Plato did not neglect, but rather encouraged, classificatory science is shown, not only by a well-known fragment of the comic poet Epicrates, which describes a party of Academics engaged in investigating, under the eye of Plato, the affinities of the common pumpkin, but also by the Timaeus, which, while it carefully discriminates science from ontology, plainly recognizes the importance of the study of natural kinds.
The lastnamed method has proved little more than that there is a remarkable similarity between the zooids of all recent corals, the differences which have been brought to light being for the most part secondary and valueless for classificatory purposes.
The question of species in the bacteria is essentially the same as in other groups of plants; before a form can be placed in a satisfactory classificatory position its whole lifehistory must be studied, so that all the phases may be known.
Of classificatory value, and p, p, Pericardial cavity.
Obviously these two conditions may merge into one another, and the distinction is not of classificatory value.
But, whereas the new scholarch, confining himself to the detailed examination of natural kinds, attempted no comprehensive explanation of the universe, Aristotle held that a theory of its origin, its motions, and its order was a necessary adjunct to the classificatory sciences; and in nearly all his references to Speusippus he insists upon this fundamental difference of procedure.
The dual nature of the lichen thallus introduces at the outset a classificatory difficulty.
Thus while Plato hoped to ascend through classificatory science to the knowledge of eternal and immutable laws of thought and being, Speusippus, abandoning ontological speculation, was content to regard classificatory science not as a means but as an end, and (6) to rest in the results of scientific observation.