Physically and physiologically dry habitats, with the accompanying plant communities of sand dunes and sandy heaths with little humus in the soil.
Xerophytes.These plants have devices (a) for procuring water, (b) or for storing water, (c) or for limiting transpiration; and these adaptations are obviously related to the physically or physiologically dry habitats in which the plants live.
All soils which are physically dry are also physiologically dry; and hence only the physiological dryness or wetness of soils need be considered in ecology.
That this shape is intimately associated with flight is apparent from the fact that the rowing feathers of the wing of the bird are every one of them distinctly spiral in their nature; in fact, one entire rowing feather is equivalent - morphologically and physiologically - to one entire insect wing.
In infantile palsy, for example, and in tabes dorsalis, there is good reason to believe of that, definitely as the traces of the disease are found in certain physiologically distinct nervous elements, they are due nevertheless to toxic agents arriving by way of the blood.
He shows how morality can be viewed physically, as evolving from an indefinite incoherent homogeneity to a definite, coherent heterogeneity; biologically, as evolving from a less to a more complete performance of vital functions, so that the perfectly moral man is one whose life is physiologically perfect and therefore perfectly pleasant; psychologically, as evolving from a.
The group has attained an importance of late even beyond that to which it was brought by Pasteur's researches on alcoholic fermentation, chiefly owing to the exact results of the investigations of Hansen, who first applied the methods of pure cultures to the study of these organisms, and showed that many of the inconsistencies hitherto existing in the literature were due to the coexistence in the cultures of several species or races of yeasts morphologically almost indistinguishable, but physiologically very different.
A consideration of these facts emphasizes still more fully the view with which we set out, that all living substance is fundamentally, the same, though differentiated both anatomically and physiologically in many directions and in different degrees.
The best feature of the Data of Ethics is its anti-ascetic vindication of pleasure as man's natural guide to what is physiologically healthy and morally good.
A soil may be physically wet; but if the plants absorb the water only with difficulty, as in a salt marsh, then the soil is, as regards plants, physiologically dry.