Fuller knowledge has shown that Macgillivray was ill-advised in laying stress on the systematic value of adaptive characters, but his contributions to anatomy were valuable, and later investigators, in particular H.
There results from continental and local adaptive radiations the presence in the same geographical region of numerous distinct lines in a given group of animals.
Their distinctive and adaptive characteristics doubtless began to be established as soon as the phanerogamic flora was constituted.
To what extent such responses are transmitted to offspring, and what part they play in the formation of the adaptive characters that are conspicuous in many animals, remain dubious, but it is at least clear that natural selection can favour those individuals and those races which show the greatest power of responsive plasticity in the individual.
The stimulus of water on the breast may be regarded as a sensory presentation which is followed by a definite and adaptive application of behaviour.
To other monocotyledonous families the resemblances are merely of adaptive or vegetative characters.
The former classification into Holochlamyda, Pneumochlamyda and Siphonochlamyda has been abandoned, as it was founded on adaptive characters not always indicative of true affinities.
The net result of observation is not favourable to the essentially Darwinian view that the adaptive arises out of the fortuitous by selection, but is rather favourable to the hypothesis of the existence of some quite unknown intrinsic law of life which we are at present totally unable to comprehend or even conceive.
With this comes the whole vast and ever-widening range of inventive and adaptive art, where the uniform hereditary instinct of the cell-forming bee and the nest-building bird is supplanted by multiform processes and constructions, often at first rude and clumsy in comparison to those of the lower instinct, but carried on by the faculty of improvement and new invention into ever higher stages.
With regard to adaptations, it is becoming more and more apparent, as experimental knowledge advances, that it is a fundamental property of every living organism in every stage of its existence to display adaptive response to its environment.