SUCCESSIVE APPROXIMATION I N DESCRIPTIVE ECOLOGY
65
It is true that some vegetational situations can be submitted t o experiment, especially, perhaps, those concerned with the operation of biotic
factors such as grazing and fire; and, wherever experimental synecological methods can be used to test hypotheses, this is desirable. Experimental methods may also be applied t o autecological problems ; but,
such is the operation of competition, that the results of controlled culture are often of very limited application to the situation in the field.
The ecologist should not ignore any avenue open to experiment and
he should be fully aware of the implications t o the phenomena which
he is studying of the work of the experimental biologist. Nevertheless
he must frequently use other means of investigation and reasoning t o
try to elucidate the problems that face him.
The best of these is extensive, critical observation coupled with the
classification of data. By following this method correlations can be
discovered, hypotheses formed, and checked and rechecked for consistency by further observation. Any inconsistency leads t o the reformulation of the hypotheses. The hypothesis held at any time is that which
is consistent with all the data available. No hypothesis can be more. It
is this well-known part of scientific method that I have called “SUCcessive approximation”. Its principles are the same as those of classification, and the method, if applied extensively, leads inevitably t o a
classification of the phenomena being studied. The method has frequently been used for reconnaissance, but need not be confined to
superficial observation. The detail of the results will be commensurate
with the detail of observations.
Cain (1944) wrote: “The complex interrelations among the environmental factors, and between them and the organism, with its complex
physiological and morphological interrelations, are such as to defy
solution in exact terms of causation. Ecological problems may not
only be dificult of solution because of the interaction of factors and responses, but they may really be insoluble in a mathematical sense.’’
It is very important therefore that any detailed situation which is
investigated by experimental methods or by time-consuming quantitative methods should be representative of a number of situations and
such that useful generalizations may be drawn from it.
The alternative, rigidly quantitative approach of statistical description and factor analysis cannot, by the sheer volume of work it
necessitates, provide the wide coverage necessary for the initial assessment of critical problems. By choosing only those features which are
quantitative, it abstracts from the full biology of the community, and
the analysis, in those instances when it has been fully applied, leads t o
the extraction of environmental complexes which are already known.
Appiied, however, to critical Situations of the detailed distribution of
C
E.R.-I
65
It is true that some vegetational situations can be submitted t o experiment, especially, perhaps, those concerned with the operation of biotic
factors such as grazing and fire; and, wherever experimental synecological methods can be used to test hypotheses, this is desirable. Experimental methods may also be applied t o autecological problems ; but,
such is the operation of competition, that the results of controlled culture are often of very limited application to the situation in the field.
The ecologist should not ignore any avenue open to experiment and
he should be fully aware of the implications t o the phenomena which
he is studying of the work of the experimental biologist. Nevertheless
he must frequently use other means of investigation and reasoning t o
try to elucidate the problems that face him.
The best of these is extensive, critical observation coupled with the
classification of data. By following this method correlations can be
discovered, hypotheses formed, and checked and rechecked for consistency by further observation. Any inconsistency leads t o the reformulation of the hypotheses. The hypothesis held at any time is that which
is consistent with all the data available. No hypothesis can be more. It
is this well-known part of scientific method that I have called “SUCcessive approximation”. Its principles are the same as those of classification, and the method, if applied extensively, leads inevitably t o a
classification of the phenomena being studied. The method has frequently been used for reconnaissance, but need not be confined to
superficial observation. The detail of the results will be commensurate
with the detail of observations.
Cain (1944) wrote: “The complex interrelations among the environmental factors, and between them and the organism, with its complex
physiological and morphological interrelations, are such as to defy
solution in exact terms of causation. Ecological problems may not
only be dificult of solution because of the interaction of factors and responses, but they may really be insoluble in a mathematical sense.’’
It is very important therefore that any detailed situation which is
investigated by experimental methods or by time-consuming quantitative methods should be representative of a number of situations and
such that useful generalizations may be drawn from it.
The alternative, rigidly quantitative approach of statistical description and factor analysis cannot, by the sheer volume of work it
necessitates, provide the wide coverage necessary for the initial assessment of critical problems. By choosing only those features which are
quantitative, it abstracts from the full biology of the community, and
the analysis, in those instances when it has been fully applied, leads t o
the extraction of environmental complexes which are already known.
Appiied, however, to critical Situations of the detailed distribution of
C
E.R.-I