The place of statistics in the study of growth and form

Much of the statistical work involved in the study of growth and form consists of the fitting of some mathematical relation to the observed data. This fitting may be carried out with a number of rather different purposes in view, which may be classified as follows: (а) descriptive, as, for example, when a table of values is replaced by a simple equation: (b) for the purpose of smoothing data; (c) to enable objective comparisons to be made between groups of data, similar curves being fitted to the different groups; (d) to test whether some mathematical relation derived from other considerations is confirmed by the data; (e) in an attempt to obtain an indication of the underlying physical laws. These objectives are not mutually exclusive, but the types of relation and the statistical procedures that are appropriate differ somewhat in the different cases.