Geoffrey R. Dolby, PhD One of the principal characteristics of a
scientific theory is that it be falsifiable. It must contain predictions
about the real world which can be put to experimental test. Another very
important characteristic of a good theory is that it should take full
cognisance of the literature of the discipline in which it is embedded,
and that it should be able to explain, at least as well as its
competitors, those experimental results which workers in the discipline
accept without dispute. Readers of John Parks' book will be left in no
doubt that his theory of the feed- ing and growth of animals meets both
of the above criteria. The author's knowl- edge of the literature of
animal science and the seriousness of his attempt to incor- porate the
results of much previous work into the framework of the present theory
result in a rich and imaginative integration of diverse material
concerned with the growth and feeding of animals through time, a theory
which is made more precise through the judicious use of mathematics. The
presentation is such that the key concepts are introduced gradually and
readers not accustomed to a mathematical treatment will find that they
can appreciate the ideas without undue trauma. The key concepts are
clearly illustrated by means of a generous set of figures. The crux of
the theory comprises three differential Eqs. (7. 1-7.