the changes progressing—let us say, in the solar system, or in
the process of a crystallisation, would appear as lines sloping
downwards from left to right.
Whatever our views on the origin of death may be, we have to
recognise a periodicity of functions in the life-history of the
successive individuals of the present day; and whether or not we
trace this directly or indirectly to
90
a sort of interference with the rising wave of life, imposed by
the activity of a series of derived units, each seeking energy,
and in virtue of its adaptation each being more fitted to obtain
it than its predecessor, or even leave the idea of interference
out of account altogether in the origination or perpetuation of
death, the truth of the diagram (Fig. 4) holds in so far as it
may be supposed to graphically represent the dynamic history of
the individual. The point chosen on the curve for the origination
of a derived unit is only applicable to certain organisms, many
reproducing at the very close of life. A chain of units are
supposed here represented.[1]
THE LENGTH OF LIFE
If we lay out waves as above to a common scale of time for
different species, the difference of longevity is shown in the
greater or less number of vibrations executed in a given time,
_i.e._ in greater or less "frequency." We cannot indeed draw the
curvature correctly, for this would necessitate a knowledge which
we have not of the activity of the organism at different periods
of its life-history, and so neither can we plot the direction of
the organic line of propagation with respect to the
[1] Projecting upon the axes of time and energy any one complete
vibration, as in Fig. 4, the total energy consumed by the
organism during life is the length E on the axis of energy, and
its period of life is the length T on the time-axis. The mean
activity is the quotient E/T.
91
axes of reference as this involves a knowledge of the mean
activity.[1]
The group of curves which follow, relating to typical animals
possessing very different activities (Fig. 5), are therefore
entirely diagrammatic, except in respect to the approximate