efore, by
natural selection, soon become established as the regular course of
things, and thus we have the origin of _old age, decay, and death_; for
it is evident that when one or more individuals have provided a
sufficient number of successors they themselves, as consumers of
nourishment in a constantly increasing degree, are an injury to their
successors. Natural selection therefore weeds them out, and in many
cases favours such races as die almost immediately after they have left
successors. Many moths and other insects are in this condition, living
only to propagate their kind and then immediately dying, some not even
taking any food in the perfect and reproductive state."[107]

[Sidenote: Savages and some men of science agree that death is not a
natural necessity.]

Thus it appears that two of the most eminent biologists of our time
agree with savages in thinking that death is by no means a natural
necessity for all living beings. They only differ from savages in this,
that whereas savages look upon death as the result of a deplorable
accident, our men of science regard it as a beneficent reform instituted
by nature as a means of adjusting the numbers of living beings to the
quantity of the food supply, and so tending to the improvement and
therefore on the whole to the happiness of the species.

[Footnote 57: H. Callaway, _The Religious System of the Amazulu_, Part
i. pp. 1, 3 _sq._, Part ii. p. 138; Rev. L. Grout, _Zululand, or Life
among the Zulu-Kafirs_ (Philadelphia, N.D.), pp. 148 _sq._; Dudley Kidd,
_The Essential Kafir_ (London, 1904), pp. 76 _sq._ Compare A. F.
Gardiner, _Narrative of a Journey to the Zoolu Country_ (London, 1836),
pp. 178 _sq._, T. Arbousset et F. Daumas, _Relation d'un voyage
d'Exploration au Nord-Est de la Colonie du Cap de Bonne-Esperance_
(Paris, 1842), p. 472; Rev. J. Shooter, _The Kafirs of Natal and the
Zulu Country_ (London, 1857), p. 159; W. H. I. Bleek, _Reynard the Fox in
South Africa_ (London, 1864), p. 74; D. Leslie, _Among the Zulus and
Amatongas_, Second Edition (Edinburgh, 1875), p. 209; F. Speckmann, _Die
Hermannsburger Mission in Afrika_ (Hermannsburg, 1876), p. 164.]

[Footnote 58: J. Chapman, _Travels in the Interior of South Africa_
(London, 1868), i. 47.]

[Footnote 59: E. Casalis, _The Basutos_ (London, 1861), p. 242; E.
Jacottet, _The Treasury of Ba-suto Lore_, i. (Morija, Basutoland, 1908),
pp. 46 _sqq._]

[Footnote 60: H. A. Junod, _Les Ba-Ronga_ Neuchate