The Evening dispatch. [volume] (Provo, City, Utah) 1891-1895, 1895-11-11
THE SPANS OF LIFE.
DIFFERENCES OF DURA1 ION IN MEN
AND ANIMALS.

Adult Life Varies Greatly.
An essay of Weismann, charming
and profound and written before the
obsession Of a logical theory had car
ried him into arid metaphysics, dis
cussed the duration of life in men and
animals. To many, perhaps to most
living things, death comes unexpected
", with an ironical indifference to the
| period of the animals life or to its bus
mess of the moment. The man may be
! preparing to be merry; the bird may be
a-building, the butterfly not yet dry
| from the chrysalis, when they are fallen
dpon by blind mischanoe, by enemies
| intent only on dinner or by unthinking
microbes. Confronted by such extrinsic
| accidents, men cry out after their kind.
the poet attuning an Intellectual lam
entation, the moralist preaching, the
pagan urging to the day of pleasure,
but the naturalist must be dumb. His
opportunity comes with the animals
that avoid or escape colliding fates, and
that yet after fixed period run down
like clock The seeds of deaths appar-
emily have been lying inert in the body
and come to fatal maturity after lapse
Of time that varies little among indi-
yiduals of the same species, but that is
widely different among different kinds
of animals.
Threescore and ten is the natural
period of mans life. The elephant will
live 200 years, tGs horse but half cen.
fury Singing birds and fowls and pleas.
ants will live for nearly 20 years, but
parrots, eagles, falcons and swans are
known to survive their century. Some
live through nearly two centuries.
Queen ants and working ants may live
for years Sir John Lubbock kept a
queen ant alive for IS years, during all
which period she continued to lay FER.
tile eggs, but the males live only a few
days. Queen bees live two or three
years; workers and drunes a few months,
although indeed liz one sense the death
of the latter is unnatural, as the work
ers drive them away from the stores of
food, SO that they perish Of starvation.
Among insects generally the period Of
adult life varies greatly. Many, like
she May flies, dance IN the sun only for
q few hours; the sexes meet, the eggs
are deposited and the creatures die be-
fore nightfall Many butterflies and
moths are unprovided with feeding or.
gans and live only few hours, others
for many days.
Leaving out of count certain minor
factors, like the time required for grow
ing to larger size and the slower
growth of animals that must waste time
and energy in capturing living food, it
is certain that there is an intimate con.
nection all through the animal kingdom |
between the duration of life and the |
reproductive habits. Animals, in one
sense. are like the bright and fragrant
flowers of plants; since when their
function is accomplished, when seeds
are formed, they wither and perish.
The business of the animal seems to be,
not to live its own life, but to reproduce
it's own kind, and the term of life at its
disposal is adjusted accurately to the
special difficulties of this purpose.
Weismann and Alfred Russell Wallace
suggest that death comes as soon as pos
siple after the due number of successors
has been produced, In order that each
species may always be represented by a
full tale of young and vigorous indivi-
duals, Natural selection acts like a con-
tractor who has undertaken to keep a
window box gay with fresh blossoms;
each plant must be removed almost be-
fore its flowers fade.
But our present concern is with the
fact rather than with explanation of the
fact. Taking the needs of reproduction
as a master key, we find it unlocking
the secrets of inequalities of life The
May flies live only a few hours but
their eggs are produced abundantIy and
have only to be dropped into pools from
which their parents, leaving their chrys-
ais, sprang into the sunny air. The
short lived moths and butterflies SINH
arly are untroubled by family cares.
When the eggs have to be deposited on
common and abundant food plants the
'omales need and possess few hours in
which to accomplish their easy task.
The males, on the other hand, have to
ly about seeking and sometimes fight.
ng for possession of the females and
% them longer life is t,llotted. But
critics and moths that live for more
han few days are those whose cater
pillars require rarer food plant, a
more carefully chosen nursery and feed.
ng ground. The females have to fly
bout seeking convenient spots for theiY
fspring, and the eggs instead of ripep
ng and being deposited simultaneous
y, are laid from day to day until the
ull tale be accomplished. In many {
RIDES of bees the males play their par,
ut once and that during the nuptia' ,.
light of the queen. Immediately after. !
7ard they die or shortly after are killed
y the workers. The queens, secluded in :
be middle of the hive, produce crops
workers year after year, and SO their :
YES are prolonged
Among the birds and beasts parental Z
ares have brought length of days with !.
lem. The small singing birds are rapid u
reeders, sometimes producing five or
sx nestllngs twice year, but their
lemles are equally numerous, and de- =
olte the constant attention of the male ::
ld female play such havoc with the u
Dung that hardly in 20 years will *
air rear up young enough to maintain =
le species. Birds like pheasants and -
wis are still more prolific, but old =
I'D young like are preyed upon by mul- ~ :"
tude of enemies. The birds of prey are =, -
ow breeders. Their active fight makes y
impossible that the females should =.
try with them burden of developing -
,gs, and in their long lives they leave
hind them no more progeny than
Kicker breeding, shorter lived cres
res Saturday Rev lew, ID
SehooIboy (wearily)-W what's the use by