The Topeka state journal. [volume] (Topeka, Kansas) 1892-1980, 1910-06-07

writings with q growing impression
that there are forces at work which
our blinded eyes wholly fail to appre-
bend; and where this is the case, the
part Of wisdom is to say that we be-
lieve we have such and such partial
explanations, but that we are not war
ranted in saying that we have the
whole explanation. In tracing the his
tory of the development of faunal life
during this period, the age of nam
mails, there are some facts which are
clearly established, some great and
sweeping changes for which we car
ascribe with certainty reason. There
are other facts as to which we grope
In the dark, and vast changes, vast
catastrophes, of which we can give nc
adequate explanation.
Before illustrating these types, let US
settle one or two matters of terminol-
ogy. In the changes, the development
and extinction, of species we must re-
member that such expressions as "a
new species" or as "a species becom-
ing extinct" are each commonly and
Unfortunately used to express totally
different and opposite meanings. OF
course the new" species is not new
in the sense that its ancestors ap-
peared later on the globes surface
than those of any old species tottering
to extinction. Phylogenetically, each
animal now living must necessarily
trace its ancestral descent back
through countless generations, through
aeons of time, to the early stages of
the appearance of life on the globe.
All that we mean by a new species
causes, one of these ancestral stems
slowly or suddenly develops into a
form unlike any that has preceded it;
so that while in one form of life the
ancestral type is continuously repeated
and the old species continues to exist,
in another form of life there is devil
alton from the ancestral type and a
new species appears.
Extinction of Species.
Similarly, extinction of species" is a
term which has two entirely different
meanings. The type may become ex-
tinct by dying out and leaving no de-
scendants. Or it may die out because,
change, slow or swift, until new form
is produced Thus in one case the line
of life comes to an end. In the other
case it changes into something differ
emit The huge titanothere and the
small three-toed horse both existed at
what may roughly be called the same
period of the worlds history, back in
the middle of the mammalian age
Both are extinct in the same sense that
each has completely disappeared and
that nothing like either is to be found
In the world today. But whereas all
the individual titanotheres finally died
out, leaving no descendants, a number
of the three-toed horses did leave
descendants, constantly changing as
the ages went by, finally developed into
the highly specialized one-toed horses,
asses, and zebras of today
The analogy between the facts thus
indicated and certain facts in the de-
velopment of human societies is strik-
ing. A further analogy is supplied by
a very curious tendency, often visible
N n nj md axy4~ toll
ization. When an animal form becomes
highly specialized, the type at first be-
cause of its specialization, triumphs
over its allied rivals and it's enemies,
and attains great development; until
in many cases the specialization be-
comes so extreme that, from some
cause unknown to US, or at which we
merely guess, it disappears. The new
species which mark a new era COM
monty come from the less specialized
types, tho less distinctive, dominant,
and striking types, of the preceding
era.
When dealing with the changes, cata-
clysmic or otherwise, which divide one
period of archaeological history from
another, We can sometimes assign
causes, and again we cannot even
guess at them. In the case of single
species or of faunas of very restricted
localities the explanation is often self
evident. A comparatively slight change
in the amount of moisture in the cli-
mate, with the attendant change in
vegetation, might readily mean the de-
structfon of group of huge herbiVores
with bodily size such that they need
ed a vast quantity of food and with
teeth SO weak or so peculiar that but
one or two kinds of plants could furnish
this food. Again, we now know that
the most deadly foes of the higher
forms Of life are various lower forms
of life, such as insects or microscopic
creatures conveyed into the blood by
insects. There are districts in South
wild and domestic, cannot live because
of the presence either of certain ticks
or of certain baleful flies.
Sleeping Sickness.
In Africa there is terrible benus Of
poison fly, each species acting as the
host Of microscopic creatures which
are deadly to certain of the higher YER
tebrates. One of these species, though
harmless to man, is fatal to all donnes-
tic amin ais, and this although harmless
to the closely related wild kinsfolk Of
these animals. Another is fatal to man
himself, beng the cause of the sleep
iLg sickness which in many large dis
tricts has killed out the entire popula-
ton. OF course the develr. pmert or the
extension of the range of any such in
sects, and any one of many other causes
which we see actually at work around
us, would readily account for the de-
struction of some given species or even
for the destruction of several species il
a limited area of country.
When whole faunal groups die out,
over large areas, the question is dif err
emf, and may or may not be SuScepti-
bile of explanation with the knowledge
we actually possess. In the old arcto-
geal continent, for instance, in what is
low Europe, Asia, and North America
the glacial period made a complete but
af 1iae,l 10 Oh,
nal life of the region. At ono time the
continent held a rich and varied fauna.
Then a period Of great cold supervened,
and a different fauna succeeded the
first. The explanation of the change is
obvious.
But in many other cases we cannot sr,
much as hazard a guess as to why
given change occurred. One of the most