The sun. [volume] (New York [N.Y.]) 1833-1916, 1903-05-17

But the Cerdtodus can live only in streams
that never go entirely dry. His one lung
Is not no able as the two lungs Of the African
fish.
Now, where the Cerdtodus lives, the ex-
treme of drought goes only 30 far as 10
dry the main stream, leaving water holes
here and there. Into these holes crowds
everything that needs water 10 live.
Soon the dcnsely packed creatures ex-
haust the oxygen in the water holes. Inc
water becomes foul, and the creatures that
have only gils are in dire trouble. Hordes
of the true fishes die.
But the Cerdtodus remains we'll and happy
He keeps his nostris above the surface
and breathes the upper air with his lungs.
Now let liz imagine that gray, dim
time when there stood mighty forests OF
fern and other long-past growths that
we burn to-day as anthracite. Picture
waters that experienced periodical droughts
like those Australian waters Of to-day
Now think of those ancient water holes
crowded with struggling forms, and you
see what an advantage the existence OF
lung meant for the survival of the
| Cerdtodus.
or course, YOU will object that the mere
fact that the lung was an advantage could
not produce one. Where did the lung
come from? Cerdtodus shows us. The
lung did not fall on him from the blue
sky.
The true Ash owns wel-known organ
the swimming bladder. This air-infiated
bladder regulates his weight for him. Civ
| ing him the same specific weight as Ia that
| Of the water where he lives.
Anatomcally. this swimming bladder
| belongs to the almentary canal. In many
| fish there is an air connection with tms
| canal The inference is simple that such
| an air-flled sac might have served on occa-
| sion for taking air into the blood, that Is,
| for breathing.
In certain existing forms of true fishes
| we have found the little beginnings of such
a development,
| In the Ccrdtodus the development became
complete.
Along the wall of the swimming bladder
there began to form air-sucking blood
vessels the mouth of the bladder began
to lengthen from the depths Of the canal
| toward the mouth as it was used more and
more to suck in air Tho air passage
became a wind pipe, and the swimming
| bld'iIltI IL luitp'
Now, let us think further. III he course
Of centuries, perhaps many centuries,
| some Of the water holes became entirely
dry Then everything died that had not
advanced beyond the stage Of Ferdfodms,
the creature of ono lung, needing at least
some water
| To picture any survivors. we must pct
ure a creature that had gone beyond the
old Cerd'odi-a creature that had reached
still higher state OF conformity TO condi-
tons. like the African two-lunged fish that
can live in sun baked mud.
| And then another step. The water dis
| appears entirely and forever at last from
some of the holes The lizard fish that had
learned to breathe with their lungs ex-
clusiveiy began TO wriggle across country
TO seek wet places elsewhere
Now geology tells us that at this time
| in the Devonian epoch. most areas OF the
world held shallow waters that became
smaller and smaller steadily. partly from,
evaporation and partly from draining
away in the sands that now form our old
red sandstone.
The izard-fsh had to wander "ftener
and oftencr. farther and farther. Tn"
swimming bladder lungs became strength
ened more and more. The glls degen-
Grated more and more,
At last they appeared only in tn" m
ripe forms during Incubation ancc-'ra
portraits shown to-day in tho Unborn
birds. and more plainly in tho frog while
it is still "polywog, only to disappear
entirely with growth.
The liznld-fsh had become lizard, al
amphibian!
They surely are not particularly agree.
able or attractive animals these lizard-fsh
In The museum the layman would prob
ably overlook them in his interest in he
mass Of fishes that seem far more curious
and bizarre. And y"t. how much hides
behind these, oldest lung -breathers in tho
world.
Millions of years ago those lizard-hsf
Of the Devonian or the carboniferous age
played their role the great advancement
of life. Then they became almost lost
They disappeared from the land. where
culture, the ideal sun-bossom nr nature
unfolded itself No tie seemed TO remain
be, wc,n their last survivors in the swamps
of Africa or South America and in two lost
streams of Australia, and the lin" of light
that began 10 arise in the life Of earth far
upward for the animal.
And yet from This line Of light, from
culture, there grows one day the great desire
for knowledge And after the measureless
procession of time it turns back to the
lizard fish, il seeks him in his lonely Queens
land wastes and helps him to wonderful
resurrection.
Ii is the true resurrection of Nature
through the Spirit. WILHELM BoElscHE.