Evening star., 1898-02-26
LIFE BELOW GROUND
Acquired characteristics of the Bur-
rowing Animals.
BIRDS THAT LIVE UNDER GROUND
Subteranean Granaries for Winter
Support.
RABBITS, MOLES AND RATS

From the London Spectator
An interesting find of buried treasure has
just been credited TO a mole. Coins were
seen shining in the earth of a freshly cast
UP mole hill at Penicuick. near Edinburgh
and a. search showed that The mole had
driven his gallery through a hoard OF an
cient coins of the date Edward l.
Life underground and in the dark is abb
soiuteiy contrary 10 the normal habits.
tastes and structure of almost all animals
except the very few, like the common
moies, tuco-tuco. and the marsupIal sand
moles, which obtain their food below the
earth surface diving birds catch fish be-
low the sea surface Ii Is almost an inver-
sion of their normal way of life and is
probably due to some such compulston as
has also forced many animals TO become
nocturnal Nor is it doubtful that If once
TINS necessity were removed their tendency
| would be to abandon this unnatural lIfe
and return to the regions of light How
strong the pressure must have been which
forced them underground NAV be gathered
from the list of English terrestrial mann
mais. Twelve of these are bats; but OF the
remaining twenty-nine no less than sixteen.
or more than half. live either wholly or
partly underground. The list includes tho
iox, three shrews. the mole the badger, the
otter three species of mice, two rats. three
Noies ana the rabbit Besides there are
several species OF birds. as widely different
| IN habit as the stormy petrels sand mar
tins. puffins, sheldrake ducks and the king
fisher. which for time live in holes exca-
waited In the earth. To abandon the sun, to
bask IN whose rays IL to most animals one
OF the most agreeable OF physical enjoy
ments- is an almost greater sacrifice than
the REIMBURSEMENT of fresh air. Yet tho
sacrifice is made. and the creatures. though
| not without occasional suffering and loss OF
Eealth directly attributable to this cause
have succeeded i'm adapting themselves with
great success to the new conditions.
Eyes I'm the Dark.
How most of the burrowlng animals lind
| life endurable at all Is difficult to discover
No one who has seen GOLFERS coming for
| their lamps and about to descend into the
pit can have failed to note the marks OF
physical strain exhibited by all-from old
men to boys. But burrowing animals are
among the merriest Of the merry: there are
rev creatures more full of gsiety and buoy
ant spirits than a prairie dog or even n
sand hill rabbit Some have coats so close
and fine that sand runs of them like water
does from feathers; others have "shivering
muscles by which they can shake their
jackets without taking them of The eyes
means protected against damage. IL the
rat and the rabbit had ;lo:a plate over
their eyes, as a snake has. or overhlnxing
eyebrows and deeply sunk orbits, the modi-
luton. but they exhibit no su III nodthca-
ton whatever. On the contrary. both Of
| them have prominent. rather staring eyes.
without protection and no eyelashes to
speak of. We believe that lust as divers
| learn to keep their eyes open under wster
without feeling pain, many of the min
ing animals can endure the presence of
aust and grit on the eye without discoTn-
Tort. Tame rats will allow dust or fire
SAND TO rest on the eyeball without trying
| 10 remove it, and 1T may be Inferred that
mi x-Oln Iol.x
same. The moles eyes have become SO
| atrophied that when mole is skinned the
eyes come off with the skin, but this is
probably not because the mining hurts the
eye, but because the mole having learnt
to work by scent and touch, had little fur
ther use for sight.
Ventilation, or rather the want Of H.
must be another difficulty in ihe under
ground life of almost all mammals. The rab-
bits and the rat secure current of air by
forming a bolt-hole in connection with
tnelr system OF passages, but the fox the
badger. and many OF the field voles and
mice seem Indifferent to any such precau-
tion There is no doubt that whatever gave
the first impulse to burrow. many animals
look upon this, to U.S. most unpleasant ex
ertion as form Of actual amusement
Property Rights.
Burrowing also confers right of prop-
erty. Prairie dogs constantly set to work
10 dig holes for the love of the thing Ie
they cannot have a suitable place to exer-
else their talent in, they will gnaw into
BOXES or chests OF drawers, and there bur-
row. A Young prairie dog let loose In a
.mell eravel-fioored house instantly dug a
hole large enough to sit in. turned round
In IL, and bit the first person who attempt-
ed to touch him. Property gave him cour-
age, for before he had been as meek as a
mouse. 1t is noticeable that the two weak
est ana least hume rous of our mice. tho
dcrmoGse and the harvest mouse do not
burrow. hut make Lests: and that these do
not multiply or maintain their numbers
Ike the burrowing mice and voles.
But the fact that there are members of
very closely allied species. some of which
do burrow, while others do not, seems to
indicate that the habit is an acquired one
In this connection ii is worth noting that
many animals which do not burrow at
other times form burrows in which to con-
ceal and protect their young. or. IL they do
burrow. make a different kind of a more
elaborate character. Among these nursery
burrows are those of the dog. the fox. the
sand martin, the kingfisher and the shell
drake. Fox hound litters never do so well
as when the mother is allowed TO make a
burrow on the sunny side of straw stack.
In Time she will work this five feet six
feet into the stack. and keep the puppies
at the far end, while she lies in the en-
trance Nixens either dig or appropriate a
clean burrow for their cubs. which is a
quired previously 10 the use Of earths by
adult foxes.
saving ROOD.
The sand-martiEs are. however. the most
complete examples of creatures which have
taken to underground life entirely to pro-
tect their young. and abandon it with joy
the instant these have flown. How far tho
kingfsher and the sheldrake contribute to
the making of the burrows fin which they
lay their eggs Is doubtful, but IL is a very
notable change of habit I'm birds of such
strong flight and open-air, active habits.
Ii may be paralleled by the case OF the
stormy petrels and fork-tailcd petrels. true
ocean birds, which. nevertheless. abandon
the sea and air to dig deep holes In the soil
of the Hebridean islets, and rear their
young in these dark and tortuous passages
Rabbits, rats and some other rodents make
a nursery burrow of a very rudimentary
kind. having only one opening. which the
mothers close up when leaving the nest.
This probably gives the clue to the process
by which the true underground animals
have been evolved. First they scratched
roles in which to shelter their young
Then they made use of the same device to
protect themselves, and acquired much
greater skill in working. In time the habit
became so easy that its exercise afforded