Evening star., 1953-07-15
Purochutinq Snakes
Reported by Biologist
Ability Developed After
Generations in Treetops
BY Thomos R. Henry

There are nylng snakes.
Some frogs and toads have taken
up aviation, OF q sort.
This is reported in the American
Journal Of Biology by DR.. James G.
Oliver Of the University Of Florida.
The reptiles and amphibians that are
air really should be considered expert
parachutists, rather than actual flyers.
DR.. Oliver says, and they are confined
to few species.
The tree snakes, dendrelaphis and
chrySopelea he has observed, leap
from high limbs stretched out length
wise, flattening and broadening the
body so that it presents concave
surface. They come down slowly, at
an angle to the vertical, and land
apparently without injury.
Frogs Of some species, he says, have
enormous webs between the fingers
A Brazilian tree frog dropped from an
away uninjured. Other frogs Of the
same size dropped vertically. he says.
so parachuting must be considered
trait Of this particular species, de.
veloped over many generations of life
In tree tops.
Lizard Parachutes.
DR.. Oliver found South Carolina
lizard, frequenter of bushes and fences,
that landed 10 to IL feet away from
the point where it was dropped from
height Of 81 feet, and hoped away
unhurt. 1t took a rigid posture when
dropped, limbs outstretched and
stomach taut. It fell vertically third
the distance to the ground and then
started to glide. Another species of
lizard from the same habitat wriggled
all the way down and landed hard.
One day last June New Brunswick
fisheries patrol boat cruising in Miri-
michi Bay observed a sand bar where
none had been reported before and
suspected hazard to navigation.
Actually there was no sand bar. The
surface of the sea over wide area was
in state of boiling turmoil due to
sWarming of countless millions of tiny
marine worms. or polychaetes. They
covered an area $50 yards in radius
broken into several patches, the largest
of which was IS feet long and Is feet
wide. The mass of worms was feet
thick, over water about 7 feet deep.
They were indistinguishable from sand
a short distance away.
The phenomenon has just been re-
ported in the British journal Nature by
Drs. C. and E. Berkely Of the British
Columbia Pacific biological station, to
whom the worms were submitted for
Identification.
In the same journal DR.. H. j. Baal
of LIE Societe Jersiaise tells of strange
swarming of spider crabs in the harbor
Of La ROGUE, Isle of Jersey. The chan
mel tide sometimes recedes as much as
two miles leaving behind 1t many large
lagoons with sandy bottoms in which
the spider crabs are stranded. They
are speared by the islanders.
Infested by Octopi.
The shallow water is infested, espe-
cially in September, by octopi that feed
on the fish. Thus few fish are found
in the lagoons. But DR.. Baal observed
that the crabs were collected in large
balls, two feet high and three feet in
diameter, with legs so entangled that it
was difficult to separate one from the
heap. The octopi. he found. were able
to pull few from the outSides of the
balls. but the great majority survived.
The human body louise evidently has
found sheltered place in nature. It
has a relatively low reproduction rate,
most of it's eggs hatch and most of the
larvae grow to maturity.
This is the finding of Drs. F. c. Evans
and F. E. Smith of the University of
Michigan, reported in the American
Journal of Biology. They raised coll
ony of lice in a laboratory cabinet.
Females, they found, produced an aver
age of 81 eggs at rate of about five
day. Eighty-six per cent of the larvae
survived. The average life of louise
was about II days. 1t required about
week for the population to double.
This, they point out, is very low
reproductive and high survival rate for
any kind of parasite.