Evening star., 1935-03-02

is better equipped for fighting in
every respect, just as a person who
is afraid is better equipped for escape.
The lower emotional Threshold, he
says, is probably intricately related to
ease and to her greater constitutional
vigor. 1t labels the feminine as, when
all is said and done. the superior sex.
A new theory of cosmic ray origin
is advanced by the British physicist.
A. A. Milne, in the current issue of
Nature. They result, he holds, from
the occasional collision of free par
ticles, moving with the approximate
speed Of light, in the vast reaches of
intergalactic space. In the expanses
of emptiness millions of light years
in diameter between the galactic syS-
TENS, he holds, there must be numer-
GUS tiny particles moving independ-
emily. They are pulled this way and
that by the gravitational attraction of
the great star system themselves and
finally this cumulative pull on some
of them causes a speed in the vicin-
ity Of that of light itself-approxi-
mately 10000 miles a second.
When two bodies, however minute,
crash into each other at such ve!cci-
ties they annihilate each other, re-
leasing energy in the process. This
Is what is detected on earth as cos
mic radiation. Under this theory,
Prof. Milne says, there is no upper
limit to the energy of a single ray
The energy is drawn from the infinite
energy associated with the infinitely
many particles constituting the uni
verse"
A half billion years ago, when the
records of the rocks show the first un-
mistakable evidences of animal life
on this planet, the dominant form
was that of scab-like creatures known
as trilobites, which existed in vast
numbers, and with great diversity of
form, in the ancient shallow seas.
The race became extinct and has
no living representatives, but is of
exceptional interest to psychologists
in their efforts to retrace the road life
has followed through the ages. Its
remains stand at the frontier Of the
hitherto impenetrable darkness of per-
haps billion years or more in the
story of life
The trilobite, of course, had its life
history, like any other living thing.
There were baby trilobites and aged
trilobites. 1t now is possible to follow
part of the "growing-up" story of one
species Of these strange creatures
through remarkable series of fossils
studied by DR.. G. Arthur Cooper,
Smithsonian Institution paleontolo-
gist.
This particular species is COM
paratively late one in point of time.
The fossils are almost 100000, 900
years later than the earliest known
specimens of the race. Already, it
is probable, the first fishes were ven
turing on the mud flats to become
ancestors of the vertebrate fauna of
the land, and the trilobites we're far
along in the decline of their domi-
nance.
DR.. Cooper studied 90 fossils, rep
resenting 10 individuals and showing
part of the life range from baby
hood to the status of young adults.
The youngest specimens represented
by the fossils were approximately eight
millimeters in length, or less than
a third Of an inch. with a body like
the adult, but tail and head quite
different. The largest known adult
in the collection was almost four
inches long. The species actually at
tanned a length of o or 10 inches.
But, DR.. Cooper found, when a trilo-
bite had attained a length a little
over half an inch its head and body
form were approximately that of the
adult. with the exception of the
tail, which would continue to grow
smoother.