Evening star., 1950-04-24
Non-FiIterubIe Viruses
Studied in Habitat
Border Between the Non-Livinq
And Living Explored
By Thomos r. Henry

tissue sometimes less than 800. .0ooth OF
an inch thick. Public Health Service
scientist is studying the inhniteSimal
border between the living and nom
living.
With an electron microscope DR., Ralph
W. G. Wyckof is photographing the
incredibly minute filterable vtruSeS.
bugs" which cause some of the most
deadly animal and plant diseases, At
home inside living cells. These sup
posedly living organisms range in size
from the vaccinia virus, about 100, ,00othS
Of an inch in diameter. to the tobacco
mosaic organism whose radius is about
Is hundred millionths of an inch. DR..
Wyckoff told the National Academy OF
Sciences meeting here today,
Before the advent Of the electron
microscope a few years ago the abode OF
these organisms" was realm Of COM
plete mystery. They were far too small
to be seen under any optical microscope.
About three years ago DR.. Wyckof and
other scientists were able to observe
them for the first time but only in test
tube cultures outside living cells. which
was an unnatural habitat and where 1t
was possible to observe little more than
their general appearance. They looked
very much like other bugs. Some had
the appearance of pollywogs with
wriggling tails Others were like fine
threads or little globes.
Live Only Inside Cells.
Unlike bacteria, protozoa and other
diseaSe-cauSing organisms. the filterabls
viruses live only inside cells. They are
projected by the cell walls and hence
have proved generally immune to any
chemicals or antibioticS. Also they were
securely hidden from observation.
The present success stems from an
incredibly delicate tissue Slicing tech
nique developed by Bureau Of Standards
scientists late last year. 1t permits slices
to be made as thin as deSired-actually,
DR.. Wyckoff says. to the point where
they nearly vanish and become useless
for observation. The slicing technique
has been supplemented by greater
resolving power of the electron micro
scope itself.
Slices are made through cells. Inside.
the microscope reveals a chaotic mass
of particles the size of small molecules.
Some of these are normal constituents
of the interior of the cell and differ for
various parts of the body. Others are
the viruseS themselves. or the parts into
which they break up-to recombine into
new viruseS, which is their peculiar
method of reproduction-once they have
found refuge inside the cell. AT a single
step 100 or more new viruSeS may be
born. The cell "explodes" and these are
released into the blood stream to invade
other cells. This apparently is the rea-
son for the severity of some OF these
virus diseases.
Influenza Shape Varies.
A major advance up to now, DR..
Wyckoff explained. has been the ability
to distinguish some Of the actual viruses
from the normal large intracellular
molecules. Thus far he has been able
to distinguish the organisms of tobacco
mosaic. potato virus disease. fowl pox.
vaccinia, parrot fever and influenza. The
latter is especially puzzling. Sometimes
it is spherical in form and sometimes
appears as fine filament Apparently
the organism can change its shape and
perhaps does so in the course OF its nor
NAL lifetime Thus far it has been
impossible to determine which shape
comes first.
The major problem, DR.. Wyckof says.
is whether these viruses actually are liv-
ing things or dead matter with the
unique property of reproducing itself at
the expense of the normal constituents
of the cell solution now Is possible
for the first time. but the problem is so
complicated that observations over sew
eral years probably will be necessary be-
fore there can be any adequate answer.
1t may be that the virus itself Is non.
living-an aggregation of atoms having
some of the characteristics which must
have appeared at the beginning OF life
on earth 1t may be a parasite. or 1t
may be chemical which can recombine
into its own form the normal protoplasm
of which all living things are composed.
Evidence Points Both Ways.
Almost certainly, it was pointed out TO
the National Academy members, the
electron microscope is showing for the
first time a transitional stage between
life and non-life.
As to whether the viruses are on one
side or another of the line, DR.. Wyckof
said, there can be no answer except oy
the slow accumulation Of observations.
The evidence points both ways Which
1 believe really depends on the day OF the
week the observations are made" he re-
ports. Some days everything indicates
that these "macro- molecules" are alive.
Other days 1t seems almost equally GER
tain that they are lifeless particles
with unique properties.