Evening star., 1952-08-18


Dark Secret Of Life
Hormophis Homomelidis
Has Ia Lives, All Different
By Thomos r. Henry
MOUNTAIN LAKE. Va. Aug. l6.-A
pinhesd-sized plant louise may hold one
Of LIES ultimate secretS-an elixir Of
controlled growth.
The strange life ways Of hormophis
hamamelidis-one individual Of which
during years lifetime Is II different
animals-are being studied by biologists
at the University Of Virginia's field lab
oratory here in the hope Of isolating q
mysterious something, which itself prob
ably is alive. and which may open the
door to some Of the greatest paradoxeS
Of biology.
The insect Is an aphid which causes
gals. growths roughly comparable to
animal cancers, on witch hazel leaves.
These growths result when the aphid
injects into the leaf by means Of . SUBJ
microscopic apparatus like q hypoder-
0A4O &kSC04G Ola ENTHUSIASTICALLY IuAAut3
amount Of the unidentified material.
The gall grows around and over the
insect. It becomes the tiny creatures
home and sepulchre.
The substance completely changes the
nature Of the plant cells. They normally
would become leaf cells, highly special
lied to At into leaf growth. Now they
become gall cells. Something similar
happens In cancer, but In that case the
new cell growth is entirely uncontrolled.
It has escaped from the government Of
the animal body. The gall cells, how
ever, still remain under some sort Of
control. They always form gals and
they do not kill the leaf, which Is nec-
essary for their existence.
The Marvellous Aphid.
Marvellous is the life story Of the
aphid itself. The sequence starts with
a "stem mother" a newly Matched fe-
male. She injects the substance into the
leaves and the house builds itself around
her. Inside this cell she passes through
four metamorphoSes Her substance and
structure completely change four times.
That is. she becomes four different ami
mails, one after another. In the last
metamorphoSis she gives birth to from
80 to 100 living young.
Each Of these young, In turn, UNDER
goes five metamorpho five rein-
carnations. In the last of these they
have wings. The winged insects crawl
out through q hole in the bottom Of
the gall. Each produces from 10 to 20
young on the bottom Of the leaf. Each
of these young in its turn goes through
i've reincarnations. At the last meta
morphosis they are both males and fe-
males. This is the only time the male
makes its appearance in the life cycle.
All the other births are by partho-
genesis.
Each Of the females lays eggs on the
winter buds Of the witch hazel. These
buds are destined to become leaves in
the early spring. The eggs hatch few
days before the leaves. appear. Each Of
the newly Matched aphids-all females
-injects some of the house building ma
terial into the leaf upon which she
finds herself. She becomes new "stem
mother" and the strange process starts
all over again.
Fast Reproduction.
The reproduction rate is one Of the
fastest known in nature and might well
be overwhelming to the witch hazels.
and consequently suicidal for the aphids.
. except for various natural enemies
which keep down the number of the
"lice." Such tiny forms Of life as
larval lacewings are able to crawl
through the hole in the bottom Of the
. gall and feed on the occupants during
their various reincarnationS.
The university biologists are primarily
interested in the material injected into
the leaves. It must be one Of the most
potent growth factors known in nature.
The amount any one aphid Is able to
inject is indescribably minute. even
though some Of them make as many as
$50 injections. The material causes the
leaf cells to become larger and to null
tiply much more rapidly until q "house"
many times the size Of the aphid Is
complete in few days. The structure
Is perfect, even to what Is described as
q picket fence" of tiny hairs around
its base to keep out invaders.
The substance exists in such minute
amounts that thus far it has been i'm
possible to isolate 1t in anything ap-
preaching pure form. The biologists
at the Mountain Lake laboratory have
set for themselves a task requiring in
finite patience over many years-trac-
ing the increase in the salivary glands
Of each individual aphid through each
Of its IA reincarnations. and also
through the eggs with which the strange
life cycle starts.
The present clues indicate that the
material is a filterable virus-the tiniest
form of life. compared with which the
pinhead-sized aphid Is like a whale
compared to louise. II enough material
can be obtained an effort will be made
to purify it by means Of centrifuge
and then possibly to test its effects on
other forms Of life.
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