Evening star., 1955-02-17
Tiny Worms Give Birth
To Own Grand dchiIdren
e-ceIIed Octopus Porcsites
Have No Body Organs
BY Thomos Z. Henry

Animals which give birth to their
own grandchildren
Animals that have no digestive. nerv-
Gus, muscular. glandular, respiratory
or excretory systems
Such paradoxical creatures are the
"dicyemid mesozoans," tiny worms that
live inside octopi. described by DR..
Bayard McConnaughey Of the Univer-
sity of Oregon In report to the Ameri-
can Association for the Advancement
of Science.
Altogether. these little worms are
among the most curious living things
In nature. It is still uncertain whether
they are step upward in EVOLUTION
from the single-celled protozoans or a
degeneration from many-celled ami
mails. like some other worms, DIR. Nc
Connaughey says. Some scientists have
held that they represent a distinct
branch OF the animal kingdom.
Body is Single Cell.
The body Of dicyemid consists of
single cell, almost half an inch long,
in the form of hollow tube, sur
rounded by layer of small cells. The
immediate offspring are formed and,
in some cases, live their entire lives
and reproduce In turn, inside one OF
these cells. The grandchildren" break
through the body of the grandparent
at any place they choose, apparently
without causing any wound, and live
for short time as ee-swimning
animals until they find an octopus
whose kidneys they can infest. Then
the whole life cycle starts over again.
Apparently. Dr. McConnaughey says,
the infestation in no way Injuries the
octopus and the worms are Of no practi.
cal Importance in the world whatso-
ever. Each kind of octopus or squid in
coastal areas has its own particular
species Of these parasites, of which
about IS kinds are known.
The body. DR.. McConnaughey says,
contains mo organs, tissues or glands
in the usual sense of the word.
Before being born. the larvae attain
their full complement of body cells, are
able to swim about, and have within
them the germ cells that will give rise
to the next generation. Birth is very
simple. The larvae just push out, or
p1S o4ASCHC0 Oov, bklIOuSIl tk1C SiQ6S OI
ends of their parents at almost any
point. The exit closes Immediately, leav-
ing no scar, and the parent continues
to develop and bear more larvae in the
same manner. The number developing
at one time within the cell may range
from one or two to 100 or more"
Fully Developed Larvae.
These larvae are fully developed
worms, which remain in the octopus.
But at certain times the germ cells
develop into greatly reduced individ-
uals. called infusorigens, hard to dis
tinguish from large protozoa. These
oreak away from the grandparent worm
and from the octopus and become free
swimming animals They are. micro
scopic in size, less than 3/100ths of an
inch long. These infusoriforms live
from three days to a week. They are
not known to seek out young octopi and
presumably they infect some bottom
living organism upon which the mol
lusks feed. This intermediate host must
be very abundant. for practically every
octopus along coast lines is infected.
Here may be the borderline between
single-celled and multi -celled animals
or 1t may represent the greatest de-
generation known in animal life.