The San Francisco call., 1904-07-07
DR.. Jacques Loeb Removes
the Mysterious Veil That
Has Surrounded It's Past
IT is ALL AN ILLUSION
Biologist Says Structures
May Now Be Expressed
in Chemists FOrmulae
Berkeley Office San Francisco Call,
o142 Center Straat T,1I1-

versity Of California believes that after
all heredity in animals is transmitted
through a very simple mechanism, as
opposed to the theories of other scien-
fists that the machinery is most
complicated thing and difficult for men
to master. In the opinion of the great
biologist the simplicity of the process
is no mere illusion that is rendered
mysterious and enigmatic by an in
visible movement beyond the power of
man to solve.
In a lecture before the students of
the summer school in the Philosophy
building this evening DR.. Loeb stripped
the veil of mysticism from the prob
lem that has been a source of long re-
searching by himself and other biolo-
gists. The eggs of animals that he has
| investigated, he declares, do not con-
tain any very mysterious complicated
structures. They are such that might
even be expressed in the formulae of
a chemist.
DR.. Loebs views were expressed in
a discourse under the subject Theory
OF Animal Instincts From the Point
of View of Heredity.' He said in part:
INSTINCT HEREDTTY.
"The instructive actions of animals
are hereditary and can only be trans
mitted through the sexual cells. The
problem of heredity from the physio-
logical standpoint is in brief as follows:
How can an egg, simple vesicle filled
with viscous liquid which contains
some solid constituents, be the bearer
OF such complicated mechanisms as the
hereditary instincts? Two views are
possible a priOri: Either the simplicity
or homogeneity of the egg is only an
! Illusion and in reality it contains an
| invisible mysterious structure of a
/ similar degree of compleXity TO the
adult animal, or the complicated mech
anism of the instincts is the result Of
very simple circumstances, which do
not require sany complicated structure
| for their transmission through the egg
All other possible suppositions are only
! compromises between these two pos
/ sibilities Our present argument is in
/ favor of the latter solution, which, we
/ hope, will do away with some of the
/ mystic aspects Of heredity and render
q number of very complicated, albeit
/ ingenious, theories redundant.
"As to the mysterious egg structure
which this theory presupposes is ad-
mittedly invisible it is impossible to
! prove directly its non-eXistence. To the
second view we are necessarily led
when we attempt to analyze the in
/ stincts into their elements, which Will
/ deprive them of much that seemed
very mysterious before.
AS far as the instincts are concerned
/ there is no reason TO suppose that the
/ egg contains other mysterious cOmpli-
Gated structures than such as might
possibly be expressed in the formulae
/ of the chemist AS soon as we decom-
pose the complicated instincts into
1 their elements we understand that a
simple cell like the egg can be the
bearer of complicated instincts. The
conditions in the egg which are re-
quired for this purpose are, first, polar
differences in the chemical constitution
in the egg substance; and second,
the presence of such substances
in the egg as determine heliotropic,
chemotropic, stereotropic and similar
phenomena of irritability.
But the egg is the bearer of another
series of hereditary qualities, namely.
of the animals bodily system. Again
we must raise the question how such a
simple thing as the egg can be the car
rier of circumstances which determine
so complicated structures as are those
of most animals. Again we have,
priori. the choice between two answers.
Either the simplicity of the egg struc-
ture is only an illusion and we have in
reality an invisible structure of the
same degree of complexity in the egg
as that of the adult organism; or, sec
ondly. we do not require the mysteri-
Gus structures for the transmission of
such complicated mechanisms as seem
TO be necessary for the formation of
organs and comparatively simple con-
ditions of the cellular substance in con-
nection with external circumstances
are sufficient to explain the mystery.
SEA -URCHIN EXPERIMENT.
1T is wen known that the egg of the
sea-urchin is at first single spherical
CELL which, after fertilization, breaks
UP into many correspondIngly smaller
cells. from which aggregation of small
cells a hollow sphere originates filed
with liquid, the so-called blastula The
wall of this hollow sphere is formed by
of development the larvae are already
able TO swim around. A little later an
increased growth takes place in one
portion of this hollow sphere, and the
consequence is that this rapidly grow
ing part is pushed into the interior of
the hollow sphere. Thus the new en-
bryonic phase is reached, the so-called
gastrula stage. Finally, in certain
phases of the gastrula crystals of cal
cium salts are formed and the skeleton
originates, with the formation of which
the embryo enters the so-called pIuteus
stage.
What must be contained in the egg
in order to cause this succession of lar
val stages which finally lead to the
adult form of the sea-urchin? If we
analyze the conditions which lead to
the origin of these successive stages
we see that circumstances of no less
simplicity are sufficient as for the he
redity of instincts. The bastula is de-
termined through two circumstances: