The sun. [volume] (New York [N.Y.]) 1833-1916, 1892-07-10
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translation Of some important lectures deliv-
cred at the University Of Freibure BY Prof.
AUGUST WErsMANN. perhaps the most distin-
guishsd OF the German disciples OF Darwin.
In those lectures the author assailed the La
MARKHAM doctrine OF the Inheritance OF ac-
auirsd characters. discussed the causes OF old
age and death. and expounded his own theory
OF the Immortality OF the germ cells In the
higher and moro complex organisms which
are propaRatcd by sexual reproduction. In o
volume which has lately been issued from tho
Clarendon press. Oxford. England. are pre-
scented transations OF four later essays In
which tho authors teachings are revised. de-
Tended. and reafflrmcd. The novelty Of Prof.
Wesmann's conclusions and the respect COM
mnnded By him as an independent thinker
render 1t worth while to outline the contents
Of these interesting papers.
II 10 In an essay entitled "IletroEressive
Development in Nature" that Prof Weismann
restates his reasons for believing. in contra
distinction to Lamarck and Darwin. that
characters acquired in the lifetime OF an In
dividual are not transmitted by inheritance to
his offspring. At the first glance this asser-
ton seems contrary to our observations. 1t Is
. we'll known fact that parts Of the body which
are much used grow larger and moro power
full. while those which are seldom exercised
become small and weak. Constant gymnastic
exercise will immensely increase the size
and strength OF the muscles OF our
arms: while these limbs will lose what
strength they once possessed IL the
muscles are never exerted. The performances
OF athletes afford the best examples Of the ex-
tent TO which practice can increase the mus
cular strength and activity Of man: and. on
tho other hand. those who work at occupations
sntailing q sedentary life and lack OF exer-
else plainly show the weakening effects OF
disuss. Certain experiments prove this still
more clearly. Thus when the nerves supply
ing q muscle are cut, degeneration OF the
muscle ensues. because its activity is at an
end. and the same thing happens in glands
when their functions are disturbed by sever
ing tho nerves which supply them. Since.
then. We may take it for granted
that disuse OF an organ will lead to
its degeneration. oven in the lifetime
Of single individual. may we not
also conclude that the gradual disappearance
OF q superfuous structure In the course OF
generations is due simply to the tendency to
degeneration being handed down from one
generation to another. and thus gradually in
tensiHed to the extent OF complete elimina-
tion2 For. surprising disuse to produce in
nnitely small effects during the life Of each in
dividual. surely those effects will be cumu-
lative and In course Of generations the organ
will gradually diminish in Importance. be-
como smaller and weaker. and ultimately dis.
appear altogether.
This explanation. obvious as 1t seems at FIRST
sight, and although 1t was accepted by La
marck. and even by Darwin. 10 rejected by
Prof. Woismann on tho ground that there aro
many facts which are quite incompatible with
It. For instance. it involves the assumption OF
q fact which has never yet been proved viz:
the hereditary transmission OF acquired char
actor. The denial OF this transmission is. as
We have said. one OF the distinctive features Of
our authors teachings. He admits indeed.
that many mental and physical qualities OF
parents arc transmitted to their children. such
as the color OF the eyes and hair. and the shape
and size OF the finger nails: nor only these in
decd, but even such minute and indeflnable
physical and mental characteristics as like
moss OF features. bearing. gait. handwriting. q
mild and eQuable or passionate and irritable
temperament. But it is pointed out that all
these characters are blastogenic or inherent
In the parents: whether they first show them
solves early or late. they have existed In the
parents in q moro or less marked degree and
in different combinations from the beginning.
On the other hand. Prof. Weismann insists that
ton OF external circumstances acting during
the life OF the individual cannot be trans
mitted. The loss OF finger. for example. is
not inhe rited: all the thousand faculties which
are gained by exercise OF various organs. or
OF tho whole body. are purely personal &C.
Quirements and are not handed down to pos
terity. No case was ever known Of child be-
ing able to read without being taught. even
though the parents had exercised their facul-
ties in this direction all their lives. Children
do not even learn to speak untauCht. although
not only their parents but countless genera
tions Of ancestors have exercised and
perfected the brain and vocal organs
by learning and speaking tho language.
Prof. Weismann deems it satisfacto-
rily established that children OF civilized
nations. II brought UP In the wilderness and
out OF from all communication with man.
would make no attempt at speech. For proof
OF this he does not feel himself obliged to fall
back on the not very we'll authenticated story
Of the Persian monarch who is said to have
made the experiment Of taking twenty new
born children and bringing them up together
without ever allowing them to hear word OF
speech. They are supposed never to have
made any sound resembling speech. but to
nave i'm itated with great fidelity the bleatinG
OF goat which lived among them. The same
thing Is told in many wel-known cases OF
young or adult persons found living in
an utterly wild state In the woods
cases which have occurred from time
to time up to tho last century in
Germany. Franco. England. and Russia.
Nearly all these persons arc said to have ut
tered sounds resembling tho cries OF wild ami
mails with which they had associated. hut not
one was ever known to speak. When one con-
siders the constant and unremittinE practice
In speech which W, gain in Il lifetimo.
whether by speaking aloud or thinking merely
to ourselves. and remembers that. in spite Of
the effect OF this perpetual exercise for CEN
turies upon the human brain and vocal Or
Gsns. the power Of spocch has not been in the
slightest degree fixed or intensified by hered-
ity. we seem justified by this one fact alone In
doubling whether acquired characters can over
be Il transmitted in any real sense.
This. at all events. is Prol Weismann's con-
viction. and. moreover. such q transmission Is
ompntible with the only theory OF heredity
which he considers tenabo. If. however. the
results OF the exercise or use Of an organ are
not inherited. neither can the effects Of disuse
ba handed down. Hence. il this be true. the
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