The sun., 1900-12-23

modincations ~ tho leaf Witch rrorluc"i
oil the other essential parts ~ tho higher
rlnnta the snpe orivlrdons ~ s""d
l"nvca became modified into tho ,nfiou-ly
formed leaves ~ M" fully grown pi1niA,
these again were surcrssvcly modin"l
into tho calyt. corolo siamrn- and ovnry
~ the flower. lie supposed this Ia 10" du'
10 the increased refinement ~ IA" sap
under the influence NJ lisht and mir. and to
Indicate tho steps by which tho various
rnrs of tho novcr had been developed.
u was. therefore. theory ~ evolution
but Il VIA ursafisfactory. ina4much "a "
In no way accounted Tor the wonderful
variety Of the Hornl organs or indicated
any purpose served nv tho most prominent
and conspicuous part of the flower, AMI
highly coored and often strangely formed
corolla IL was also erroneous In suppnSing
that the cOroia was n modified calyS.
whereas It II now known to be modi-
fCa'ion Of the stamens.
NeIt came the great work Of Iamarcl;
In the f-st decade OF the nineteenth century.
in which he proposed a general system OF
evolution of the whole animal world. Hence
he may DO termed tho fist systematic
evolutioni-t. His system has been rather
fully described by Iycll. who. in his Prin-
ciples OF Geology devotcs whole chapter
TO n summary Of his doctrines, while Mr..
Butler gives copious quotations In three
chapters OF his Evolution. Old and New; :
and any one who Is not acquainted with
the original work Of Lamarck should read
4, a.. nj
how wide was his knowledge. how In
Genous his explanations, and in how many
important points he anticipated the views
both of Lyell and Darwin. But he was
half century In advance OF his age, and
his only alleged causes OF modification
changed conditions, use and dsuse. habit and
effort--were wholly insufficient to account
for the vast nge OF phenomena presented
by the Immune rable minute adaptations OF
living organisms to their conditions OF life.
He even imputed all the notifications OF
domestic animals to the changed conditions
Of food and habits 10 which they have been
sub ected by man. making no reference
TO the use Of selection by breeders in this
respect falling short Of his great prede-
cessor, Button.
The general laws which Iamarck deduces
from his elaborate study Of nature are
these.
First-That in every animal which
has not passed its limit Of development. tho
more frequent and sustained employment
of any organ develops and aggrandizes 1t.
giving It power proportionate to the
duration Of its employment. while the same
organ in default OF constant use becomes
insonsibly weakened and deteriorated. de-
creasing imperceptibly In power until 1t
finally disappears
Sccondly-That these gains or losses OF
organic development. due to use or disuse,
are transmitted to offspring. provided they
have been common TO both sexes. or to the
animals from which the offspring have
descended"
upon the second clause-the Inheritance
OF those individual notifications due TO
use and disuse. But no direct evidence Of
this has ever been found. while there ia
good deal Of evidence showing that it does
not OCCUR. Again, there are many struct-
ures which cannot have been produced by
use. such. for example. "a the feathers Of
the peacock's train, the poison In the SER
pent's fangs, the hard shells OF nuts. the
prickly covering Of many fruits. the varied
armor of the turtle. porcupine. crocodile
and many others. For these reasons
Lamarck's views gained few converts
and although some Of his arguments have
been upheld in recent years. the fatal OBJ
lection 70 his general principles a a means
Of explaining the evolution of organic
forms, has never been overcome.
Between the periods of Lamarck and
Darwin many advances were made which
clearly pointed to general law OF evo-
luton In nature. Such were Sir William
Groves lectures on the Correlation OF
the Physical Forccs.- In 1912; Helmholtz
on the Conservation OF Energy" in Isi7.
and Herbert Spencer's essay on The
Hypothesis" in 1852. This
latter work was q complete and almost I'M
argument for a natural process
Of continuous evolution OF the whole visible
including organic nature, man
and social phenomena. 1t IL further ex-
tended in the later editions Of the authors
First Principles" which. as coherent
exposition Of philosophy. ooordinating
and explaining all human knowledge Of
the universe into one great system OF evo-
luton everywhere conforming to the same
general principles. must be held to be one
Of the greatest intellectual achievements
NJ the nineteenth century, II left. however,
the exact method Of evolution Of organ
lsnls untouched. and thus failed to account
for those complex adaptations and appear
Rnces Of design In tho various species
Of animals and plants which have always
been the stronghold of those who advo-
Gated special creation. This difficulty was
met by Darwins theory Of The Origin
of Species by Means Of Natural Selection"
published In 1859. and the series Of works
that succeeded It: and to a brief sketch
of this theory the remainder Of our space
must be devoted
THE THEORY OF NATURAL SELECTION
Although. as we have seen. a succession
u great writers and thinkers had for more !
han half century shown the necessity
or some process Of evolution IA the only !
-ational or intelllgib.e mode of origin OF |