The sun., 1909-06-27

Ii well knOWn, repuolaHb me baiuAtCkian
factors Of tho transmissibility Of
acquired characters and OF the In
heritable effect OF use and disuse, but
accepts In its entirety Darwin's doctrine
Of Natural selection. As he puts 1t near
the close Of the essay written for this
volume, AN adaptations can be referred
to natural selection; the only point that
remains doubtful u whether they all
must be referred to it He goes on 10
say that however this. may be, whether
the Lamarokian principle In factor that
has cooperated with selection In evolution
or whether 1t is altogether fallacious,
the fact remains that natural selection
is the oause Of great part Of the phJlsao
evolution Of organisms on our earth.
Those who agree with Weismann In re-
jecting the Lamarckian principle regard
selection as the only guiding factor In
evolution. which creates what is new out
Of the transmissible variations, by order
ing and arranging these, selecting them
in relation TO their number and size. as
the architect does his building stones so
that particular style must result. But
the building stones themselves. tho varia-
tons. have their basis In the influences
which cause variation in those vital
units which are handed on from one gem
Grafton to another. whether, taken to-
gether. they form the whole organism.
as In bacteria and other low forms Of
life. or only germ substance, as In unicol-
lular and multoellular organisms
III.
The subject Of Variation 10 treated
in the book before US by high authority,
DR.. Hugo de vries, professor Of botany
in the University Of Amsterdam. He
reminds US that Darwin over and over
again insisted that man does not cause
Man merely se'eots tho vsri-
atoms given to him by the hand Of nature.
He may repeat the process In order to
different new characters in the
same family. thus producing varieties OF q
higher order. This process Of sooumula-
tion would II continued for longer time
lead to the augmentation Of the slight dif-
characteristic Of varieties into
the greater differences Characteristic Of
species and genera. 1T 10 In this way
says Prof. de Vries, that horticultural
and agricultural experience contributes
to the problem Of the conversion Of va
rietiss into species and to the explana-
ton of the admirable adaptations Of each
organism to its complex conditions Of
life. In the long run new forms, dis-
tinguished from their allies BY quite .
number Of now characters, would BY the
Of the older intermediates
become distinct species
Manifestly the theory Of the origin Of
species by means Of natural selection II
quite independent Of the question how
he varieties, which are to be selected,
rise. These may arise slowly from SIM
,le fluctuations. or suddaniy by nnuta-
ions, 'In both cases natural selection
will take hold Of them, will multiply them
I they are beneficial, and In the course
II time accumulate them, 20 a. TO produce
hat great diversity Of organic life which
We 30 highly admire Prof. de Vries
kinks that Darwin by his pangenesis
hypothesis has given the clue for a cloee
Jtudy and ultimate elucidation Of the SUBJ
ect Of variation.
w.
In an essay on sThe Descent Of Man.
Dr.. g. Schwalbe, professor Of anatomy
n the University Of Strassburg, under
axes to show that the theory which as
Iumes that man has developed parallel
With the monkeys. but without relation
% them, from very low primitive forms,
,annot be upheld, because It fails to take
nto account the close structural affinity
II man and monkeys. Such hypotbe-
lis DR.. Schvalbe regards as lamentably
for It makes impossible any
application Of the facts that have been
discovered In the course Of the anatomi-
,al and embryological study Of man and
monkeys. and indeed prejudges investi-
yations OF that class as pointlcss. sThe
whole method is perverted; an unjustifis-
de theory Of descent Is first formulated
With the aid Of the imagination, and then
We are asked to declare that all structural
citations between man and monkeys
md between the different groups Of the
after are valueless-the fact being that
hey are the only true basis on which q
tree can be constructed
There is doubtless ground for Prof.
suggestion that the theory Of
descent just discussed has found adher-
,nts only because 1t would deliver us from
he relationship to apes which many
,eopie 30 much dislike. Sharply con-
rasted with it is the hypothesis Of descent
which keeps strictly to the nearest struo-
ural relationships.
Nr Schwa lbe repeat In that stbia In thu
,nly basis that justifes the drawing up
II a special theory OF descent II this
proposition be recognized 1t
viii be admitted that the doctrine OF spe-
hal descent upheld by Haeckel and set
orth In Darwins Descent Of Man Ii still
,alid to-day That IL TO say. mans
,lace in the genealogical tree 10 quite close
o that OF the anthropoid apes; these again
,ave as their nearest relatives the lower
Did World monkeys. and the progenitors Of
hese must be sought among the less dif-
erentiated platyrrhine monkeys, whose
most important characters have been
handed on to the present day New World
Various HYPOTHESIS have been
formulated on the lines Of the close rela-
ionship Of monkeys and men. For In
stance, Pitheoanthropus Is regarded by
,ome authorities as the direct ancestor Of
nan; by others as a sidetraok failure In the
lttemp. at the evolution Of man. Then,
.gain, according to Ameghino the South
American monkeys from the oldest Ter
iary Of the Pampas are the forms from
which have arisen the existing American
monkeys and the extinct South American