Viii
.
PREFÀCE
“
dating back some 400 million years, are of the same nature.
-
‘
The un£olding of the characters follows the same general
lines in the development of the primitive forms of the
present day and in the phylogenetic succession in the past
history. But, whilst we may say that the unfolding of the
-
'
characters in development is due to the inherited tendencies,
such an interpretation would not apply to their original
.
appearance unless we widen very considerably our ideas of
,
hereditÿ. Asan example to be given presently will show,
__._
the reactions of an organiSm under the stress of new c0n—
'ditions “are
than specic. And it is just
'
‘
becauSe
stand at the beginning_of a new series, that
ëes present us with
examples of this elemental
Â Ï power
Other
ïbodièd animals."
''
Inthe making of “form
recognise
a trinity of f0rces', inheritànCe, activity, and environment.
_
For the
is p‘robable that the inheritance is
of less
ar0ng the shes than in higher animals.
Thé '
greater variability of their characters also indicates
this. “And“ experiments shoW'that thef'charaCter‘sï are very -
'
senéitiv‘e "tof changes" in the external conditions. The
ConstanCy of a Species, in fâCt, depends upon the persisteCe
of anormal environment. We might almost include the
.
latter tmder‘the inherita‘ncë, were not this usage confuSing
to the student.
-
'
,
_
"
;
‘
of
linkbetween inherit—
environment, is
the; most important
'
faÇtOr in the
remaking of characters. Under
,
normal
importance is' màsked, but under
_
- _
there is
but this activity to
the
of new
The plastic
"material
the-traditions of the past responds
,
ah“*elerriehtal‘ manner
thë':…newî
and the];
_
;
_
.resultant
be_,Ï5—:have’ frequently—been,—'ofsuch
:.
appearance that
genetic “relation
-‘g_*æanhotbe dis“cernêd. &”
‘
‘_ï‘
,_
f
_
ÛI_i€
Natural
Selection, the“ s‘urViValL—of— the ttesti and elimiiiation; of the