按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！
common sense； and common sense with high philosophy。
The common…sense view of the matter to people who are not over…
curious and to whom time is money； will be that a baby is not a baby
until it is born； and that when born it should be born in wedlock。
Nevertheless； as a sop to high philosophy； every baby is allowed to
be the offspring of its father and mother。
The high…philosophy view of the matter is that every human being is
still but a fresh edition of the primordial cell with the latest
additions and corrections； there has been no leap nor break in
continuity anywhere； the man of to…day is the primordial cell of
millions of years ago as truly as he is the himself of yesterday； he
can only be denied to be the one on grounds that will prove him not
to be the other。 Every one is both himself and all his direct
ancestors and descendants as well； therefore； if we would be
logical； he is one also with all his cousins； no matter how distant；
for he and they are alike identical with the primordial cell； and we
have already noted it as an axiom that things which are identical
with the same are identical with one another。 This is practically
making him one with all living things； whether animal or vegetable；
that ever have existed or ever willsomething of all which may have
been in the mind of Sophocles when he wrote：…
〃Nor seest thou yet the gathering hosts of ill
That shall en…one thee both with thine own self
And with thine offspring。〃
And all this has come of admitting that a man may be the same person
for two days running！ As for sopping common sense it will be enough
to say that these remarks are to be taken in a strictly scientific
sense； and have no appreciable importance as regards life and
conduct。 True they deal with the foundations on which all life and
conduct are based； but like other foundations they are hidden out of
sight； and the sounder they are； the less we trouble ourselves about
them。
What other main common features between heredity and memory may we
note besides the fact that neither can exist without that kind of
physical continuity which we call personal identity？ First； the
development of the embryo proceeds in an established order； so must
all habitual actions based on memory。 Disturb the normal order and
the performance is arrested。 The better we know 〃God save the
Queen；〃 the less easily can we play or sing it backwards。 The
return of memory again depends on the return of ideas associated
with the particular thing that is rememberedwe remember nothing
but for the presence of these； and when enough of these are
presented to us we remember everything。 So； if the development of
an embryo is due to memory； we should suppose the memory of the
impregnate ovum to revert not to yesterday； when it was in the
persons of its parents； but to the last occasion on which it was an
impregnate ovum。 The return of the old environment and the presence
of old associations would at once involve recollection of the course
that should be next taken； and the same should happen throughout the
whole course of development。 The actual course of development
presents precisely the phenomena agreeable with this。 For fuller
treatment of this point I must refer the reader to the chapter on
the abeyance of memory in my book 〃Life and Habit；〃 already referred
to。
Secondly； we remember best our last few performances of any given
kind； so our present performance will probably resemble some one or
other of these； we remember our earlier performances by way of
residuum only； but every now and then we revert to an earlier habit。
This feature of memory is manifested in heredity by the way in which
offspring commonly resembles most its nearer ancestors； but
sometimes reverts to earlier ones。 Brothers and sisters； each as it
were giving their own version of the same story； but in different
words； should generally resemble each other more closely than more
distant relations。 And this is what actually we find。
Thirdly； the introduction of slightly new elements into a method
already established varies it beneficially； the new is soon fused
with the old； and the monotony ceases to be oppressive。 But if the
new be too foreign； we cannot fuse the old and the newnature
seeming to hate equally too wide a deviation from ordinary practice
and none at all。 This fact reappears in heredity as the beneficial
effects of occasional crossing on the one hand； and on the other； in
the generally observed sterility of hybrids。 If heredity be an
affair of memory； how can an embryo； say of a mule； be expected to
build up a mule on the strength of but two mule…memories？ Hybridism
causes a fault in the chain of memory； and it is to this cause that
the usual sterility of hybrids must be referred。
Fourthly； it requires many repeated impressions to fix a method
firmly； but when it has been engrained into us we cease to have much
recollection of the manner in which it came to be so； or indeed of
any individual repetition； but sometimes a single impression； if
prolonged as well as profound； produces a lasting impression and is
liable to return with sudden force； and then to go on returning to
us at intervals。 As a general rule； however； abnormal impressions
cannot long hold their own against the overwhelming preponderance of
normal authority。 This appears in heredity as the normal non…
inheritance of mutilations on the one hand； and on the other as
their occasional inheritance in the case of injuries followed by
disease。
Fifthly； if heredity and memory are essentially the same； we should
expect that no animal would develop new structures of importance
after the age at which its species begins ordinarily to continue its
race； for we cannot suppose offspring to remember anything that
happens to the parent subsequently to the parent's ceasing to
contain the offspring within itself。 From the average age；
therefore； of reproduction； offspring should cease to have any
farther steady； continuous memory to fall back upon； what memory
there is should be full of faults； and as such unreliable。 An
organism ought to develop as long as it is backed by memorythat is
to say； until the average age at which reproduction begins； it
should then continue to go for a time on the impetus already
received； and should eventually decay through failure of any memory
to support it； and tell it what to do。 This corresponds absolutely
with what we observe in organisms generally； and explains； on the
one hand； why the age of puberty marks the beginning of completed
developmenta riddle hitherto not only unexplained but； so far as I
have seen； unasked； it explains； on the other hand； the phenomena of
old agehitherto without even attempt at explanation。
Sixthly； those organisms that are the longest in reaching maturity
should on the average be the longest…lived； for they will have
received the most momentous impulse from the weight of memory behind
them。 This harmonises with the latest opinion as to the facts。 In
his article on Weismann in the Contemporary Review for May 1890； Mr。
Romanes writes： 〃Professor Weismann has shown that there is
throughout