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Abstract
Table
of Contents
Part I
Part II
Part III
Part IV
Appendixes
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Part II: The Seed of the Woman
Chapter 19
The Life History Of The Seed Of
The Woman
A very brief consideration
of the concept of
the Continuity of the Germ Plasm
and its bearing
on the direct line relationship
between the First and the Last Adam.
This chapter
can quite safely be by-passed by anyone who is becoming impatient
with technical details and prefers to move on to the more strictly
biblical aspects of this subject. However, I do not think the
intelligent reader will have any difficulty with it and it does
show how wonderfully the Lord prepared the way, in his design
and creation of the reproductive mechanism, for the recovery
of Adam's original constitution in the midst of a dying world.
It may be helpful for those who are uninitiated
in such matters to set forth in a generalized form which is admittedly
very much oversimplified but nevertheless essentially correct,
the life history of the ovum in one generation from the time
of its fertilization until the time that it presents itself once
again for fertilization to initiate the next generation.
This will help to show perhaps why it
is possible to speak of a true continuity of the germ
plasm and in what way it is quite correct to credit the seed
with immortality in a situation where the vehicle or carrier
(the female body in this case) has a very limited life span.
Like the amoeba, the seed has the potential for unending self-replication
without
 pg.1
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experiencing death in
the sense that no corpse need be left behind to make a break
in the continuity of the germ plasm unless the germ plasm is
actually destroyed by some external agency or circumstance.
It is sometimes suggested that
when the fertilized egg divides into two, it experiences a kind
of death in that it is changed into something else. But I think
Weismann's answer to this was effective. (219) He observed that the ovum no more dies in becoming
two ova at a certain stage in development than the boy dies
in becoming a man at a certain stage of development. The
fact is that the ovum, considered as a living organism (which
indeed it is), need never experience death provided that it is
induced to divide and multiply by successive divisions. This
may happen in nature without fertilization, but normally it is
the result of fertilization by a sperm. With this one condition
fulfilled, the single ovum becomes another ovum one generation
later in history and no corpse is left behind as evidence of
its death. The two "daughter" cells in turn divide,
if fertilized, and so the line goes on unbroken and can continue
endlessly so long as accident does not terminate it. Fertilization
of the ovum is really only a means for preserving its integrity
until one generation later it is again released and presented
for fertilization. And so it is simply passed on and on, generation
after generation, in an unbroken chain of continuous life. The
living ovum is the ovum of yesterday perpetuating itself not
as a mother perpetuates herself in her daughter and then dies
while the daughter lives on, but as a girl perpetuates herself
by growing up into a woman without experiencing death in the
process. Such a process does not constitute death but fulfillment.
Now this can be set forth diagrammatically,
granting much over-simplification, in such a way that these events
can be visualized. First of all we allow a single black dot,
(a) in Fig. 14, to signify the original fertilized ovum. At (b),
cleavage has taken place and the ovum has become two ova. The
original ovum has not "died," it has merely converted
itself into two viable duplicates half the size of the original.
This process of multiplication continues, until a change takes
place (c) and further multiplication leads to the emergence of
219. Weismann, August, Essays Upon Heredity
and Kindred Biological Problems, translated by E. B. Poulton,
S. Schonland
and A. E. Shipley, Oxford University Press, 1889, vol.1, p.26.
pg
2 of 6
cells which by now differ
in their constitution from the original ovum. These differentiated
cells are shown from (c) to (e) as open circles. The undifferentiated
cells which have not changed their constitution but have retained
the full potential of the original ovum, although they are now
considerably smaller, are still shown as black dots. From then
on, the history of the two kinds of cells, the differentiated
and the undifferentiated, follows a decidedly different course.
In Fig. 15 the history of these
cells is continued and the divergent end products of each group
of cells is set forth diagrammatically by showing that the open
circles become a separate entity, the body, while the
black dots continue to replicate in a mass by themselves �
outside the body of the embryo proper. This stage is therefore
termed "extra-embryonic development."
It should be
understood that these germ cells really are multiplying
outside the body of the developing embryo. Later, this mass of
multiplying germ plasm cells will migrate by amoeboid movement
from its position beside the life-support system of the embryo
into the embryo itself. In the diagram the schematized growing
embryo at (f) is shown with a kind of harbour facing towards
the mass of germ plasm which is merely intended to indicate that
there is an appropriate place being prepared to receive the germ
plasm in due time as at (g). From this "harbour" (the
ovary), one ovum at a time is released for potential fusion with
a spermatozoon, as shown in Fig. 16 below.
The mechanism governing the differentiation
of the cells into germ cells and body cells appears to result
not from any change in the nuclear content of the cells themselves
but in some change in the surrounding cytoplasm in which the
nucleus is immersed. The initial process of replication by which
the fertilized ovum multiplies itself until it forms a mass of
germ and body cells is called a morula, (e) of Fig. 14,
results in a gradual reduction in the size of each of
the
pg.3
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multiplying cells which,
though their number is greatly increased, actually still
occupy very nearly the same total space as the original ovum.
This is called cell cleavage. It is not what will happen
later when cells divide and multiply, because from then on the
total volume of the cells begins to increase and not merely
the number of cells. In this later process each body cell
grows larger and larger until it has approximately twice the
volume it originally had, at which critical point an internal
change occurs in the cell and it divides into two, each the size
of the original cell before it began to grow. This process is
referred to as cell division. The multiplication of cells
from the initial fertilized ovum to the morula stage is therefore
quite different from cell division. The distinction is necessary
because at this earlier period in cell life history the cells
divide into two without first gaining in size. Each cleavage
therefore reduces the size of the cell but the number
of cells steadily increases. The ovum which begins as the
largest cell in the body keeps dividing until its size is very
substantially reduced. Then later in its life when the individual
reaches adolescence, and just before one of the germ cells is
presented for fertilization by a sperm cell, it increases in
size and regains its status once more as the largest cell in
the body. This will be observed in Fig. 16 below.
Now although the cell size decreases
steadily from ovum to morula, the nucleus itself remains
approximately the same size so that the ratio of cytoplasm to
nuclear material steadily decreases. This means that a selection
of the cytoplasm is being made with each subsequent cleavage,
some of it being apportioned to one daughter cell and some to
another. By this method the reduction in cell size can be achieved.
Each successive cell during this process therefore receives not
merely a different amount of cytoplasm but cytoplasm of
a different constitution containing only a selection of
the constituents in the parent cell as well as very probably
a different internal organization. It is believed that this is
what leads to progressive cell differentiation and therefore
the growth, in due course, of specifically different tissues
and the development of different organs within the body. (220)
220. See Notes at the end of this chapter
(page 6)
pg.4
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Identical
genetic material in the nucleus then finds itself surrounded
by a series of different intracellular environments, and the
interaction between nucleus and cytoplasm initiates the cell
specialization which the developing organism demands. The subdividing
of the substance of the egg qualitatively is believed to be a
sufficient cause for the initial establishment of different lines
of cells, most of which are body or somatic cells and each of
which will develop along different lines � even though the
nuclear material in every cell is thought to retain all the characteristics
of the original ovum. Any cell nucleus transferred to an enucleated
ovum is found to have the totipotency of the initial ovum. Cell
character is therefore not merely the result of the nuclear material
but the interaction of this nuclear material and its associated
cytoplasm, and this cytoplasm is in a continuous state of change
during fetal development.
In Fig. 16 we observe the
final housing of the germ plasm. This in no way disturbs the
integrity of the germ plasm itself which continues through certain
stages of development that will prepare the individual germ cells
for the time when they will be presented in the adult animal
for subsequent fertilization. The important thing to bear in
mind is that this reservoir of germ cells is given a safe haven
within the fetus which, as far as is known at present, completely
isolates the germ cells, thus preserving their integrity.
In this Figure,
one of the germ cells (h) is being ejected in enlarged form prior
to being presented at the time of ovulation. At (a2) the cell has become an ovum
and is now fertilized by the sperm. At (b2) the first cleavage has occurred and we are back
at (b) of Fig.14 and about to begin another cycle of development.
And so generation after generation, the seed of the woman reiterates
itself in its original form. Thus was preserved the continuity
of the germ plasm from the first to the second Adam, from Eve
to Mary. And just to keep the record straight, it has to be remembered
that the process is still continuing. It did not stop with
Mary.
pg.5
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NOTES
220. (See page 4) On this see a useful and readily accessible
statement by R. L. Watterson, Chairman of Biological Sciences,
Northwestern University, in the McGraw Hill Encyclopedia of
Science and Technology, 1960, vol.III, p.168.
Alfred Kuhn has much to say on this subject:
"Only in the germ line through the first germ cell and all the way
to mature gametes [the seeds of future generations, ACC] do the chromosomes
retain their original integrity. A variety of observations show now that
behaviour of the chromosomes depends on the cytoplasm region in which
they are found during division. . . Even the tiniest inequality
within the cytoplasm reverberates back and forth, resulting in the
most extreme disparities among the resulting cells" [emphasis mine]
[Lecures in Developmental Physiology, translated by Roger Milkman,
New York, Springer-Verlag, 1971, p.482, 483]. At reference #192
(see Part II, chapter 18) the reader will
find part of his discussion on the importance of the ratio between cytoplasmic
and nuclear material and the influence of cleavage upon this ratio.
pg.6
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Copyright © 1988 Evelyn White. All rights
reserved
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