WHEN DOES HUMAN LIFE BEGIN?
By the embryologists from the moment the spermatozoön joins the
nucleus of the ovum until the end of the second week of gestation
the product of conception is called the _Ovum_; from the end of the
second week to the end of the fourth week it is the _Embryo_; from
the end of the fourth week to birth it is the _Fetus_. At what moment
during these three stages does the human soul, the substantial form
of a man in the full comprehension of the term, enter the product of
conception? When does the thing become a human being?
The question is evidently one of the greatest importance. If the
rational soul does not enter until the ovum has developed into
an embryo, or only after the embryo has passed on into the fetal
condition, the destruction of this ovum, by artificial abortion
or otherwise, would be a very different act morally from such
destruction after the soul had turned the new growth into a living
man. If the product of conception has first only a vegetative vital
principle, and this is later replaced by a vital principle that is
merely sensitive, and this again is finally superseded by a rational
vital principle, the destruction by abortion or otherwise of the
vegetative or sensitive life would not be a destruction of a rational
life. In this hypothesis the killing of the embryo would be a great
crime, because the embryo would be in potency for the reception of
human life, but the act would not be murder.
The discussion concerning the moment the human soul enters the body
is older than Christianity, and it was taken up by many of the early
Greek and Latin Fathers of the Church, and revived again and again
down to the present day. Plato thought the soul enters at birth;
Asclepias, Heraclites, and the Stoics held it is not infused until
the time of puberty; Aristotle[15] said the soul is infused in the
male fetus about the fortieth day after conception, and into the
female fetus about the eightieth day.
[15] _IX, De Animalibus_.
Tertullian,[16] Apollinaris, and a few others advocated
Traducianism,[17] or a transmission of the spiritual soul by the
parents. He said souls are carried over by conception and by the
parents, so that the soul of the father is the soul of the son, and
from one man comes the whole overflow of souls. St. Augustine used
the metaphor, one soul lit from another as flame from flame, without
decay in either. Augustine was in doubt as to the origin of the
soul, and inclined to traducianism, because it seemed to him better
to explain the doctrine of the transmission of original sin. "Tell
me," he wrote to St. Jerome in 415,[18] "if souls are created singly
for each person born to-day, when do infants sin so that they need
remission in the sacrament of Christ, sin in Adam from whom the flesh
of sin is propagated?... Since we cannot say that God makes of souls
sinners, or punishes the innocent, nor may we hold that souls even of
infants which without baptism leave the body are saved, I ask you how
that opinion can be defended which thinks that all souls are not made
from the single soul of the first man, yet as that soul was one to
one man, these are particular to particular individuals."
[16] _De Anima_, cap. 27.
[17] From _tradux_, a planted vine-shoot made to take root.
[18] Migne, vol. xxxiii, col. 720.
Again, St. Augustine said:[19] "I do not know how the soul came into
my body; he knows who gave it, whether he drew it [_traxerit_] from
my father, or created it new as in the first man." In the _Book of
Retractions_,[20] speaking of the articles he had written against the
Academicians before he was a bishop, he says: "As to the origin of
the soul, how it is set in the body--whether it is from that one man
who first was created ... or, as in his case, is made particularly
for each particular individual, I did not then know, and I do not
know now." St. Gregory the Great also said he could not tell whether
the human soul descends from Adam or is given particularly to each
man.
[19] _De Anima et ejus Origine_, i, xv.
[20] I, cap. i, n. 3.
St. Gregory of Nyssa, however, who died about 385, thirty years
before St. Augustine wrote the letter to St. Jerome, held that the
soul is infused into the body at the moment of conception, and he
argues with absolute precision for his opinion.[21] St. Maximus the
Theologian, who was martyred in 662, inveighs[22] against the notion
that the soul is vegetative at first, then sensitive, and finally
intellectual, and he thinks the assertion of Aristotle that the fetus
is not animated before the fortieth day is altogether untrue.
[21] Migne, _Patrologia Graeca_, vols. xliv and xlvi.
[22] Migne, _Ibid._, vol. xci, col. 1335.
St. Anselm, who died in 1109, very dogmatically denied that the fetus
is animated at conception,[23] and after his time the doctrine of
Aristotle, which is commonly called the Thomistic opinion, became
almost general. Vincent of Beauvais, however, a contemporary of St.
Thomas, opposed the Thomistic doctrine. Albertus Magnus[24] had the
same opinion as St. Thomas, and probably taught it to St. Thomas. In
the middle ages all held that each soul is directly created by God,
and is infused into the embryo, not at the instant of conception,
but when the embryo is sufficiently formed to receive it, which, as
Aristotle said, happens at about the fortieth day in males and the
eightieth day in females. The Thomists maintained the succession of
the three souls; many others opposed this particular opinion.
[23] _De Conceptione Virginis_, cap. xii.
[24] _Summa, De Homine_, q. xvi, art. 3.
Thomas Fienus, a physician and a professor in the University of
Louvain, in 1620 published a book[25] in which he held that the soul
is infused about the third day after conception, and his argument
for the early advent of the soul is very sound. As a result of
Fienus's revolutionary argument, Florentinus in 1658 brought out a
book at Lyons, called _De Hominibus Dubiis Baptizandis_, in which he
held that no matter what the age of the aborted fetus, if it could
be differentiated from a mole it should be baptized. This book was
brought before the Congregation of the Index. The congregation did
not condemn the book, but the author was forbidden to teach that his
doctrine holds _sub gravi_. The book went through many editions and
was approved by the faculties of the principal universities and the
theologians of the leading religious orders.
[25] _De Vi Formatrice Foetus Liber._
Zacchias, chief physician to Innocent X., in 1661 published his
_Questiones Medico-Legales_, and in this he maintained that "the
human fetus has not at any time any kind of soul other than a
rational, and this is created by God at the first moment of
conception, and is then infused."[26] By 1745 the opinion of
Zacchias as to the moment life begins was virtually general among
physicians, and has since remained the doctrine of physicists. Modern
discoveries by biologists have confirmed the fact that human life
exists in the impregnated ovum exactly as it does in all stages of
life, and no scientist holds any other opinion. There are, however,
a few moralists at the present day who incline to the old Thomistic
doctrine or to modifications of it.
[26] Tom. ii, lib. ix, tr. 1.
St. Alphonsus Liguori[27] was a follower of the Thomistic opinion.
He affirmed: "They are wrong that say the fetus is animated at the
instant of conception, because the fetus certainly is not animated
before it is formed, as is proved from Exod. xxi: 22, where in the
Septuagint version we find: 'He that strikes a gravid woman and
causes abortion, will give life for life if the child was formed;
if it was not formed, he will be fined.'" This argument by St.
Alphonsus is invalid apart from any facts that may bear upon either
the Thomistic or the modern opinion concerning the quickening of
the fetus. The text from the Septuagint Exodus is (1) too doubtful
in itself to be the basis of any argument; but (2) even if it were
authentic just as it stands, the conclusion St. Alphonsus draws from
it is not warranted by the premises. The Septuagint text differs
from the Vulgate and the Hebrew texts. The Vulgate has it thus: "Si
rixati fuerint viri et percusserit quis mulierem praegnantem, et
abortum quidem fercerit, sed ipsa vixerit, subjacebit damno quantum
maritus mulieris expetierit et arbitri judicaverint; sin autem mors
fuerit subsecuta, reddit animam pro anima, oculum pro oculo, dentem
pro dente, manum pro manu, pedem pro pede, adustionem pro adustione,
vulnus pro vulnere, livorem pro livore."[28] This version has nothing
whatever to say about the _foetus formatus_ or _non formatus_; it is
merely an application of the Semitic Lex Talionis, and the form of
the law is clearly corrupt and inaccurate.
[27] _Theologia Moralis_, lib. iv, tr. 4, n. 594.
[28] If men quarrel, and one strike a woman with child, and she
miscarry indeed, but live herself, he shall be answerable for so
much damage as the woman's husband shall require and as arbiters
shall award. But if her death ensue thereupon, he shall render
life for life, eye for eye, tooth for tooth, hand for hand, foot
for foot, burning for burning, wound for wound, stripe for stripe.
The passage quoted by St. Alphonsus as that of the Septuagint is not
exact even as the Septuagint has it. The full text is: "If two men
fight, and one strike a woman that hath [a child] in the womb, and
her babe come forth not yet fully formed,[29] in a fine he shall
be mulcted; whatsoever the husband layeth upon him he shall give
according to decision [_i.e._, of the judges]. But if it [the babe]
be fully formed he will give life for life, eye for eye, tooth for
tooth, hand for hand, foot for foot, burning for burning, wound for
wound, stripe for stripe."
[29] καὶ ἐξέλθη παιδίον αὐτῆσ μὴ ἐξεικονισμένον--not moulded out
into form; ἐξεικονίζειν, to mould out into form: εἰκων, an icon,
image, likeness.
This is (1) evidently nothing but an application of the Lex Talionis,
with no thought whatever of the biological animation, as such, of
the fetus. It means that if a fully formed fetus be aborted, either
no real damage is done, as such a child is viable; or the formed
child may be maimed, and then the Lex Talionis is to be applied. If
the fetus is not fully formed it is not a fit subject of the Lex
Talionis since it cannot lose an eye, a tooth, and so on, because it
lacks these organs and therefore the law of retaliation is not to be
enforced.
(2) Suppose, however, the writer of the text as the Septuagint has
it did think with St. Alphonsus that the formed fetus is animated,
and the unformed is not animated, even then the conclusion drawn
by St. Alphonsus is not warranted by the text. The laws of Exodus
do not teach embryology, physiology, or any other part of physical
science; and no authority worth a hearing holds that the Scriptures
were intended to be infallible treatises on obstetrics or astronomy.
Like the other parts of the Bible, the laws of Exodus presuppose the
unscientific biological, astronomical, and other physical notions of
the time in which they were written--the moral truth is the matter
the Scripture is dealing with; there no inaccuracy is to be found.
St. John (1:13) speaks of those who believe in Christ's name, "Qui
non _ex sanguinibus_, neque ex voluntate carnis, neque ex voluntate
viri, sed ex Deo nati sunt." Here he expresses the contemporary
notion, which is also the Thomistic opinion, that men are generated
from the specialized blood of their parents. He was interested
solely in conveying the truth that those who received Christ were
regenerated by him, not through heredity; and he does so, although
the biology is inexact. If St. Alphonsus's conclusion is valid as
from the text of Exodus, then men are generated _ex sanguinibus_, and
so on indefinitely.
The Massoretic text of this passage seems to be the best preserved:
"If men fight, and one hurt a woman who is with child, and her child
come forth, yet there is no mischief, he [who struck her] shall be
mulcted in a fine; whatsoever the husband of the woman layeth upon
him he shall pay according to the judges. But if there be mischief,
then he shall give life for life, eye for eye, tooth for tooth, hand
for hand, foot for foot, burning for burning, wound for wound, stripe
for stripe." Here the Hebrew text follows the Lex Talionis exactly.
If, in a brawl, a man's pregnant wife is struck and abortion results,
the offender pays the penalty. If the abortion does not kill or maim
the child, the culprit is fined by the Sanhedrim; if the child is
killed or maimed, then the penalty is according to the Lex Talionis.
In the Hebrew text also there is no mention of a distinction between
a _foetus formatus_ and _non formatus_.
Whether the fetus is animated at conception or some time later,
there is no foundation whatever for the notion that the female is
quickened later than the male. As was said before, Aristotle held
that the human male fetus is animated at the fortieth day, the female
at the ninetieth day, and the old moralists accepted his statement.
At the fortieth day, however, no one can differentiate sex unless
the microscope is used, and this particular use of the microscope is
altogether modern--the knowledge requisite for such use was not in
existence sixty years ago. At the twentieth day, with the microscope
and a stained specimen, a biologist can recognize whether the
primordial ova are present or absent and thus determine sex. Only at
the eighty-fourth day can sex now be differentiated without the aid
of the microscope, but then the embryo must be dissected: nothing can
be told from its external appearance. Sex can first be distinguished
by the external appearance only at about the one hundred and twelfth
day, the end of the fourth month of gestation. Therefore when
Aristotle said the male fetus is animated at the fortieth day, and
the female at the eightieth or ninetieth day, he was romancing.
The question, then, narrows to this: Is any human fetus animated
immediately at conception, or from forty to eighty days after
conception? The reason given by the followers of Aristotle for
deferring animation is that the vital principle requires organs in
the receptive material, but the embryo in the early stages, they say,
lacks these organs. This notion, however, as to the lack of organs
is altogether erroneous, and the rational soul enters the embryo
in the oval stage, immediately after the pronuclei unite: there is
organization in that stage of human life sufficient to receive the
substantial form or soul. We do not know how long after insemination
the pronuclei unite, but the proposition here is that as soon as
they unite the human soul enters. Fecundation usually occurs after a
menstruation, but not necessarily so; the spermatozoön may live in
the tube for seventeen days awaiting the ovum.
The human body is made up of billions of microscopic living cells,
all of which are derived by fission and differentiation from the
two original single germ-cells, the ovum and the spermatozoön.
Some nerve-cells have long processes running along the white
fibres through the entire length of the body, but they cannot be
differentiated except by the microscope. In the body are also
various liquids which are not cellular, as water, saliva, tears,
urine, blood and lymph plasma, and the gastric, intestinal, and
glandular juices, and these are secreted or excreted by the somatic
cells. The cells assimilate nutritive material carried to them by
the blood, excrete refuse substances, secrete glandular products,
and are the media for all human operations below certain acts of the
intellect.
A typical animal cell is commonly spherical in shape, but it
may take a great variety of forms through compression. It has a
cell-body or protoplasm, which is called also cytoplasm, especially
when contrasted with the nuclear karyoplasm, and a nucleus. A few
cells, like fat-cells and the human ovum, have an external covering
membrane, or cell-wall. There is a part called the Centrosome
observable in many cells, and this is made up of one or two minute
dots surrounded by a radiating aster called the Attraction-Sphere.
The centrosome is concerned in the process of cell-division and
in the fertilization of the ovum; it is an important organ in the
production of cell from cell, though its full nature and function
are not yet known. The Plastid, or Protoplast, is another less
important part found in certain cells; and in this by enlargement
and differentiation are formed starch, pigment, and in some cases
chlorophyl. Vacuoles are seen in cells; and there is an opinion that
these may be a special kind of plastid: some vacuoles pulsate.
The Nucleus is the most important part of a cell, the centre of
its activity. The specific qualities of organism in origin and
development are based upon nuclei, so far as the material element
of the living cells is concerned. Vital stimuli pass through the
nucleus into the surrounding protoplasm, and these stimuli control
metabolism. The nutritive cytoplasm assimilates, but the vital
principle energizes this assimilation through the nucleus, for a
part of a cell deprived of the nucleus may live for a time, but it
cannot repair itself. Constructive metabolism ceases when the nucleus
is lost. A toxic disease like diphtheria kills by disintegrating
cellular nuclei.
In the nucleus are several elements, the chief among which is
Chromatin. Chromatin takes various forms, but commonly it is an
irregular network. From the chromatin are derived the Chromosomes
in the prophases of indirect cell-division which is the process of
cell-division in the human body, except in lymph-cells and white
blood-corpuscles, which split directly, or by Amitosis. Indirect
cell-division is called Mitosis or Karyokinesis. In the male and
female chromosomes, according to a common opinion of biologists,
all the elements of parental and phyletic physical heredity are
transmitted to the embryo.
[Illustration: Fig. I
A CELL.
Throughout the Cytoplasm is a mesh containing numerous minute
granules called Microsomes.]
The production of cell from cell is accomplished either by direct
splitting of the nucleus and cytoplasm into two new cells, or by
indirect division through a series of stages. In a typical direct,
or amitotic, division the nucleus is constricted in the middle
and divides into two daughter-nuclei. These by amoeboid movements
withdraw to the poles of the cell; the cell finally divides between
them, and thus two cells are formed. These, again, split into four,
the four into eight, and so on. An amoeba by direct division can
separate into two distinct new animals in ten minutes.
Heredity here is simple. In unicellular organisms, such as Rhizopoda
and Infusoria, each individual grows to a certain stage, and
then divides into two parts, which are exactly alike in size and
structure, so that it is not possible to decide whether one is older
or younger than the other. These organisms reduce the size of their
overgrown bodies by division. Each individual of any such unicellular
species is a part split off serially from an organism which started
into life ages ago. Some of them have come down in uninterrupted
life from geological epochs that passed away eons before the first
man was created. Many of these unicellular plants and animals have
immeasurably the most ancient form of life on earth. Heredity with
them depends upon the fact that each offspring is merely half of its
parent. In some cases the division has a sexual quality: two cells in
_Paramecium_, and, like Infusoria fuse and then divide if they come
into contact; they can, however, split without this sexual process.
Multicellular plants and animals do not reproduce by simple division,
and the half of the parental body does not pass over into the
progeny. Sexual reproduction is the chief means of multiplication in
multicellular organisms, and in no case is it completely wanting; in
most it is the only method of reproduction. In multicellular animals
the power of reproduction is in the germ-cells, which differ from
the somatic cells. Germ-cells do not maintain individual life as
the body-cells do, but the germ-cells alone preserve the species.
From two of these germ-cells under certain conditions is developed a
complete bodily organism of the same species as the parents. These
two cells are in a sense the undying cells; the somatic cells die.
Multicellular animals--Man, for example--grow embryologically by
Mitosis or Indirect Division. As in Direct Division, typically,
the nucleus in mitosis splits first and the cytoplasm secondly;
but before the nucleus divides its content undergoes a series of
changes. The chromatin loses its reticular arrangement and gives
rise to a definite number of separate bodies, usually rod-shaped,
known as Chromosomes. In this process the chromatin becomes a
convoluted thread, called the Skein or Spireme. The thread thickens
and opens out somewhat, and finally breaks transversely to form
the chromosomes, which may be rods, straight, curved, ovoid, and
sometimes annular. Commonly the nuclear material fades away and
leaves the chromosomes in the cell-plasm. (Fig. II, 2 and 3.)
[Illustration: Fig. II
DIAGRAM OF MITOSIS.
1. Cell with resting Nucleus. 2. Prophase: Chromatin in
thickened convoluted threads, beginning of Spindle. 3. Prophase:
Chromosomes. 4. Prophase: Spindle in long axis of the Nucleus,
Chromosomes dividing. 5. Anaphase: Chromosomes moving toward
the Centrosomes. 6. Chromosomes at the poles forming the
Diaster, beginning splitting of the Cell-body. 7. Telophase,
Daughter-Nuclei returning to resting state. 8. Daughter-Nuclei
showing Monaster below. 9. The two new Cells.]
It is almost an established fact that each species of animal and
plant has a fixed and characteristic number of chromosomes, which
regularly recurs in the division of all its cells. In forms arising
by sexual production the number is even. The number of chromosomes
in the human cell is said to be forty-eight. There are, according
to some observers, forty-seven chromosomes in man and forty-eight in
woman. There seem to be twice as many chromosomes in white men as
in negroes. Wilson gives the number[30] of specific chromosomes for
seventy-four animals and plants. Germ-cells as differentiated from
the somatic cells have in the perfected cell always half the number
of chromosomes found in a somatic cell.
[30] _The Cell in Development and Inheritance_, p. 207.
While these changes are going on in the chromatin the Amphiaster
forms. This consists of a fibrous spindle-shaped body, the Spindle,
at either pole of which is an Aster made up of rays. In the centre of
each aster is a Centrosome, and this may have a Centrosphere about
it. As the amphiaster grows the centrosomes are grouped in a plane at
the equator of the spindle, forming the Equatorial Plate. (Fig. II,
No. 4.) The process so far makes up the Prophases of the Mitosis.
In the Metaphases of the Karyokinesis begins the actual division of
the cell. Each chromosome splits lengthwise into exactly similar
halves, and these, in the Anaphases of the mitosis, drift out to the
opposite poles of the spindle to form the daughter-nuclei of the new
cells. The daughter-nuclei receive precisely equivalent portions of
chromatin from the mother-nucleus, and this is an important fact in
mitosis. As the chromosomes go toward the poles the cell-body begins
to constrict at the equator.
In the final phases, the Telophases, the cell divides in a plane
passing through the equator of the spindle, and each daughter-cell
receives half the chromosomes, half the spindle, and one of the
asters with its centrosome. A daughter-nucleus is reconstructed
in each cell from the chromosomes. The aster commonly disappears
and the centrosome persists, usually outside the new nucleus, but
sometimes within it. Every phase of mitosis is subject to variation
in different kinds of cells, but the outline of the division given
here is the fundamental method.
The germ-cells differ from the body-cells in general by containing
half the number of chromosomes characteristic of a given animal
or plant. If the body-cell has, say, twenty-four chromosomes, the
spermatozoön of the animal or plant from which the cells are taken
will have twelve chromosomes and the ovum will have twelve. When
the nuclei of these two cells unite in fertilization the resulting
primordial cell will have the twenty-four chromosomes restored,
the specific number for this plant or animal. In oögenesis and
spermatogenesis the phases of "Reduction," wherein the ovum and
spermatozoön get rid of half the chromosomes during the stages of
maturation of these germ-cells, are somewhat similar for both sexes.
The process is very complicated, but it is of importance in the
theories of inheritance. All the physical characteristics in a human
being that come to him from his parents and remoter ancestors are
supposed, by the biologists, to reach him through the chromosomes in
the nuclei of the single parental germ-cells. The maternal physical
heredity is handed on through the chromosomes in the ovum. The fetus
in the womb is a parasite, autocentric, feeding at the start from
the deutoplasm, or yolk, in the ovum, and later from the supplies
brought to it by the maternal blood. The physical material it gets
directly from the mother is very probably all in the chromosomes
of the fecundated ovum. Some weeks elapse, and the embryo is quite
advanced before it begins to draw food from the mother at all. So far
as the father is concerned, there is no doubt whatever that every
physical and pathological characteristic that can be handed down--and
there are many such qualities--must come through the chromosomes
of the paternal spermatozoön. Certain physical characteristics
are passed on for centuries in a family--the Norseman's body in
northeastern Ireland, the skin-pigment in the American negro, and so
on indefinitely--and these qualities cannot come down except through
the chromosomes. The germ-plasm has come to us from the first man,
and it will be passed on to the last person of the race--we are all
literally uterine brothers.
In the reduction of the germ-cells, if the primordial cell that
finally produces the ovum has, say, four chromosomes, these four
chromosomes first split longitudinally and reduce into two tetrads,
or two groups of four chromosomes. Outside the nucleus is a spindle
toward which the two tetrads move; they pass out of the nucleus and
become the equatorial plane of the spindle; each tetrad divides into
dyads (pairs of chromosomes), and one pair of these dyads remains in
the ovum, while the other pair leaves the ovum entirely and becomes
the nucleus of an abortive cell, called the First Polar Body. Later
a second polar body forms and carries another dyad (two chromosomes)
out of the ovum, leaving only one dyad, or two chromosomes, in the
germ-cells; that is, half the number of chromosomes that were in the
primordial cell.
The reduction-division in spermatozoa is similar, but the end process
leaves four active spermatozoa, whereas in the ovum the final
result is one ovum and three practically inert and cast-off polar
bodies. The reduction-division in both ovum and spermatozoön is in
reality far more complicated than the broad summary given here. In
parthenogenetic insects and animals a polar body takes the place of
the spermatozoön, and fuses with the egg-nucleus to start mitosis.
In general, the new nuclei in the cells formed by division are not
made _de novo_, but arise from the splitting of the nucleus in the
mother-cell. The new nucleus assimilates material, grows to maturity,
and divides again into two daughter-nuclei. Whatever be the number
of chromosomes that enter a new nucleus as it forms, the same number
issues from it in mitosis. Boveri said,[31] "We may identify every
chromatic element arising from a resting nucleus with a definite
element that enters into the formation of that nucleus, from which
the remarkable conclusion follows that in all cells derived in the
regular course of division from the fertilized egg, one half of
the chromosomes are of strictly paternal origin, the other half of
maternal." It is not strictly true to say that the germ-nuclei fuse:
they send in two sets of chromosomes that lie side by side, as has
been frequently demonstrated since 1892[32] in many of the lower
forms of life, and this law almost certainly extends also to man.
[31] _Jenaische Zeitschrift_, 1891, p. 410.
[32] See Wilson, _op. cit._, p. 299.
The primordial germ-cells appear in the human fetus about the
twentieth day and finally mature at puberty. Then an ovum at
menstruation breaks out through the surface of the ovary, and is
taken by the fimbriae of the Fallopian tube into the lumen of this
tube. Fecundation happens near the outer or ovarian end of the
Fallopian tube, and the fecundated ovum finally is passed on to
fasten on the wall of the uterus. The spermatozoön is a ciliated cell
with the power of locomotion, through the movement of the tail of the
cell. It can move 0.05 to 0.06 mm., or its own length, in a second.
It thus passes up through the uterus and out through the Fallopian
tube, against the cilary motion of the tubal cells, until it meets
the ovum.
A human ovum is a typical cell, but it has a covering membrane, and
a minute quantity of deutoplasm or yolk, which is not alive, and
is food for the growing embryo before the embryo begins to draw
sustenance through the placenta. The eggs of birds have a large
quantity of food stored in the yolk, since their embryos live in
the ovum and draw food therefrom during the entire period which
corresponds to the time of gestation in mammals. The "white" and the
calcareous shell of a hen's egg are adventitious parts, added in the
oviduct after the egg leaves the ovary.
The spermatozoön is a complicated organism. The head is partly
covered with a thin protoplasmic cap, and it contains the nucleus
with the chromatin. In the neck are two centrosomes. The tail
is in three parts with an axial filament throughout, which is a
bundle of extremely minute fibrils. In the middle part the axial
filament is surrounded by an inner sheath; outside this sheath
is a spiral filament lying in a clear substance; and outside the
spiral filament is a finely granular layer of protoplasm, called the
Mitochondria. This organism is a living animal cell, and it can live
in an incubator, or in the Fallopian tube for two or three weeks,
altogether removed from the living male body that produced it. Sir
John Lubbock[33] says he kept a queen ant alive for thirteen years.
This ant, which died in 1888, had been fertilized in 1874, and never
afterward. She laid fertile eggs for thirteen years; that is, the
spermatozoa in her oviduct retained their vitality for thirteen years.
[33] _Journal of the Linnean Society_, vol. xx, p. 133.
The human spermatozoön is a living cell: it has (1) the requisite
structure; (2) the chemical composition of an organic being;
(3) a figure in keeping with its species; (4) an origin from a
living progenitor; (5) the _explicatio naturae_; (6) the power
of assimilation; (7) the _duratio viventium_; (8) the power of
reproduction; (9) motion and locomotion. As soon as the ovum breaks
through the surface of the ovary it has all the qualities of the
spermatozoön except locomotion. These two cells are animal cells,
not vegetable; just as single-celled protozoa, like Actinophrys,
Actinosphaerium, Closterium, Stentor, and the Amoebas are animals,
not plants. It is not possible in our present knowledge sharply to
differentiate ultimate forms of plants from animals. To say that
animals have the qualities of plants plus a sentient vital principle
is not enough. It is very doubtful that even the so-called sensitive
plants feel, and it is practically certain that many low forms of
animal life do not feel--they have no sentient mechanism. Plants have
the qualities enumerated above plus the power of drawing nutriment
directly from inorganic material, while animals can draw nutriment
directly only from organic material; yet some fungi, bacteria
for example, will grow and thrive only on organic material, and
animals will take up mineral drugs. It is questionable, however,
that minerals which thus find a way into animal cells are really
assimilated. They excite or irritate these cells into intenser
action, and thus cause growth, rather than affect development by
direction. The so-called mineral tonics used in medicine act by
irritation.
This irritation or stimulation by drugs can in certain very low forms
of animal life start mitosis in the unfertilized ovum, and thus build
up part, at the least, of a specific embryo parthenogenetically:
here probably a polar body takes the place of the spermatozoön.
Loeb, by treating the unfertilized egg of Arbacia (a sea-urchin) with
magnesium chloride, started mitosis that resulted, it is said, in a
perfect Pluteus larva.[34]
[34] _American Journal of Physiology_, 1899, iii, 3.
The human ovum is about half the size of a period in the type of this
page, and two hundred and fifty spermatozoa will fit side by side
along the horizontal diameter of the lowercase letter _o_ here. The
nuclei of these cells are extremely minute: they must be stained and
be observed with a high-power objective on the microscope before they
become visible. This small nucleus of the spermatozoön penetrates
the covering membrane of the ovum, enlarges, and becomes the male
pronucleus. The pronucleus unites permanently with the pronucleus of
the ovum, and together they form the Cleavage or Segmentation Nucleus
of the fertilized ovum. This new nucleus gives rise by division to
the innumerable myriads of nuclei in the growing body. Hence every
nucleus of the child apparently contains nuclear material derived
from both parents, as has been said.
The two perfected germ-cells before fecundation are in a state of
nuclear rest after the numerous mitotic changes that have taken
place in the maturation of these cells. When these nuclei unite in
the ovum an intense activity at once is set up. Biologists offer
very many theories to explain this awakening force. Herbert Spencer,
Herting, and others held that protoplasm when perfected tends to
pass into a state of stable equilibrium and consequent lessened
activity, but fertilization restores it to a labile state. This and
similar theories are verbose amplifications of the obvious fact that
the cells start to divide and the biologists do not know the cause.
The soul, of course, cannot have anything to do with the matter,
because you cannot smell a soul. "Senescence and rejuvenescence" is
another sonorous explanation that does not explain, used by Minot,
Engelmann, and Hansen. Weismann rejects these theories for his own
"Fertilization as a Source of Variation." Anyhow, the fertilized cell
starts to divide regardless of the biologists. Adult cells may be
stimulated to divide by chemical irritation, by mechanical pressure
as in the formation of calluses, traumatism, by any agency that
brings about an abnormal condition of the body, but this fact does
not explain the normal fission of the fecundated ovum.
In about fifteen days from the date of fertilization the ovum passes
through the following stages:
1. The ovum, with a full series of mitotic changes of the ordinary
somatic type described above, divides, subdivides, and grows within
the cell-wall until a rounded mass of cells is formed, which is
called the Morula or Blastula--the original cell-wall, of course,
stretches to hold these new cells. They are of unequal size, and they
divide at unequal rates.
2. An albuminous fluid collects within the morula, and thus the
Vesicle or Blastocyst is formed. The blastocyst is called more
commonly the Cleavage Cavity or the Segmentation Cavity. As this
cavity widens the cells are seen to be arranged in two groups--(_a_)
an enveloping layer, the epiblast, from the outermost plate of which
develops later the Trophoblast, or the nourishing and protecting
covering of the embryo; (_b_) an Inner Cell Mass, made up of granular
cells, attached to the epiblastic layer at the Embryonic Pole of the
Vesicle. These two stages probably take place in the Fallopian tube,
and thereafter the embryo is in the cavity of the uterus.
3. In the third stage the Inner Cell-Mass separates into two layers
derived from the inner cell-plate of the blastula. The mass flattens
and spreads peripherally, until finally it is divided into two
layers. The outer is the Ectoderm and the inner is the Endoderm or
Hypoblast. The three steps just described have not yet been seen in
the human species by any one, but they are inferred very confidently
from what is well known of the development in mammals most closely
resembling man in physical formation.
4. By the conversion of the one-layered blastula into two layers of
cells, the Gastrula stage of the embryo is attained. The Gastrula
consists of two layers of cells surrounding a central cavity, which
is the Archenteron, or the body-cavity that will hold the intestines.
During the past twelve years many specimens of human gastrulas have
been observed. The earliest form was that seen in 1908 by Teacher
and Boyce.[35] This embryo was 1.95 mm. in length by 0.95 mm. in
width, about twice the size of a pin-head. It showed on section the
endoderm, the ectoderm, and the beginning mesoderm, enclosed in a
spherical mass of trophoblastic cells. The mesoderm is a plate of
cells lying between the endodermic and ectodermic plates. When the
mesoderm develops into two plates, a cavity, called the Primitive
Coelom, appears between the plates. The Coelom becomes the space
between the viscera and the body-walls in later development.
[35] _Contributions to the Study of the Early Development and
Embedding of the Human Embryo._ Glasgow, 1911.
From the primary embryonic layers of cells, the ectoderm, the
endoderm, and mesoderm, all the parts of the body are built up. From
the ectoderm are produced the skin, nails, hair, the epithelium of
the sebaceous, sweat, and mammary glands, the epithelium of the mouth
and salivary glands, the teeth-enamel, the epithelium of the nasal
tract, of the ear, of the front of the eye, and the whole spinal cord
and the brain, with their outgrowths.
From the endoderm come the epithelium of the respiratory tract,
of most of the digestive tract with the liver and pancreas, the
epithelium of the thyroid body, the bladder, and other minor parts.
From the mesoderm are developed bone, dentine, cartilage, lymph,
blood, fibrous and alveolar tissues, muscles, all endothelial cells,
as of joint-cavities, blood-vessels, the pleura and peritoneum, the
spleen, kidneys and ureters, and the reproductive bodies.
The epiblast now with its mesoblastic lining begins to form the
Chorion, an embryonic intrauterine appendage; and the endoderm
encloses the Archenteron or primitive gut. Before the end of the
second week of gestation the heart is indicated as two tubes in the
mesoderm, and the blood-vessels begin to be produced in the yolk-sac.
About the twelfth day the mouth-pit shows, and the gut-tract is
partly separated from the yolk-sac. The medullary plate of the
nervous system is laid down about the fourteenth day, and the nasal
area is observable. The maternal blood escapes into spaces about
the embryo enclosed by masses of embryonic cells, which have not
separated from one another, but which are known collectively as
Syncytium.
5. With the third week the stage of the embryo, technically so
called, begins. During this week the body of the embryo is indicated.
There are three layers of cells, already mentioned, the ectoderm,
mesoderm, and endoderm, and these lie on the floor of the enveloping
Amnion. The amnion is a loose fluid-filled sac (the caul) enveloping
the fetus to protect it from jarring. The fluid in it is the "waters"
that escape in parturition when the infant breaks through the caul.
The archenteron in the third week shows the beginning of a division
into two parts: the part that will go to the body proper of the
embryo, and the part outside the body of the embryo which will form
the yolk-sac, or umbilical vesicle, from which the embryo will draw
sustenance until the placental vessels have been formed. The part of
the archenteron that remains within the embryo proper begins in this
third week to be moulded into the head-cavity. The forepart of the
archenteron will later make the alimentary tract from the mouth to
the middle of the duodenum, or small intestine beyond the stomach.
The other part of the archenteron wall make the Allantois, the hind
gut and the bladder. The allantois becomes a part of the fetal
umbilical cord after the formation of the placenta.
During this third week the dorsal outline of the embryo is concave;
the heart has a single cavity, which will begin to divide during
the fourth week; the vitelline blood circulation begins, and the
blood-vessels of the visceral arch are laid down. The digestive
system is advanced to a gut-tract, which is a straight tube connected
with the yolk-sac. The liver evagination is present and the oral
pit is a five-sided fossa. The respiratory system is represented by
the _anlage_ of the lungs, a longitudinal protrusion of the ventral
wall of the esophagus. The genito-urinary system begins as the
Wolffian bodies. The mesoderm starts to segment to form the skin,
and the neural canal (from which develop the spinal cord and brain)
for the nervous system forms. The fourth ventricle of the brain is
indicated, and the vesicles of the fore brain, mid brain, and hind
brain are recognizable. The ears, nose, and eyes, muscular system,
skeleton, and limbs are also beginning to be recognizable. At about
the sixteenth or eighteenth day of gestation the various parts of the
embryo rapidly differentiate.
In the fourth week all these parts advance. The atrium cavity of
the heart begins to divide; the alimentary tract shows the pharynx
and esophagus, stomach, and gut; the pancreas starts, the liver
diverticulum divides, and the bile-ducts appear. The lung _anlage_
bifurcates and the primitive trachea is seen. The ventral roots
of the spinal nerves appear, the interior ear is indicated, and
the eye is deeper. The buds of the legs and arms appear about the
twenty-first day--by the thirty-second day even the fingers are
present. The four heart-cavities are formed, the intestinal canal is
nearly closed, the first indications of the liver and kidneys appear.
The child now has reached the fetal stage, and its living body is
made up of myriads of cells all derived from the original fertilized
ovum. The fetus is then one centimetre, or two-fifths of an inch, in
length--about the length of the word "fetus" here.
At the end of the second month the fetus is two and a half
centimetres long. The ears appear, and the tail-like process at the
lower end of the spine disappears. The arms show the three parts,
arm, forearm, and hand; and a little later the thigh, leg, and foot
are differentiated. The navel begins to close, the liver develops,
the abdomen is yet partly open.
At the end of the third lunar month the fetus is seven to nine
centimetres long. The intestinal canal is formed and contains
bile. The body resembles that of a human being, but the head is
proportionately very large. Bony tissue begins to appear.
[Illustration: FIG. III.
The Development of the Fetus.]
At the end of the fourth lunar month the fetus is ten to seventeen
centimetres long. Some muscles are movable. The heart-beat is strong.
Sex is distinguishable externally. The skin is bright red, and so
transparent that the blood-vessels are visible through it.
Toward the close of the fifth lunar month the head is about the size
of a hen's egg. The skin is somewhat less transparent. There are
indications of hair and nails. The eyelids are closed. Parts of the
brain and spinal cord are formed. Such a fetus may live for five or
ten minutes if removed from the womb, and it may make attempts at
respiration.
At the end of the sixth lunar month the fetus, if born, may live
for several hours under favorable circumstances. Its respiratory,
digestive, and related organs are not developed, and no artificial
feeding will keep such a child alive. The brain cortex, the organ of
consciousness, begins to laminate into three strata of nerve-cells at
the beginning of the sixth month.
Here the time of fetal viability outside the womb may be considered.
Langstein, of the Augusta Victoria Hospital in Berlin, reported[36]
a study of the growth and nutrition of 250 prematurely born infants,
and he found that a weight of 1000 grammes (2-1/5 pounds) and a full
body length of 34 centimetres (13-3/5 inches) are the lowest limits
for viability under proper circumstances. A fetus 1000 grammes in
weight and 34 centimetres in length has completed the sixth solar
month, or the sixth and a half lunar month; that is, it is viable at
the _beginning_ of its seventh month, _servatis servandis_.
[36] _Berliner klinische Wochenschrift_, June 14, 1915.
The child at term, as a rough average, is from 48 to 52 centimetres
(19 to 20-1/2 inches) in length, and it weighs from about 6-3/5 to
7-1/2 pounds. It is impossible, however, to obtain the sizes and
weights of infants _in utero_ with scientific accuracy, because the
date of conception cannot be determined with absolute certainty, and
individual fetuses vary as do infants after birth. A full-term infant
sometimes may weigh only 3-1/2 pounds when the mother is diseased,
and again an eight-month fetus will weigh as much as 8 pounds. Large
muscular and fat women have large babies; women of the well-to-do
classes have larger babies than do the poor; women who work during
gestation bear smaller babies than do those women that rest. Mothers
who work in tobacco, lead, or phosphorus have puny babies; white
children are larger at birth than negro children; boys at term are 3
to 5 ounces heavier than girls.
Langstein says that prematurely born infants weighing from 900
grammes (31-1/2 ounces) to 1500 grammes (3-1/2 pounds)--that is,
all born before the seventh solar month--must be kept in hot-water
incubators in a room with ordinary ventilation. Babies weighing 2000
grammes (4-1/2 pounds) or more get along in an ordinary crib if they
are kept surrounded with hot-water bags. Such children are to be fed
with human milk through a catheter passed into the mouth or they
die of inanition. Only a few of them are strong enough to suck from
a bottle, and these give up the effort after a few days and die.
They cannot utilize fat, even from milk; and all artificial food is
dangerous.
Most of the prematurely born become rachitic, and even human milk
is not preventive of this condition. Rachitis is a constitutional
disease, characterized by impaired nutrition of the bones and
changes in their shape. In the third or fourth month craniotabes is
frequent--that is, an atrophy of the skull bones with the formation
of small conical pits. These infants show also a morbid tendency
to convulsions--spasmophilia. Such diseases are caused by a lack
of mineral salts, which normally are carried to the fetus by the
placental blood during the last two months of gestation. Because of
this lack premature infants require the administration of lime salts
in their food; they also need iron because they are anemic.
A fetus, then, of six calendar, or solar, months (not lunar) is
viable if treated in a hospital by competent physicians. Otherwise
it is not viable, except in a strictly technical sense; it will not
live more than a few days or weeks. Reports of infants younger than
six months as having been successfully reared are not credible--it is
easy to make an error in the reckoning.
A full seven-months infant may be reared with proper feeding and
skilled care; a six-months infant may be reared (with difficulty) in
a hospital with skilled care. If it is certain that the removal of a
six-months fetus will here and now save the life of a mother (a very
difficult matter to judge by the best diagnosticians), this removal
may be done, provided the infant is delivered in circumstances where
skilled care, incubator, and proper food are obtainable; otherwise
the removal is not justifiable. That the ordinary physician says it
is necessary to empty the uterus is not a sufficient reason, as he is
likely to act from ill-digested information set forth by professorial
pagans, who place no value whatever on human life in an infant.
A most important and essential circumstance in the matter of
inducing abortion at the end of the sixth month of gestation to
save a mother's life is that in practically every case requiring
such interference the diseased condition of the mother has checked
the growth of the fetus, and the fetus therefore is really not a
six-months child in development. Such an undeveloped fetus is not
viable. Eclamptic women, and those who have nephritis, are most
likely to have undeveloped fetuses. In cases of this kind the seventh
month should be completed before interference.
How is this human body in all its complexity developed from the
microscopic germ-cells? There has been a vast deal of ink spilled in
striving to solve this mystery, but we come out empty by the same
door wherein we went. The early Preformationists guessed that the
ovum contains an embryo fully formed in miniature, and development
is a mere unfolding of what had already existed. The biologists of
to-day mention the Preformationists with superior scorn, and then
present Preformationism under other names. Weismann's theory is the
most fashionable at present.
In a paper read at the Darwinian Memorial Congress in 1909, Weismann
said: "With others I regard the minimal amount of substance which
is contained within the nucleus of the germ-cells in the form of
rods, bands, or granules, as the _germ-substance_, or _germ-plasm_,
and I call the individual granules[37] _ids_. There is always a
multiplicity of such _ids_ present in the nucleus, either occurring
individually or united in the forms of rods and bands (chromosomes).
Each _id_ contains the primary constituents of the _whole_
individual, so that several _ids_ are concerned in the development
of a new individual." Actually there are such things as chromosomes,
and when these are stained and are under the highest power of the
microscope they appear to be granular. These granules Weismann calls
_ids_. Beyond the fact that there are such granules, all else is
sheer guessing.
[37] _Id_ is a word derived from Nägeli's term idioplasm, which
means the chromosome granule.
He says further: "In every complex structure thousands of primary
constituents must go to make up a single _id_; these I call
_determinants_, and I mean by this name very small individual
particles, far beyond the limit of microscopic visibility, vital
units, which feed, grow, and multiply by division. These determinants
control the parts of the developing embryo,--in what manner need not
here concern us."
There is some truth here. The _id_ is made up of molecules and atoms,
ions and electrons, and in some manner, of course, these have to do
with the development of the embryo; but as to the manner we have not
the slightest knowledge, and just this knowledge is what we need
to make the theory anything more dignified than a child's game at
guessing. There is a structural differentiation in the unsegmented
ovum, with all the embryonal axes foreshadowed in it, but this tells
us nothing more than that the egg contains the man in germ.
He goes on: "The determinants differ among themselves; those of a
muscle are differently constituted from those of a nerve-cell or a
glandular cell, etc., and each determinant is in its turn made up of
minute vital units, which I call _biophors_, or the bearers of life."
That these so-called determinants differ among themselves may be
true, if they exist at all, which is just the point to be proved.
Giving Greek names to inventions does not turn invention into fact.
These supposed determinants, he says, "may vary quantitatively if
the elements of which they are composed vary; they ... and their
variations may give rise to _corresponding_ variations of the organ,
cell, or cell-group which they determine." Professor Dwight said:[38]
"This is what is palmed off on us for science!" Weismann assures us
we _must_ admit this farrago of clumsy fiction, otherwise we should
be forced "to assume the help of a principle of design."[39] In the
name of common sense, then, admit a principle of design, and be done
with it!
[38] _Thoughts of a Catholic Anatomist_, p. 48.
[39] _Contemporary Review_, September, 1893.
Darwin's Gemmule Theory is the same guessing; and Weismann rejects it
because he did not think of it first. As a theory the gemmule plot
is just as good and just as bad scientifically as Weismann's. The
chief objection to such imagining is that after its authors have put
it into print a few times they lose all sense of humor, and mistake
phantasms for facts.
Up to the present time we have discovered no living organism lower in
grade than the cell. If life ever originated from inorganic matter,
it appeared in an organized cell. The Weismann ids, biophors, and
the rest, supposing they existed outside his own imagination, are
not more capable of independent life than is a chromatin granule. In
any event, these biophors could not have originated spontaneously
in the first living being; and if they could not so have come into
existence, life could never have begun. However primitive any
organism is, it must be able to nourish itself and to develop into
a higher specific form; but such a variety of functions supposes
differentiated structure, composed of unstable chemical substances,
a correlation of parts, a purposeful anticipation of ends. Inorganic
substances, crystals, and the like are characteristically stable,
not unstable; and these could not have been brought into the organic
state on an earth burnt to a cinder and devoid of chlorophyl, which
itself presupposes organic cells. Whence came also the absolutely
essential form of energy, directive of vegetative life? The only
possible explanation is that life was created, not evolved by a
stranger miracle from a lump of lava.
We know the successive steps in the growth of the embryo from the
time of fertilization to the end of gestation, but how this vital
process is effected is not so evident. What we are certain of is
that there is a vital principle of some kind from the beginning,
and this is the matter of real importance in the present discussion.
The old moralists held that this principle in the human being is
at first vegetative; after a while that vegetative vital principle
is expelled by a sensitive principle; and finally this sensitive
soul is expelled by the rational vital principle, or human soul.
St. Thomas[40] says: "Some tell us the vital acts that appear in
the embyro are not from its soul, but from the soul of the mother,
or from the primitive force in the semen. Both these statements are
false. Vital operations, as sensation, nutrition, growth, cannot come
from an extrinsic principle; therefore it must be admitted that a
soul preëxisted in the embryo, nutritive at first, then sensitive,
and finally intellectual." After showing that an intellectual soul
cannot be evolved from lower forms, he concludes: "Therefore we say
that since the generation of one thing is always the corruption of
another, in man as in other animals, when a more perfect form comes
in this supposes the corruption of any precedent form; so, however,
that the sequent form has all perfection that was in the destroyed
forms, and something in addition: and thus through many generations
and corruptions the final substantial form is attained in man and
other animals. This is apparent to the senses in animals generated
from putrefaction. Therefore the intellectual soul is created by God
at the end of human generation, and this soul is both sensitive and
nutritive, all precedent forms having been destroyed."
[40] I, q. 118, a. 2, ad 2.
There is no such thing as the generation of any animal or other
living being from putrefaction; but that is irrelevant. St. Thomas's
argument proves conclusively that _if_ man has first a merely
vegetative soul, and secondly a merely sensitive soul, which includes
the power of the vegetative soul, and thirdly an intellectual soul,
which does the work of all three, that this final intellectual
soul is not an evolution of the first two, but a new form that
replaces these after they have served their purpose and have been
annihilated. It does not even attempt to prove that man really has
first a merely vegetative soul, and secondly a sensitive, and lastly
an intellectual soul; it supposes all this. It starts out with the
erroneous Aristotelian theory and takes it for granted. The reason
for this statement is that the rational substantial form requires
disposed matter to work upon, and the Thomists suppose (again
erroneously) that in the human embryo during the period immediately
after conception there is not enough matter to be a receptacle for
the rational soul.
The soul according to the Thomists, who use the Aristotelian
definition, is the first entelechy of a natural organic body that has
life in potency.[41] It is the determination that gives the body its
specific and substantial being; the primal actuation of a body or
matter, since only in matter is there a distinction between potency
for substantial being and substantial actuality. An entelechy is a
realization, actuality, full perfection; sight, for example, is the
entelechy of the eye. This body is natural, not merely instrumental;
it is energized by an immanent principle, not moved by an external
force like a tool. The body is also organic; it must have organs,
faculties, parts destined to perform definite functions. To say the
entelechy has life in potency means that since life, or the operation
of the soul, is an immanent act, there must be a receptacle within
which it can be immanent, and the soul is the primal actualization
of that organic body, which is in potency to produce those immanent
actions in which life consists. A body might be in potency while it
still has no principle of operation, or, secondly, while it has such
a principle but is not using it. In the second condition the human
body is in potency for life at the moment of actualization.
[41] ἡ ψυχή ἐστιν ἐντελέχεια ἡ πρώτη σώματος ψυσικοῦ ὀργανικοῦ
δυνάμει ζωὴν ἔχοντοσ (_De Anima_, ii, 1).
A form fixes a thing in its prχοντοσoper species, and the rational
soul is such a form for the human body. This substantial form is the
completion, perfection, in operability and existence, of the matter
that receives it. It is the formal cause of man, not the efficient
cause, although it is the efficient cause of subsequent vital
operations. An efficient cause makes something numerically different
from itself by its own real and physical action; a formal cause and
a material cause do not make anything different from themselves
numerically, but they intrinsically constitute the effect--they are
intrinsic causes.
The human soul as the substantial form virtually contains vegetative
and sensory faculties, and through these lower organic capacities it
informs and animates the body. That form, together with the matter,
the body, does the vital acts of the composite human nature. The
rational soul enters the body at the beginning, and first uses its
vegetative faculty until the fetus is far enough advanced to be a
subject for the action of the sensory faculty of the soul. Later,
some time after the birth of the child, when the body is sufficiently
formed, the intellectual faculty comes into use.
The nature of a vital principle is that in which it normally
issues. If it issues as a rational substantial form, as in man, it
was rational from the beginning. If it was not rational from the
beginning, a rational principle replaced a sensory vital principle,
and that sensory vital principle replaced a vegetative vital
principle. The only reason for these replacements would be that the
early human embryo, as has been said, lacks organization sufficient
to sustain a form higher than a vegetative principle. If this were
sufficient reason for deferring the advent of the rational soul, then
a baby six months after birth would have no rational soul because
it certainly lacks the supposedly requisite organs. However, as the
rational soul is whole in each part of the adult body in the totality
of its essence and perfection, but not in the totality of its virtue,
because certain organs are lacking in particular parts of the
body, it is in the embryo whole in the totality of its essence and
perfection, but not in its virtue because certain organs are not yet
formed, and it is thus from the moment of conception.
As to the soul itself, Kant held that the soul is not a real, but
only a logical substance. The Pantheists, Transcendentalists, and
Neo-Hegelians try to identify the soul with the divine consciousness.
The Associationists (Hume, Davis, Höffding, Sully) say that the soul
is a mere group of sensations. The Agnostics and Positivists (Locke,
Herbert Spencer, James, Comte) write volume after volume on the
soul to prove that they know nothing about it. Then the Materialists
assert that there is no soul of any kind; that we secrete thought
as a mule secretes sweat. Yet the vital operations of man are
inexplicable as resultants of the physical and chemical properties
of matter. There is an intrinsic energy that unifies the actions
of man, directs processes, controls the tendency of organic matter
to pass into the fixity of the inorganic, and effects metabolism.
This intrinsic energy is the entelechy, substantial form, or what is
popularly called the soul.
In any organic body there is a formal principle. We know that there
are activities that proceed from organic bodies, and a formal
principle of such activity is a substantial entity whence the
organism derives basically its own kind of action, which determines
and orders the activity. There are acts of perception in animals
such that an external object becomes so internal to the organism of
these animals that it is known by one expressed and immanent image,
not only as something objectively existing but as good or hurtful to
the perceiving animal. The innate and elicited appetites by which
the animal tends toward or away from the object are recognized, as
are the spontaneous motions which are directed by that knowledge.
There must be a principle whence these actions proceed, and this is
either an accident of matter or something substantial. It is not an
accident of matter, because action can never arise from an accident;
it must proceed from a substance. If you say this principle whence
these actions arise is not an accident of matter, but matter itself,
you would have an extended, composite, inert mass acting; but even if
such thing could act, it could never effect a simple immanent image
of an object or group of objects external to itself.
No mere machine can build up itself, can make any remote approach
to metabolism as an organized body can; and the principle of this
immanent action is not matter itself, because it uses, makes,
subordinates matter to itself. That principle is positively one, not
one by continuity as matter is. Matter as in a crystal grows by mere
aggregation, an organism grows by assimilation; a crystal loses
force in formation and growth, an organism accumulates force.
The theory that denies the existence of this formal principle does
not explain the phenomena of life in organic beings. Uniformity
of tendency toward an end is not a characteristic of mere matter;
neither is a harmonious interaction of parts, nor the dependence of
parts on the unit, nor motion, nor the reproduction of the species.
Moreover, most of the greatest physical scientists strongly maintain
that there must be a formal substantial principle in all living
things. Among these are Wallace, Nägeli, Askenasy, Preyer, Fechner,
Agassiz, von Baer, E. de Beaumont, Blanchard, A. Braun, Brongniart,
Bronn, Burmeister, Delff, Milne-Edwardes, Flourens, Goeppert,
Griesbach, Heer, Koelliker, Mivart, Quatrefages, Quenstedt, Spiers,
Volger, R. Wagner, Liebig, and Joseph Hyrtl.
The formal principle which coexists with matter in the organic
body is really though not perfectly distinguished from matter. A
formal principle which is necessary for sensation should be either
perfectly simple, or at the least so one that its parts together
make up one essence: matter, however, cannot have such unity, and
as a consequence the formal principle must be distinct from matter.
Anything is like its operation, and the parts of any sensitive
activity always result in an activity that is essentially one. If we
touch a table, by that single touch we at once know that the object
is one, wooden, hard, angular, smooth, extended, and so on, and we
also know that one subject perceives all these varied qualities.
One eye can convey knowledge at once of a thousand objects miles
apart, and these objects can be brought into one perception only by a
simple subject. An extended complex subject like matter would get one
impression (if it could perceive any impression) on one side, one on
another, and so on, but it could not unite these.
The formal principle which is in organic bodies is a true substantial
form, actuating the body both as to its nature and substance.
Together with the body, this principle makes a being one in itself,
such that the matter and the form separably are incomplete as
regards operation and being. Now, a form is that principle through
which anything is established in its own species; light, for example,
is the form of a luminous body, heat of a hot substance. A body,
however, is established in the human species by receiving a rational
soul, and this soul, then, is its form. It is also a substantial form
because the soul itself is a substance, not an accident dependent
upon another subject. Moreover, from its union with the body another
substance--man--arises, and not a thing added to a substance. Man's
body is alive, therefore it is a living substance; but life in its
secondary actuality is an operation; in its primary actuality it is
an essence. The body is made a living substance, not from itself, but
from the soul which is added to it. When the soul departs the body is
no longer alive. Now, a principle which by a communication of itself
determines the body in its essence and differentiates it as a living
substance from everything else, is a substantial form. A substantial
form, then, or a soul, exists.
The soul, however, must have disposed matter for most of its
operations; it cannot exist as a substantial form _bombinans in
vacuo_; but it does not need a human organism complete in all its
parts as a necessary condition for its indwelling. There is organized
matter enough in the first cell that comes into existence after the
fusion of the germ-nuclei to hold this rational form, or soul, as
perfectly as it needs to be held in this first stage of human life.
To inform the embryo any principle, whether it is the rational soul
or a force derived from the parental organism, must have organs; and
if organs are present, then the embryo is fit to receive the human
soul, as the only objection to its presence is a supposed lack of
organs. To use other principles when the human soul itself could be
present would be a _multiplicatio entium sine necessitate_, which is
a condition repugnant to the universal method of the Creator.
It has been said that the vital activity in the fertilized ovum does
not proceed from the rational soul because, "in the first place, it
results from the fusion of two vital activities, neither of which is
rational; secondly, it results in the formation, by fission, and
differentiation, of two distinct and separate living cells, each
containing within itself a principle of vital activity. Now this
principle of vital activity cannot be a rational soul, for each cell
has its own principle of activity, and in man there is but one soul."
In the first place, that vital activity does _not_ result from the
fusion of two vital activities neither of which is rational. It
results _after_ the nuclei come together, by particular creation,
and replaces their activity--the generation of the last vital force
is the corruption of the first that existed in the separate nuclei,
not a derivative of that first force. Again, when the embryo is
in the two, four, eight cell stage, and so on, there are not two,
four, eight vital principles present, but one. Substantial unity is
essential to life of any kind, no matter how low its grade; and if
each cell had an independent vital principle, any form of resultant
life in the mass would be impossible. An aggregation has no unity of
substance; there would be as many substances or natures as there are
individual beings in the aggregate, no matter whether ordered or in a
mob, consequently no life at all as a life.
The embryo in the two-cell stage is not made up of two independent
organisms, any more than the right and left halves of an adult man
are two independent organisms. The cells in the two-cell stage
of the embryo are the right and left halves of the body, not two
individuals, as has been proved repeatedly by biologists. Roux[42]
punctured with a hot needle one of the cells in the two-cell stage
of a frog embryo without killing the embryo, and it grew into a
half-frog larva. Analogous results were obtained by operating in
the four-cell stage. Later, Pflüger, Schultze, Enders, and Morgan
corroborated the work of Roux. Newport[43] discovered this fact sixty
years ago.
[42] Virchow's Archiv (1888), 114.
[43] _Phil. Trans._, 1854.
In analyzing the structure and functions of the individual cell we
regard it as an independent elementary organic unit, but this view is
solely a matter of convenience, almost a convention. All the billions
of cell's in an adult man are inseparable parts of the single living
person. No cell exists as an independent organism in multicellular
animals, except the germ-cells, and these only after separation from
the gland of origin. Indeed, the biological theory of heredity,
already mentioned here, wherein the germ-cell is supposed to carry
forward the entire heredity, is now changing toward the view which
makes all the somatic cells influence the germ-cells; that is, the
body-mass of cells sends on heredity through the germ-cell as the
instrument. Adult organisms do not make cells _de novo_. New cells
are formed by division from preëxisting cells, but some biologists
think the body-cells so affect the new germ-cells as to influence
heredity.
The cells are organs, nodal points, of a single formative power
which pervades the mass of cells as a whole. The protoplasm of each
cell is not only in direct apposition with its neighbors, but nearly
all biologists are now inclining to the opinion, which Heitzmann
proposed in 1873, that division of cell from cell is incomplete
in nearly all forms of tissue; and that even where cell-walls are
present (an exceptional condition in mammals) they are traversed by
strands of protoplasm, by means of which the cells are in organic
continuity. The whole body, he contended, is thus a syncytium (a
mass of continuous protoplasm stippled with nuclei), with the cells
as mere nodal points in an almost homogeneous protoplasmic mass.
There are cell-bridges between the sieve-tubes of plants. In 1879
Tangl discovered such connection between the endosperm cells of
plants, and later Gardiner, Kienitz-Gerloff, A. Meyer, and many
others demonstrated that in nearly all plant tissues the cell-walls
are connected by intracellular bridges. Ranvier, Bizzozero, Retzius,
Fleming, Pfitzner, and many other observers have found these
protoplasmic bridges in animal epithelium. In the skin of a larval
salamander they are quite conspicuous. They are known to occur also
in smooth muscle-fibre, in cartilage cells, in connective-tissue
cells, and in some nerve-cells. Harrison found, in 1908, that in
frogs the nerve-fibres develop out of these intracellular bridges.
Dendy in 1888, Retzius in 1889, and Palladino in 1890 have shown
that the follicle cells of the ovary are connected by protoplasmic
bridges, not only with one another, but also with the ovum; and
similar connection between somatic cells and germ-cells has been
found in a number of plants. Thus even the germ-cell is not
independent until it has actually broken away from the gland. A.
Meyer holds that both the plant and animal individual are continuous
masses of protoplasm, in which the cytoplasmic substance forms a
morphological unit, no matter what the cell is. That opinion is
not finally settled as regards the animal after the fetal stage,
but it is much stronger as regards embryos. In the early stages of
many arthropods it is certain that the whole embryo is at first
an unmistakable syncytium. This is almost established also for
Amphioxus, the Echinoderm Volvox, and other animals. Adam Sedgwick
holds that it is true for vertebrates up to a late embryonic stage.
Mitosis, then, is a form of growth of a mass, not a generation of new
individuals.
Whether chromatin or any other element in the germ-cell be the
idioplasm in which heredity inheres, differentiation is a progressive
transformation, through physical and chemical changes, of the
substance of the ovum, and this transformation occurs in a definite
order and a definite distribution in the ovum. The changes result in
a cleavage of the egg into cells, the boundaries of which sharply
mark the areas of differentiation. These cells take on specific
characters. In the four-celled stage of an annelid egg these four
cells contribute equally to the formation of the alimentary canal
and the cephalic nervous system, but only one of them, the left-hand
posterior cell, gives rise to the nervous system of the trunk and to
the muscles, connective tissues, and germ-cells. The relation between
the four original cells, or blastomeres, and the adult parts arising
from them, is not fixed, because in some eggs these relations may
be artificially changed. A portion of the egg which normally would
develop into a fragment of the body will, if split off from the
others, give rise to an entire body of a diminished size.
Conklin says[44] that in the ascidian Styela "there are four or
five substances in the egg which differ in color, so that their
distribution to different regions of the egg and to different
cleavage cells may be easily followed, and even photographed, while
in the living condition. The peripheral layer of protoplasm is yellow
and it gathers at the lower pole of the egg, where the sperm enters,
forming a yellow cap. This yellow substance then moves, following the
sperm nucleus, up to the equator of the egg on the posterior side,
and there forms a yellow crescent extending around the posterior side
of the egg. On the anterior side of the egg a gray crescent is formed
in a somewhat similar manner, and at the lower pole between these two
crescents is a slate-blue substance, while at the upper pole is an
area of colorless protoplasm. The yellow crescent goes into cleavage
cells which become muscle and mesoderm, the gray crescent into cells
which become nervous system and notochord, the slate-blue substance
into endoderm cells, and the colorless substance into ectoderm cells.
Thus within a few minutes after the fertilization of the egg, and
before or immediately after the first cleavage, the anterior and
posterior, dorsal and ventral, right and left poles are clearly
distinguishable, and the substances which will give rise to ectoderm,
endoderm, mesoderm, muscles, notochord, and nervous system are
plainly visible in their characteristic positions." Conklin followed
these cells in every division until the embryo was developed, making
a complete genealogy up to the ovum proper.
[44] _Heredity and Environment_, p. 123, Oxford Press.
De Vries[45] assumed that the character of each cell is determined
by "Pangens" that migrate from the nucleus into the protoplasm.
Driesch and Oscar Hertwig held that the peculiar development of a
given blastomere is a result of its relation to the remainder of the
cell-mass, an outcome of the action upon it by the whole system of
cells of which it is a part. Hertwig said:[46] "Each of the first
two blastomeres contains the formative and differentiating forces
not simply for the production of a half-body, but for the entire
organism; the left blastomere develops into the left half of the
body only because it is placed in relation to a right blastomere."
Wilson[47] and Driesch[48] came to the same conclusion about the
time Hertwig wrote. Driesch said:[49] "The relative position of a
blastomere in the whole determines in general what develops from it;
if its position be changed it gives rise to something different; in
other words, its prospective value is a function of its position."
[45] _Intracelluläre Pangenesis._ Jena, 1889.
[46] _Jenaische Zeitschrift_, 1892, 1.
[47] _Journal of Morphology_, 1893, 1894.
[48] _Studien_, iv, p. 25.
[49] _Ibid._, p. 39.
A discussion of this matter will be found in Wilson,[50] but the many
experiments made in the study of this subject show conclusively that
the cells, singly, grouped, and in mass, are a morphological unit,
not an aggregation of distinct individuals. They are not, of course,
absolutely homogeneous, because such a body could not have organs.
The substantial form, therefore, is not confined to the first cell.
[50] _The Cell in Development and Inheritance_, pp. 413 _et seq._
New York, 1906.
The cell-mass, then, has a unity sufficient to be the receptacle of
a human vital principle; again, the basic vital operation of the
human body at any age is metabolism, and this is actually carried on
in the first somatic cell of the embryo as in the cells of the adult
man. In the development of the human body in the embryonal stage
the energy of cell-division is most intense in the early cleavage
stage, and this diminishes as the limit of growth approaches because
further division is not needed. When that limit is attained a more
or less definite equilibrium is established. Some of the cells in
the fully formed body cease to divide, the nerve-cells, for example;
others divide under special conditions, as the blood-cells, the
connective-tissue cells, gland-cells, epithelial and muscle cells;
others continue to divide throughout life and thus replace worn-out
cells of the same tissue, as the Malpighian layer of the skin.
Cells grow, divide, function, reproduce themselves, and so on, all
through their vital activity, sustained by the material brought to
them by the blood. Weismann[51] and other biologists think that the
vital processes of the higher animals are accompanied by a renewal
of the morphological elements in most tissues. The material is
carried to the fetus in the womb by various agents, but mostly by the
maternal blood after the embryo uses up the yolk; and when the fetal
circulation has been established the nutritive material is taken from
the maternal blood into the fetal circulation through the placenta,
and then carried to the cells by the fetal circulation itself. After
the child has been born the stomach and intestines take in the food.
The stomach does very little with it except in a preparatory manner;
the intestines further prepare it, pass it into the body, where it
is again modified by other organs, and finally it is carried by the
blood to the cells. The cells really use it; the other organs are
the farmers, grocers, railways, and the like; the cells are the
consumers. So far as the essential processes are concerned, the
embryological cells act as do the adult cells.
[51] _The Duration of Life._
The first cell has contractility, protoplasmic motion; it can absorb
perfectly all food-stuffs necessary for it from the deutoplasm of
the ovum, and the water that passes in from without to the ovum. In
a few days the embryonic cells have used up the deutoplasm and are
taking up food from the maternal blood as perfectly as any adult cell
does, and are exercising their function of building up and sustaining
whatever part of the body they are destined for; and this with all
the complicated metabolism of the adult cell. Cell metabolism is the
fundamental, chief, organic act of any human body at any age. That
the embryo does this impelled by the _virtus formativa_ transmitted
from the parents is a mere gratuitous assumption to fit the theory
that the embryonic cell lacks organic power. The fundamental organ
that conserves the body in its very existence under the government
of the soul is the apparatus which effects metabolism. Incessant
chemico-vital change is a characteristic of all living substances,
from the single cell up to the adult man; and in all cases this
activity has to do with a transformation of the complex molecules
which build up the protoplasm or are associated with its operations.
The totality of the chemical changes, or exchanges, in living cells,
the transformation of unorganized food materials so that these may be
assimilated, and the chemical processes in the tissues themselves,
all are metabolism. Growth and repair (anabolism) occur side by side
with the destruction of elementary tissue substance (katabolism),
and the duration of life rests on these processes; and all are mere
cell activities. Food-stuffs (water, inorganic salts, proteids,
albuminoids, carbohydrates, and fats) undergo more or less combustion
or oxidation. Oxygen unites with carbon to form carbon dioxide, and
with hydrogen to form water; the nitrogen of the highly complex
proteid substances reappears in combination with carbon, hydrogen,
and oxygen as urea, uric acid, and other compounds; and other ingesta
are thus transformed through oxidation. All maintain the temperature
of the body, replace outworn parts, and accomplish the body's work.
Oxidation occurs to a slight extent in the blood, but the specific
reactions are intracellular. Even when nothing exists but the cells
and the blood, as in the beginning embryo, the cells really do the
work, and they do the work as they do in the adult.
The cells also from the very beginning are the organs that make the
animal heat necessary for life. Rubner[52] proved that the source of
at least 90 per cent. of the animal heat in the body is a result of
the chemical changes--oxidation--in the food ingested: the other 10
per cent. is caused by muscular contractions, the flow of blood, the
friction of joints, and like motions. This oxidation is more active
in young animals than in adults, and in each it is, of course, a
cellular process.
[52] _Zeitschrift f. Biologie_, 1893, bd. 30, p. 73.
Living matter contains hydrogen, oxygen, sulphur, chlorine, iodine,
fluorine, nitrogen, phosphorus, carbon, silicon, potassium,
sodium, calcium, magnesium, and iron. The removal of one of these
elements causes the death of the body. They must be arranged in a
definite, prescribed order to constitute cellular protoplasm, and
any disarrangement of this order causes intoxication, disease,
or death. Hydrogen is a constant product in the putrefaction of
animal matter, of animal food, and is present in the intestinal
tract. Oxygen is found dissolved in water and loosely combined in
blood as oxyhemoglobin. All the elements, except fluorine, combine
with oxygen, forming oxides, and the process is called oxidation.
The production of heat and all vital motion depend on oxidation,
decomposition of matter. In the nuclei of cells there is a so-called
"oxygen-carrier," a nucleo-proteid, which contains iron, and this
appears to be the chief oxidizing agent in the body. Chlorine, which
in hydrochloric acid is essential to digestion, is ingested as
chloride, and leaves the body chiefly through the urine and sweat.
Iodine is a necessary part of the thyroid gland, an indispensable
vital organ. Fluorine is found in all cells. Nitrogen goes into the
body combined in proteids; and phosphorus, combined in the alkalies
and alkaline earths of the foods. Carbon occurs in all cells and
leaves them through the lungs as carbon dioxide.
The amount of energy set in action in the body in the decomposition
of any food is equal to the energy that had been expended in the
synthesis of that food from its organic elements, and the liberated
energy set free in the body appears as heat, work, and nervous
impulse. In a plant the chlorophyl and the sun's rays combine water
and the carbon dioxide of the air into sugar and free oxygen. This
sugar is changed in a plant into starch, cellulose, and fat, and
also, when combined with some nitrogen, into proteid. An animal eats
this plant, which contains starch, cellulose, fat, and proteid, and
it either adds these ingredients to its own substance or oxidizes
them so as to prevent the destruction of its own substance. These are
the ends of all food. Broadly speaking, plants synthesize elements;
animals analyze them, reduce them into simpler bodies.
Such processes, and those of the other elements of the body, which
have to do with the changing constituents of the human organism,
are all cellular processes--metabolism. Hence the chief organic
act of the body is metabolic; the basic organ of man is the cell.
Arms, legs, heart, brain, stomach, and similar organs are secondary,
though some of the latter are essential for certain operations. Now,
one cell is an organ amply sufficient for metabolism, for the chief
organic act of the body; hence it is a fitting receptacle for a
substantial form, a soul. Therefore there is no reason why the soul
may not be present in the one-cell stage of the embryo; and since
there is no reason why it should not be present, but many why it
should, it is present.
Conklin says:[53] "The fertilized egg of a star-fish, or frog, or
man is not a different individual from the adult form into which it
develops, rather it is a star-fish, a frog, or a human being in the
one-celled stage. This fertilized egg fuses with no other cells,
it takes into itself no living substance, but manufactures its own
protoplasm from food substances; it receives food and oxygen from
without and it gives out carbonic acid and other waste products;
it is sensitive to certain alterations in the environment, such
as thermal, chemical, and electrical changes--it is, in short, a
distinct living thing, an individuality. Under proper environmental
conditions this fertilized egg-cell develops, step by step, without
the addition of anything from the outside except food, water, oxygen,
and such other raw materials as are necessary to the life of any
adult animal, into the immensely complex body of a star-fish, a frog,
or a man. At the same time, from the relatively simple reactions
and activities of the fertilized egg there develop, step by step,
without the addition of anything from without except raw materials
and environmental stimuli, the multifarious activities, reactions,
instincts, habits, and intelligence of the mature animal."
[53] _Heredity and Environment._
An objection to the opinion that the soul is in the embryo from
the beginning is made from a consideration of the facts that there
appears to be an aptitude for life in certain animal cells and
tissues after removal from the original host, or after the death
of the host; and, secondly, that in other separated tissues life
is undoubtedly made evident under proper conditions. Some parts of
the human body can be grafted upon another human body, and human
sarcomatous cells have been made to grow _in vitro_. Hair often
lengthens after the death of a person, if no embalming fluid has been
injected. Dr. Alexis Carrel[54] substituted a piece of a popliteal
artery, taken from an amputated human leg and kept in cold storage
for twenty-four days, for a part of the aorta of a small bitch,
and the dog lived for four years afterward and died in parturition.
Magitot of Paris, in 1911, took a piece of the cornea from an
extirpated human eye, and with it replaced a part of an opaque cornea
on another man, and this second man could see through the new cornea.
Surgeons now remove skin, bone, and other tissues from still-born
infants and accident cases, preserve these, for weeks if necessary,
in petrolate and Ringer's solution in cold storage, and then graft
them on patients to repair lesions in skin, bone, cartilage, or other
parts of the body.
[54] _Journal of the American Medical Association_, vol. lix, n.
7, p. 523.
If these separated tissues are alive, what is the origin and nature
of the life? Again, if there is a low form of life in these separated
tissues, remaining after the departure of the human soul, why could
not such a low form of life precede in the embryo the advent of the
human soul?
What is the nature of the "life" in the parasitic sarcomatous tissue
which has been seen to proliferate for a short time _in vitro_? We
do not know, nor is it relevant to the question. That there is life
of any kind in the cold-storage graft of bone and skin is certainly
not evident; rather every evidence points to the absence of all life.
When taken out of cold storage, and the ordinary forces which corrupt
a dead body are permitted to work, these grafts corrupt exactly as
any part of a corpse does. That there is life of any kind in these
grafts is a gratuitous assumption. In cold storage they are kept
ready for assimilation into the body as food may be kept. Bone and
skin grafting is merely a peculiar form of assimilation. Food taken
into the body through the stomach and entrails is prepared in the
body and assimilated into the substance of the bones or skin or other
tissues; the graft is ready for assimilation without this preparation
because it is already bone or skin.
The vital principle in a man, or in anything else, is at the end,
when it normally issues, of the same nature as it was in the
beginning. If it is at perfection a substantial primary form, it
always was such--a substantial form cannot issue from an accidental
form. If the substantial form is the form of the cells in the
completed organism, it was such before that organism was perfected,
unless it replaced a lower substantial form; but there is, we repeat,
absolutely no need for such a secondary form at the beginning. If
the cells of the embryo (not the infused germ-cells, which are
not the embryo) had a _forma corporeitatis_, or _cellularis_, or
whatever you wish to call it, the human soul when it did come would
not confer primal existence, would not be a _forma substantialis_,
but an accidental form. "In proof of which," says St. Thomas,[55]
"we must consider that a substantial form differs from an accidental
form in this, that an accidental form does not give being simply, but
such or such being; as heat does not give being simply, but heated
being. So when an accidental form comes in, a thing is not said to
come into existence or to be generated, simply, but to become such or
such an object, or to find itself in such or such a condition. So,
also, when an accidental form disappears, a thing is not said to be
destroyed simply, but only to a certain degree. A substantial form,
however, gives being simply; and therefore by its advent a thing is
said to be generated simply, and by its recession to be destroyed
simply. If, therefore, it happened that any substantial form other
than the intellectual soul preëxisted in matter, by which the subject
of that soul would come into actual being, it would follow that
the soul would not confer being simply, and therefore would not
be a substantial form; also that the coming of the soul would not
be a generation simply, but only _secundum quid_--all of which is
evidently false." Again, St. Thomas says:[56] "Some tell us the vital
acts that appear in the embryo are not from the soul, but from the
soul of the mother, or from the primitive force in the semen. Both
these statements are false."
[55] I, q. 76, corp.
[56] Ia, q. 118, a. 2, ad 2.
An application of the opinion offered here--that is, that the human
soul is infused at the instant of conception--to multiple and
monstrous embryos offers no real difficulty. There are two kinds of
human twins--those from two distinct ova and those from one ovum. Two
ova may come from one or different ovaries, or even from one Graafian
follicle, be fertilized at the same time and develop synchronously.
If the ova are placed at some distance apart in the uterus, two
placentas appear; if the ova are near each other the placentas may
fuse, but their circulations do not. Each child will have its own
fetal envelope.
In twins from two distinct ova there is no difficulty in seeing that
the souls are placed in these in the same manner as the soul is put
in the normal single embryo. When the twins come from one ovum the
condition is not so simple. The oval nucleus is the essential part
that goes from the maternal side, and human ova at times contain
two nuclei, as occasionally hens' eggs do; a double-yoked hen's egg
has two nuclei, and two nuclei have been found in a single yolk.
Kölliker, Stöckel, and von Franque have observed double germinal
vesicles in single human ova. In such a condition two spermatozoa
could fecundate the two nuclei and the development go on as in the
case of twins from distinct ova.
There is a theory which holds that homologous twins (uni-oval)
can develop from a single germinal vesicle which splits into two
primitive streaks and two gastrulas. According to this opinion, if
the germinal vesicle divide entirely, two fetuses develop which are
always of the same sex, and which resemble each other so closely in
appearance that it is very difficult to differentiate them. This
theory holds also that should the germinal vesicle not split fully,
the lack of fission causes the various kinds of double monsters. The
germinal vesicle that supposedly splits into two is not fecundated by
two spermatozoa, they say, because where there is only one nucleus in
the beginning, the entrance of a second spermatozoön commonly kills
the ovum. This last assertion has been disproved of late.
Some followers of the splitting theory hold that double monsters
arise from the union of two originally separate primitive traces
(_Verwachsungstheorie_). Others say that a single primitive trace
of blastoderm cleaves more or less thoroughly and makes the double
monster (_Spaltungstheorie_). The earliest human double monster
(Ahlfeld's case) was in the fourth week of gestation; therefore
whatever is held in these theories as regards human monsters is only
through analogy with lower animals.
Gerlach[57] saw bifurcation at the cephalic end of a chicken embryo
sixteen hours old. In this case the first change was a broadening of
the anterior end of the primitive streak; next a forked divergence
appeared, and by the twenty-sixth hour the bifurcation was half as
long as the undivided posterior part. Whether this was a case of two
nuclei or not is not known.
[57] _U. d. Entstchungsweise der vordern Verdoppelung. Deutsch.
Archiv. f. klin. Med._, 1887.
What seems to make for the fission theory is that in non-parasitic
double terata, no matter how unequally nourished or how variable in
extent, the union between the halves of double monsters is symmetric,
and the same part of each twin is joined. This fact is used as a
reason to exclude a fortuitous growing together of dissimilar areas
of cell-masses, at least in non-parasitic cases. Born,[58] in a study
of fish ova, found that eggs which produce double monsters begin
with a segmentation like that of the simple normal ovum. Composite
spermatozoa have been observed with two and three heads and one body
and tail-piece, but the significance of these abnormal cells is not
known.
[58a] _U. d. Furchung des Eies bei Doppelbildungen. Breslauer
Aertzliche Zeitschrift_, 1887.
Embryos of sea-urchins in the two-cell and four-cell stages can be
separated by shaking into isolated blastomeres, and the segments will
grow into full though dwarfed larvae. The same division with the
growth of dwarfed larvae has been made in Amphioxus, in the teleost
Fundulus, in Triton, in a number of Hydromedusae and several other
low forms of life. When the division is not made completely double
monsters result.
Up to a certain stage of development the blastomeres of the Medusa
embryo are totipotent, or capable of developing into any part of
the body. The limitation of development in a particular case lies
in the cytoplasm rather than in the nuclei of the cells. If frogs'
eggs are fastened in abnormal positions, inverted or on the side, a
rearrangement of the egg material results, wherein the nucleus and
cytoplasm rise and the deutoplasm sinks. This change of axis shifts
the embryo. If an egg is turned upside down in the two-cell stage,
a whole embryo, or half a double embryo, may arise from each of the
two blastomeres, instead of a normal half-embryo. A half-embryo or
a whole dwarf may arise according to the artificial position of the
blastomere. Each of the two blastomeres contains all the materials
potentially for the formation of the whole body, and these materials
build up a whole body or a half body according to the grouping they
take on. Primarily the egg cytoplasm, in low forms of animal life,
is totipotent; it has no fixed relation with the parts to which it
gives rise, and may be artificially modified or differentiated.
These effects, from position and traumatic dislocation, suggest
explanations for teratic forms in higher animals.
Human terata are now commonly classified in four groups: (1)
Hemiteratic; (2) Heterotaxic; (3) Hermaphroditic; and (4) Monstrous.
Hemiterata are giants, dwarfs, persons showing anomalies in shape,
color, closure of embryonal clefts, in absence or excess of digits,
or like defects. The Heterotaxic group are persons whose left or
right organs are reversed in position. A true Hermaphrodite would
have the complete reproductive organs of both sexes, but such an
individual has not been observed. There is never any question of
double personality in hermaphrodites.
Terata more properly so called may be single, double, or triple;
and single monsters may be autositic or independent of another
fetus, or they may be omphalositic, dependent upon another which is
commonly well developed and which supplies blood for both through
the umbilical vessels. There are four genera of autositic single
monsters, with eight species and thirty-four varieties. Of the
_monstra per defectum_ the commonest are caused by a failure of
closure in the embryonal medullary canal, which leaves part of
the brain and spinal cord or their bony covering lacking. Some
terata, as the Acephalia, have no brain or spinal cord, but they
die in the fetal stage. The Anencephalia may have a spinal cord, a
medulla oblongata, and parts of the basal ganglia, but the cerebral
hemispheres are wanting. Such monsters are sometimes born at term
and live for several days: they cry, suckle, show some reflexes and a
sense of pain, and move the arms and legs.
I described the various kinds of terata in _Essays in Pastoral
medicine_,[58b] and of these the most important in the matter under
discussion here are the double and triple monsters. Many of the
double monsters evidently were two persons. There is only one well
authenticated case of a triple human monster, and this happened in
Italy in 1831. It had a single broad body with three distinct heads
and two necks, and was killed in delivery. There is no proof as to
whether it was one or more persons. The standard of judgment in such
cases as regards the presence of one or two souls in the monster
is the evidence of one or more distinct consciousnesses. A monster
double from the navel or breast downward (_terata anadidyma_) is,
I think, one person. There was an example of a monster in this
group which was divided from the foreheads downward; or better,
the distinct twins were united by their foreheads only; but such a
form is very exceptional. In my article on "Human Terata and the
Sacraments," in _Essays in Pastoral Medicine_, in 1906, I expressed
the opinion that a monster which is single to the navel and double
below is composed of two persons, but I now am of the opinion that
such a monster is only one person, because there is apparently only
one consciousness. There are about eight cases of two-headed monsters
known which were evidently two persons in each case, and several
terata kata-anadidyma, divided above and below but joined at the
sternum, abdomen or sacrum. Several ischiopagic twins, joined at the
pelvis with the heads at the opposite ends of the double body, are
grouped with either the katadidyma or kata-anadidyma. It is commonly
not difficult to recognize individuality or duality of personality in
monsters, but it is not easy to explain the origin of life, to point
out the moment the _second_ soul enters these fused or undivided
twins.
[58b] Chap. vi, p. 69. New York, 1906.
We can artificially obtain double embryos of frogs by inverting
the blastomeres in the two-cell stage.[58c] We thus get united
twins with heads turned in opposite directions, twins united back
to back like the Blazek Sisters, twins united by their ventral
sides, and double-headed tadpoles, but we have no knowledge of
how similar doubling in human monsters takes place; we must guess
vaguely from analogy. There was one soul, at least, present from
the one-cell stage of the human monster; when the second soul
is created and infused we do not know, but the moment of the
creation of this second soul has no practical significance in
this discussion.
[58c] See Wilson, _op cit._., p. 421.
The presence of certain kinds of monsters in the uterus can
be diagnosed before labor, but double monsters are mistaken
for ordinary twins. A woman who has given birth to a monster
is likely to have subsequent monstrous fetuses. Where the
intrauterine existence of a single monster is suspected the X-ray
will at times clear up the diagnosis. Women gravid with monsters
commonly abort early in pregnancy, but even united twins may go
on to term. Those monsters that offer an obstacle to delivery
by the abnormal bulk of one or the other end are mostly twins
joined above or below the navel; those joined at the middle are
easier of delivery. Monsters that are joined at the pelves are
commonly in a straight line, and may not be difficult to deliver.
Most double monsters cannot be delivered alive except by cesarean
section, and the fact that the content of the uterus is monstrous
is, as a rule, not diagnosed until it is impossible to attempt
cesarean section without killing the mother through infection.
In such a condition the double monster would, in the ordinary
medical practice, be delivered by craniotomy, exenteration,
cleidotomy, or the like operation.
The _Rituale Romanum Pauli V_[59] gives the following directions
for the baptizing of human terata:
"18. In monstris vero baptizandis, si casus eveniat, magna
cautio, adhibenda est, de quo si opus fuerit, ordinarius loci,
vel alii periti consulantur, nisi mortis periculum immineat.
"19. Monstrum, quod humanam speciem non praeseferat baptizari non
debet; de quo si dubium fuerit, baptizatur sub hac conditione;
_Si tu es homo ego te baptizo_, etc.
"20. Illud vero, de quo dubium est, una ne, aut plures sint
personae non baptizetur, donee id discernatur: discerni autem
potest si habeat unum vel plura capita, unum vel plura pectora;
tune enim totidem erunt corda et animae, hominesque distincti, et
eo casu singuli seorsim sunt baptizandi, unicuique dicendo: _Ego
te baptizo_, etc. Si vero periculum mortis immineat, tempusque
non suppetat, ut singuli separatim baptizentur, poterit minister
singulorum capitibus aquam infundens omnes simul baptizari,
dicendo: _Ego vos baptizo in nomine Patris, et Filii, et Spiritus
Sancti_. Quam tamen formam in iis solum, et in aliis similibus
mortis periculis, ad plures simul baptizandos, et ubi tempus non
patitur, ut singuli separatim baptizentur, aliis nunquam, licet
adhibere.
"21. Quando vero non est certum in monstro duas esse personas, ut
quia duo capita et duo pectora non habet distincta; tune debet
primus unus absolute baptizari, et postea alter sub conditione,
hoc modo: _Si non es baptizatus, ego te baptizo in nomine Patris,
et Filii, et Spiritus Sancti_."
[59] Tit. ii, cap. 1, nn. 18, 19, 20, 21.
Any kind of monster coming from the human womb, if it is only a
head and lacks a body (Acardiacus Acormus), or is a body and lacks
a head and heart (Acardiacus Acephalus), or is a Foetus Anideus,
which is a shapeless mass of flesh covered with skin, should be
baptized, provided _it shows signs of life_. Number 19 in the Ritual
would be liable to an interpretation which is too narrow if it were
not that very monstrous fetuses, which appear to a lay observer to
be not human, are as a rule delivered dead. Here it may be worth
while to mention that a hybrid between a human being and a lower
animal is impossible. As to number 20, the rule for differentiating
unity or duality of personality is not the number of heads, but the
number of evident consciousnesses, and this differentiation commonly
cannot be made at birth. There have been examples of two-headed
monsters delivered alive, which were single as to soul because the
consciousness evidently was one.