skull-less animal lancelet, which is still living, affords a faint idea
of the members of this group (acrania). Since this little animal, in its
earliest embryonic state, entirely agrees with the ascidia, and in its
further development shows itself to be a true vertebrate animal, it forms
a direct transition from the vertebrata to the invertebrata.
[Illustration: FIG. I.--Appendicularia, seen from the left side, _m_,
mouth; _k_, gill intestine; _o_, oesophagus; _v_, stomach; _a_, anus;
_n_, nerve ganglia (upper throat-knots); _g_, ear vesicle; _f_, ciliated
groove under the gill; _h_, heart; _e_, ovary; _c_, notochord; _s_,
tail.--_Haeckel._]
[Illustration: FIG. II.--Represents Sack Worms (Himatega), and is the
structure of an Ascidian, seen from the left. _sb_, gill-sac; _v_,
stomach; _i_, large intestine; _c_, heart; _t_, testes; _vd_, seed duct;
_o_, ovary; _o'_, matured eggs in the body cavity. After
_Milne-Edwards_.]
[Illustration: FIG. III.--Represents the ACRANIA SERIES. Lancelet
(Amhioxus Lanceolatus), twice the actual size, seen from the left. _a_,
mouth-opening, surrounded by cilia; _b_, anal-opening; _c_,
ventral-opening (Porus abdominalis); _d_, gill-body; _e_, stomach; _f_,
liver-coecum; _g_, large intestine; _h_, coelum; _i_, notochord
(under it the aorta); _k_, arches of the aorta; _l_, main gill-artery;
_m_, swellings on its branches; _n_, hollow vein; _o_, intestinal
vein.--_Haeckel._]
[Illustration: FIG. I.--Represents the MONORHINA SERIES. Lamprey
(Petromyzon Americanus) from the Atlantic--_Orton._]
[Illustration: FIG. II.--Represents the Selachii. Shark (Carcharias
vulgaris) from the Atlantic--_Orton._]
[Illustration: FIG. III.--Represents the Mud-fish (Dipneusta).
Lepidosiren annecteus, one-fourth natural size; African
rivers.--_Orton._ Form a link between typical fishes and the
Amphibians.]
At this stage, most probably, the separation of the two sexes began. The
simpler and most ancient form of sexual propagation is through
double-sexed individuals (hermaphroditismus). It occurs in the great
majority of plants, but only in a minority of animals; for example, in
the garden-snails, leeches, earth-worms and many other worms. Every
single individual among hermaphrodites produces within itself materials
of both sexes--egg and sperm. In most of the higher plants every blossom
contains both the male organs (stamen and anther) and the female organs
(style and germ). Every garden-snail produces in one part of its sexual
gland eggs, and in another sperm. Many hermaphrodites can fructify
themselves; in others, however, copulation and reciprocal fructification
of both hermaphrodites are necessary for causing the development of the
eggs. This latter case is evidently a transition to sexual separation
(gonoehorismus).
Out of the members of the last group arose animals with skulls or
craniata, having round mouths, and which are divided into hags and
lampreys. The hags (myxinoides) have long cylindrical worm-like bodies.
The lampreys (petromyxontes) includes those well known "nine eyes"
common at the seaside.
These single-nostril animals (monorrhina) arose during the primordial
period out of the skull-less animals by the anterior end of the dorsal
marrow developing into the brain, and the anterior end of the dorsal
skull into the skull. By the division of the single nostril of the
members of the last group into two lateral halves, by the formation of a
sympathetic nervous system, a jaw skeleton, a swimming bladder and two
pairs of legs (breast fins or fore-legs, and ventral fins or
hind-legs), arose the primæval fish (selachii), which is best
represented by the still-living shark (squalacei).
Out of the primæval fish arose the mud-fish (dipneusta), which is very
imperfectly represented by the still-living salamander fish; the
primæval fish adapting itself to land, and by the transforming of the
swimming bladder into an air-breathing lung, and of the nasal cavity
(which was now open into the mouth cavity) into air-passages. Their
organization _might_, in some respect, be like the ceratodus and
proloptems; but this is not certain.
The dipneusta is an intermediate stage between the selachii and
amphibia. Out of the dipneusta arose the class of amphibia, having five
toes (the pentadactyla). The gill amphibians are man's most ancient
ancestors of the class amphibia. Besides possessing lungs as well as the
mud-fish, they retain throughout life regular gills like the
still-living proteus and axolotl. Most gilled batrachia live in North
America. The paddle-fins of the dipneusta changed into five-toed legs,
which were afterwards transmitted to the higher vertebrata up to man.
The gilled amphibia (sozobrachia) of the last group finally lost their
gills but retained their tail, and tailed amphibians (sozura) were
produced, such as the salamander and newt of the present day. Out of the
sozura originated the primæval amniota (protamnia) by the complete loss
of the gills by the formation of the amnion of the cochlea, and of the
round window in the auditory organ, and of the organ of tears. Out of
the protamnia originated the primary mammals (promammalia). The most
closely related were the ornithostoma; they differed through having
teeth in their jaws.
No fossil remains of the primary mammals have as yet been found,
although they lived during the trias period--they possessed a very
highly developed jaw. From the primary mammal arose the pouched animals
(marsupialia). Numerous representatives of this group still exist:
kangaroos, pouched rats and pouched dogs. The marsupial animals
developed, very probably, in the mesolithic epoch (during the Jura) out
of the cloacal animals; by the division of the cloaca into the rectum
and the urogenital sinus, by the formation of a nipple on the mammary
gland, and the partial suppression of the clavicles.
[Illustration: FIGS. I and II.--The Ceratodus Forsteri occur in the
swamps of Southern Australia. Form transition between fishes and
Amphibia.--_Haeckel._]
[Illustration: FIG. I.--Represents the Gilled Amphibians (Soyobranchia).
The Axolotl (Siredon pisciforme), after Tegetmeier. The ordinary form
with persistent branchiæ.]
[Illustration: FIG. II.--Proteus Anguinus. Europe.--_Orton._]
[Illustration: FIG. III.--Represents the Tailed Amphibians (Soyura).
Great Water-Newt (Triton cristatus), after _Bell._]
From the marsupialia originated a most interesting small group of
semi-apes (prosimiæ), for they are the primary forms of genuine apes and
consequently of man. They developed out of handed or ape-footed
marsupials (pedumana), of rat-like appearance, by the formation of a
placenta, the loss of the marsupium and the marsupial bones, and by the
higher development of the commissures of the brain. The still-living
short-footed semi-ape (brachytarsi), especially the muki, indie and
lori, possess possibly a faint resemblance.
Out of the semi-apes developed two classes of genuine apes; but as the
narrow-nosed or catarrhini class are the only ones related to man, the
others will not be considered. These narrow-nosed apes originated by the
transformation of the jaw, and by the claws on the toes changing into
nails. The still-living long-tail nose-apes and holy apes
(semnopithecus) probably resembled the oldest ancestors of this group.
The tailed apes by the loss of their tail and some of their hair
covering, and by the excessive development of that portion of their
brain above the facial portion of the skull, developed into the man-like
apes (anthropoides)--such as the gorilla and chimpanzee of Africa, and
the orang and gibbon of Asia. The human ancestors of this group existed
during the miocene period. From the anthropoides developed the ape-like
men (pithecanthropi) during the tertiary period. The speechless
primæval men (alali), then, is the connecting link between the man-like
apes and man. The fore-hand of the anthropoides became the human hand,
their hinder-hand a foot for walking. They did not possess the
articulate human language of words and the higher developments, as
consciousness and the formation of ideas must have been very imperfect.
Out of the pithecanthropi men developed genuine man, by the development
of the animal language of sounds into a connected or articulate language
of words--the brain also developed higher and higher. This transition
took place, probably, at the beginning of the quaternary period, or
possibly in the tertiary.
We have now very briefly reviewed the principal outlines of the
ancestors of man, showing that man has developed from the little mass of
protoplasm, as have all animals and plants. He therefore was not
_spontaneously_ created, but was developed. The question is often asked
by simple-minded people, with much delight, Why do we not behold the
interesting spectacle of the transformation of a chimpanzee into a man,
or conversely of a man by retrogression into an orang?--it only shows
that they are not acquainted with the first principles of the Doctrine
of Descent. "Not one of the apes," says Schmidt, "can revert to the
state of his primordial ancestors, except by retrogression--by which a
primordial condition is by no means attained--he cannot divest himself
of his acquired characters fixed by heredity, nor can he exceed himself
and become man; for man does not stand in the direct line of development
from the ape. The development of the anthropoid apes has taken a lateral
course from the nearest human progenitors, and man can as little be
transformed into a gorilla as a squirrel can be changed into a rat."
[Illustration: FIG. I.--Salamandra Maculata.--_Haeckel_. The Water Newts
and Salamanders were the next higher stage after the Proteus and the
Axolotl.]
[Illustration: FIG. I.--Represents Primæval Amniota (Protamnia). Lizard
(Lacerta), after _Orton_.]
[Illustration: FIG. II.--Represents Primary Mammals (Promammalia).
AMNIOTA SERIES. Duck-billed Platypus (Ornithorhynchus
paradoxus).--_Haeckel_.]
"Feeling evidently,"[17] says Haeckel, "rather than understanding,
induces most people to combat the theory of their 'descent from apes.'
It is simply because the organism of the ape appears a caricature of
man, a distorted likeness of ourselves in a not very attractive form;
because the customary æsthetic ideas and self-glorification of man are
touched by this in so sensitive a point, that most men shrink from
recognizing their descent from apes. It seems much pleasanter to be
descended from a more highly developed divine being, and hence, as is
well known, human vanity has from the earliest times flattered itself by
assuming the original descent of the race from gods or demi-gods."
EVOLUTION.
In the last chapter a description was given of the various stages in
man's development, from the microscopic monad up. It will be necessary
now to describe briefly the various laws which have governed this
evolutionary chain from the monad to man. But before proceeding directly
to the subject, let us look at the doctrine of evolution as a whole, and
trace it first in the formation of the world.
The doctrine of evolution is also called the theory of development--it
must not, however, be confused with Darwinism--for they are not exactly
synonymous. Darwinism is an attempt to explain the laws or manner of
evolution. Strictly speaking, only the theory of selection should be
called Darwinism, which was established in 1859. The theory of descent,
or transmutation theory, or doctrine of filiation, should properly be
called Lamarckism, who for the first time worked out the theory of
descent as an independent scientific theory of the first order, and as
the philosophical foundation of the whole science of biology.
"According to the theory of development (evolution) in its simplest
form," says Henry Hartshorne,[18] "the universe as it now exists is a
result of 'an immense series of changes,' related to and dependent upon
each other as successive steps, or rather growths, constituting a
progress; analogous to the unfolding or evolving of the parts of a
growing organism." Herbert Spencer defined evolution as consisting
in a progress from the homogeneous to the heterogeneous, from general to
special, from the simple to the complex; and this process is considered
to be traceable in the formation of worlds in space, in the
multiplication of the types and species of plants and animals on the
globe, in the origination and diversity of languages, literature, arts
and sciences, and in all changes of human institutions and society.
[Illustration: FIG. I.--Skeleton of Platypus.--_Haeckel._]
[Illustration: FIG. I.--Represents Pouched Animals (Marsupialia).
Kangaroo. (Popular Science Monthly, Feb., 1876.)]
Let us now apply this theory of evolution to the physical world. No
determined opposition by the mass of people is likely to be manifested
to the doctrine of evolution as applied to the physical world, or even
to the vegetable or animal world up to man; but the minute man is
included--then is a voice raised up against it, and it was for this
reason that Darwin in his first work on the "Theory of Descent" did not
mention man as being included in the evolutionary series. He knew too
well the foolish human weakness that existed.
In a recent work by Prof. Challes, he states that he regards the
material universe as "a vast and wonderful mechanism of which the least
wonderful thing is its being so constructed that we can understand it."
The following is a brief description of the various theories of the
world's formation:
_First Theory._--By the first theory the world is supposed to have
existed from eternity under its actual form. Aristotle embraced this
doctrine, and conceived the universe to be the eternal effect of an
eternal cause; maintaining that not only the heavens and the earth, but
all animate and inanimate beings, are without beginning. To use Huxley's
illustration: If you can imagine a spectator on the earth, however far
back in time, he would have seen a world "essentially similar, though
not perhaps in all its details, to that which now exists. The animals
which existed would be the ancestors of those which now exist, and like
them; the plants in like manner would be such as we have now, and like
them; and the supposition is that, at however distant a period of time
you place your observer, he would still find mountains, lands, and
waters, with animal and vegetable products flourishing upon them and
sporting in them just as he finds now." This theory being perfectly
inconsistent with facts, had to be abandoned.
_Second Theory._--The second theory considers the universe eternal, but
not its form. This was the system of Epicurus and most of the ancient
philosophers and poets, who imagined the world either to be produced by
fortuitous concourse of atoms existing from all eternity, or to have
sprung out of the chaotic form which preceded its present state.
_Third Theory._--By this theory the matter and form of the earth is
ascribed to the direct agency of a spiritual cause. It is needless to
say that this last theory has for its basis the popular account,
generally credited to Moses in the first chapter of Genesis. I say
popular, for it certainly is not a scientific account, nor was it the
intention of the writer to make it so. The supposed object was to show
the relation between the Creator and his works. If it had been an
ultimate scientific account, the ablest minds of to-day would be unable
to comprehend it, as science is progressive and constantly changing; in
fifty thousand years to come, it would still appear utterly absurd. It
cannot be said for this fact that the account is any the less true
because it is not presented in scientific phraseology; for instance,
when we remark in popular language "the sun rises," who shall say that
though the expression is not astronomically true, we do not, for all
practical purposes, utter as important a truth, as when we say, "The
earth by its revolution brings us to that point where the sun becomes
visible?" The language, also, in which the writer wrote was very
imperfect; it had no equivalent to our word "air" or "atmosphere,"
properly speaking, for they knew not the words. "Their nearest
approaches," according to J. Pye Smith, "were with words that denoted
watery vapor condensed, and thus rendered visible, whether floating
around them or seen in the breathing of animals; and words for smoke
from substances burning; and for air in motion, wind, a zephyr whisper
or a storm." It must also be remembered, "that the Hebrews had no term
for the abstract ideas which we express by 'fluid' or 'matter.' If the
writer had designed to express the idea, 'In the beginning God created
_matter_,' he could not have found words to serve his purpose" (Phin).
[Illustration: FIG. I.--Skeleton of Kangaroo. (Popular Science
Monthly.)]
[Illustration: FIG. I.--Represents Semi-Apes (Prosimiæ). The Slow Loris,
after _Tickel_ and _Alp. Miln-Edwards_. (Natural History, by _Duncan_.)]
It is unnecessary to state how the Bible, which contains the so-called
Mosaic account, is regarded by the different church denominations, as
undoubtedly that is familiar to every one. But with respect to the view
entertained by the scientist and critical school of Biblical scholars,
represented chiefly by modern Germans, I may state briefly: "They regard
the Bible as the human record of a divine revelation; not absolutely
infallible, since there is no book written in any human language but
must partake in a measure of the imperfections of that language. Many of
this school, while admitting the Bible to contain the record of a true
supernatural revelation, do not consider it to be without positive error
of historical fact, not without false coloring from popular legend and
tradition, but nevertheless a record as good as human hands could make a
truly divine revelation."[19]
There is, though, a class of thinkers that altogether reject the Bible;
that is to say, refuse to believe it to be a divine revelation. Hume,
whom Huxley calls "the most acute thinker of the eighteenth century,"
thus ends one of his essays: "If we take in hand any volume of divinity
or school metaphysics, for instance, let us ask, _Does it contain any
abstract reasoning concerning quantity or number?_ No. _Does it contain
any experimental reasoning concerning matter of fact and existence?_ No.
Commit it, then, to the flames, for it can contain nothing but sophistry
and illusion." To this Huxley says: "Permit me to enforce this wise
advice, Why trouble ourselves about matters of which, however important
they may be, we do know nothing, and can know nothing? We live in a
world which is full of misery and ignorance, and the plain duty of each
and all of us is to try to make the little corner he can influence
somewhat less miserable and somewhat less ignorant than it was before he
entered it. To do this effectually, it is necessary to be fully
possessed of only two beliefs: the first, that the order of nature is
ascertainable by our faculties to an extent which is practically
unlimited; the second, that our volitions count for something as a
condition of the course of events. Each of these beliefs can be verified
experimentally, as often as we like to try. Each, therefore, stands upon
the strongest foundation upon which any belief can rest, and forms one
of our highest truths."
The first words in the Mosaic account are:[20] "In the beginning God
created the heaven and the earth."[21] It is seen, then, that the
so-called revelation points to a beginning. The beginning referred to is
an absolute beginning, for we find: "In the beginning was the Word, and
the Word was with God, and the Word was God."[22] * * * "All things were
made by Him; and without Him was not anything made that was made."[23]
Science points also to a beginning.
Geology points to a time when man did not inhabit the earth; when for
him there was a beginning. So, too, for lower organisms; so, too, for
the rocky minerals; so, too, for the round world itself. But the
beginning that science points to is not an absolute beginning. Science
has to start from some point, and that point must have a scientific
foundation--the foundation of science is matter, which is inseparable
from form and force. Natural science teaches that matter is eternal and
imperishable; for experience has never shown us that even the smallest
particle of matter has come into existence or passed away. "A
naturalist," says Haeckel, "can no more imagine the coming into
existence of matter than he can imagine its disappearance, and he
therefore looks upon the existing quantity of matter in the universe as
a given fact." "The creation of matter, if, indeed," says Haeckel,[24]
"it ever took place, is completely beyond human comprehension, and can
therefore never become a subject of scientific inquiry. We can as little
imagine a _first beginning_ of the eternal phenomena of the motion of
the universe as of its final end."[25] It is evident, then, that the
absolute beginning of the universe and its absolute end are not
questions of science, and can be known only as revealed by faith. Paul
says: "By faith we understand that the world was framed by the word of
God, so that things which are seen were not made of things which
appeared."[26]
[Illustration: FIG. I.--Represents Tailed Apes (Menocerca). Proboscis
Monkey (Presbytes larvatus). (Mammalia.)--_Louis Figuier._
The natives of Borneo pretend that these monkeys, or, as sometimes
called, Kahan, are men who have retired to the woods to avoid paying
taxes; and they entertain the greatest respect for a being who has found
such ready means of evading the responsibilities of society.--_Figuier._]
[Illustration: GIBBON. ORANG. CHIMPANZEE. GORILLA. MAN.
FIG. I.--Photographically reduced from diagrams of the natural size
(except that of the Gibbon, which was twice as large as nature), drawn
by _Waterhouse Hawkins_, from specimens in the museum of the Royal
College of Surgeons. (_Huxley's_ "Man's Place in Nature.")]
If, therefore, science makes the "history of creation" its highest and
most difficult and most comprehensible problem, it must deal with "_the
coming into being of the form_ of natural bodies." Let us look for a
minute at Kant's Cosmogony, or, as Haeckel says,[27] Kant's Cosmological
Gas Theory: "This wonderful theory," says Haeckel, "harmonizes with all
the general series of phenomena at present known to us, and stands in no
irreconcilable contradiction to any one of them. Moreover, it is purely
mechanical and monistic, makes use exclusively of the inherent forces
of eternal matter, and entirely excludes every supernatural process,
every prearranged and conscious action of a personal creator." Compare
this last statement with the following: "I will, however," says
Haeckel,[28] "not deny that Kant's grand cosmogony has some weak
points." * * * "A great unsolved difficulty lies in the fact that the
cosmological gas theory furnishes no starting-point at all in
explanation of the first impulse which caused the rotary motion in the
gas-filled universe."
Whewell[29] has pointed out, that the nebular hypothesis is null without
a creative act to produce the inequality of distribution of cosmic
matter in space.