THE LIBRARY
OF
THE UNIVERSITY
OF CALIFORNIA
PRESENTED BY
PROF. CHARLES A. KOFOID AND
MRS. PRUDENCE W. KOFOID
V
V
FATHERS OF BIOLOGY
FATHERS OF BIOLOGY
BY
CHARLES McRAE, M.A., F.L.S.
FORMERLY SCHOLAR OF EXETER COLLEGE, OXFORD
PERCIVAL & CO.
KING STREET, COVE NT GARDEN
Uonfcon
1890
M/AA
PREFACE.
IT is hoped that the account given, in the following
pages, of the lives of five great naturalists may
not be found devoid of interest. The work of
each one of them marked a definite advance in
the science of Biology.
There is often among students of anatomy and
physiology a tendency to imagine that the facts
with which they are now being made familiar have
all been established by recent observation and
experiment. But even the slight knowledge of the
history of Biology, which may be obtained from
a perusal of this little book, will show that, so far
from such being the case, this branch of science
is of venerable antiquity. And, further, if in the
place of this misconception a desire is aroused
in the reader for a fuller acquaintance with the
writings of the early anatomists the chief aim
of the author will have been fulfilled.
CONTENTS.
PAGE
HIPPOCRATES . . . . . . . . . i
ARISTOTLE 19
GALEN 45
VESALIUS 63
HARVEY .. .. .. .. .. ..83
HIPPOCRATES.
HIPPOCRATES.
OWING to the lapse of centuries, very little is known
with certainty of the life of Hippocrates, who was called
with affectionate veneration by his successors "the
divine old man," and who has been justly known to
posterity as " the Father of Medicine."
He was probably born about 470 B.C., and, according
to all accounts, appears to have reached the advanced
age of ninety years or more. He must, therefore, have
lived during a period of Greek history which was cha-
racterized by great intellectual activity; for he had, as
his contemporaries, Pericles the famous statesman ; the
poets ^Eschylus, Sophocles, Euripides, Aristophanes,
and Pindar ; the philosopher Socrates, with his disciples
Xenophon and Plato; the historians Herodotus and
Thucydides ; and Phidias the unrivalled sculptor.
In the island of Cos, where he was born, stood one of
the most celebrated of the temples of ^Esculapius, and
in this temple because he was descended from the
Asclepiadse Hippocrates inherited from his forefathers
FATHERS OF BIOLOGY.
an important position. Among the Asclepiads the habit
of physical observation, and even manual training in
dissection, were imparted traditionally from father to
son from the earliest years, thus serving as a preparation
for medical practice when there were no written treatises
to study. 1
Although Hippocrates at first studied medicine under
his father, he had afterwards for his teachers Gorgias and
Democritus, both of classic fame, and Herodicus, who is
known as the first person who applied gymnastic exercises
to the cure of diseases.
The Asclepions, or temples of health, were erected
in various parts of Greece as receptacles for invalids,
who were in the habit of resorting to them to seek the
assistance of the god. These temples were mostly
situated in the neighbourhood of medicinal springs, and
each devotee at his entrance was made to undergo a
regular course of bathing and purification. Probably
his diet was also carefully attended to, and at the
same time his imagination was worked upon by music
and religious ceremonies. On his departure, the re-
stored patient usually showed his gratitude by presenting
to the temple votive tablets setting forth the circum-
stances of his peculiar case. The value of these to men
about to enter on medical studies can be readily under-
stood ; and it was to such treasures of recorded obser-
1 Crete's "Aristotle," vol. i. p. 3.
HIPPOCRATES: 5
vations collected during several generations that
Hippocrates had access from the commencement of
his career.
Owing to the peculiar constitution of the Asclepions,
medical and priestly pursuits had, before the time of
Hippocrates, become combined; and, consequently,
although rational means were to a certain extent applied
to the cure of diseases, the more common practice
was to resort chiefly to superstitious modes of working
upon the imagination. It is not surprising, therefore,
to find that every sickness, especially epidemics and
plagues, were attributed to the anger of some offended
god, and that penance and supplications often took the
place of personal and domestic cleanliness, fresh air, and
light.
It was Hippocrates who emancipated medicine from
the thraldom of superstition, and in this way wrested
the practice of his art from the monopoly of the priests.
In his treatise on "The Sacred Disease" (possibly epi-
lepsy), he discusses the controverted question whether
or not this disease was an infliction from the gods ; and
he decidedly maintains that there is no such a thing
as a sacred disease, for all diseases arise from natural
causes, and no one can be ascribed to the gods more
than another. He points out that it is simply because
this disease is unlike other diseases that men have come
to regard its cause as divine, and yet it is not really
FATHERS OF BIOLOGY.
more wonderful than the paroxysms of fevers and many
other diseases not thought sacred. He exposes the
cunning of the impostors who pretend to cure men by
purifications and spells; "who give themselves out as
being excessively religious, and as knowing more than
other people;" and he argues that "whoever is able,
by purifications and conjurings, to drive away such an
affection, will be able, by other practices, to excite it,
and, according to this view, its divine nature is entirely
done away with." "Neither, truly," he continues, "do
I count it a worthy opinion to hold that the body of
a man is polluted by the divinity, the most impure by the
most holy ; for, were it defiled, or did it suffer from any
other thing, it would be like to be purified and sanctified
rather than polluted by the divinity." As an additional
argument against the cause being divine, he adduces the
fact that this disease is hereditary, like other diseases, and
that it attacks persons of a peculiar temperament, namely,
the phlegmatic, but not the bilious ; and " yet if it were
really more divine than the others," he justly adds, " it
ought to befall all alike."
Again, speaking of a disease common among the
Scythians, Hippocrates remarks that the people attri-
buted it to a god, but that " to me it appears that such
affections are just as much divine as all others are, and
that no one disease is either more divine or more human
than another, but that all are alike divine, for that each
HIPPOCRATES.
has its own nature, and that no one arises without a
natural cause."
From this it will be seen that Hippocrates regarded
all phenomena as at once divine and scientifically deter-
minable. In this respect it is interesting to compare
him with one of his most illustrious contemporaries,
namely, with Socrates, who distributed phenomena into
two classes : one wherein the connection of antecedent and
consequent was invariable and ascertainable by human
study, and wherein therefore future results were accessible
to a well-instructed foresight ; the other, which the gods
had reserved for themselves and their unconditional
agency, wherein there was no invariable or ascertainable
sequence, and where the result could only be foreknown
by some omen or prophecy, or other special inspired
communication from themselves. Each of these classes
was essentially distinct, and required to be looked at
and dealt with in a manner radically incompatible with
the other. Physics and astronomy, in the opinion of
Socrates, belonged to the divine class of phenomena in
which human research was insane, fruitless, and impious. 1
Hippocrates divided the causes of diseases into two
classes : the one comprehending the influence of seasons,
climates, water, situation, and the like; the other con-
sisting of such causes as the amount and kind of food
and exercise in which each individual indulges. He
1 Crete's "History of Greece," vol. i. p. 358.
8 FATHERS OF BIOLOGY
considered that while heat and cold, moisture and dry-
ness, succeeded one another throughout the year, the
human body underwent certain analogous changes which
influenced the diseases of the period. With regard to
the second class of causes producing diseases, he attri-
buted many disorders to a vicious system of diet, for
excessive and defective diet he considered to be equally
injurious.
In his medical doctriries Hippocrates starts with the
axiom that the body is composed of the four elements
air, earth, fire, and water. From these the four fluids
or humours (namely, blood, phlegm, yellow bile, and
black bile) are formed. Health is the result of a right
condition and proper proportion of these humours,
disease being due to changes in their quality or distribu-
tion. Thus inflammation is regarded as the passing of
blood into parts not previously containing it. In the
course of a disorder proceeding favourably, these humours
undergo spontaneous changes in quality. This process
is spoken of as coction, and is the sign of returning health,
as preparing the way for the expulsion of the morbid
matters a state described as the crisis. These crises
have a tendency to occur at certain periods, which are
hence called critical days. As the critical days answer to
the periods of the process of coction, they are to be
watched with anxiety, and the actual condition of the
patient at these times is to be compared with the state
HIPPOCRATES.
which it was expected he ought to show. From these
observations the physician may predict the course which
the remainder of the disease will probably take, and
derive suggestions as to the practice to be followed in
order to assist Nature in her operations.
Hippocrates thus appears to have studied "the natural
history of diseases." As stated above, his practice was
to watch the manner in which the humours were under-
going their fermenting coction, the phenomena displayed
in the critical days, and the aspect and nature of the
critical discharges not to attempt to check the process
going on, but simply to assist the natural operation.
His principles and practice were based on the theory of
the existence of a restoring essence (or Averts) penetrat-
ing through all creation ; the agent which is constantly
striving to preserve all things in their natural state, and
to restore them when they are preternaturally deranged.
In the management of this vis medicatrix natures the
art of the physician consisted. Attention, therefore, to
regimen and diet was the principal remedy Hippocrates
employed; nevertheless he did not hesitate, when he
considered that occasion required, to administer such a
powerful drug as hellebore in large doses.
The writings which are extant under the name of
Hippocrates cannot all be ascribed to him. Many were
doubtless written by his family, his descendants, or his
pupils. Others are productions of the Alexandrian
TO FATHERS OF BIOLOGY.
school, some of these being considered by critics as
wilful forgeries, the high prices paid by the Ptolemies
for books of reputation probably having acted as induce-
ments to such fraud. The following works have gene-
rally been admitted as genuine :
1. On Airs, Waters, and Places.
2. On Ancient Medicine.
3. On the Prognostics.
4. On the Treatment in Acute Diseases.
5. On Epidemics [Books I. and III.].
6. On Wounds of the Head.
7. On the Articulations.
8. On Fractures.
9. On the Instruments of Reduction.
10. The Aphorisms [Seven Books].
11. The Oath.
The works "On Fractures," "On the Articulations,"
" On Injuries to the Head," and " On the Instruments of
Reduction," deal with anatomical or surgical matters,
and exhibit a remarkable knowledge of osteology and
anatomy generally. It has sometimes been doubted if
Hippocrates could ever have had opportunities of gaining
this knowledge from dissections of the human body, for
it has been thought that the feeling of the age was dia-
metrically opposed to such a practice, and that Hippo-
crates would not have dared to violate this feeling. The
language used, however, in some passages in the work
HIPPOCRATES. \\
" On the Articulations," seems to put the matter beyond
doubt. Thus he says in one place, " But if one will strip
the point of the shoulder of the fleshy parts, and where
the muscle extends, and also lay bare the tendon that
goes from the armpit and clavicle to the breast," etc.
And again, further on in the same treatise, " It is evident,
then, that such a case could not be reduced either by
succussion or by any other method, unless one were to
cut open the patient, and then, having introduced the
hand into one of the great cavities, were to push outwards
from within, which one might do in the dead body, but
not at all in the living."
His descriptions of the vertebrae, with all their pro-
cesses and ligaments, as well as his account of the
general characters of the internal viscera, would not have
been as free from error as they are if he had derived all
his knowledge from the dissection of the inferior animals.
Moreover, it is indisputable that, within less than a
hundred years from the death of Hippocrates, the human
body was openly dissected in the schools of Alexandria
nay, further, that even the vivisection of condemned
criminals was not uncommon. It would be unreasonable
to suppose that such a practice as the former sprang up
suddenly under the Ptolemies, and it seems, therefore,
highly probable that it was known and tolerated in the
time of ; Hippocrates. It is not surprising, when we
remember the rude appliances and methods which then
12 FATHERS OF BIOLOGY,
obtained, that in his knowledge of minute anatomy
Hippocrates should compare unfavourably with anato-
mists of the present day. Of histology, and such other
subjects as could not be brought within his direct per-
sonal observation, the knowledge of Hippocrates was '
necessarily defective. Thus he wrote of the tissues
without distinguishing them ; confusing arteries, veins,
and nerves, and speaking of muscles vaguely as " flesh."
But with matters within the reach of the Ancient Phy-
sician's own careful observation, the case is very different.
This is well shown in his wonderful chapter on the club-
foot, in which he not only states correctly the true nature
of the malformation, but gives some very sensible direc-
tions for rectifying the deformity in early life.
When human strength was not sufficient to restore a
displaced limb, he skilfully availed himself of all the
mechanical powers which were then known. He does
not appear to have been acquainted with the use of
pulleys for the purpose, but the axles which he describes
as being attached to the bench which bears his name
(Scamnum Hippocratis) must have been quite capable of
exercising the force required.
The work called "The Aphorisms," which was probably
written in the old age of Hippocrates, consists of more
than four hundred short pithy sentences, setting forth
the principles of medicine, physiology, and natural
philosophy. A large number of these sentences are
HIPPO CRA TES. 1 3
evidently taken from the author's other works, especially
those " On Air," etc., " On Prognostics," and " On the
Articulations." They embody the result of a vast
amount of observation and reflection, and the majority
of them have been confirmed by the experience of two
thousand years. A proof of the high esteem in which
they have always been held is furnished by the fact
that they have been translated into all the languages
of the civilized world ; among others, into Hebrew,
Arabic, Latin, English, Dutch, Italian, German, and
French. The following are a few examples of these
aphorisms :
" Spontaneous lassitude indicates disease."
" Old people on the whole have fewer complaints than
the young; but those chronic diseases which do befall
them generally never leave them."
" Persons who have sudden and violent attacks of
fainting without any obvious cause die suddenly."
" Of the constitutions of the year, the dry upon the
whole are more healthy than the rainy, and attended
with less mortality."
" Phthisis most commonly occurs between the ages of
eighteen and thirty-five years."
" If one give to a person in fever the same food which
is given to a person in good health, what is strength to
the one is disease to the other."
" Such food as is most grateful, though not so whole-
14 FATHERS OF BIOLOGY.
some, is to be preferred to that which is better, but
distasteful."
" Life is short and the art long ; the opportunity fleet-
ing ; experience fallacious and judgment difficult. The
physician must not only do his duty himself, but must
also make the patient, the attendants and the externals,
co-operate."
Hippocrates appears to have travelled a great deal,
and to have practised his art in many places far distant
from his native island. A few traditions of what he did
during his long life remain, but differences of opinion
exist as to the truth of these stories.
Thus one story says that when Perdiccas, the King
of Macedonia, was supposed to be dying of consump-
tion, Hippocrates discovered the disorder to be love-
sickness, and speedily effected a cure. The details of
this story scarcely seem to be worthy of credence, more
especially as similar legends have been told of entirely
different persons belonging to widely different times.
There are, however, some reasons for believing that
Hippocrates visited the Macedonian court in the exer-
cise of his professional duties, for he mentions in the
course of his writings, among places which he had
visited, several which were situated in Macedonia ; and,
further, his son Thessalus appears to have afterwards
been court physician to Archelaus, King of Macedonia.
Another story connects the name of Hippocrates with
HIPPOCRATES. 15
the Great Plague which occurred at Athens in the time
of the Peloponnesian war. It is said that Hippocrates
advised the lighting of great fires with wood of some
aromatic kind, probably some species of pine. These,
being kindled all about the city, stayed the progress of
the pestilence. Others besides Hippocrates are, how-
ever, famous for having successfully adopted this practice.
A third legend states that the King of Persia, pur-
suing the plan (which in the two celebrated instances of
Themistocles and Pausanias had proved successful)
of attracting to his side the most distinguished persons
in Greece, wrote to Hippocrates asking him to pay
a visit to his court, and that Hippocrates refused to go.
Although the story is discarded by many scholars, it is
worthy of note that Ctesias, a kinsman and contem-
porary of Hippocrates, is mentioned by Xenophon in
the " Anabasis " as being in the service of the King of
Persia. And, with regard to the refusal of the venerable
physician to comply with the king's request, one cannot
lose sight of the fact that such refusal was the only
course consistent with the opinions he professed of
a monarchical form of government.
After his various travels Hippocrates, as seems to be
pretty generally admitted, spent the latter portion of his
life in Thessaly, and died at Larissa at a very advanced age.
It is difficult to speak of the skill and painstaking
perseverance of Hippocrates in terms which shall not
1 6 FATHERS OF BIOLOGY.
appear exaggerated and extravagant. His method of
cultivating medicine was in the true spirit of the
inductive philosophy. His descriptions were all de-
rived from careful observation of its phenomena, and,
as a result, the greater number of his deductions have
stood unscathed the test of twenty centuries.
Still more difficult is it to speak with moderation of
the candour which impelled Hippocrates to confess
errors into which in his earlier practice he had fallen;
or of that freedom from superstition which entitled
him to be spoken of as a man who knew not how to
deceive or be deceived (" qui tarn fallere quam falli
nescit ") ; or, lastly, of that purity of character and true
nobility of soul which are brought so distinctly to light
in the words of the oath translated below :
11 1 swear by Apollo the Physician and ^Esculapius,
and I call Hygeia and Panacea and all the gods and
goddesses to witness, that to the best of my power and
judgment I will keep this oath and this contract ; to wit
to hold him, who taught me this Art, equally dear to
me as my parents ; to share my substance with him ;
to supply him if he is in need of the necessaries of life ;
to regard his offspring in the same light as my own
brothers, and to teach them this Art, if they shall desire
to learn it, without fee or contract ; to impart the pre-
cepts, the oral teaching, and all the rest of the instruc-
tion to my own sons, and to the sons of my teacher,
HIPPOCRATES. 17
and to pupils who have been bound to me by contract,
and who have been sworn according to the law of
medicine.
" I will adopt that system of regimen which, accord-
ing to my ability and judgment, I consider for the
benefit of my patients, and will protect them from every-
thing noxious and injurious. I will give no deadly
medicine to any one, even if asked, nor will I give any
such counsel, and similarly I will not give to a woman
the means of procuring an abortion. With purity and
with holiness I will pass my life and practise my art. . . .
Into whatever houses I enter I will go into them for the
benefit of the sick, keeping myself aloof from every
voluntary act of injustice and corruption and lust.
Whatever in the course of my professional practice, or
outside of it, I see or hear which ought not to be
spread abroad, I will not divulge, as reckoning that all
such should be kept secret. If I continue to observe
this oath and to keep it inviolate, may it be mine to
enjoy life and the practice of the Art respected among
all men for ever. But should I violate this oath and
forswear myself, may the reverse be my lot."
ARISTOTLE.
ARISTOTLE.
ABOUT the time that Hippocrates died, Aristotle, who
may be regarded as the founder of the science of
" Natural History," was born (B.C. 384) in Stagira, an
unimportant Hellenic colony in Thrace, near the Mace-
donian frontier. His father was a distinguished physician,
and, like Hippocrates, boasted descent from the Ascle-
piadae. The importance attached by the Asclepiads to
the habit of physical observation, which has been already
referred to in the life of Hippocrates, secured for Aristotle,
from his earliest years, that familiarity with biological
studies which is so clearly evident in many of his works.
Both parents of Aristotle died when their son was
still a youth, and in consequence of this he went to
reside with Proxenus, a native of Atarneus, who had
settled at Stagira. Subsequently he went to Athens and
joined the school of Plato. Here he remained for
about twenty years, and applied himself to study with
such energy that he became pre-eminent even in that
distinguished band of philosophers. He is said to have
22 FATHERS OF BIOLOGY.
been spoken of by Plato as " the intellect " of the school,
and to have been compared by him to a spirited colt
that required the application of the rein to restrain its
ardour.
Aristotle probably wrote at this time some philoso-
phical works, the fame of which reached the ears of
Philip, King of Macedonia, and added to the reputation
which the young philosopher had already made with
that monarch ; for Philip is said to have written to him
on the occasion of Alexander's birth, B.C. 356: "King
Philip of Macedonia to Aristotle, greeting. Know that
a son has been born to me. I thank the gods not so
much that they have given him to me, as that they have
permitted him to be born in the time of Aristotle.
I hope that thou wilt form him to be a king worthy to
succeed me and to rule the Macedonians."
After the death of Plato, which occurred in 347 B.C.,
Aristotle quitted Athens and went to Atarneus, where
he stayed with Hermias, who was then despot of that
town. Hermias was a remarkable man, who, from being
a slave, had contrived to raise himself to the supreme
power. He had been at Athens and had heard Plato's
lectures, and had there formed a friendship for Aristotle.
With this man the philosopher remained for three years,
and was then compelled suddenly to seek refuge in
Mitylene, owing to the perfidious murder of Hermias.
The latter was decoyed out of the town by the Persian
ARISTOTLE. 23
general, seized and sent prisoner to Artaxerxes, by whom
he was hanged as a rebel. On leaving Atarneus, Aris-
totle took with him a niece of Hermias, named Pythias,
whom he afterwards married. She died young, leaving
an infant daughter.
Two or three years after this, Aristotle became tutor
to Alexander, who was then about thirteen years old.
The philosopher seems to have been a favourite with
botii the king and the prince, and, in gratitude for his
services, Philip rebuilt Stagira and restored it to its
former inhabitants, who had either been dispersed or
carried into slavery. The king is said also to have
established there a school for Aristotle. The high respect
in which Alexander held his teacher is expressed in his
saying that he honoured him no less than his own father,
for while to one he owed life, to the other he owed all
that made life valuable.
In 336 B.C. Alexander, who was then only about
twenty years of age, became king, and Aristotle soon
afterwards quitted Macedonia and took up his residence
in Athens once more, after an absence of about twelve
years. Here he opened a school in the Lycseum, a
gymnasium on the eastern side of the city, and continued
his work there for about twelve years, during which time
Alexander was making his brilliant conquests. The
lectures were given for the most part while walking in
the garden, and in consequence, perhaps, of this, the
24 FATHERS OF BIOLOGY.
sect received the name of the Peripatetics. The dis-
courses were of two kinds the esoteric, or abstruse, and
the exoteric, or familiar ; the former being delivered to
the more advanced pupils only. During the greater part
of this time Aristotle kept up correspondence with
Alexander, who is said l to have placed at his disposal
thousands of men, who were busily employed in collect-
ing objects and in making observations for the com-
pletion of the philosopher's zoological researches.
Alexander is, moreover, said to have given the philo-
sopher eight hundred talents for the same purpose.
In spite of these marks of friendship and respect,
Alexander, who was fast becoming intoxicated with
success, and corrupted by Asiatic influences, gradually
cooled in his attachment towards Aristotle. This may
have been hastened by several causes, and among others
by the freedom of speech and republican opinions of
Callisthenes, a kinsman and disciple of Aristotle, who
had been, by the latter's influence, appointed to attend
on Alexander. Callisthenes proved so unpopular, that
the king seems to have availed himself readily of the
first plausible pretext for putting him to death, and to
have threatened his former friend and teacher with a
similar punishment. The latter, for his part, probably
had a deep feeling of resentment towards the destroyer
of his kinsman.
1 Pliny, " Natural History," viii. c. 16.
ARISTOTLE. 25
Meanwhile the Athenians knew nothing of these
altered relations between Aristotle and Alexander, but
continued to regard the philosopher as thoroughly im-
bued with kingly notions (in spite of his writings being
quite to the contrary) ; so that he was an object of
suspicion and dislike to the Athenian patriots. Never-
theless, as long as Alexander was alive, Aristotle was safe
from molestation. As soon, however, as Alexander's
death became known, the anti-Macedonian feeling of
the Athenians burst forth, and found a victim in the
philosopher. A charge of impiety was brought against
him. It was alleged that he had paid divine honours
to his wife Pythias and to his friend Hermias. Now,
for the latter, a eunuch, who from the rank of a slave
had raised himself to the position of despot over a
free Grecian community, so far from coupling his name
(as Aristotle had done in his hymn) with the greatest
personages of Hellenic mythology, the Athenian public
felt that no contempt was too bitter. To escape the
storm the philosopher retired to Chalcis, in Euboea, then
under garrison by Antipater, the Governor of Mace-
donia, remarking in a letter, written afterwards, that
he did so in order that the Athenians might not have
the opportunity of sinning a second time against philo-
sophy (the allusion being, of course, to the fate of
Socrates) .
He probably intended to return to Athens again so
26 FATHERS OF BIOLOGY.
soon as the political troubles had abated, but in Sep-
tember, 322 B.C., he died at Chalcis. An overwrought
mind, coupled with indigestion and weakness of the
stomach, from which he had long suffered, was most
probably the cause of death. Some of his detractors,
however, have asserted that he took poison, and others
that he drowned himself in the Euboean Euripus.
It is not easy to arrive at a just estimate of the cha-
racter of Aristotle. By some of his successors he has
been reproached with ingratitude to his teacher, Plato ;
with servility to Macedonian power, and with love of
costly display. How far these two last charges are due
to personal slander it is impossible to say. The only
ground for the first charge is, that he criticised adversely
some of Plato's doctrines.
The manuscripts of Aristotle's works passed through
many vicissitudes. At the death of the philosopher
they were bequeathed to Theophrastus, who continued
chief of the Peripatetic school for thirty-five years.
Theophrastus left them, with his own works, to a philo-
sophical friend and pupil, Neleus, who conveyed them
from Athens to his residence at Scepsis, in Asia Minor.
About thirty or forty years after the death of Theo-
phrastus, the kings of Pergamus, to whom the city of
Scepsis belonged, began collecting books to form a
library on the Alexandrian plan. This led the heirs of
Neleus to conceal their literary treasures in a cellar, and
ARISTOTLE. 27
there the manuscripts remained for nearly a century and
a half, exposed to injury from damp and worms. At
length they were sold to Apellicon, a resident at Athens,
who was attached to the Peripatetic sect. Many of the
manuscripts were imperfect, having become worm-eaten
or illegible. These defects Apellicon attempted to
remedy ; but, being a lover of books rather than a philo-
sopher, he performed the work somewhat unskilfully.
When Athens was taken by Sylla, 86 B.C., the library of
Apellicon was transported to Rome. There various
literary Greeks obtained access to it; and, among others,
Tyrannion, a grammarian and friend of Cicero, did good
service in the work of correction. Andronicus of Rhodes
afterwards arranged the whole into sections, and pub-
lished the manuscripts with a tabulated list.
The three principal works on biology which are
extant are : " The History of Animals ; " " On the Parts
of Animals ; " " On the Generation of Animals." The
other biological works are : " On the Motion of Ani-
mals ; " " On Respiration ; " " Parva Naturalia ; " a
series of essays which are planned to form an entire
work on sense and the sensible.
" The History of Animals " is the largest and most
important of Aristotle's works on biology. It contains
a vast amount of information, not very methodically
arranged, and spoiled by the occurrence here and there
of very gross errors. It consists of nine books.
28 FATHERS OF BIOLOGY.
The first book opens with a division of the body into
similar and dissimilar parts. Besides thus differing in
their parts, animals also differ in their mode of life, their
actions and dispositions. Thus some are aquatic, others
terrestrial ; of the former, some breathe water, others air,
and some neither. Of aquatic animals, some inhabit
the sea, and others rivers, lakes, or marshes. Again,
some animals are locomotive, and others are stationary.
Some follow a leader, others act independently. Various
differences are in this way pointed out, and there is no
lack of illustration and detail, but a suspicion is excited
that the generalizations are sometimes based upon in-
sufficient facts. The book closes with a description of
the different parts of the human body, both internal and
external. In speaking of the ear, Aristotle seems to
have been aware of what we now call the Eustachian
tube, for he says, " There is no passage from the ear into
the brain, but there is to the roof of the mouth." !
In the second book he passes on to describe the
organs of animals. The animals are dealt with in groups
viviparous and oviparous quadrupeds, fish, serpents,
birds, etc. The ape, elephant, chameleon, and some
others are especially noticed.
The third book continues the description of the
internal organs. References which are made to a diagram
by letters, a, b, c, d, show that the work was originally
1 " History of Animals," i. n.
ARISTOTLE. 29
illustrated. At the close of this book Aristotle has some
remarks on milk, and mentions the occasional appearance
of milk in male animals. He speaks of a male goat at
Lemnos which yielded so much that cakes of cheese
were made from it. Similar instances of this phenomenon
have been recorded by Humboldt, Burdach, Geoffroy
St. Hilaire, and others.
In the first four chapters of the fourth book the
anatomy of the invertebrata is dealt with, and the accounts
given of certain mollusca and Crustacea are very careful
and minute. The rest of the book is devoted to a de-
scription of the organs of sense and voice ; of sleep, and
the distinctions of sex. The accurate knowledge which
Aristotle exhibits of the anatomy and habits of marine
animals, such as the Cephalopoda and the larger Crus-
tacea, leaves no doubt that he derived it from actual
observation. Professor Owen says, " Respecting the living
habits of the Cephalopoda, Aristotle is more rich in detail
than any other zoological author." What is now spoken
of as the hectocotylization of one or more of the arms
of the male cephalopod did not escape Aristotle's eye.
And while he speaks of the teeth and that which serves
these animals for a tongue, it is plain from the context
that he means in the one case the two halves of the
parrot-like beak, and in the other the anterior end of the
odontophore.
Books five to seven deal with the subject of generation.
30 FATHERS OF BIOLOGY.
The eighth book contains a variety of details respect-
ing animals, their food, migrations, hibernation, and
diseases ; with the influence of climate and locality upon
them.
The ninth book describes the habits and instincts of
animals. The details are interesting; but there is, as
usual, very little attempt at classification. Disjointed
statements and sudden digressions occur, the subjects
being treated in the order in which they presented them-
selves to the author. Such curious statements as the.
following are met with : " The raven is an enemy to the
bull and the ass, for it flies round them and strikes their
eyes." " If a person takes a goat by the beard, all the
rest of the herd stand by, as if infatuated, and look at
it." " Female stags are captured by the sound of the
pipe and by singing. When two persons go out to
capture them, one shows himself, and either plays upon
a pipe or sings, and the other strikes behind, when the
first gives him the signal." " Swans have the power of
song, especially when near the end of their life ; for they
then fly out to sea, and some persons sailing near the
coast of Libya have met many of them in the sea singing
a mournful song, and have afterwards seen some of
them die." " Of all wild animals, the elephant is the
most tame and gentle ; for many of them are capable of
instruction and intelligence, and they have been taught
to worship the king."
ARISTOTLE. 31
In the work " On the Parts of Animals," the author
considers not only the phenomena of life exhibited by each
species, but also the cause or causes to which these
phenomena are attributable. After a general introduc-
tion, he proceeds to enumerate the three degrees of
composition, viz. :
(1) " Composition out of what some call the elements,
such as air, earth, water, and fire," or " out of
the elementary forces, hot and cold, solid and
fluid, which form the material of all compound
substances."
(2) Composition out of these primary substances of
the homogeneous parts of animals, e.g. blood,
fat, marrow, brain, flesh, and bone.
(3) Composition into the heterogeneous parts or
organs. These parts he describes in detail,
considering those belonging to sanguineous
animals first and most fully.
These divisions correspond roughly to the threefold
study of structure which we nowadays recognize as
chemical, histological, and anatomical.
As examples of Aristotle's method of treatment, his
descriptions of blood, the brain, the heart, and the lung
may be considered.
Of the blood he says, " What are called fibres are
found in the blood of some animals, but not of all.
There are none, for instance, in the blood of deer and
32 FATHERS OF BIOLOGY.
of roes, and for this reason the blood of such animals
as these never coagulates. . . . Too great an excess of
water makes animals timorous. . . . Such animals, on
the other hand, as have thick and abundant fibres in their
blood are of a more choleric temperament, and liable to
bursts of passion. . . . Bulls and boars are choleric,
for their blood is exceedingly rich in fibres, and the bull's,
at any rate, coagulates more rapidly than that of any
other animal. ... If these fibres are taken out of the
blood, the fluid that remains will no longer coagulate."
From these quotations it will be noted that Aristotle
attributed the coagnlum to the presence of fibres, and in
this he anticipated Malpighi's discovery made in the
seventeenth century. His remarks on the proportion of
coagulum and serum in different animals, which is en-
larged upon in the " History of Animals," l harmonize
with modern observations. In another of his works 2 he
remarks that the blood in certain diseased conditions will
not coagulate. This is known to be the case in cholera,
certain fevers, asphyxia, etc. ; and the fact was probably
obtained from Hippocrates. Although Aristotle speaks
here of entire absence of coagulation in the blood of the
deer and the roe, in the " History of Animals " he admits
an imperfect coagulation, for he says, " so that their
blood does not coagulate like that of other animals."
The animals named are commonly hunted, and it was
1 Bk. iii. 19. 2 " Meteorology," iv. 7-11.
ARISTOTLE. 33
probably after they had been hunted to death that he
examined them. Now, it is generally admitted that
coagulation under such circumstances is imperfect and
even uncommon. The statement as to the richness in
fibres of the blood of bulls and boars has been con-
firmed by some modern investigations, which have
shown that the clot bears a proportion to the strength
and ferocity of the animal. The remarks, however, as
to the relative rapidity of coagulation would appear to
be contradicted by later observations, for Thackrah
came to the conclusion that coagulation commenced
sooner in small and weak animals than in strong.
Of the brain Aristotle makes the following among
other assertions : " Of all parts of the body there is
none so cold as the brain. ... Of all the fluids of the
body it is the one that has the least blood, for, in fact, it
has no blood at all in its proper substance. . . . That
it has no continuity with the organs of sense is plain
from simple inspection, and still more closely shown by
the fact that when it is touched no sensation is produced.
. . . The brain tempers the heat and seething of the
heart. ... In order that it may not itself be absolutely
without heat, blood-vessels from the aorta end in the
membrane which surrounds the brain. ... Of all animals
man has the largest brain in proportion to his size : and
it is larger in men than in women. This is because the
region of the heart and of the lung is hotter and richer
D
si FATHERS OF BIOLOGY.
in blood in man than in any other animal ; and in men
than in women. This again explains why man alone
of animals stands erect. For the heat, overcoming any
opposite inclination, makes growth take its own line of
direction, which is from the centre of the body upwards.
. . . Man again has more sutures in his skull than any
other animal, and the male more than the female. The
explanation is to be found in the greater size of the
brain, which demands free ventilation proportionate to
its bulk. . . . There is no brain in the hinder part of
the head. . . . The brain in all animals that have one
is placed in the front part of the head . . . because the
heart, from which sensation proceeds, is in the front part
of the body,"
Although it would perhaps be difficult to find anywhere
as many errors in as few words, yet it should be observed
that Aristotle here shows himself to have been aware of
the existence of the membranes of the brain the pia
mater and the dura mater ; and elsewhere 1 he says more
explicitly, " Two membranes enclose the brain ; that
about the skull is the stronger; the inner membrane is
slighter than the outer one." And further, it should be
noted that he describes the latter membrane as a vascular
one. The fact of the brain substance being insensible to
mechanical irritation was known to Aristotle, and may
have been learnt from the practice of Hippocrates.
1 " History of Animals," i. 16.
ARISTOTLE. 35
Lastly, it should be remembered that though this may
have been but a lucky guess on Aristotle's part the
relative weight of brain to the entire body has been
shown, with few exceptions, to be greater in man than in
any other animal.
In describing the heart Aristotle says : " The heart lies
about the centre of the body, but rather in its upper
than in its lower half, and also more in front than
behind. ... In man it inclines a little towards the left,
so that it may counterbalance the chilliness of that side.
It is hollow, to serve for the reception of the blood ;
while its wall is thick, that it may serve to protect the
source of heat. For here, and here alone, in all the
viscera, and in fact in all the body, there is blood without
blood-vessels, the blood elsewhere being always contained
within vessels. The heart is the first of all the parts of
the body to be formed, and no sooner is it formed than
it contains blood. . . . For no sooner is the embryo
formed than its heart is seen in motion like a living
creature, and this before any of the other parts. The
heart is abundantly supplied with sinews. ... In no
animal does the heart contain a bone, certainly in none
of those that we ourselves have inspected, with the
exception of the horse and a certain kind of ox. In
animals of great size the heart has three cavities ; in
smaller animals it has two ; and in all it has at least
36 FATHERS OF BIOLOGY.
It will be observed that here Aristotle so correctly
describes the position of the human heart as to render it
probable that he is speaking from actual inspection ;
although man is not the only animal in which the heart
is turned towards the left. In contrasting the heart with
the other viscera he appears to have overlooked the
existence of the coronary vessels, and to have imagined
that the nutrition of the heart was effected directly by
the blood in its cavities. Although the heart is not really
the first part to appear, the observation of its very early
appearance in the embiyo, which he treats more fully
elsewhere, 1 is alone enough to establish his reputation as
an original observer. It is remarkable that Aristotle
should have overlooked the presence of the valves of the
heart, the structure and functions of which were fully
investigated within thirty years of his death by the
anatomists of the Alexandrian school. This is the more
remarkable, as he calls attention here, and in the " History
of Animals," to the sinews or tendons (vevpa) with which,
he says, the heart is supplied, and by which he probably
meant chiefly the chorda tendinea. The " bone in the
heart " of which he speaks was probably the cruciform
ossification which is normally found in the ox and the
stag below the origin of the aorta. It is found in the
horse only in advanced age, or under abnormal condi-
tions. The statement that the heart contains no more
1 " History of Animals," vi. 3.
ARISTOTLE. 37
than three chambers has always been considered as a
very gross blunder on the part of Aristotle. Even
Cuvier, who generally lavishes upon the philosopher
the most extravagant praise, sneers at this. Professor
Huxley, 1 however, has shown, by a comparison of
several passages from the " History of Animals," that
what we now call the right auricle was regarded by the
author as a venous sinus, as being a part not of the heart,
but of the great vein (i.e. the superior and the inferior
vena cava).
Aristotle speaks of the lung as a single organ, sub-
divided, but having a common outlet the trachea.
Elsewhere 2 he says, " Canals from the heart pass to the
lung and divide in the same fashion as the windpipe
does, closely accompanying those from the windpipe
through the whole lung." His theory of respiration, as
explained in his treatise on the subject, is that it tempers
the excessive heat produced in the heart. The lung is
compared to a pair of bellows. When the lung is ex-
panded, air rushes in; when^it is contracted, the air is
expelled. The heat from the heart causes the lung to
expand cold air rushes in, the heat is reduced, the lung
collapses, and the air is expelled. The cold air drawn
into the lung reaches the bronchial tubes, and as the
vessels containing hot blood run alongside these tubes,
1 " On some of the errors attributed to Aristotle."
2 " History of Animals," i. 17.
FATHERS OF BIOLOGY.
the air cools it and carries off its superfluous heat. Some
of the air which enters the lung gets from the bronchial
tubes into the blood-vessels by transudation, for there is
no direct communication between them; and this air,
penetrating the body, rapidly cools the blood throughout
the vessels. But Aristotle did not consider the "pneuma,"
which thus reached the interior of the blood-vessels, to
be exactly the same thing as air it was " a subtilized and
condensed air." l And this we now know to be oxygen.
The treatise " On the Generation of Animals " is an
extraordinary production. " No ancient and few modern
works equal it in comprehensiveness of detail and pro-
found speculative insight. We here find some of the
obscurest problems of biology treated with a mastery
which, when, we consider the condition of science at
that day, is truly astounding. That there are many
errors, many deficiencies, and not a little carelessness in
the admission of facts, may be readily imagined ; never-
the less at times the work is frequently on a level with,
and occasionally even rises above, the speculations of
many advanced embryologists." 2
It commences with the statement that the present
work is a sequel to that " On the Parts of Animals ;" and
first the masculine and feminine principles are defined.
The masculine principle is the origin of all motion and
1 See Professor Huxley's article already referred to.
2 "Aristotle," by G. H. Lewes, p. 325.
ARISTOTLE. 39
generation; the feminine principle is the origin of the
material generated. Aristotle's philosophy of nature was
teleological, and the imperfect character of his anatomical
knowledge often gives him occasion to explain particular
phenomena by final causes. Thus animals producing
soft-shelled eggs (e.g. cartilaginous fish and vipers) are
said to do so because they have so little warmth that
the external surface of the egg cannot be dried.
Among insects, some (e.g. grasshopper, cricket, ant,
etc.) produce young in the ordinary way, by the union of
the sexes ; in other cases (e.g. flies and fleas) this union
of the sexes results in the production of a skolex ; while
others have no parents, nor do they have congress such
are the ephemera, tipula, and the like. Aristotle dis-
cusses and rejects the theory that the male reproductive
element is derived from every part of the body. He
concludes that "instead of saying that it comes from all
parts of the body, we should say that it goes to them. It
is not the nutrient fluid, but that which is left over, which
is secreted. Hence the larger animals have fewer young
than the smaller, for by them the consumption of nutrient
material will be larger and the secretion less. Another
point to be noticed is, that the nutrient fluid is universally
distributed through the body, but each secretion has its
separate organ. ... It is thus intelligible why children
resemble their parents, since that which makes all the
parts of the body, resembles that which is left over as
40 FATHERS OF BIOLOGY.
secretion : thus the hand, or the face, or the whole
animal pre-exists in the sperm, though in an undifferen-
tiated state (dSio/no-rus) ; and what each of these is in
actuality (ci/epyetp), such is the sperm in potentiality
In later times the two great rival theories put for-
ward to account for the development of the embryo
have been
(a) The theory of Evolution, which makes the embryo
pre-existent in the germ, and only rendered
visible by the unfolding and expansion of its
organs.
(b) The theory of Epigenesis, which makes the em-
bryo arise, by a series of successive differentia-
tions, from a simple homogeneous mass into
a complex heterogeneous organism.
The above quotation will show how closely Aristotle
held to the theory of Epigenesis ; and in another place
he says, " Not at once is the animal a man or a horse,
for the end is last attained; and the specific form is
the end of each development."
Spontaneous generation is nowadays rejected by
science ; but Aristotle went so far as to believe that
insects, molluscs, and even eels, were spontaneously
generated. It is, however, noteworthy, in view of modern
investigations, that he looked upon putrefying matter as
the source of such development.
ARISTOTLE. 41
A chapter of this work is devoted to the considera-
tion of the hereditary transmission of peculiarities from
parent to offspring.
The fifth and last book contains inquiries into the
cause of variation in the colour of the eyes and hair,
the abundance of hair, the sleep of the embryo, sight
and hearing, voice and the teeth.
Widely different opinions have been held from time
to time of the value of Aristotle's biological labours.
This philosopher's reputation has, perhaps, suffered most
from those who have praised him most. The praise
has often been of such an exaggerated character as to
have become unmeaning, and to have carried with it
the impression of insincerity on the part of the writer.
Such are the laudations of Cuvier. To say as he does,
" Alone, in fact, without predecessors, without having
borrowed anything from the centuries which had gone
before, since they had produced nothing enduring, the
disciple of Plato discovered and demonstrated more
truths and executed more scientific labours in a life of
sixty-two years than twenty centuries after him were
able to do," is of course to talk nonsense, for the method
which Aristotle applied was that which Hippocrates
had used so well before him ; and it is evident to any
one that both his predecessors and contemporaries are
frequently laid under contribution by Aristotle, although
the authority is rarely, if ever, stated by him unless he
42 FATHERS OF BIOLOGY.
is about to refute the view put forward. Exaggerated
praise of any author has a tendency to excite depre-
ciation correspondingly unjust and untrue. It has been
so in the case of this great man. In the endeavour to
depose him from the impossible position to which his
panegyrists had exalted him, his detractors have gone to
any length. The principal charges brought against his
biological work have been inaccuracy and hasty gene'-
ralization. In support of the charge of inaccuracy, some
of the extraordinary statements which are met with in his
works are adduced. " These," Professor Huxley says,
" are not so much to be called errors as stupidities."
Some, however, of the inaccuracies alleged against
Aristotle are fancied rather than real. Thus he is charged
with having represented that the arteries contained
nothing but air ; that the aorta arose from the right ven-
tricle; that the heart did not beat in any other animal
but man ; that reptiles had no blood, etc. ; although in
reality he made no one of these assertions. There
remain, nevertheless, the gross misstatements referred to
above, and which really do occur. Such, for instance,
as that there is but a single bone in the neck of the
lion ; that there are more teeth in male than in female
animals ; that the mouth of the dolphin is placed on
the under surface of the body ; that the back of the
skull is empty, etc. Although these absurdities un-
doubtedly occur in Aristotle's works, it by no means
ARISTOTLE. 43
follows that he is responsible for them. Bearing in
mind the curious history of the manuscripts of his trea-
tises, we shall find it far more reasonable to conclude
that such errors crept in during the process of correction
and restoration, by men apparently ignorant of biology,
than that (to take only one case) an observer who had
distinguished the cetacea from fishes and had detected
their hidden mammae, discovered their lungs, and recog-
nized the distinct character of their bones, should have
been so blind as to fancy that the mouth of these
animals was on the under surface of the body.
That Aristotle made hasty generalizations is true ;
but it was unavoidable. Biology was in so early a stage
that a theory had often of necessity to be founded on
a very slight basis of facts. Yet, notwithstanding this
drawback, so great was the sagacity of this philosopher,
that many of his generalizations, which he himself pro-
bably looked upon as temporary, have held their ground
for twenty centuries, or, having been lost sight of, have
been discovered and put forward as original by modern
biologists. Thus "the advantage of physiological
division of labour was first set forth," says Milne-
Edwards, "by myself in 1827;" and yet Aristotle had
said l that " whenever Nature is able to provide two
separate instruments for two separate uses, without the
one hampering the other, she does so, instead of acting
1 "De Part. Anim.," iv. 6.
44 FATHERS OF BIOLOGY.
like a coppersmith, who for cheapness makes a spit-and-
a-candlestick in one. 1 It is only when this is impossible
that she uses one organ for several functions."
In conclusion, we may say that the great Stagirite
expounded the true principles of science, and that when
he failed his failure was caused by lack of materials.
His desire for completeness, perhaps, tempted him at
times to fill in gaps with such makeshifts as came to
his hand; but no one knew better than he did that
" theories must be abandoned unless their teachings
tally with the indisputable results of observation." 2
2 "De Gener.," iii. 10, quoted by Dr. Ogle.
GALEN.
GALEN.
UNDER the Ptolemies a powerful stimulus was given to
biological studies at Alexandria. Scientific knowledge
was carried a step or two beyond the limit reached by
Aristotle. Thus Erasistratus and Herophilus thoroughly
investigated the structure and functions of the valves of
the heart, and were the first to recognize the nerves as
organs of sensation. But, unfortunately, no complete
record of the interesting work carried on by these men
has come down to our times. The first writer after
Aristotle whose works arrest attention is Caius Plinius
Secundus, whose so-called " Natural History," in thirty-
seven volumes, remains to the present day as a monument
of industrious compilation. But, as a biologist properly
so called, Pliny is absolutely without rank, for he lacked
that practical acquaintance with the subject which alone
could enable him to speak with authority. Of informa-
tion he had an almost inexhaustible store; of actual
knowledge, the result of observation and experience, so
far as biological studies were concerned, he had but
48 FATHERS OF BIOLOGY
little. This was largely due to the encyclopaedic
character of the work he undertook ; his mental powers
were weighed down by an enormous mass of unarranged
and ill-digested materials. But it was due also to the
peculiar bent of Pliny's mind.. He was not, like Aristotle,
an original thinker ; he was essentially a student of
books, an immensely industrious but not always judicious
compiler. Often his selections from other works prove
that he failed to appreciate the relative importance of the
different subjects to which he made reference. His
knowledge of the Greek language appears, too, to have
been defective, for he gives at times the wrong Latin
names to objects described by his Greek authorities.
To these defects must be added his marvellous readiness
to believe any statement, provided only that it was
uncommon; while, on the other hand, he showed an
indefensible scepticism in regard to what was really
deserving of attention. The chief value of his work
consists in the historical and chronological notes of the
progress of some of the subjects of which he treats
fragments of writings which would otherwise be lost to
us. Pliny was killed in the destruction of Pompeii,
A.D. 79.
Claudius Galenus was born at Pergamus, in Asia Minor,
in the hundred and thirty-first year of the Christian era.
Few writers ever exercised for so long a time such an
undisputed sway over the opinions of mankind as did
GALEN. 49
this wonderful man. His authority was estimated at a
much higher rate than that of all the biological writers
combined who flourished during a period of more than
twelve centuries, and it was often considered a sufficient
argument against a hypothesis, or even an alleged matter
of fact, that it was contrary to Galen.
Endowed by nature with a penetrating genius and a
mind of restless energy, he was eminently qualified to
profit by a comprehensive and liberal education. And
such he received. His father, Nicon, an architect, was
a man of learning and ability a distinguished mathe-
matician and an astronomer and seems to have devoted
much time and care to the education of his son.
The youth appears to have studied philosophy suc-
cessively in the schools of the Stoics, Academics,
Peripatetics, and Epicureans, without attaching himself
exclusively to any one of these, and to have taken from
each what he thought to be the most essential parts
of their system, rejecting, however, altogether the tenets
of the Epicureans. At the age of twenty-one, on the
death of his father, he went to Smyrna to continue the
study of medicine, to which he had now devoted himself.
After leaving this place and having travelled extensively,
he took up his residence at Alexandria, which was then
the most favourable spot for the pursuit of medical
studies. Here he is said to have remained until he was
twenty-eight years of age, when his reputation secured
E
50 FATHERS OF BIOLOGY.
his appointment, in his native city of Pergamus, to the
office of physician in charge of the athletes in the
gymnasia situated within the precincts of the temple of
./Esculapius, For five or six years he lived in Pergamus,
and then a revolt compelled him to leave his native
town. The advantages offered by Rome led him to
remove thither and take up his residence in the capital
of the world. Here his skill, sagacity, and knowledge
soon brought him into notice, and excited the jealousy
of the Roman doctors, which was still further increased
by some wonderful cures the young Greek physician
succeeded in effecting. Possibly it was owing to the
ill feeling shown to Galen that, on the outbreak of
an epidemic a year afterwards, he left the imperial city
and proceeded to Brindisi, and embarked for Greece.
It was his intention to devote his time to the study
of natural history, and for this purpose he visited
Cyprus, Palestine, and Lemnos. While at the last-named
place, however, he was suddenly summoned to Aquileia
to meet the Emperors Marcus Aurelius and Lucius
Verus. He travelled through Thrace and Macedonia on
foot, met the imperial personages, and prepared for them
a medicine, for which he seems to have been famous,
and which is spoken of as the theriac. It was probably
some combination of opium with various aromatics and
stimulants, for antidotes of many different kinds were
habitually taken by the Romans to preserve them from
GALEN. 51
the ill effects of poison and of the bites of venomous
animals. 1
With the Emperor M. Aurelius he returned to Rome,
and became afterwards doctor to the young Emperor
Commodus. He did not, however, remain for a long
period at Rome, and probably passed the greater part
of the rest of his life in his native country.
Although the date of his death is not positively known,
yet it appears from a passage 2 in his writings that he
was living in the reign of Septimius Severus ; and Suidas
seems to have reason for asserting that he reached his
seventieth year.
Galen's writings represent the common depository of
the anatomical knowledge of the day; what he had
learnt from many teachers, rather than the results of
his own personal research. Roughly speaking, they
deal with the following subjects : Anatomy and Physio-
logy, Dietetics and Hygiene, Pathology, Diagnosis and
Semeiology, Pharmacy and Materia Medica, Thera-
peutics.
The only works of this voluminous writer at which
we can here glance are those dealing with Anatomy
and Physiology. These exhibit numerous illustrations
of Galen's familiarity with practical anatomy, although
it was most likely comparative rather than human
1 Hence the name 6-rjpiaKat.
2 " De Antidotis," i. 13, vol. xiv. p. 65, Kuhn.
52 FATHERS OF BIOLOGY.
anatomy at which he especially worked. Indeed, he
seems to have had but few opportunities of carrying
on human dissections, for he thinks himself happy in
having been able to examine at Alexandria two human
skeletons ; and he recommends the dissection of monkeys
because of their exact resemblance to man. To this dis-
advantage may, perhaps, be attributed the readiness, which
sometimes appears, to assume identity of organization
between man and the brutes. Thus, because in certain
animals he found a double biliary duct, he concluded
the same to be the case in man, and in one instance he
proceeded to deduce the cause of disease from this
erroneous assumption.
He supposed that there were three modes of existence
in man, namely
(a) The nutritive, which was common to all animals
and plants, of which the liver was the source.
(b) The vital, of which the heart was the source.
(c) The rational, of which the brain was the source.
Again, he considered that the animal economy pos-
sessed four natural powers
(1) The attractive.
(2) The alterative or assimilative.
(3) The retentive or digestive.
(4) The expulsive.
Like his predecessors, he asserted that there were
four humours, namely, blood, yellow bile, black bile, and
GALEN. 53
aqueous serum. He held that it was the office of the
liver to complete the process of sanguification commenced
in the stomach, and that during this process the yellow
bile was attracted by the branches of the hepatic duct
and gall-bladder; the black bile being attracted by the
spleen, and the aqueous humour by the two kidneys ;
while the liver itself retained the pure blood, which was
afterwards attracted by the heart through the vena cava,
by whose ramifications it was distributed to the various
parts of the body.
Following Aristotle especially, he regarded hair, nails,
arteries, veins, cartilage, bone, ligament, membranes,
glands, fat, and muscle as the simplest constituents of
the body, formed immediately from the blood, and per-
fectly homogeneous in character. The organic members,
e.g. lungs, liver, etc., he looked upon as formed of several
of the foregoing simple parts.
The osteology contained in Galen's worts is nearly
as perfect as that of the present day. He correctly
names and describes the bones and sutures of the
cranium ; notices the quadrilateral shape of the parietals,
the peculiar situation and shape of the sphenoid, and
the form and character of the ethmoid, malar, maxillary,
and nasal bones. He divides the vertebral columns
into cervical, dorsal, and lumbar portions.
With regard to the nervous system, he taught that
the nerves of the senses are distinct from those which
54 FATHERS OF BIOLOGY.
impart the power of motion to muscles that the former
are derived from the anterior parts of the brain, while
the latter arise from the posterior portion, or from the
spinal cord. He maintained that the nerves of the finer
senses are formed of matter too soft to be the vehicles
of muscular motion ; whereas, on the other hand, the
nerves of motion are too hard to be susceptible of fine
sensibility. His description of the method of demon-
strating the different parts of the brain by dissection is
very interesting, and, like his references to various in-
struments and contrivances, proves him to have been
a practical and experienced anatomist.
In his description of the organs and process of nutri-
tion, absorption by the veins of the stomach is correctly
noticed, and the union of the mesenteric veins into one
common vena portce is pointed out. The communica-
tions between the ramifications of the vena portse and
of the proper veins of the liver are supposed by Galen
to be effected by means of anastomosing pores or
channels. Although it is evident that Galen was ignorant
of the true absorbent system, yet he appears to have
been aware of the lacteals ; for he says that in addition
to those mesenteric veins which by their union form
the vena portse, there are visible in every part of the
mesentery other veins, proceeding also from the intes-
tines, which terminate in glands ; and he supposes that
these veins are intended for the nourishment of the
GALEN. 55
intestines themselves. Some of Galen's contemporaries
asserted that upon exposing the mesentery of a sucking
animal several small vessels were seen filled first with
air, and afterwards with milk. They had, doubtless,
mistaken colourless lymph for air; but Galen ridicules
both assertions, and thereby shows that he had not
examined the contents of the lacteals. This is some-
what remarkable, because as a rule he omitted no oppor-
tunity of determining with certainty, by vivisection and
experiments on living animals, the uses of the various
parts of the body. As an illustration of this, we have
his correct statement, established by experiment, that
the pylorus acts as a valve only during the process of
digestion, and that it is relaxed when digestion is com-
pleted.
He recognizes that the flesh of the heart is somewhat
different to that of the muscles of voluntary motion. Its
fibres are described as being arranged in longitudinal
and transverse bundles ; the former by their contractions
shortening the organ, the latter compressing and narrow-
ing it. Such statements show that he regarded the heart
as essentially muscular. He thought, however, -that it
was entirely destitute of nerves. Although he admitted
that possibly it had one small branch derived from the
nervus vagus sent to it, yet he entirely overlooked the
great nervous plexus surrounding the roots of the blood-
vessels, from which branches proceed in company with
56 FATHERS OF BIOLOGY.
the branches of the coronary arteries and veins, and
penetrate the muscular substance of the ventricles. He
endeavoured to prove, by experiment, observation, and
reasoning, that the arteries as well as the veins contained
blood, and in this connection he tells an amusing story.
A certain teacher of anatomy, who had declared that the
aorta contained no blood, was earnestly desired by his
pupils, who were ardent disciples of Galen, to exhibit
the requisite demonstration, they themselves offering
animals for the experiment. He, however, after various
subterfuges, declined, until they promised to give him a
suitable remuneration, which they raised by subscription
among themselves to the amount of a thousand drachmae
(perhaps ^30). The professor, being thus compelled
to commence the experiment, totally failed in his attempt
to cut down upon the aorta, to the no small amusement
of his pupils, who, thereupon taking up the experiment
themselves, made an opening into the thorax in the way
in which they had been instructed by Galen, passed one
ligature round the aorta at the part where it attaches
itself to the spine, and another at its origin, and then, by
opening the intervening portion of the artery, showed
that blood was contained in it.
The arteries, Galen thought, possessed a pulsative and
attractive power of their own, independently of the heart,
the moment of their dilatation being the moment of their
activity. They, in fact, drew their charge from the heart,
GALEN. 57
as the heart by its diastole drew its charge from the vena
cava and the pulmonary vein. The pulse of the arteries,
he also thought, was propagated by their coats, not by
the wave of blood thrown into them by the heart. He
taught that at every systole of the arteries a certain
portion of their contents was discharged at their ex-
tremities, namely, by the exhalents and secretory vessels.
Though he demonstrated the anastomosis of arteries and
veins, he nowhere hints his belief that the contents of the
former pass into the latter, to be conveyed back to the
heart, and from it to be again diffused over the body.
He made a near approach to the Harveian theory of
the circulation, as Harvey himself admits in his " De
Motu Cordis;" 1 but the grand point of difference between
Galen and Harvey is the question whether or not, at
every systole of the left ventricle, more blood is thrown
out than is expended on exhalation, secretion, and
nutrition. Upon this point Galen held the negative,
and Harvey, as we all know, the affirmative.
The famous Asclepiads held that respiration was for
the generation of the soul itself, breath and life being
thus considered to be identical. Hippocrates thought
it was for the nutrition and refrigeration of the innate
1 "Ex ipsius etiam Galeni verbis hanc veritatem confirmari posse,
scilicet : non solum posse sanguinem e vena arteriosa in arteriam
venosam et inde in sinistrum ventriculum cordis, et postea in
arterias transmitti." " De Motu Cordis," cap. vii,
FATHERS OF BIOLOGY.
heat, Aristotle for its ventilation, Erasistratus for the
filling of the arteries with spirits. All these opinions are
discussed and commented upon by Galen, who deter-
mines the purposes of respiration to be (i) to preserve
the animal heat ; (2) to evacuate from the blood the
products of combustion.
He conjectured that there was in atmospheric air not
only a quality friendly to the vital spirit, but also a
quality inimical to it, which conjecture he drew from
observation of the various phenomena accompanying
the support and the extinction of flame ; and he says that
if we could find out why flame is extinguished by absence
of the air, we might then know the nature of that sub-
stance which imparts warmth to the blood during the
process of respiration.
On another occasion he says that it is evidently the
quality and not the quantity of the air which is necessary
to life. He further shows that he recognized the analogy
between respiration and combustion, by comparing the
lungs to a lamp, the heart to its wick, the blood to the
oil, and the animal heat to the flame.
From certain observations in various parts of his
works, it appears that, although ignorant of the doctrine
of atmospheric pressure, he was acquainted with some
of its practical effects. Thus, he says, if you put one
end of an open tube under water and suck out the air
with the other end, you will draw up water into the
GALEN". 59
mouth, and that it is in this way that infants extract the
milk from the mother's breast.
Again, Erasistratus supposed that the vapour of char-
coal and of certain pits and wells was fatal to life because
lighter than common air, but Galen maintained it to be
heavier.
He describes two kinds of respiration, one by the
mouths of the arteries of the lungs, and one by the
mouths of the arteries of the skin. In each case, he
says, the surrounding air is drawn into the vessels during
their diastole, for the purpose of cooling the blood, and
during their systole the fuliginous particles derived from
the blood and other fluids of the body are forced out.
He considers the diaphragm to be the principal muscle
of respiration, but he makes a clear distinction between
ordinary respiration, which he calls a natural and involun-
tary effort, and that deliberate and forced respiration
which is obedient to the will ; and he says that there are
different muscles for the two purposes. Elsewhere he
particularly points out the two sets of intercostal muscles
and their mode of action, of which, before his time, he
asserts that anatomists were ignorant.
He describes various effects produced on respiration
and on the voice by the division of those nerves which
are connected with the thorax; and shows particularly
the effect of dividing the recurrent branch of his sixth
pair of cerebral nerves (the pneumogastric of modern
60 FATHERS OF BIOLOGY.
anatomy). He explains how it happens that after divi-
sion of the spinal cord, provided that division be beneath
the lower termination of the neck, the diaphragm will
still continue to act in consequence, namely, of the
origin of the phrenic nerve being above the lower termina-
tion of the neck.
Before the time of Galen the medical profession was
divided into several sects, e.g. Dogmatici, Empiric!,
Eclectici, Pneumatic!, and Episynthetici, who were
always disputing with one another. After his time all
sects seem to have merged in his followers. The subse-
quent Greek and Roman biological writers were mere
compilers from his works, and as soon as his writings
were translated into Arabic they were at once adopted
throughout the East to the exclusion of all others. He
remained paramount throughout the civilized world until
within the last three hundred years. In the records of
the College of Physicians of England we read that Dr.
Geynes was cited before the college in 1559 for impugn-
ing the infallibility of Galen, and was only admitted
again into the privileges of his fellowship on acknowledg-
ment of his error, and humble recantation signed with
his own hand. Kurt Sprengel has well said that " if
the physicians who remained so faithfully attached to
Galen's system had inherited his penetrating mind, his
observing glance, and his depth, the art of healing would
have approached the limit of perfection before all the
GALEN. 61
other sciences ; but it was written in the book of destiny
that mind and reason were to bend under the yoke of
superstition and barbarism, and were only to emerge
after centuries of lethargic sleep."
VESALIUS.
VESA LI US.
THE authority of Galen, at once a despotism and a
religion, was scarcely ever called in question until the
sixteenth century. No attempt worth recording was
made during thirteen hundred years to extend the
boundary of scientific knowledge in anatomy and phy-
siology. It is true that the scholastic philosopher, Albertus
Magnus, who was for a short time (1260-1262) Bishop
of Ratisbon, in the middle of the thirteenth century
wrote a " History of Animals," which was a remarkable
production for the age in which he lived ; although Sir
Thomas Browne, in his famous " Enquiries into Common
Errors," speaks of these " Tractates " as requiring to be
received with caution, adding as regards Albertus that
" he was a man who much advanced these opinions by
the authoritie of his name, and delivered most conceits,
with strickt enquirie into few."
As regards human anatomy, it was considered, during
the Middle Ages, to be impiety to touch with a scalpel
"the dead image of God," as man's body was called.
F
66 FATHERS OF BIOLOGY.
Mundinus, the professor of medicine at Bologna from
1315 to 1318, was the first to attempt any such thing.
He exhibited the public dissection of three bodies, but
by this created so great a scandal that he gave up the
practice, and contented himself with publishing a work,
" De Anatome," which formed a sort of commentary on
Galen. This work, with additions, continued to be the
text-book of the schools until the time of Vesalius, who
founded the study of anatomy as nowadays pursued.
Andreas Vesalius was bom at Brussels, on the last day
of the year 1514, of a family which for several genera-
tions had been eminent for medical attainments. He
was sent as a boy to Louvain, where he spent the greater
part of his leisure in researches into the mechanism of
the lower animals. He was a born dissector, who, after
careful examination, in his early days, of rats, moles, dogs,
cats, monkeys, and the like, came, in after-life, to be dis-
satisfied with any less knowledge of the anatomy of man.
He acquired great proficiency in the scholarship of the
day. Indeed the Latin, in which he afterwards wrote his
great work, is so singularly pure that one of his detractors
pretended that Vesalius must have got some good scholar
to write the Latin for him. Latin was not the only lan-
guage in which he was proficient ; he added Greek and
Arabic to his other accomplishments, and this for the
purpose of reading the great biological works in the lan-
guages in which they were originally written. From
VESALIUS. 67
Louvain the youth went to Paris, where he studied
anatomy under a most distinguished physician, Sylvius.
It was the practice of that illustrious professor to read
to his class Galen on the " Use of Parts," omitting nearly
all the sections where exact knowledge of anatomical
detail was necessary. Sometimes an attempt was made
to illustrate the lecture by the dissection of a dog, but
such illustration more often exposed the professor's
ignorance than it added to the student's knowledge.
Indirectly, however, it did good, for whenever Sylvius,
after having tried in vain to demonstrate some muscle,
or nerve, or vein, left the room, his pupil Vesalius slipped
down to the table, dissected out the part with great neat-
ness, and triumphantly called the professor's attention to
it on his return.
Besides studying under Sylvius, Vesalius had for his
teacher at Paris the famous Winter, of Andernach, who
was physician to Francis I. This learned man, in a work
published three years after this period, speaks of Vesalius
as a youth of great promise. At the age of nineteen
Vesalius returned to Louvain ; and here for the first time
he openly demonstrated from the human subject. In
this connection a somewhat ghastly story is told, which
serves to show the intensity of the enthusiasm with which
our anatomist was inspired. On a certain evening it
chanced that Vesalius, in company with a friend, had
rambled out of the gates of Louvain to a spot where the
68 FATHERS OF BIOLOGY.
bodies of executed criminals were wont to be exposed.
A noted robber had been executed. His body had been
chained to a stake and slowly roasted; and the birds
had so entirely stripped the bones of every vestige of
flesh, that a perfect skeleton, complete and clean, was
suspended before the eyes of the anatomist, who had
been striving hitherto to piece together such a thing out
of the bones of many people, gathered as occasion
offered. Mounting upon the shoulder of his friend,
Vesalius ascended the charred stake and forcibly tore
away the limbs, leaving only the trunk, which was
securely bound by iron chains. With these stolen bones
under their clothes the two youths returned to Louvain.
In the night, however, and alone, the sturdy Vesalius
found his way again to the place which to most men, at
any rate in those times, would have been associated with
unspeakable horrors and there, by sheer force, wrenched
away the trunk, and buried it. Then leisurely and care-
fully, day after day, he smuggled through the city gates
bone after bone. Afterwards, when he had set up the
perfect skeleton in his own house, he did not hesitate to
demonstrate from it. But such an act of daring plunder
could not escape detection, and he was banished from
Louvain for the offence. This story is here quoted
only to show the extraordinary physical and moral
courage which the anatomist possessed; which upheld
him through toils, dangers, and disgusts ; and by which
VESALIUS. 69
he was strengthened to carry on, even in a cruel and
superstitious age, and placed, as he was, on the very
threshold of the Inquisition, a work at all times repulsive
to flesh and blood.
After serving for a short time as a surgeon in the army
of the Emperor Charles V., Vesalius went to Italy,
where he at once attracted the attention of the most
learned men, and became, at the age of twenty-two,
Professor of Anatomy at the University of Padua. This
was the first purely anatomical professorship that had
been established out of the funds of any university.
For seven years he held the office, and he was at the
same time professor at Bologna and at Pisa. During
these years his lectures were always well attended, for
they were a striking innovation on the tameness of con-
ventional routine. In each university the services of
the professor were confined to a short course of demon-
strations, so that his duties were complete when he had
spent, during the winter, a few weeks at each of the three
towns in succession. He then returned to Venice, which
he appears to have made his head-quarters. At this
city, as well as at Pisa, special facilities were offered to
the professor for obtaining bodies either of condemned
criminals or others. At Padua and Bologna the enthu-
siasm of the students, who became resurrectionists on
their teacher's behalf, kept the lecture-table supplied
with specimens. They were in the habit of watching all
70 FATHERS OF BIOLOGY.
the symptoms in men dying of a fatal malady, and noting
where, after death, such men were buried. The seclusion
of the graveyard was then invaded, and the corpse
secretly conveyed by Andreas to his chamber, and con-
cealed sometimes in his own bed. A diligent search was
at once made to determine accurately the cause of death.
This pitiless zeal for correct details in anatomy, associated
as it was with indefatigable practice in physic, appeared
to Vesalius, as it does to his successors of to-day, to be
the only satisfactory method of acquiring that knowledge
which is essential to a doctor. Thus it was that he, who
at the age of twenty-two was able to name, with his eyes
blindfolded, any human bone put into his hand, who
was deeply versed in comparative anatomy, and had
more accurate knowledge of the human frame than any
graybeard of the time, enjoyed afterwards a reputation
as a physician which was unbounded. One illustration
of his sagacity in diagnosis will suffice. A patient of
two famous court physicians at Madrid had a big and
wonderful tumour on the loins. It would have been
easily recognized in these days as an aneurismal tumour,
but it greatly puzzled the two doctors. Vesalius was
therefore consulted, and said, " There is a blood-vessel
dilated ; that tumour is full of blood." They were sur-
prised at such a strange opinion ; but the man died, the
tumour was opened ; blood was actually found in it, and
we are told in admirationem raptifuere omnes.
VESA LI us.
It was not until after Vesalius had been three years
professor that he began to distrust the infallibility of
Galen's anatomical teaching. Constant practical expe-
rience in dissection, both human and comparative, slowly
convinced him that great anatomist as the " divus
homo " had undoubtedly been his statements were not
only incomplete, but often wrong ; further, that Galen
very rarely wrote from actual inspection of the human
subject, but based his teaching on a belief that the struc-
ture of a monkey was exactly similar to that of a man.
With this conviction established, Vesalius proceeded to
note with great care all the discrepancies between the
text of Galen and the actual parts which it endeavoured
to describe, and in this way a volume of considerable
thickness was soon formed, consisting entirely of annota-
tions upon Galen. The generally received authorities
being thus found to be unreliable, it became necessary in
the next place to collect and arrange the fundamental
facts of anatomy upon a new and sounder basis. To
this task Vesalius, at the age of twenty-five, devoted
himself, and began his famous work on the " Fabric of
the Human Body." Owing possibly to the good fortune
of his family, and to the income which he derived from
his professorships, Andreas was able to secure for his
work the aid of some of the best artists of the day. To
Jean Calcar, one of the ablest of the pupils of Titian,
are due the splendid anatomical plates which illustrate
72 FATHERS OF BIOLOGY.
the " Corporis Human! Fabrica," and which are incom-
parably better than those of any work which preceded it.
To him most likely is due also the woodcut which adorns
the first page, and which represents the young Vesalius,
wearing professor's robes, standing at a lecture-table and
pointing out, from a robust subject that lies before him,
the inner secrets of the human body ; while the tiers of
benches that surround the professor are completely
crowded with grave doctors struggling to see, even
climbing upon the railings to do so.
But throughout the work the plates are used simply to
illustrate and elucidate the text, and the information
furnished in the latter is minute and accurate, and stated
in well-polished Latin. As the author proceeds, he finds
it necessary to disagree with Galen, and the reasons for
this disagreement are given. The inevitable result follows
that Vesalius is placed at issue not only with " the divine
man," but also with all those who for thirteen centuries
had unquestioningly followed him. Such a result Vesalius
must have foreseen. It was not, therefore, a great sur-
prise to him, perhaps, to receive, soon after the publica-
tion of his work, a violent onslaught from his old master
Sylvius. He simply replied to it by a letter full of respect
and friendly feeling, inquiring wherein he had been
guilty of error. The answer he got was that he must
show proper respect for Galen, if he wished to be
regaided as a friend of Sylvius.
VESALIUS. 73
In 1546, three years after the publication of his great
work, Andreas was summoned to Ratisbon to exercise
his skill upon the emperor, and from that date he was
ranked among the court physicians. In the same year,
1546, in a long letter, entitled " De usu Radicis Chinae,"
he not only treats of the medicine by which the emperor's
health had been restored, but he vindicates his teaching
against his assailants, and again gives cumulative proof
of the fact that Galen had dissected only brutes.
It was the practice of Vesalius, while he was professor
in Italy, to issue a public notice the day before each
demonstration, stating the time at which it would take
place, and inviting all who decried his errors to attend
and make their own dissections from his subject, and
confound him openly. It does not appear that any one
was rash enough ever to accept the challenge ; yet,
although the majority of the young men were on the
side of Vesalius, the older teachers continued to regard
him as a heretic, and in 1551 Sylvius published a bitterly
personal attack. It was nothing to him that the results
of actual dissection were against him he even went so
far as to assert that the men of his time were constructed
somewhat differently to those of the time of Galen !
Thus, to the proof that Vesalius gave that the carpal
bones were not absolutely without marrow, as Galen had
asserted, Sylvius replied that the bones were harder and
more solid among the ancients, and were, in consequence,
74 FATHERS OF BIOLOGY.
destitute of medullary substance. Again, when Vesalius
showed that Galen was wrong in describing the human
femur and humerus as greatly curved, Sylvius explained
the discrepancy by saying that the wearing of narrow
garments by the moderns had straightened the limbs.
Through these attacks, however, the writings of Vesalius
fell into somewhat bad odour in the court ; for in that
very superstitious age there was a kind of vague dread
felt of reading the works of a man against whom such
serious charges of arrogance and impiety were brought.
And so it came about that when he received the
summons to take up his residence permanently at
Madrid, and the orthodoxy of the day seemed for the
moment to triumph, in a fit of proud indignation, he
burned all his manuscripts ; destroying a huge volume
of annotations upon Galen; a whole book of medical
formulae; many original notes on drugs; the copy of
Galen from which he lectured, and which was covered
with marginal notes of new observations that had
occurred to him while demonstrating; and the paraphrases
of the books of Rhases, in which the knowledge of the
Arabian was collated with that of the Greeks and others.
The produce of the labour of many years was thus
.reduced to ashes in a short fit of passion, and from this
time Vesalius lived no more for controversy or study.
He gave himself up to pleasure and the pursuit of wealth,
resting on his reputation and degenerating into a mere
VESALIUS. 75
courtier. As a practitioner he was held in high esteem.
When the life of Don Carlos, Philip's son, was despaired
of, it was Vesalius who was called in, and who, seeing
that the surgeons had bound up the wound in the head
so tightly that an abscess had formed, promptly brought
relief to the patient by cutting into the pericranium.
The cure of the prince, however, was attributed by the
court to the intercession of St. Diego, and it is possible
that on the subject of this alleged miraculous recovery
Vesalius may have expressed his opinion rather more
strongly than it was safe for a Netherlander to do. At
any rate, the priests always looked upon him with dislike
and suspicion, and at length they and the other enemies
of the great anatomist had their revenge.
A young Spanish nobleman had died, and Vesalius,
who had attended him, obtained permission to ascertain,
if possible, by a post-mortem examination, the cause of
death. On opening the body, the heart was said by
the bystanders to beat ; and a charge, not merely of
murder, but of impiety also, was brought against Vesalius.
It was hoped by his persecutors that the latter charge
would be brought before the Inquisition, and result in
more rigorous punishment than any that would be in-
flicted by the judges of the common law. The King of
Spain, however, interfered and saved him, on condition
that he should make a pilgrimage to the Holy Land.
Accordingly he set out from Madrid for Venice, and
76 FATHERS OF BIOLOGY.
thence to Cyprus, from which place he went on to
Jerusalem, and was returning, not to Madrid, but to
Padua, where the professorship of physic had been
offered him, when he suffered shipwreck on the island
of Zante, and there perished miserably of hunger and
grief, on October 15, 1564, before he had reached the
age of fifty. His body was found by a travelling gold-
smith, who recognized, notwithstanding their starved
outlines, the features of the renowned anatomist, and
respectfully buried his remains and raised a statue to his
memory.
Two of the works of this great man have been already
referred to, namely: " De corporis Humani Fabrica;"
"De usu Radicis Chinae." Besides these the following
have appeared : " Examen Observationum Gabrielis
Fallopii ; " " Gabrielis Cunei Examen, Apologias Fran-
cisci Putei pro Galeno in Anatome ; " a great work on
Surgery in seven books.
With respect to the last of these, it may be sufficient
to remark that there is every reason to believe that the
name of the famous anatomist was stolen after his death
to give value to the production, which was compiled and
published by a Venetian named Bogarucci ; and that
Vesalius is not responsible for the contents.
The other works are undoubtedly genuine. In 1562
Andreas seems to have been roused for a short time
from the lethargy into which he had sunk, by an attack
VESALIUS. 77
from Franciscus Puteus ; for to this attack a reply ap-
peared from a writer calling himself Gabriel Cimeus
which has always been attributed by the most competent
authorities to Vesalius himself. In this rather long work,
covering as it does more than fifty pages in the folio
edition, the views of Vesalius, which are at variance with
Galen, are gone through seriatim and defended.
In 1561 Fallopius, who had studied under Vesalius,
published his " Anatomical Observations," containing
several points in which he had extended the knowledge
of anatomy beyond the limits reached by his master.
He had taught publicly for thirteen years at Ferrara,
and had presided for eight years over an anatomical
school, so that he was no novice in the field of biology.
Yet so completely had Vesalius lost the philosophic
temperament that he regarded this publication as an
infringement of his rights, and in this spirit wrote an
" Examen Observationum Fallopii," in which he decried
the friend who had made improvements on himself, as
he had been decried for his improvements on Galen.
The manuscript of this work, finished at the end of
December, 1561, was committed by the author to the
care of Paulus Teupulus of Venice, orator to the King
of Spain, who was to give it to Fallopius. The orator,
however, did not reach Padua until after the death of
Fallopius, and he consequently retained the document
until Vesalius, on his way to Jerusalem, took possession
78 FATHERS OF BIOLOGY.
of it, and caused it to be published without delay. It
appeared at Venice in I564. 1
The letter on the China root a plant we know nowa-
days as sarsaparilla by the use of which the emperor's
recovery was effected, has been already referred to. It
was addressed to the anatomist's friend, Joachim Roelants.
Very little space, however, is taken up with a description
of the medicine which gives title to the letter. Some-
thing certainly is said of the history and nature of the
plant, the preparation of the decoction and its effects ;
but the writer soon introduces the subject which was at
that time of very vital importance to him, namely, his
position with regard to the statements of Galen and his
followers. He collects together various assertions of the
Greek anatomist, on the bones, the muscles and liga-
ments, the relations of veins and arteries, the nerves,
the character of the peritoneum, the organs of the thorax,
the skull and its contents, etc., and shows from each and
all of these that reference had not been made to the
human subject, and that therefore the statements were
unreliable.
To the work on the " Fabric of the Human Body " we
have already alluded, as well as to the causes which led
to its being written. More than half of this great treatise
1 See Professor Morley's article on " Anatomy in Long Clothes,"
in Eraser's Magazine, 1853, from which most of the facts in this
sketch have been taken.
VESALIUS. 79
is occupied with a minute description of the build of the
human body its bones, cartilages, ligaments, and muscles.
It may have been owing to the thorough acquaintance
which Vesalius showed with these parts that his detractors
pretended afterwards that he only understood superficial
injuries. But other branches of anatomy are fully dealt
with. The veins and arteries are described in the third
book, and the nerves in the fourth ; the organs of nutri-
tion and reproduction are treated of in the next ; while
the remaining two books are devoted to descriptions of
the heart and brain.
Vesalius gives a good account of the sphenoid bone,
with its large and small wings and its pterygoid processes ;
and he accurately describes the vestibule in the interior
of the temporal bone. He shows the sternum to consist,
in the adult, of three parts and the sacrum of five or six.
He discovered the valve which guards the foramen ovale
in the foetus ; and he not only verified the observation of
Etienne as to the valve-like fold guarding the entrance of
each hepatic vein into the inferior vena cava, but he also
fully described the vena azygos. He observed, too, the
canal which passes in the foetus between the umbilical
vein and vena cava, and which has since been known
as the ductus venosus. He was the first to study and
describe the mediastinum, correcting the error of the
ancients, who believed that this duplicature of the pleura
contained a portion of the lungs. He described the
8o FATHERS OF BIOLOGY.
omentum and its connections with the stomach, the
spleen, and the colon ; and he enunciated the first correct
views of the structure of the pylorus, noticing at the
same time the small size of the csecal appendix in man.
His account of the anatomy of the brain is fuller than
that of any of his predecessors, but he does not appear
to have well understood the inferior recesses, and his
description of the nerves is confused by regarding the
optic as the first pair, the third as the fifth, and the fifth
as the seventh. The ancients believed the optic nerve
to be hollow for the conveyance of the visual spirit, but
Vesalius showed that no such tube existed. He observed
the elevation and depression of the brain during respira-
tion, but being ignorant of the circulation of the blood,
he wrongly explained the phenomenon.
Exclusively an anatomist, he makes but brief references
in his great work to the functions of the organs which he
describes. Where he differs from Galen on these matters
he does so apologetically. He follows him in regarding
the heart as the seat of the emotions and passions the
hottest of all the viscera and source of heat of the whole
body ; although he does not, as Aristotle did, look upon
the heart as giving rise to the nerves. He considers the
heart to be in ceaseless motion, alternately dilating and
contracting, but the diastole is in his opinion the in-
fluential act of the organ. He knows that eminences or
projections are present in the veins, and indeed speaks of
VESALIUS. 81
them as being analogous to the valves of the heart, but
he denies to them the office of valves. To him the
motion of the blood was of a to-and-fro kind, and valves
in the veins acting as such would have interfered with
anything of the sort. He expresses clearly the idea, that
was entertained in the old physiology, of the attractions
exerted by the various parts of the body for the blood ;
and especially that of the veins and heart for the blood
itself. " The right sinus of the heart," he says, " attracts
blood from the vena cava, and the left attracts air from
the lungs through the arteria venalis (pulmonary vein),
the blood itself being attracted by the veins in general,
the vital spirit by the arteries." Again, he speaks of the
blood filtering through the septum between the ventricles
as if through a sieve, although he knows perfectly well
from his dissection that the septum is quite impervious.
It will thus be seen that the physiological teaching of
Galen was left undisturbed by Vesalius.
HARVEY.
HARVEY.
THE importance of Harvey's discovery of the circulation
of the blood can only be properly estimated by bearing
in mind what was done by his predecessors in the same
field of inquiry. Aristotle had taught that in man and
in the higher brutes the blood was elaborated from the
food in the liver, conveyed to the heart, and thence dis-
tributed by it through the veins to the whole body.
Erasistratus and Herophilus held that, while the veins
carried blood from the heart to the members, the arteries
carried a subtle kind of air or spirit. Galen discovered
that the arteries were not merely air-pipes, but that they
contained blood as well as vital air or spirit. Sylvius,
the teacher of Vesalius, was aware of the presence of
valves in the veins ; and Fabricius, Harvey's teacher at
Padua, described them much more accurately than
Sylvius had done ; but neither of these men had a true
idea of the significance of the structures of which they
wrote. Servetus, the friend and contemporary of Vesalius,
writing in 1533, correctly described the course of the
86 FATHERS OF BIOLOGY.
lesser circulation in the following words : " This com-
munication (i.e. between the right and left sides of the
heart) does not take place through the partition of the
heart, as is generally believed ; but by another admirable
contrivance, whereby from the right ventricle the subtle
blood is agitated in a lengthened course through the
lungs, wherein prepared, it becomes of a crimson colour,
and from the vena arterialis (pulmonary artery) is trans-
ferred into the arteria venalis (pulmonary vein). Mingled
with the inspired air in the arteria venalis, freed by re-
spiration from fuliginous matter, and become a suitable
home of the vital spirit, it is attracted at length into the
left ventricle of the heart by the diastole of the organ."
But when Servetus comes to speak of the systemic circu-
lation, what he has to say is as old as Galen.
The opinions, therefore, on the subject of the blood
and its distribution which were prevalent at the end of
the sixteenth century prove
(1) That although the blood was not regarded as
stagnant, yet its circulation, such as is nowa-
days recognized, was unknown ;
(2) That one kind of blood was thought to flow from
the liver to the right ventricle, and thence to
the lungs and general system by the veins, while
another kind flowed from the left ventricle to
the lungs and general system by the arteries ;
(3) That the septum of the heart was regarded as
HARVEY. 87
admitting of the passage of blood directly from
the right to the left side ;
(4) That there was no conception of the functions of
the heart as the motor power of the movement
of the blood, for biologists of that day doubted
whether the substance of the heart were really
muscular ; they supposed the pulsations to be
due to expansion of the spirits it contained \
they believed the only dynamic effect which it
had on the blood to be that of sucking it in
during its active diastole, and they supposed
the chief use of its constant movements to be
the due mixture of blood and spirits.
This was the state of knowledge before Harvey's time.
By his great work he established
(1) That the blood flows continuously in a circuit
through the whole body, the force propelling it
in this unwearied round being the rhythmical
contractions of the muscular walls of the
heart ;
(2) That a portion only of the blood is expended in
nutrition each time that it circulates ;
(3) That the blood conveyed in the systemic arteries
communicates heat as well as nourishment
throughout the body, instead of exerting a
cooling influence, as was vulgarly supposed ;
and
88 FATHERS OF BIOLOGY.
(4) That the pulse is not produced by the arteries
enlarging and so filling, but by the arteries
being filled with blood and so enlarging.
We can now consider the method by which Harvey
arrived at these results. The work, " De Motu Cordis
et Sanguinis," after giving an account of the views of
preceding physiologists, ancient and modern, commences
with a description of the heart as seen in a living animal
when the chest has been laid open and the pericardium
removed. Three circumstances are noted
(a) The heart becomes erect, strikes the chest, and
gives a beat ;
(b) It is constricted in every direction ;
(c) Grasped by the hand, it is felt to become harder
during the contraction.
From these circumstances it is inferred
(1) That the action of the heart is essentially of the
same nature as that of voluntary muscles, which
become hard and condensed when they act ;
(2) That, as the effect of this, the capacity of the
cavities is diminished, and the blood is ex-
pelled ;
(3) That the intrinsic motion of the heart is the systole,
and not the diastole, as previously imagined.
The motions of the arteries are next shown to be
dependent upon the action of the heart, because the
arteries are distended by the wave of blood that is thrown
HARVEY. 89
into them, being filled like sacs or bladders, and not ex-
panding like bellows. These conclusions are confirmed
by the jerking way in which blood flows from a cut
artery.
In the heart itself two distinct motions are observed
first of the auricles, and then of the ventricles. These
alternate contractions and dilatations can have but one
result, namely, to force the blood from the auricle to the
ventricle, and from the ventricle, on the right side, by
the pulmonary artery to the lungs, and on the left side
by the aorta to the system.
These considerations suggest to the mind of Harvey
the idea of the circulation. " I began to think," he
says, "whether there might not be a motion, as it were,
in a circle." This is next established by proving the
three following propositions :
(1) The blood is incessantly transmitted by the action
of the heart from the vena cava to the arteries
in such quantity that it cannot be supplied from
the ingesta, and in such wise that the whole
mass must very quickly pass through the organ ;
(2) The blood, under the influence of the arterial
pulse, enters, and is impelled in a continuous,
equable, and incessant stream through every
part and member of the body, in much larger
quantity than were sufficient for nutrition, or
than the whole mass of fluids could supply ;
90 FATHERS OF BIOLOGY.
(3) The veins in like manner return this blood in-
cessantly to the heart from all parts and members
of the body.
As to the first proposition Harvey says, " Did the
heart eject but two drachms of blood on each contraction,
and the beats in half an hour were a thousand, the
quantity expelled in that time would amount to twenty
pounds and ten ounces ; and were the quantity an ounce,
it would be as much as eighty pounds and four ounces.
Such quantities, it is certain, could not be supplied by
any possible amount of meat and drink consumed within
the time specified. It is the same blood, consequently,
that is now flowing out by the arteries, now returning by
the veins ; and it is simply matter of necessity that
the blood should perform a circuit, or return to the place
from whence it went forth."
Demonstration of the second proposition that the
blood enters a limb by the arteries and returns from it
by the veins is afforded by the effects of a ligature.
For if the upper part of the arm be tightly bound, the
arteries below will not pulsate, while those above will
throb violently. The hand under such circumstances
will retain its natural colour and appearance, although, if
the bandage be kept on for a minute or two, it will
begin to look livid and to fall in temperature. But
if the bandage be now slackened a little, the hand and
the arm will immediately become suffused, and the super-
HARVEY. 91
ficial veins show themselves tumid and knotted, the pulse
at the wrist in the same instant beginning to beat as
it did before the application of the bandage. The tight
bandage not only compresses the veins, but the arteries
also, so that blood cannot flow through either. The
slacker ligature obstructs the veins only, for the arteries
lie deeper and have firmer coats. " Seeing, then," says
Harvey, " that the moderately tight ligature renders the
veins turgid, and the whole hand full of blood, I ask,
Whence is this ? Does the blood accumulate below the
ligature coming through the veins, or through the
arteries, or passing by certain secret pores ? Through
the veins it cannot come ; still less can it come by any
system of invisible pores ; it must needs, then, arrive by
the arteries."
The third position to be proved is that the veins
return the blood to the heart from all parts of the body.
That such is the case might be inferred from the
presence and disposition of the valves in the veins ; for
the office of the valves is by no means explained by the
theory that they are to hinder the blood from flowing
into inferior parts by gravitation, since the valves do not
always look upwards, but always towards the trunks of
the veins, invariably towards the seat of the heart. The
action of the valves is then demonstrated experimentally
on the arm bound as for blood-letting. The point
of a finger being kept on a vein, the blood from
92 FATHERS OF BIOLOGY.
the space above may be streaked upwards till it passes
the valve, when that portion of the vein between the
valve and the point of pressure will not only be emptied
of its contents, but will remain empty as long as the
pressure is continued. If the pressure be now removed,
the empty part of the vein will fill instantly and look as
turgid as before.
Other confirmatory evidence is then added, e.g. the
absorption of animal poisons and of medicines applied
externally, the muscular structure of the heart and the
necessary working of its valves.
William Harvey, the illustrious physiologist, anatomist,
and physician, to whom this discovery is due, was the
eldest k son of a Kentish yeoman, and was born in April,
.1578. At the age of ten he entered the Canterbury
Grammar School, where he appears to have remained
for some years. At sixteen he passed to Caius-Gonvil
College, Cambridge, and three years afterwards took his
B.A. degree and quitted the university. Like most
students of medicine of that day, he found it necessary
to seek the principal part of his professional education
abroad. He travelled to Italy, selected Padua as his
place of study, and there continued to reside for four
years, having as one of his teachers the famous Fabricius
of Aquapendente. On his return to England, in 1602,
he took his doctor's degree at Cambridge, and entered
on the practice of his profession.
HARVEY. 93
In 1604 he joined the College of Physicians, and
three years later was elected a Fellow of that learned
body. Two years afterwards he applied for the post
of physician to St. Bartholomew's Hospital ; and his
application being supported by letters of recommendation
to the governor, from the king and from the president
of the College of Physicians, he was duly elected to the
office in the same year, as soon as a vacancy occurred.
In 1615, when thirty-seven years of age, Harvey was
chosen to deliver the lectures on surgery and anatomy
to the College of Physicians, and it is possible that at
this time he gave an exposition of his views on the
circulation. He continued to lecture on the same
subject for many years afterwards, although he did
not publish his views until 1628, when they appeared
in the work " De Motu Cordis."
Some few years after his appointment as lecturer
to the college, he was chosen one of the physicians
extraordinary to King James I., and about five or six
years after the accession of Charles I. he became physician
in ordinary to that unfortunate monarch. The physio-
logist's investigations seem to have interested King
Charles, for he had several exhibitions made of the
punctum saliens in the embryo chick, and also witnessed
dissections from time to time.
When, in 1630, the young Duke of Lennox made a
journey on the Continent, Harvey was chosen to travel
24 FATHERS OF BIOLOGY.
with him, and probably remained abroad about two years.
During this time Harvey most likely visited Venice. Of
this tour the doctor speaks in the following terms in a
letter written at the time : " I can only complayne that
by the waye we could scarce see a dogg, crow, kite, raven,
or any bird or any thing to anatomise ; only sum few
miserable poeple the reliques of the war and the plauge,
where famine had made anatomies before I came."
Six years after this, in April, 1636, he accompanied the
Earl of Arundel in his embassy to the emperor. Having
to visit the principal cities of Germany, he was thus
afforded an opportunity of meeting the leading biologists
of the time, and at Nuremberg he probably met Caspar
Hoffmann, and made that public demonstration of the
circulation of the blood which he had promised in his
letter dated from that city, and which convinced every
one present except Hoffmann himself. Hollar, the artist,
informs us that Harvey's enthusiasm in his search for
specimens often led him into danger, and caused grave
anxiety to the Earl of Arundel. " For he would still be
making of excursions into the woods, making observations
of strange trees, plants, earths, etc., and sometimes like
to be lost ; so that my lord ambassador would be really
angry with him, for there was not only danger of wild
beasts, but of thieves."
Soon after his return to England, as court physician,
his movements became seriously restricted by the
HARVEY. 95
fortunes of the king. Aubrey says, " When King
Charles I., by reason of the tumults, left London, Harvey
attended him, and was at the fight of Edgehill with him ;
and during the fight the Prince and the Duke of York
were committed to his care. He told me that he with-
drew with them under a hedge, and tooke out of his
pockett a booke and read; but he had not read very
long before a bullet of a great gun grazed on the ground
neare him, which made him remove his station. . . .
I first sawe him at Oxford, 1642, after Edgehill fight,
but was then too young to be acquainted with so great
a doctor. I remember he came severall times to our
Coll. (Trin.) to George Bathurst, B.D., who had a
hen to hatch egges in his chamber, which they dayly
opened to see the progress and way of generation."
In 1645, Charles, after the execution of Archbishop
Laud, took upon himself the functions of visitor of
Merton College, and having removed Sir Nathaniel
Brent from the office of warden for having joined " the
Rebells now in armes against" him, he directed the
Fellows to take the necessary steps for the election of
a successor. This course consisted in giving in three
names to the visitor, in order that one of the three (the
one named first, probably) should be appointed. Harvey
was so named by five out of the seven Fellows voting,
and was accordingly duly elected. A couple of days
after his admission he summoned the Fellows into the
96 FATHERS OF BIOLOGY.
hall and made a speech to them, in which he pointed
out that it was likely enough that some of his predecessors
had sought the office in order to enrich themselves, but
that his intentions were quite of another kind, wishing as
he did to increase the wealth and prosperity of the
college ; and he finished by exhorting them to cherish
mutual concord and amity. After the surrender of
Oxford, July, 1646, Harvey retired from the court. He
was in his sixty-ninth year, and doubtless found the
hardships and inconveniences which the miserable war
entailed far from conducive to health. The rest and
seclusion to be had at the residence of one or other of
his brothers offered him the much-needed opportunity of
renewing his inquiries into the subject of generation, and
it is of this time that Dr. Ent speaks in the preface to
the published work on that subject which appeared in
1651. "Harassed with anxious and in the end not
much availing cares, about Christmas last, I sought to
rid my spirit of the cloud that oppressed it, by a visit to
that great man, the chief honour and ornament of our
college, Dr. William Harvey, then dwelling not far from
the city. I found him, Democritus-like, busy with the
study of natural things, his countenance cheerful, his
mind serene, embracing all within its sphere. I forthwith
saluted him, and asked if all were well with him. ' How
can it,' said he, 'whilst the Commonwealth is full of
distractions, and I myself am still in the open sea ? And
HARVEY. 97
truly/ he continued, ' did I not find solace in my studies,
and a balm for my spirit in the memory of my observa-
tions of former years, I should feel little desire for longer
life. But so it has been, that this life of obscurity, this
vacation from public business, which causes tedium and
disgust to so many, has proved a sovereign remedy
to me.' "
Harvey died in June, 1657. Aubrey, his con-
temporary, says, " On the morning of his death, about
ten o'clock, he went to speake, and found he had the
dead palsey in his tongue ; then he sawe what was to
become of him, he knew there was then no hopes of his
recovery, so presently sends for his young nephews to
come up to him, to whom he gives one his watch, to
another another remembrance, etc. ; made sign to Sam-
broke his Apothecary to lett him blood in the tongue,
which did little or no good, and so he ended his dayes.
. . . The palsey did give him an easie passeport. . . .
He lies buried in a vault at Hempsted in Essex,
which his brother Eliab Harvey built; he is lapt in
lead, and on his brest, in great letters, ' Dr. William
Harvey.' I was at his Funerall, and helpt to carry him
into the vault."
The publication of Harvey's views on the movement
of the blood excited great surprise and opposition. The
theory of a complete circulation was at any rate novel,
but novelty was far from being a recommendation in
H
98 FATHERS OF BIOLOGY.
those days. According to Aubrey, the author was
thought to be crackbrained, and lost much of his practice
in consequence. He himself complains that contume-
lious epithets were levelled at the doctrine and its
author. It was not until after many years had elapsed,
and the facts had become familiar, that men were struck
with the simplicity of the theory, and tried to prove that
the idea was not new after all, and that it was to be
found in Hippocrates, or in Galen, or in Servetus, or in
Caesalpinus anywhere, in fact, except where alone it
existed, namely, in the work, " De Motu Cordis et
Sanguinis." No one seems to have denied, while Harvey
lived, that he was the discoverer of the circulation of the
blood; indeed, Hobbes of Malmesbury, his contem-
porary, said of him, " He is the only man, perhaps, that
ever lived to see his own doctrine established in his life-
time."
In one important respect Harvey's account of the
circulation was incomplete. He knew nothing of the
vessels which we now speak of as capillaries. Writing
to Paul Marquard Slegel, of Hamburg, in 1651, he says,
" When I perceived that the blood is transferred from
the veins into the arteries through the medium of the
heart, by a grand mechanism and exquisite apparatus
of valves, I fudged that in like manner, wherever trans-
udation does not take place through the pores of the
flesh, the blood is returned from the arteries to the veins,
HARVEY. 99
not without some other admirable artifice" (non sine
artificio qiwdam admirabili). It was this artificium
admiralnle of which Harvey was unable to give a de-
scription. On account of the minuteness of their struc-
ture, the capillaries were beyond his sight, aided as it
was by a magnifying glass merely. He indeed demon-
strated physiologically the existence of some such pas-
sages ; but it remained for a later observer, with improved
appliances, to verify the fact. This was done by Malpighi
in 1 66 1, who saw in the lung of a frog, which was so
mounted in a frame as to be viewed by transmitted light,
the network of capillaries which connect the last rami-
fications of the arteries with the radicles of the veins.
Harvey rightly denied that the arteries possessed any
pulsific power of their own, and maintained that their
pulse is owing solely to the sudden distension of their
walls by the blood thrown into them at each contraction
of the ventricles. But the remission which succeeds
the pulse was regarded by him as caused simply by
collapse of the walls of the arteries due to elastic re-
action. Knowing nothing of the muscular coat of the
arteries, he was unaware of the fact that the elastic
reaction of the arteries, after their distension, is aided
by the tonic contractility of their walls ; the two forces,
physical and vital, acting in concert with each other
the former converting the intermittent flow from the
heart into an even stream in the capillaries and veins ;
ioo FATHERS OF BIOLOGY.
the latter, through the vaso motor system, regulating the
flow of blood to particular parts in order to meet
changing requirements.
It is somewhat surprising to find that such an accurate
observer as Harvey should have failed to recognize the
significance and importance of the system of lacteal
vessels. But such was the case. Eustachius, in the
sixteenth century, had discovered the thoracic duct in
the horse, although he seems to have thought that it
was peculiar to that animal. Aselli, while dissecting the
body of a dog in 1622, accidentally discovered the
lacteals, and thought at first that they were nerves ; but
upon puncturing one of them, and seeing the milky fluid
which escaped, found them to be vessels. He, however,
failed to trace them to the thoracic duct, and believed
them to terminate in the liver. Pecquet of Dieppe
followed them from the intestines to the mesenteric
glands, and from these into a common sac or reservoir,
which he designated receptaculum chyli, and thence to
their entry by a single slender conduit into the venous
system at the junction of the jugular and subclavian
veins. The existence of the lacteals had not entirely
escaped Harvey, however. He had himself noticed them
in the course of his dissections before Aselli's book was
published, but " for various reasons " could not bring
himself to believe that they contained chyle. The small-
ness of the thoracic duct seemed to him a difficulty, and
HARVEY. 101
as it was a demonstrated fact that the gastric veins were
largely absorptive, the lacteals appeared to him super-
fluous. He is not "obstinately wedded to his own
opinion," and does not doubt "but that many things,
now hidden in the well of Democritus, will by-and-by
be drawn up into day by the ceaseless industry of a
coming age."
Late in the author's life, as we have seen, the work
on the " Generation of Animals " appeared ; but neither
physiological nor microscopical science was sufficiently
advanced to admit of the production of an enduring
work on a subject necessarily so abstruse as that of
generation. It was impossible, however, for so shrewd
and able an investigator as Harvey to work at a subject
even as difficult as this without leaving the impress of
his original genius. He first announced the general
truth, " Ornne animal ex ovo," and clearly proved that
the essential part of the egg, that in which the repro-
ductive processes begin, was not the chalazce, but the
cicatricula. This Fabricius had looked upon as a blemish,
a scar left by a broken peduncle. Harvey described
this little cicatricula as expanding under the influence
of incubation into a wider structure, which he called
the eye of the egg, and at the same time separating into
a clear and transparent part, in which later on, according
to him, there appeared, as the first rudiment of the
embryo, the heart, or punctum saliens^ together with the
H 3
102 FATHERS OF BIOLOGY.
blood-vessels. He was clearly of opinion that the
embryo arose by successive formation of parts out of
the homogeneous and nearly liquid mass. This was the
doctrine of epigenesis, which, notwithstanding its tem-
porary overthrow by the erroneous theory of evolution, 1
is, with modifications, the doctrine now held.
Of Harvey's scholarship and culture we are not left in
ignorance. Bishop Pearson, writing about seven years
after the doctor's death, and Aubrey 2 have told us of his
appreciation of the works of Aristotle, and in his own
writings he refers more frequently to the Stagirite than
to any other individual. Sir William Temple 3 has also
put it on record that the famous Dr. Harvey was a
great admirer of Virgil, whose works were frequently
in his hands. His store of individual knowledge must
have been great; and he seems never to have flagged
in his anxiety to learn more. He made himself master
of Oughtred's " Clavis Mathematica " in his old age ,
according to Aubrey, who found him " perusing it and
working problems not long before he dyed."
Nor should it be forgotten that this illustrious physiolo-
1 According to the theory of evolution, the egg contained from
the first an excessively minute, but complete animal, and the changes
which took place during incubation consisted not in a formation
of parts, but in a growth, i.e. in an expansion of the already existing
embryo (see p. 40).
2 See p. Ixxxii. of " Life," by Dr. Willis.
* " Miscellanies:" Part II. on Poetry, p. 314.
HARVEY. 103
gist and scholar was also the first English comparative
anatomist. Of his knowledge of the lower animals he
makes frequent use, and he says (in his work on the
heart), "Had anatomists only been as conversant with
the dissection of the lower animals as they are with that
of the human body, many matters that have hitherto kept
them in a perplexity of doubt, would, in my opinion, have
met them freed from every kind of difficulty." Aubrey
says that Harvey often told him " that of all the losses
he sustained, no grief was so crucifying to him as the
loss of his papers (containing notes of his dissections of
the frog, toad, and other animals), which, together with
his goods in his lodgings at Whitehall, were plundered
at the beginning of the rebellion."
INDEX.
Albertus Magnus, 65
Alexander the Great, 23, 24
Andronicus of Rhodes, 27
" Animals, History of," by Aris-
totle, 27
" Animals, On the Parts of," by
Aristotle, 31
Antipater, Governor of Mace-
donia, 25
Apellicon, 27
"Aphorisms" of Hippocrates,
12
Aristotle, birth, 21 ; youth, 22 ;
zoological researches, 24 ;
charge against, 25 ; death, 26 ;
history of the manuscripts of
his works, 26 ; account of
his biological writings, 27-44 ;
his philosophy,of nature teleo-
logical, 39
Arundel, Earl of, 94
Asclepiads, physical training
among the, 4
Asclepions, description of the, 4
Aselli, 100
Aubrey, 95, 97, 98, 102
Bathurst, George, 95
Blood, description of, by Aris-
totle, 31
Blood, opinions before the time
of Harvey as to the move-
ments of the, 85, 86
Bogarucci, 76
Brain, description of the, by
Aristotle, 33
Browne, Sir Thomas, 65
Csesalpinus, 98
Calcar, Jean, 71
Callisthenes, 24
Capillaries, discovery of the, 99
" Corporis Humani Fabrica,"
72
Cuvier's exaggerated praise of
Aristotle, 41
"Dead image of God," the,
65
" De Anatome," 66
"De Motu Cordis et Sanguinis,"
88-92
" De usu Radicis, Chinse," 73
Disease, causes of, 7
"Disease, The Sacred," 6
Diseases, natural history of, 9
Dissection of the human body,
10, 52
" Divine old man," the, 3
io6
INDEX.
Don Carlos, cure of, 75
Ductus venosus, observed by
Vesalius, 79
Ent, Dr., 96
" Epigenesis " and " evolution "
compared, 40, 102
Etienne's observation confirmed
by Vesalius, 79
Erasistratus, 47, 58, 85
Eustachius, discovery of the
thoracic duct of the horse by,
100
Fabricius of Aquapendente, 85,
92
Fallopius, anatomical observa-
tions of, 77
"Father of medicine," the, 3
Franciscus Puteus, reply to, by
Gabriel Cuneus, 77
Foramen ovale, valve guarding
the, 79
Galen, birth, 48 ; influence, 49,
60, 65 ; education, 49 ; at
Smyrna, 49 ; at Alexandria,
49 ; at Pergamus, 50 ; at
Rome, 50 ; return to Greece,
50 ; summoned to meet the
Emperors at Aquileia, 50 ;
death, 51 ; writings, 51; views
as to the modes of existence,
52 ; and osteology, 53 ; and
the nervous system, 53 ; and
the lacteals, 54 ; the heart,
55 ; the arteries, 56 ; and
respiration, 57-59 ; made a
near approach to the Har-
veian theory of the circula-
tion, 57
Generation of animals, the, 38,
101
Geynes, Dr., 60
Harvey, date and place of birth,
92 ; at Canterbury School,
92 ; at Cambridge, 92 ; at
Padua, 92 ; elected Fel-
low of the College of Physi-
cians, 93 ; appointed physi-
cian to St. Bartholomew 1 ^
Hospital, 93 ; physician to
Charles I., 93 ; foreign travels,
94 ; present at the battle of
Edgehill, 95 ; elected Warden
of Merton College, 95 ; death,
97 ; discovery of the circula-
tion incomplete in one re-
spect, 98, 99 ; work on the
generation of animals, 101 ; a
scholar, 102 ; and compara-
tive anatomist, 103
Heart, description of the, by
Aristotle, 35
Hellebore, administered by
Hippocrates, 9
Hermias despot of Atarneus,
22 ; murder of, 23
Herophilus, 47, 58, 85
Hippocrates, date of birth, 3 ;
Greek contemporaries, 3 ;
birthplace, 3 ; his freedom
from superstition, 5, 16 ; com-
pared with Socrates, 7 ; medi-
cal doctrines of, 8 ; works,
10 ; knowledge of osteology,
INDEX.
107
10 ; traditions concerning, 14 ;
oath of, 1 6
Hobbes of Malmesbury, 98
Hoffmann, Caspar, 94
Humours, the four, 8
Huxley, Professor, on errors at-
tributed to Aristotle, 37, 42
Lacteals, the, 54, 100
Lennox, Duke of, 93
Lungs, Aristotle's description of
the, 37
Malpighi, discovery of the capil-
laries by, 99
Marcus Aurelius, 50
Marine animals, description of,
by Aristotle, 29
Mediastinum, correct description
of the, by Vesalius, 79
Milk in male animals, occa-
sional appearance of, 29
Mundinus, 66
Neleus, 26
Nicon, father of Galen, 49
Omentum, the, and its connec-
tions, 80
Owen, Professor, on Aristotle's
knowledge of the cephalo-
poda, 29
" Parva naturalia," 27
Pausanias, 15
Pecquet of Dieppe, 100
Peripatetics, the, 24
Philip, father of Alexander, 22,
23
"Physiological division of la-
bour," 43
Plato, 22
Pliny, 47, 48
Pneunia, 38
Punctum sa/iens, 35, 93, 101
Pylorus, the, described by Vesa-
lius, 80
Pythias, 23
Receptaculum chyli, 100
Roelants, Joachim, 78
Scamnum Hippocratis, 12
Servetus, 86
Septimius Severus, 51
Slegel of Hamburg, 98
Socrates compared with Hippo-
crates, 7
Sprengel's opinion of Galen, 60
Sylla, 27
Sylvius, 67, 72, 73, 74
Teupulus, Paulus, 77
Theophrastus, 26
Theriac, the, 50
Thoracic duct, discovery of, 100
Tyrannion, 27
Vesalius, birth, 66 ; scholarship,
66 ; studied under Sylvius,
67 ; and Winter of Ander-
nach, 67 ; adventure at Lou-
vain, 67, 68 ; appointed pro-
fessor at Padua, at Bologna,
io8
INDEX.
and at Pisa, 69 ; zeal for cor-
rectness in anatomy, 70 ; skill
in diagnosis, 70 ; distrusts in-
fallibility of Galen's teaching,
71 ; writes " Fabric of the
Human Body," 72 ; is sum-
moned to Ratisbon, 73 ; de-
stroys his manuscripts, 74;
his success as a practitioner,
75 ; charged with impiety,
75 ; is sent on pilgrimage, 75 ;
shipwreck and death at Zante,
76 ; works, 76-80
Vix medicatrix natures^ 9
Winter of Andernach, 67
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