"I went by the field of the slothful,
and by the vineyard of the man void of understanding; and lo, it was all grown
over with thorns, and nettles had covered the face thereof, and the stone wall
thereof was broken down. Then I saw and considered it well; I looked upon it and
received instruction.--
SOLOMON.
"How
shall we escape if we neglect so great salvation?"
--Hebrews.
"We
have as possibilities either Balance, or Elaboration, or Degeneration."--E.
Ray
Lankester.
IN
one of his best known books, Mr. Darwin brings out a fact which may be
illustrated in some such way as this: Suppose a bird fancier collects a flock of
tame pigeons distinguished by all the infinite ornamentations of their race.
They are of all kinds, of every shade of colour, and adorned with every variety
of marking. He takes them to an uninhabited island and allows them to fly off
wild into the woods. They found a colony there, and after the lapse of many
years the owner returns to the spot. He will find that a remarkable change has
taken place in the interval. The birds, or their descendants rather, have all
become changed into the same colour. The black, the white and the dun, the
striped, the spotted, and the ringed, are all metamorphosed into one--a dark
slaty blue. Two plain black bands monotonously repeat themselves upon the wings
of each, and the loins beneath are white; but all the variety, all the beautiful
colours, all the old graces of form it may be, have disappeared. These
improvements were the result of care and nurture, of domestication, of
civilization; and now that these influences are removed, the birds themselves
undo the past and lose what they had gained. The attempt to elevate the race has
been mysteriously thwarted. It is as if the original bird, the far remote
ancestor of all doves, had been blue, and these had been compelled by some
strange law to discard the badges of their civilization and conform to the ruder
image of the first. The natural law by which such a change occurs is called
The Principle of Reversion to Type.
It
is a proof of the universality of this law that the same thing will happen with
a plant. A garden is planted, let us say, with strawberries and roses, and for a
number of years is left alone. In process of time it will run to waste. But this
does not mean that the plants will really waste away, but that they will change
into something else, and, as it invariably appears, into something worse; in the
one case, namely, into the small, wild strawberry of the woods, and in the other
into the primitive dog-rose of the hedges.
If
we neglect a garden plant, then, a natural principle of deterioration comes in,
and changes it into a worse plant. And if we neglect a bird, by the same
imperious law it will be gradually changed into an uglier bird. Or if we neglect
almost any of the domestic animals, they will rapidly revert to wild and
worthless forms again.
Now the same thing
exactly would happen in the case of you or me. Why should Man be an exception to
any of the laws of Nature? Nature knows him simply as an animal--Sub-kingdom
Vertebrata, Class Mammalia, Order Bimana. And the law of
Reversion to Type runs through all creation. If a man neglect himself for a few
years he will change into a worse man and a lower man. If it is his body that he
neglects, he will deteriorate into a wild and bestial savage--like the
de-humanized men who are discovered sometimes upon desert islands. If it is his
mind, it will degenerate into imbecility and madness--solitary confinement has
the power to unmake men's minds and leave them idiots. If he neglect his
conscience, it will run off into lawlessness and vice. Or, lastly, if it is his
soul, it must inevitably atrophy, drop off in ruin and
decay.
We have here, then, a thoroughly natural
basis for the question before us. If we neglect, with this universal principle
staring us in the face, how shall we escape? If we neglect the ordinary means of
keeping a garden in order, how shall it escape running to weeds and waste? Or,
if we neglect the opportunities for cultivating the mind, how shall it escape
ignorance and feebleness? So, if we neglect the soul, how shall it escape the
natural retrograde movement, the inevitable relapse into barrenness and
death?
It is not necessary, surely, to pause
for proof that there is such a retrograde principle in the being of every man.
It is demonstrated by facts, and by the analogy of all Nature. Three
possibilities of life, according to Science, are open to all living
organisms--Balance, Evolution, and Degeneration. The first denotes the
precarious persistence of a life along what looks like a level path, a character
which seems to hold its own alike against the attacks of evil and the appeals of
good. It implies a set of circumstances so balanced by choice or fortune that
they neither influence for better nor for worse. But except in theory this state
of equilibrium, normal in the inorganic kingdom, is really foreign to the world
of life; and what seems inertia may be a true Evolution unnoticed from its
slowness, or likelier still a movement of Degeneration subtly obliterating as it
falls the very traces of its former height. From this state of apparent Balance,
Evolution is the escape in the upward direction, Degeneration in the lower. But
Degeneration, rather than Balance or Elaboration, is the possibility of life
embraced by the majority of mankind. And the choice is determined by man's own
nature. The life of Balance is difficult. It lies on the verge of continual
temptation, its perpetual adjustments become fatiguing, its measured virtue is
monotonous and uninspiring. More difficult still, apparently, is the life of
ever upward growth. Most men attempt it for a time, but growth is slow; and
despair overtakes them while the goal is far away. Yet none of these reasons
fully explains the fact that the alternative which remains is adopted by the
majority of men. That Degeneration is easy only half accounts for it. Why is it
easy? Why but that already in each man's very nature this principle is supreme?
He feels within his soul a silent drifting motion impelling him downward with
irresistible force. Instead of aspiring to Conversion to a higher Type he
submits by a law of his nature to Reversion to a lower. This is
Degeneration--that principle by which the organism, failing to develop itself,
failing even to keep what it has got, deteriorates, and becomes more and more
adapted to a degraded form of life.
All men who
know themselves are conscious that this tendency, deep-rooted and active, exists
within their nature. Theologically it is described as a gravitation, a bias
toward evil. The Bible view is that man is conceived in sin and shapen in
iniquity. And experience tells him that he will shape himself into further sin
and ever deepening iniquity without the smallest effort, without in the least
intending it, and in the most natural way in the world if he simply let his life
run. It is on this principle that, completing the conception, the wicked are
said further in the Bible to be lost. They are not really lost as yet, but they
are on the sure way to it. The bias of their lives is in full action. There is
no drag on anywhere. The natural tendencies are having it all their own way; and
although the victims may be quite unconscious that all this is going on, it is
patent to every one who considers even the natural bearings of the case that
"the end of these things is Death." When we see a man fall from the top of a
five-storey house, we say the man is lost. We say that before he has fallen a
foot; for the same principle that made him fall the one foot will undoubtedly
make him complete the descent by falling other eighty or ninety feet. So that he
is a dead man, or a lost man from the very first. The gravitation of sin in a
human soul acts precisely in the same way. Gradually, with gathering momentum it
sinks a man further and further from God and righteousness, and lands him, by
the sheer action of a natural law, in the hell of a neglected
life.
But the lesson is not less clear from
analogy. Apart even from the law of Degeneration, apart from Reversion to Type,
there is in every living organism a law of Death. We are wont to imagine that
Nature is full of Life. In reality it is full of Death. One cannot say it is
natural for a plant to live. Examine its nature fully, and you have to admit
that its natural tendency is to die. It is kept from dying by a mere temporary
endowment, which gives it an ephemeral dominion over the elements--gives it
power to utilize for a brief span the rain, the sunshine, and the air. Withdraw
this temporary endowment for a moment and its true nature is revealed. Instead
of overcoming Nature it is overcome. The very things which appeared to minister
to its growth and beauty now turn against it and make it decay and die. The sun
which warmed it, withers it; the air and rain which nourished it, rot it. It is
the very forces which we associate with life which, when their true nature
appears, are discovered to be really the ministers of
death.
This law, which is true for the whole
plant-world, is also valid for the animal and for man. Air is not life, but
corruption--so literally corruption that the only way to keep out corruption,
when life has ebbed, is to keep out air. Life is merely a temporary suspension
of these destructive powers; and this is truly one of the most accurate
definitions of life we have yet received--"the sum total of the functions which
resist death."
Spiritual life, in like manner,
is the sum total of the functions which resist sin. The soul's atmosphere is the
daily trial, circumstance, and temptation of the world. And as it is life alone
which gives the plant power to utilize the elements, and as, without it, they
utilize it, so it is the spiritual life alone which gives the soul power to
utilize temptation and trial; and without it they destroy the soul. How shall we
escape if we refuse to exercise these functions--in other words, if we
neglect?
This destroying process, observe, goes
on quite independently of God's judgment on sin. God's judgment on sin is
another and a more awful fact of which this may be a part .But it is a distinct
fact by itself, which we can hold and examine separately, that on purely natural
principles the soul that is left to itself unwatched, uncultivated, unredeemed,
must fall away into death by its own nature. The soul that sinneth "it shall
die." It shall die, not necessarily because God passes sentence of death upon
it, but because it cannot help dying. It has neglected "the functions which
resist death," and has always been dying. The punishment is in its very nature,
and the sentence is being gradually carried out all along the path of life by
ordinary processes which enforce the verdict with the appalling faithfulness of
law.
There is an affectation that religious
truths lie beyond the sphere of the comprehension which serves men in ordinary
things. This question at least must be an exception. It lies as near the natural
as the spiritual. If it makes no impression on a man to know that God will visit
his iniquities upon him, he cannot blind himself to the fact that Nature will.
Do we not all know what it is to be punished by Nature for disobeying her? We
have looked round the wards of a hospital, a prison, or a madhouse, and seen
there Nature at work squaring her accounts with sin. And we knew as we looked
that if no Judge sat on the throne of heaven at all there was a Judgment there,
where an inexorable Nature was crying aloud for justice, and carrying out her
heavy sentences for violated laws.
When God
gave Nature the law into her own hands in this way, He seems to have given her
two rules upon which her sentences were to be based. The one is formally
enunciated in this sentence, "WHATSOEVER A MAN SOWETH THAT SHALL HE ALSO REAP."
The other is informally expressed in this, "IF WE NEGLECT HOW SHALL WE
ESCAPE?"
The first is the positive law, and
deals with sins of commission. The other, which we are now discussing, is the
negative, and deals with sins of omission. It does not say anything about
sowing, but about not sowing. It takes up the case of souls which are lying
fallow. It does not say, if we sow corruption we shall reap corruption. Perhaps
we would not be so unwise, so regardless of ourselves, of public opinion, as to
sow corruption. It does not say, if we sow tares we shall reap tares. We might
never do anything so foolish as sow tares. But if we sow nothing, it says, we
shall reap nothing. If we put nothing into the field, we shall take nothing out.
If we neglect to cultivate in summer, now shall we escape starving in
winter?
Now the Bible raises this question, but
does not answer it--because it is too obvious to need answering. How shall we
escape if we neglect? The answer is, we cannot. In the nature of things we
cannot. We cannot escape any more than a man can escape drowning who falls into
the sea and has neglected to learn to swim. In the nature of things he cannot
escape--nor can he escape who has neglected the great
salvation.
Now why should such fatal
consequences follow a simple process like neglect? The popular impression is
that a man, to be what is called lost, must be an open and notorious sinner. He
must be one who has abandoned all that is good and pure in life, and sown to the
flesh with all his might and main. But this principle goes further. It says
simply, "If we neglect." Any one may see the reason why a notoriously wicked
person should not escape; but why should not all the rest of us escape? What is
to hinder people who are not notoriously wicked escaping--people who never sowed
anything in particular? Why is it such a sin to sow nothing in
particular?
There must be some hidden and vital
relation between these three words, Salvation, Neglect, and Escape--some
reasonable, essential, and indissoluble connection. Why are these words so
linked together as to weight this clause with all the authority and solemnity of
a sentence of death?
The explanation has partly
been given already. It lies still further, however, in the meaning of the word
Salvation. And this, of course, is not at all Salvation in the ordinary sense of
forgiveness of sin. This is one great meaning of Salvation, the first and the
greatest. But this is spoken to people who are supposed to have had this. It is
the broader word, therefore, and includes not only forgiveness of sin but
salvation or deliverance from the downward bias of the soul. It takes in that
whole process of rescue from the power of sin and selfishness that should be
going on from day to day in every human life We have seen that there is a
natural principle in man lowering him, deadening him, pulling him down by inches
to the mere animal plane, blinding reason, searing conscience, paralysing will.
This is the active destroying principle, or Sin. Now to counteract this, God has
discovered to us another principle which will stop this drifting process in the
soul, steer it round, and make it drift the other way. This is the active saving
principle, or Salvation. If a man find the first of these powers furiously at
work within him, dragging his whole life downward to destruction, there is only
one way to escape his fate--to take resolute hold of the upward power, and be
borne by it to the opposite goal. And as this second power is the only one in
the universe which has the slightest real effect upon the first, how shall a man
escape if he neglect it? To neglect it is to cut off the only possible chance of
escape. In declining this he is simply abandoning himself with his eyes open to
that other and terrible energy which is already there, and which, in the natural
course of things, is bearing him every moment further and further from
escape.
From the very nature of Salvation,
therefore, it is plain that the only thing necessary to make it of no effect is
neglect. Hence the Bible could not fail to lay strong emphasis on a word so
vital. It was not necessary for it to say, how shall we escape if we trample
upon the great salvation, or doubt, or despise, or reject it. A man who has been
poisoned only need neglect the antidote and he will die. It makes no difference
whether he dashes it on the ground, or pours it out of the window, or sets it
down by his bedside, and stares at it all the time he is dying. He will die just
the same, whether he destroys it in a passion, or coolly refuses to have
anything to do with it. And as a matter of fact probably most deaths,
spiritually, are gradual dissolutions of the last class rather than rash
suicides of the first.
This, then, is the
effect of neglecting salvation from the side of salvation itself; and the
conclusion is that from the very nature of salvation escape is out of the
question. Salvation is a definite process. If a man refuse to submit himself to
that process, clearly he cannot have the benefits of it. As many as received
Him to them he gave power to become the sons of God. He does not
avail himself of this power. It may be mere carelessness or apathy. Nevertheless
the neglect is fatal. He cannot escape because he will
not.
Turn now to another aspect of the case--to
the effect upon the soul itself. Neglect does more for the soul than make it
miss salvation. It despoils it of its capacity for salvation. Degeneration in
the spiritual sphere involves primarily the impairing of the faculties of
salvation and ultimately the loss of them. It really means that the very soul
itself becomes piecemeal destroyed until the very capacity for God and
righteousness is gone.
The soul, in its highest
sense, is a vast capacity for God. It is like a curious chamber added on to
being, and somehow involving being, a chamber with elastic and contractile
walls, which can be expanded, with God as its guest, illimitably, but which
without God shrinks and shrivels until every vestige of the Divine is gone, and
God's image is left without God's Spirit. One cannot call what is left a
soul; it is a shrunken, useless organ, a capacity sentenced to death by
disease, which droops as a withered hand by the side, and cumbers nature like a
rotted branch. Nature has her revenge upon neglect as well as upon extravagance.
Misuse, with her, is as mortal a sin as
abuse.
There are certain burrowing animals--the
mole for instance--which have taken to spending their lives beneath the surface
of the ground. And Nature has taken her revenge upon them in a thoroughly
natural way--she has closed up their eyes. If they mean to live in darkness, she
argues, eyes are obviously a superfluous function. By neglecting them these
animals made it clear they do not want them. And as one of Nature's fixed
principles is that nothing shall exist in vain, the eyes are presently taken
away, or reduced to a rudimentary state. There are fishes also which have had to
pay the same terrible forfeit for having made their abode in dark caverns where
eyes can never be required. And in exactly the same way the spiritual eye must
die and lose its power by purely natural law if the soul choose to walk in
darkness rather than in light.
This is the
meaning of the favourite paradox of Christ, "From him that hath not shall be
taken away even that which he hath;" "take therefore the talent from him." The
religious faculty is a talent, the most splendid and sacred talent we possess.
Yet it is subject to the natural conditions and laws. If any man take his talent
and hide it in a napkin, although it is doing him neither harm nor good
apparently, God will not allow him to have it. Although it is lying there rolled
up in the darkness, not conspicuously affecting any one, still God will not
allow him to keep it. He will not allow him to keep it any more than Nature
would allow the fish to keep their eyes. Therefore, He says, "take the talent
from him." And Nature does it.
This man's crime
was simply neglect--"thou wicked and slothful servant." It was a wasted
life-- a life which failed in the holy stewardship of itself. Such a life is a
peril to all who cross its path. Degeneration compasses Degeneration. It is only
a character which is itself developing that can aid the Evolution of the world
and so fulfil the end of life. For this high usury each of our lives, however
small may seem our capital, was given us by God. And it is just the men whose
capital seems small who need to choose the best investments. It is significant
that it was the man who had only one talent who was guilty of neglecting it. Men
with ten talents, men of large gifts and burning energies, either direct their
powers nobly and usefully, or misdirect them irretrievably. It is those who
belong to the rank and file of life who need this warning most. Others have an
abundant store and sow to the spirit or the flesh with a lavish hand. But we,
with our small gift, what boots our sowing? Our temptation as ordinary men is to
neglect to sow at all. The interest on our talent would be so small that we
excuse ourselves with the reflection that it is not worth
while.
It is no objection to all this to say
that we are unconscious of this neglect or misdirection of our powers. That is
the darkest feature in the case. If there were uneasiness there might be hope.
If there were, somewhere about our soul, a something which was not gone to sleep
like all the rest; if there were a contending force anywhere; if we would let
even that work instead of neglecting it, it would gain strength from hour to
hour, and waken up one at a time each torpid and dishonoured faculty till our
whole nature became alive with strivings against self, and every avenue was open
wide for God. But the apathy, the numbness of the soul, what can be said of such
a symptom but that it means the creeping on of death? There are accidents in
which the victims feel no pain. They are well and strong they think. But they
are dying. And if you ask the surgeon by their side what makes him give this
verdict, he will say it is this numbness over the frame which tells how some of
the parts have lost already the very capacity for life.
Nor is it the least tragic accompaniment of
this process that its effects may even be concealed from others. The soul
undergoing Degeneration, surely by some arrangement with Temptation planned in
the uttermost hell, possesses the power of absolute secrecy. When all within is
festering decay and rottenness, a Judas, without anomaly, may kiss his Lord.
This invisible consumption, like its fell analogue in the natural world, may
even keep its victim beautiful while slowly slaying it. When one examines the
little Crustacea which have inhabited for centuries the lakes of the
Mammoth Cave of Kentucky, one is at first astonished to find these animals
apparently endowed with perfect eyes. The pallor of the head is broken by two
black pigment specks, conspicuous indeed as the only bits of colour on the whole
blanched body; and these, even to the casual observer, certainly represent
well-defined organs of vision. But what do they with eyes in these Stygian
waters? There reigns an everlasting night. Is the law for once at fault? A swift
incision with the scalpel, a glance with a lens, and their secret is betrayed.
The eyes are a mockery. Externally they are organs of vision--the front of the
eye is perfect; behind, there is nothing but a mass of ruins. The optic nerve is
a shrunken, atrophied and insensate thread. These animals have organs of vision,
and yet they have no vision. They have eyes, but they see
not.
Exactly what Christ said of men: They had
eyes, but no vision. And the reason is the same. It is the simplest problem of
natural history. The Crustacea of the Mammoth Cave have chosen to abide
in darkness. Therefore they have become fitted for it. By refusing to see they
have waived the right to see. And Nature has grimly humoured them. Nature had to
do it by her very constitution. It is her defence against waste that decay of
faculty should immediately follow disuse of function. He that hath ears to hear,
he whose ears have not degenerated, let him
hear.
Men tell us sometimes there is no such
thing as an atheist. There must be. There are some men to whom it is true that
there is no God. They cannot see God because they have no eye. They have only an
abortive organ, atrophied by neglect.
All this,
it is commonplace again to insist, is not the effect of neglect when we die, but
while we live. The process is in full career and operation now. It is useless
projecting consequences into the future when the effects may be measured now. We
are always practising these little deceptions upon ourselves, postponing the
consequences of our misdeeds as if they were to culminate some other day about
the time of death. It makes us sin with a lighter hand to run an account with
retribution, as it were, and delay the reckoning time with God. But every day is
a reckoning day. Every soul is a Book of Judgment, and Nature, as a recording
angel, marks there every sin. As all will be judged by the great Judge some day,
all are judged by Nature now. The sin of yesterday, as part of its penalty, has
the sin of to-day. All follow us in silent retribution on our past, and go with
us to the grave. We cannot cheat Nature. No sleight-of-heart can rob religion of
a present, the immortal nature of a now. The poet
sings--
"I looked
behind to find my past,
And lo, it had gone
before."
But no, not all. The unforgiven
sins are not away in keeping somewhere to be let loose upon us when we die; they
are here, within us, now. To-day brings the resurrection of their past,
to-morrow of to-day. And the powers of sin, to the exact strength that we have
developed them, nearing their dreadful culmination with every breath we draw,
are here, within us, now. The souls of some men are already honey-combed through
and through with the eternal consequences of neglect, so that taking the natural
and rational view of their case just now, it is simply inconceivable that
there is any escape just now. What a fearful thing it is to fall
into the hands of the living God! A fearful thing even if, as the philosopher
tells us, "the hands of the Living God are the Laws of
Nature."
Whatever hopes of a "heaven" a
neglected soul may have, can be shown to be an ignorant and delusive dream. How
is the soul to escape to heaven if it has neglected for a lifetime the means of
escape from the world and self? And where is the capacity for heaven to come
from if it be not developed on earth? Where, indeed, is even the smallest
spiritual appreciation of God and heaven to come from when so little of
spirituality has ever been known or manifested here? If every Godward aspiration
of the soul has been allowed to become extinct, and every inlet that was open to
heaven to be choked, and every talent for religious love and trust to have been
persistently neglected and ignored, where are the faculties to come from that
would even find the faintest relish in such things as God and heaven
give?
These three words, Salvation, Escape, and
Neglect, then, are not casually, but organically and necessarily connected.
Their doctrine is scientific, not arbitrary. Escape means nothing more than the
gradual emergence of the higher being from the lower, and nothing less. It means
the gradual putting off of all that cannot enter the higher state, or heaven,
and simultaneously the putting on of Christ. It involves the slow completing of
the soul and the development of the capacity for
God.
Should any one object that from this
scientific standpoint the opposite of salvation is annihilation, the answer is
at hand. From this standpoint there is no such
word.
If, then, escape is to be open to us, it
is not to come to us somehow, vaguely. We are not to hope for anything startling
or mysterious. It is a definite opening along certain lines which are definitely
marked by God, which begin at the Cross of Christ and lead direct to Him. Each
man in the silence of his own soul must work out this salvation for himself with
fear and trembling--with fear, realizing the momentous issues of his task; with
trembling, lest before the tardy work be done the voice of Death should summon
him to stop.
What these lines are may, in
closing, be indicated in a word. The true problem of the spiritual life may be
said to be, do the opposite of Neglect. Whatever this is, do it, and you shall
escape. It will just mean that you are so to cultivate the soul that all its
powers will open out to God, and in beholding God be drawn away from sin. The
idea really is to develop among the ruins of the old a new "creature"--a new
creature which, while the old is suffering Degeneration from Neglect, is
gradually to unfold, to escape away and develop on spiritual lines to spiritual
beauty and strength. And as our conception of spiritual being must be taken
simply from natural being, our ideas of the lines along which the new religious
nature is to run must be borrowed from the known lines of the
old.
There is, for example, a Sense of Sight in
the religious nature. Neglect this, leave it undeveloped, and you never miss it.
You simply see nothing. But develop it and you see God. And the line along which
to develop it is known to us. Become pure in heart. The pure in heart shall see
God. Here, then, is one opening for soul-culture--the avenue through purity of
heart to the spiritual seeing of God.
Then
there is a Sense of Sound. Neglect this, leave it undeveloped, and you never
miss it. You simply hear nothing. Develop it, and you hear God. And the line
along which to develop it is known to us. Obey Christ. Become one of Christ's
flock. "The sheep hear His voice, and He calleth them by name." Here, then, is
another opportunity for the culture of the soul--a gateway through the
Shepherd's fold to hear the Shepherd's
voice.
And there is a Sense of Touch to be
acquired-- such a sense as the woman had who touched the hem of Christ's
garment, that wonderful electric touch called faith, which moves the very heart
of God.
And there is a Sense of Taste--a
spiritual hunger after God; a something within which tastes and sees that He is
good. And there is the Talent for Inspiration. Neglect that, and all the scenery
of the spiritual world is flat and frozen. But cultivate it, and it penetrates
the whole soul with sacred fire, and illuminates creation with God. And last of
all there is the great capacity for Love, even for the love of God--the
expanding capacity for feeling more and more its height and depth, its length
and breadth. Till that is felt no man can really understand that word, "so great
salvation," for what is its measure but that other "so" of Christ--God so loved
the world that He gave His only begotten Son? Verily, how shall we escape if we
neglect that?
For the scientific basis of thls spiritual law the following works may be consulted:--
"The Origin of Species." By Charles Darwin, F.R.S. London: John Murray. 1872.
"Degeneration." By E. Ray Lankester, F.R.S. London: Macmillan. 1880.
"Der Ursprung der Wirbelthiere und das Princip des Functions-Wechsels." Dr. A. Dorhn. Leipzig: 1875.
"Lessons from Nature." By St. George Mivart, F.R.S. London: John Murray. 1876.
"The Natural Conditions of Existence as they Affect Animal Life." Karl Semper London: C. Kegan Paul & Co. 1881.