THE BIOLOGY OF SUMMER
ARGUMENT.—Life is rhythmic and is punctuated by the seasons. Summer
is the crest of the annnal wave. I. It is the time of intensest life, when both
output and income of energy reach their maximum. The activity of unconscious
plant-life is crowned in the flowers, and the growing brilliancy of colour is an
index of increasing intensity. II. Conscious animal industry also reaches its
climax, both in instinctive and intelligent activity, as in bees and birds. III.
But the vigorous intensity of life is interrupted by sleep, weariness, and death.
Yet Love is strongest after all.
I
THE tide which sets in with a rush in Spring:
reaches its high-water mark in Midsummer, and
often makes for itself a new shore. The buds
are replaced by hard-working leafy boughs
whose activity during the day is intense; the
budlike early flowers are succeeded by more
liberal beauty; young things pass through adolescence to
mature strength; and love is justified in her children. For
Summer is the time of maximum output and income of
energy, when the fires of life not only burn brightest, but are
built up for another season; it is the time of intensest effort,
rising even to madness, the time of richest beauty and fullest
joy.
Although we are wont to associate Summer with rest and
holiday-making, this is rather an urban than a rustic general-
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isation. Midwinter is the countnrman’s resting time; in Mid-
summer he is hard at work. So with Nature, for in Summer
most work is done, and the stores of energy are accumulated
for another year. Whether we think of the green leaves in
which the powers of light and of life co-operate to raise simple
substances into complexity, the inorganic into the organic;
or of the bees who so industriously visit the flowers and store
up honey in the hive; or of the birds gathering food for their
callow young; or of the haymakers busy in the heat of the day,
we get the same impression of vigorous work, at the various
planes of unconscious, instinctive, intelligent, and rational life.
The biggest fact in the Biology of Summer is perhaps the
most obvious one, that it is then that life comes nearest, or,
what comes to the same thing, is most exposed to the source
of almost all mundane energy—the sun. Thus the Biology of
Summer has for its central problem—the influence of heat and
light upon life. Now there is heat that burns, witness the
steppe vegetation after the dry season; and there is light that
kills, notably in the case of the disease germs or Bacteria
which a forenoon of dear sunshine destroys so beneficently,
but the general fact, demonstrable by numberless experiments,
is that the heat and light of Summer renew the energies of
living creatures. Indeed, we all depend from year to year on
the power that green plants have of inducing the sunlight to
help them to make food for us. At the very opposite end of the
scale—for there is long gamut of life from wheat plant to man
—is it not true that seeking the sun and seeking more life are
synonymous for some of us? It is idle to point to the fact
that London has about one-third less sunshine than Madrid,
but certainly not less vitality; for it is obvious that London is
mainly an area for uncorking sunshine bottled elsewhere.
Every one knows how the pulse-register or sphygmograph
proves that the sunshine vivifies the system. Quite irrespective
of holiday-mood, of the delights of being free and hearing the
birds sing and seeing the flowers in bloom, the sunlight
quickens the pulse and man’s life.
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‘O solemn-beating heart
Of Nature! I have known that thou art
Bound unto man’s by cords he cannot sever.
And what time they are slackened by him ever,
So to attest his own supernal part,
Still runneth thy vibration, fast and strong.,
The slackened cord along!’
And if in man—with his slackened cord—the sunlight still
awakens the responses of vitality, how much more so in the
animals who throb with every pulsation of Nature’s heart!
And if the sunlight find voice in the bravura of birds, how
much more directly yet in the bustle of growing wheat I
The growing intensity of unconscious vegetable life is re-
gistered in the incresising brightness of floral colour. For
although there are many bright flowers in early Spring,—the
marsh marigold which raises its golden cups from the dark
ditch, the bright yellow celandine which welcomes the swallow,
the blue hyacinths, which make the wood-glade glorious,—’the
heavens upbreaking through the earth,’ the laburnum with its
‘dropping wells of fire,’ the periwinkle and the ground ivy,
and the golden daffodils whose dance ‘outdoes the sparkling
waves in glee,’—yet the broad fact is that as the days grow
warmer and brighter, the colours increase in intensity.
Although we may not accept the sagacious meteorologist’s
suggestion that the annual succession of colour corresponds to
the colour-scheme of the rainbow, yet it seems demonstrable
that red and purple,” blue and violet flowers—in short, those of
richer colour, become more numerous as the days lengthen.
Ruskin, following Goethe, defined the real nature of the flower,
when he said, ‘The leaf which loves the light has above
all things the purpose of being married to another leaf, and
having child-leaves, and children’s children of leaves, to
make the earth fair for ever. And when the leaves marry
they put on wedding-robes, and are more glorious than
Solomon in all his glory, and they have feasts of honey, and we
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call them flowers.’ For we recognise that the petals are but
transfigured leaves, and that the pollen-producing and seed-
bearing parts are also modified leaves. The feasts of honey or
nectar are overflows of sugar in more or less useful places; the
fragrance may possibly correspond to a kind of essence of
sweat, remotely analogous to the muskiness which exudes
from the skins of some animals; and the beauty of the
wedding-robes, like that of some butterflies’ wings, is in some
cases due to waste-products, the ashes of the flowers’ hidden
fires.
It cannot be said that we have by any means attained to an
understanding of either nectar or fragrance or colour; we are
still children with flowers in our hands, just beginning to know
something about them. We have at any rate got past the pre-
liminary stage of giving their insect visitors the whole credit for
evolving flowers, which is like crowning snakes for evolving the
wisdom of the East; we are now busy trying to find out what
nectar, fragrance, and pigments mean primarily in the life of
the plant The poet says, ‘It must be the flag of my disposi-
tion, out of hopeful green stuff woven’; the religious mind says,
‘It is the handkerchief of the Lord, a scented gift and remem-
brancer designedly dropt, bearing the owner’s name someway
in the comers’; the biologist says,’ Overflow of surplus sugar,
sublimated sweat, and beauty for ashes;’ but the flower in the
crannied wall is a hieroglyphic still.
II
We have spoken of the unconscious work of the sunlit leaves,
the results of which are seen in the filling of tubers and other
storehouses, in the formation of next year’s buds, in the making
of seeds and fruits,—and again, indirectly, in the increased store
of energy which is brought by plants within reach of animal
life. The sunbeams dance over the meadow, but some of them
are trapped, and their dance is lost in a dance of molecules
which, changing partners in the maze, eventually sink into
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complex combinations; we can hardly see the grass for flowers,
each is in a sense a fixed sunbeam; the butterflies float from
blossom to blossom, the sunbeam is in motion again. It is a
ceaseless series of transformations of energy.
One of the main impressions of Summer is surely that of a busy
animal life, swayed in great part by the twin impulses of Hunger
and Love. There is eager endeavour after individual well-being,
there is not less careful effort which secures the welfare of the
young. The former varies from a keen struggle for existence
to a gay pursuit of æsthetic luxuries; the latter rises from
physiologically necessary life-losing and instinctive industry to
remarkable heights of what seems to us affectionate devotion.
Whether we look out on plants or animals or men during the
intense life of Summer, the old question rises to our lips,
‘Warum treibt sich das Volk so und schreit?’ and the answer
ever fundamentally true, but changeable within limits for
different existences, comes, ‘Es will sich ernähren. Kinder zeu-
gen, und die nähren so gut es vermag.’
The activity of the ants, bees, wasps, and other insects, repre-
sents Summer industry at a higher level than that in the leaves;
it is, we believe, conscious and instinctive. By which we mean
that most of those activities, which it is one of the delights of
Summer to watch, are performed without intelligent control,
and are more or less independent of education and experience,
in virtue of inherited cerebral mechanism, if such an ignorance-
confessing phrase be admissible. The animals are, so to speak,
constitutionally wound up to do what they do when suitable
stimuli occur. In many of their activities they are conscious
automata. But the beauty of it is that the results of this con-
scious automatism are often as perfect as the outcome of the
most profound deliberation. It seems, as we look at the bee’s
honeycomb, the wasp’s nest, the spider’s web, that art is per-
fected in becoming most instinctive; and surely the rationality
of our world is at least as plain in the web or termitary as in the
Forth Bridge or Eiffel Tower. ‘A mouse is miracle enough to
stagger sextillions of infldels.’
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Animal industry in its instinctive forms gives one an impression
of ease and spontaneity; they do not sweat nor whine, nor hesi-
tate nor look puzzled. One has the same impression in watch-
ing a very perfect mechanism which performs its task without
noise or jar. But just as the machine has certainly its wear
and tear, however well concealed that may be, so it is with the
instinctively industrious animals. Recent researches show that
the nerve-cells of the bee’s brain are, at the end of a hard day’s
work, unmistakably fatigued; and, more than this, a certain
number seem gradually to go out of gear as the Summer’s work
continues; they die off until no more are left than are sufficient
for the necessary vital functions. There are hints of the same
sad fact even in man, and though our knowledge of the matter
is very slight, we may dimly see why it is that we are doomed,
not only to become ‘old fogies,’ but to die of ‘old foginess’
should we escape a more merciful ending. Along the same
line of thought we may also perhaps advance to a better under-
standing of such facts as the saving reaction of daily and
seasonal sleep.
Representing a higher grade of activity than that of the bees is
the parental industry of the birds, for it is to a larger degree
intelligent. We do not mean the building of nests, which we
prefer to regard as an activity of Spring (often continued on into
Summer), for that seems to us in the main instinctive, we mean
rather the untiring activity which so many exhibit in protecting,
feeding, and finally educating their young. The songsters are
quieter than they were, the wild lyrics have given place to more
measured psalms of life, partly, of course, because the ecstasy
of passion is over for the season, partly, perhaps, because the
birds have found keeping house a much more serious business
than falling in love and getting married. But were it less
familiar it would appear to us more beautiful—the manner in
which the love of mates broadens into and is lost in the love of
offspring. Yet not lost either, since it surely returns purified and
strengthened. Every one knows that the two parent birds will
work themselves thin in their untiring solicitude for the young
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brood. We are not warranted in supposing that they think
of their sacrifice, any more than of the welfare of the species,—
they do not control their conduct in reference to an ideal, they
are not moral, poor things,—but is there not something won-
derful in it, something, as Socrates said, moving to tears, and
yet consoling in our rdations one with another ?
III
But it must be noticed that the intensity of life, which seems to
us so characteristic of Summer, is by no means unrelieved.
Every one familiar with the country has noticed that in days of
intense heat, the whole aspect of Nature occasionally suggests
sleepiness, especially about noon. A few clouds hang motion-
less in a lofty blue sky, the air is tremulous over the hot earth,
the birds are all hushed in the woods, the leaves droop after
extreme transpiration, the labourers have lain down by the
hedge-side, and there is scarce a sound save that of the grass-
hoppers, whose interrupted chirping makes a sort of background
for the silence. Doubtless our own sleepiness exaggerates the
impression, but when even the leaves fall asleep, few living
things are likely to be wakeful. In fact, what we experience
even in this country is a suggestion of the Summer slumbers—
or aestivation—of mud-fish, amphibians, and crocodiles, when
the waters dry up in the pools of tropical countries. We may
corroborate this very strikingly by visiting half a dozen shore
pools in the heat of the day when there is stillness like that of
an Eastern city in siesta, and in the twilight when there is all
the activity of a Donnybrook Fair.
There is another phenomenon which has often impressed us on
a bright and breezy Summer day,—the sudden appearance of a
dark cloud, which, though heavy with dust and rain, drifts
rapidly across the sky. We can follow its shadow over the
fields and the firth, and as it blots out the sun from us for a few
long seconds, we feel a shiver of suspense. Of course this is
a mere sentimentalism, but the precise physiology of the shiver
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might be interesting, especially in reference to the connection
between emotion and muscular movements. This cloud, no
bigger than a man’s hand, is the external counterpart of the
tear which comes sometime to all of us to blot out God’s sun.
Its shadow is death’s.
For in the midst of all the beauty and virility, all the bustle
and gaiety of Summer days, he with the ever-harvesting sickle
walks with swift feet. He mingles with the haymakers and
one is carried senseless off the field; he troubles the waters of
the seaside town, and the ranks of the children who romped
merrily on the sands are thinned; he passes among the flocks,
and many need no more shepherding; he breathes upon the
dancing day-flies, and they sink with the setting sun; he
touches the meadows with his skirts, and the grass withereth
and the flower fadeth. But why in the midst of life is there
so much death, against whom there is no standing nor de-
fiance? It is partly that at an early chapter in life’s history
immortality was pawned for love, and death was made a price
for giving rise to new life; as is illustrated by so many butter-
flies and other animals which die soon after reproducing. It
is partly that the machinery of life is by no means perfectly
self-repairing, and that the organism in living is continually
going into debt to itself,—debts only payable by death; as is
illustrated by all organisms whose efforts are followed by
irremediable nerve-fatigue. It is in great part also due to the
fact that although the sunlight is the most powerful antago-
nist of the pestilence that walketh in darkness, to wit, the
omnipresent disease-germs or Bacteria, the warmth and plenty
of Summer days favour their fatal multiplication, as is illus-
trated by many fevers.
But no one can have realised what the work of Summer
actually means, without feeling the profound truth of the
Buddhist doctrine of reincarnations, that nothing is ever really
lost in this economical world:
‘That nothing walks with aimless feet,
That not one life shall be destroyed,
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Or cast as rubbish to the void,
When God hath made the pile complete.’
Matter is ever circulating, in Summer most actively; energy
is ever changing, in Summer most of all. Nothing is ever lost.
The moistened dust and the quivering air become the grass,
the grass the deer, the deer the huntsman, the huntsman the
tiger, the tiger—with the aid of Bacteria—grass again. For
so the world goes round, and, ‘after Last, returns the First,
though a wide compass round be fetched.’
But if one asks for more than this profound, though perhaps
cold truth; asks, in fact, not for the flowers of yester-year,
but for the ‘souls of the flowers,’ for the psychical or metakinetic
aspects of the dayflies and butterflies, the sun-stricken hay-
maker, the fevered child, then we have but an answer as vague
as the question is vague:—
‘You must begone,’ said Death; ‘these walks are mine.
Love wept and spread his sheeny vans for flight;
Yet ere he parted said, ‘This hour is thine;
Thou art the shadow of life, and as the tree
Stands in the sun and shadows all beneath,
So in the light of great eternity
Life eminent creates the shade of death;
The shadow passeth when the tree shall fall
But I shall reign for ever over all!’
J. ARTHUR THOMSON.
MLA citation:
Thomson, J Arthur. “The Biology of Summer.” The Evergreen: A Northern Seasonal, vol. 3, Summer 1896, pp. 19-27. Evergreen Digital Edition, edited by Lorraine Janzen Kooistra, 2016-2018. Yellow Nineties 2.0, Ryerson University Centre for Digital Humanities, 2019. https://1890s.ca/egv3_thomson_biology/