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rivers were infinitely more abundant. When this is understood we can
reasonably reduce the extension of the ancient glaciers, the lowering
of the temperature at the quaternary age, and account for the
uninterrupted life of the fauna and flora. However, we must not fall
into the opposite excess and assert, as some have done, that the
glacial period is comparatively recent, the traces of which are too
plain and fresh in some localities to assign to it an age prior to
man, and that the temperature has rather lowered itself since this
epoch. The ancient extension of the glaciers has been followed by a
corresponding growth and extension of animal life, thus proving that
the permanence of glaciers is a wise provision and absolutely
essential to man and the high orders of animals and vegetation. The
ancient extension does not prove alone that it was much colder than in
historic times, for the animals themselves are proof of this. At that
time the plains of Europe, and of France in particular, were animated
by herds of reindeer, gluttons, camels, and marmots, which one does
not find to-day except in the higher latitudes or more considerable
heights. The mammoth and rhinoceros are no exception to this, for
naturalists know they were organized to live in cold countries.

Space will not permit us to pursue this point further, or speculate on
the probable climatic conditions of the ice age; but we can carry
ourselves back a few thousand years and describe the climate of Europe
and neighboring countries of Africa and Asia. Herodotus describes the
climate of Scythia in terms which would indicate in our day the
countries of Lapland and Greenland. He shows us the country completely
frozen during eight months of the year; the Black Sea frozen up so
that it bore the heaviest loads; the region of the Danube buried under
snow for eight months, and watered in summer by the abundant rains
which gave to the river its violent course. The historian adds that
the ass cannot live in Scythia on account of the extreme cold which
reigns there. The following century Aristotle makes the same remarks
concerning Gaul. His contemporary, Theophrastes, tells us that the
olive tree did not succeed in Greece more than five hundred furlongs
from the sea. We can assure ourselves that both the ass and the olive
thrive in these countries at the present day.

Three centuries later, Cæsar speaks frequently and emphatically of the
rigor of winters and early setting in of cold in France, the abundance
of snow and rain, and the number of lakes and marshes which became
every moment serious obstacles to the army. He says he is careful not
to undertake any expedition except in summer. Cicero, Varro,
Possidonius, and Strabo insist equally on the rigor of the climate of
Gaul, which allows neither the culture of the vine nor the olive.
Diodorus of Sicily confirms this information: "The cold of the winters
in Gaul is such that almost all the rivers freeze up and form natural
bridges, over which numerous armies pass quite safely with teams and
baggages; in order to hinder the passengers to slip out upon the ice
and to render the marching more secure, they spread straw thereon."

Virgil and Ovid insist on the severity of cold in the regions of the
Danube. The first describes the inhabitants of these miserable
countries withdrawing themselves into caves dressed with the skins of
wild beasts. Ovid, who had passed several years of his life in that
region, is more precise in his description. He says the wine has
changed itself here (Black Sea) into a solid frozen mass; one gives it
to drink by pieces. Fearing of being accused of poetic exaggeration he
appeals to the testimony of two ancient governors of Moesia, who could
establish the facts like himself. The author who would give such
accounts of the Black Sea in our days would risk his reputation for
veracity.

Italy, too, experienced its part of the cold in early days. Virgil
tells us of the snows being, heaped up, rivers which carried ice
along, the sad winter which split the stone and bound up the course of
large streams, and all this in the warmest part of Italy, at the base
of the walls of Taranto. Heratius affirms that the Soracte, a
neighboring mountain of Rome, was whitened with thick snow, rivers
frozen, and the country covered with snow. To-day the snow stays very
little upon the Soracte and never in the country around Rome. During
the four or five centuries which followed, writers speak of the
severity of climate in Northern Italy, the lagoons on the Adriatic
being frozen over. Algiers was much colder then than now. The Danube,
Rhine, and other rivers in Europe, the Nile in Africa, the Amazon in
South America, the Mississippi and Missouri in North America, had
quite different volumes two thousand years ago than their present
actual ones, and they especially rolled much greater masses of water.

There is everything to show a modification of climate in our own days.
If this goes on in the future as in the past, there will be a marked
difference in the temperature two or three hundred years from now.
Even a degree in a thousand years would effect a great change in the
course of time. The lowering of four degrees established the ancient
extension of glaciers, though it did not interrupt animal or vegetable
life. Fifty-four of the fifty-seven species of _Mollusca_ have
outlived the glacial age, and all our savage animals - even a certain
number which have disappeared - date equally from the quaternary, and
were contemporary with the great extension of the glaciers. - _Popular
Science News_.

* * * * *




THE ERUPTION OF KRAKATOA.


Before the year 1883 physical geographers, in speaking of the most
disastrous volcanic eruption on record, referred first, in point of
time, to the celebrated eruption of Vesuvius, in A.D. 79, when the
cities of Herculaneum, Pompeii and several smaller towns on the slope
of the mountain were destroyed by lava or buried under a mass of
pumice stones and ashes; second to that of Hecla and Skaptar Jokull,
contiguous mountains in Iceland, in 1783, when two enormous lava
streams, one 15 miles wide and over 100 ft. deep and the other
scarcely inferior, flowed, the first, 50 miles and the other 40, till
they reached the sea, pouring a flood of white hot lava into the
ocean, destroying everything in their paths and killing in the waters
of the ocean the fish, the mainstay of the inhabitants, who were
reduced by the disaster, directly or indirectly, to less than
five-sixths of their former strength; and third to that of Galungung,
in 1822, which devastated such an immense area in Java; but all the
eruptions known besides were as mere child's play to the terrible one
of Krakatoa in 1883.

If the reader will examine the map of the East Indies he will find
represented in the straits of Sunda, which lie between Sumatra and
Java, the little island of Krakatoa. In maps made before 1883 he will
hunt in vain for the name, for like Bull Run before 1861, it was then
unknown to fame, though navigators who passed through the straits knew
it as a beautiful tropical isle, with an extinct volcanic cone in the
center. In the beginning of 1883, however, the little well behaved
island showed symptoms of wrath that boded no good to the larger
islands in the vicinity. Noted for the fine fruits with which it
abounded, it was a famous picnic ground for towns and cities even 100
miles away, and when the subterranean rumblings and mutterings of
wrath became conspicuous the people of the capital of Java, Batavia,
put a steamboat into requisition and visited the island in large
numbers. For a time the island was constantly in a slight tremor, and
the subterranean roar was like the continued but distant mutterings of
thunder, but the crisis was reached August 23, at 10 o'clock A.M. It
was a beautiful Sunday morning and the waters of the straits of Sunda
were like that sea of glass, as clear as crystal, of which John in his
apocalyptic vision speaks. The beauty that morning was enhanced by the
extraordinary transparency of the tropical air, for distant mountain
ranges seemed so near that it seemed possible to strike them with a
stone cast from the hand. Only the mysterious rumblings and mutterings
of the pent up forces beneath the island disturbed the breathless calm
and silence that lay on nature - the calm before the terrible
storm - the mightiest, the most awful on record! It burst forth! Sudden
night snatched away day from the eyes of the terrified beholders on
the mainland, but the vivid play of lightnings around the ascending
column of dust penetrated even the deep obscurity to a distance of 80
miles. This awful darkness stretched within a circle whose diameter
was 400 miles, while more or less darkness reigned within a circle
with a diameter three times as great. Within this latter area dust
fell like snow from the sky, breaking off limbs of trees by its weight
miles distant, while in Batavia, 100 miles away from the scene of the
disaster, it fell to the depth of several inches. The explosions were
so loud as to be distinctly heard in Hindostan, 1,800 miles away, and
at Batavia the sound was like the constant roar of cannon in a field
of battle. Finally the whole island was blown to pieces, and now came
the most awful contest of nature - a battle of death between Neptune
and Vulcan; the sea poured down into the chasm millions of tons, only
to be at first converted into vapor by the millions of tons of
seething white hot lava beneath. Over the shores 30 miles away, waves
over 100 ft. high rolled with such a fury that everything, even to a
part of the bedrock, was swept away. Blocks of stone, of 50 tons
weight were carried two miles inland. On the Sumatra side of the
straits a large vessel was carried three miles inland. The wave, of
course growing less in intensity, traveled across the whole Indian
Ocean, 5,000 miles, to the Cape of Good Hope and around it into the
Atlantic. The waves in the atmosphere traveled around the globe three
times at the rate of 700 miles per hour. The dust from the volcano was
carried up into the atmosphere fully twenty miles and the finest of it
was distributed through the whole body of air. The reader doubtless
remembers the beautiful reddish or purple glow at sunrise and sunset
for fully six months after August, 1883 - that glow was caused by
volcanic dust in the atmosphere interfering with the passage of the
sun's rays of the upper part of the solar spectrum, more manifest at
sun rising and setting than at other times during the day, because at
these periods the sun's rays have to travel obliquely through the
atmosphere, and consequently penetrating a very deep layer, were
deprived of all their colors except the red.

The loss of life was appalling. The last sight on earth to 35,000
people was that of the awful eruption. Engulfed in the ocean or
covered with heaps of ashes, a few hours after the eruption commenced
the awful work was done, and that vast multitude had vanished from off
the face of the earth. The fact that in the neighborhood of the
mountain there was a sparse population accounts for there not being
even a far greater loss of life.

Notwithstanding the awfulness of volcanic and earthquake phenomena,
there is some silver lining to the dark clouds. They prove that the
earth is yet a _living_ planet. Centuries must pass away before it
will become like the moon - a dead planet - without water, air or life.
Our satellite is a prophecy indeed of what the earth must eventually
become when all its life forces, its internal energies, are dissipated
into space. - _Granville F. Foster, Min. Sci. Press_.

* * * * *




PENTAPTERYGIUM SERPENS.


This is one of five species of Himalayan plants which, until recently,
were included in the genus vaccinium. The new name for them is ugly
enough to make one wish that they were vacciniums still.
Pentapterygium serpens is the most beautiful of the lot, and, so far
as I know, this and P. rugosum are the only species in cultivation in
England. The former was collected in the Himalayas about ten years ago
by Captain Elwes, who forwarded it to Kew, where it grows and flowers
freely under the same treatment as suits Cape heaths. Sir Joseph
Hooker says it is abundant on the Sikkim mountains at from 3,000 to
8,000 feet elevation, and that it usually grows on the stout limbs of
lofty trees. In this it resembles many of the rhododendrons of that
region, and it has been suggested that they are epiphytic from force
of circumstances, not from choice. On the ground they would have no
chance against the other vegetation, which would strangle or starve
them out. Remove them from this struggle for existence, and they at
once show their preference for rich soil and plenty of it. All the
pentapterygiums have the lower part of the stem often swelling out
into a prostrate trunk, as thick as a man's leg sometimes, and sending
out stout branching roots which cling tightly round the limbs of the
tree upon which it grows. These swollen stems are quite succulent, and
they serve as reservoirs of moisture and nourishment. In the wet
season they push out new shoots, from which grow rapidly wands three
or four feet long, clothed with box-like leaves, and afterward with
numerous pendulous flowers. These are elegant in shape and richly
colored. They are urn-shaped, with five ribs running the whole length
of the corolla, and their color is bright crimson with deeper colored
V-shaped veins, as shown in the illustration of the flowers of almost
natural size. They remain fresh upon the plant for several weeks. The
beautiful appearance of a well grown specimen when in flower may be
seen from the accompanying sketch of the specimen at Kew, which was at
its best in July, and remained in bloom until the middle of September.


[Illustration: PENTAPTERYGIUM SERPENS (FLOWERS NEARLY NATURAL SIZE)]

P. rugosum is also grown as a greenhouse plant at Kew, where it has
been in cultivation about twenty years. It has larger leaves and a
more bushy habit than P. serpens, while the flowers are produced in
fascicles on the old wood. They are as large as those here figured,
but differ in color, being whitish, with brown-red V-shaped marks.
Both species may be propagated from cuttings. The plants thrive in
sandy peat, and they like plenty of moisture at all times. - _W.
Watson, in The Gardeners' Magazine_.

[Illustration: PENTAPTERYGIUM SERPENS (FLOWERS DEEP CRIMSON)]

* * * * *




THE PERFORATION OF FLOWERS.


The subject of the relations and adaptations which exist between
flowers and insects does not appear to excite as much popular
attention as many other branches of natural science which are no more
interesting. Sprengel, Darwin, and Hermann Muller have been the chief
authors in giving us our present knowledge and interest in the study;
Sir John Lubbock has helped to popularize it, and Prof. W. Trelease
and others have carried on the work in this country.

The perforation as well as the fertilization of flowers has received
attention, but there is a wide field for further study for those who
have leisure to pursue it, as it requires much time and patience, as
well as closeness and accuracy of observation.

The accompanying figures, from drawings by Mr. C.E. Faxon, show a few
characteristic perforations and mutilations, and also represent two of
the principal kinds of insects which make them.

Any one interested in the subject will find an excellent brief review
of the work already done, a fair bibliography, and a list of
perforated flowers in Professor L.H. Pammel's paper on the
"Perforation of Flowers," in the _Transactions of the St. Louis
Academy of Science_, vol. v., pp. 246-277.

The general beauty of flowers is usually not greatly marred by the
perforations except in a few cases, as when the spurs of columbines
and corollas of trumpet creepers are much torn, which frequently
happens.

The great object of the perforations by insects is the obtaining of
the concealed nectar in an easy way. Very naturally, flowers which
depend on insect agency for fertilization rarely produce seed when
punctured if they are not also entered in the normal way. Perforating
is only practiced by a small number of species of insects, and many
but not all of the perforators do so because their tongues are too
short to reach the nectar by entering the flower. Some obtain nectar
from the same kind of flower both in the normal way and by
perforating.

The chief perforators of flowers, in this part of the continent at
least, appear to be some kinds of humble bees (Bombus) and carpenter
bees (Xylocopa). These insects have developed an unerring instinct as
to the proper point to perforate the corollas from the outside, in
order to readily get at the nectar. The holes made by the humble bees
and by the carpenter bees are usually quite different and easily
distinguished.

The humble bees have short, stout, blunt jaws, ill adapted for
cutting, and the perforations made by them are apparently always
irregular in shape, and have jagged edges. It has been stated that the
humble bees often bore through the tubes of their corollas with their
maxillæ, but in all cases observed by me the mandibles were first
brought into use in effecting an opening. The noise caused by the
tearing is often audible for a distance of several feet.

The true jaws of the carpenter bees are not any more prominent or
better adapted for making clean-cut perforations than those of the
humble bees; but behind the jaws there is a pair of long,
sharp-pointed, knife-like, jointed organs (maxillæ) which seem to be
exclusively used on all ordinary occasions in making perforations. The
inner edges of these maxillæ are nearly straight, and when brought
together they form a sharp-pointed, wedge-shaped, plow-like instrument
which makes a clean, narrow, longitudinal slit when it is inserted in
the flower and shoved forward. The slits made by it are often not
readily seen, because the elasticity of the tissues of some flowers
causes them to partially close again. When not in use the instrument
can be folded back, so that it is not conspicuous. The ordinary
observer usually sees no difference between the humble bees and the
carpenter bees, but they may be readily distinguished by a little
close observation.

[Illustration: THE PERFORATION OF FLOWERS.

1. Xylocopa and heads of male and female. 2. Bombus and head. 3.
Dicentra spectabilis, showing punctures. 4. Ribes aureum. 5. Ligustrum
Ibota. 6. Æsculus glabra. 7. Lonicera involucrata. 8. Caragana
arborescens. 9. Andromeda Japonica. 10. Buddleia Japonica. 11.
Mertensia Virginica. 12. Rhododendron arborescens. 13. Corydalis
bulbosa.]

No doubt, in some of the recorded cases of perforations, carpenter
bees have been mistaken for humble bees. The heads of all our Northern
humble bees are rather narrow, retreating from the antennæ toward the
sides, and with a more or less dense tuft of hair between the antennæ.
The abdomen, as well as the thorax, is always quite densely covered
with hair, which may be black or yellowish or in bands of either
color. With possibly one or two exceptions, the only species I have
seen doing the puncturing is Bombus affinis, Cresson.

The carpenter bees (Xylocopa Virginica) of this region have the head
very broad and square in front, and with no noticeable hair between
the antennæ. The heads of the male and female differ strikingly. In
the male the eyes are lighter colored and are hardly half as far apart
as in the female, and the lower part of the face is yellowish white.
The female has eyes smaller, darker, and very far apart, and the whole
face is perfectly black. The abdomen is broad, of a shining blue-black
color, very sparsely covered with black hairs, except on the first
large segment nearest the thorax. On this segment they are more dense
and of the same tawny color as those on the thorax. But it is
particularly from the character of the head that the amateur observer
of the perforators may soon learn to distinguish between a Xylocopa
and a Bombus as they work among the flowers. It is also interesting to
know that the Xylocopas are not so inclined to sting as the humble
bees, and the males, of course, being without stinging organs, may be
handled with impunity.

Among other insects, honey bees have been said to perforate flowers,
but authentic instances are rare of their doing much damage, or even
making holes. I have only recorded a single instance, and in this a
honey bee was seen to perforate the fragile spurs of Impatiens. When
searching for nectar they quite commonly use the perforations of other
insects. Wasps and other allied insects also perforate for nectar. My
only observations being a Vespa puncturing Cassandra calyculata, an
Andrena (?) perforating the spurs of Aguilegia, and Adynerus
foraminatus biting holes close to the base on the upper side of
rhododendron flowers. The holes made by some of the wasp-like insects
are often more or less circular and with clean-cut edges. The ravages
committed by larvæ, beetles and other insects in devouring flowers, or
parts of them, do not properly come under the head of perforations.

The question as to the cause of the handsome corollas of the trumpet
creeper (Tecoma radicans) being so often split and torn has been
accounted for in various ways in published notes on the subject.
Humming birds and ants have been blamed, the humming birds being such
constant visitors of these flowers that it really seemed as though
they must be the authors of the mischief. I have often watched them
when they appeared as though they were pecking at the blossoms, but
careful examinations, both before and after their visits, always
failed to show any trace of injury. Finally, on July 26, 1890, I was
rewarded by seeing a number of Baltimore orioles vigorously pecking at
and tearing open a lot of fresh blossoms, and this observation was
afterward repeated. That the oriole should do this was not surprising,
considering its known habits in relation to some other flowers. J.G.
JACK.

[Mr. Jack adds a list of sixteen plants whose flowers he has seen
punctured by the carpenter bee and seventeen others whose flowers were
punctured by the humble bee. He names more than thirty other flowers
which he has found perforated without having seen or identified the
authors of the mischief. - ED.] - _Garden and Forest_.

* * * * *




ELECTRICITY IN HORTICULTURE.


The influence of electricity upon vegetation has been the subject of
numerous investigations. Some have been made to ascertain the effects
of the electric current through the soil; others to ascertain the
effect of the electric light upon growth through the air. Among the
latter are those of Prof. L.H. Bailey of the Cornell University
Agricultural Experiment Station. In Bulletin No. 30 of the
Horticultural Department is given an account of experiments with the
electric light upon the growth of certain vegetables, like endive,
spinach, and radish; and upon certain flowers like the heliotrope,
petunia, verbena primula, etc. The results are interesting and
somewhat variable. The forcing house where the experiments were
carried on was 20 × 60 ft., and was divided into two portions by a
partition. In one of these the plants received light from the sun by
day and were in darkness at night. In the other they received the
sunlight and in addition had the benefit of an arc light the whole or
a part of the night. The experiment lasted from January until April
during two years, six weeks of the time the first year with a naked
light and the balance of the time with the light protected by an
ordinary white globe. It is not the purpose here to enter into any
great details, but to give the general conclusions.

The effect of the naked light running all night was to hasten
maturity, the nearer the plants being to the light the greater being
the acceleration. The lettuce, spinach, etc., "ran to seed" in the
"light" house long before similar plants in the dark. An examination
of the spinach leaves with the microscope showed the same amount of
starch in each, but in the electric light plants the grains were
larger, had more distinct markings and gave a deeper color with
iodine.

With lettuce it was found that the nearer the plants were to the light
the worse the effect; and conversely those furthest away were the best
developed. Cress and endive gave the same results. In the case of the
latter, some of the plants were shaded from the light by an iron post,


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Online LibraryVariousScientific American Supplement, No. 841, February 13, 1892 → online text (page 3 of 11)