[1] A passage (long overlooked) in Cicero, _De republica_, shows
that, by the 1st century B.C. the interpolation had already been
made; the quotation is evidently taken from the list in c. xli. of
the _Constitution_, which it reproduces.
DRACO ("the Dragon"), in astronomy, a constellation of the northern
hemisphere, mentioned by Eudoxus (4th century B.C.) and Aratus (3rd
century B.C.); it was catalogued by Ptolemy, 31 stars, Tycho Brahe, 32,
Hevelius, 40. The Greeks had many fables concerning this constellation;
one is that when Heracles killed the dragon guarding the Hesperian fruit
Hera transferred the creature to heaven as a reward for its services.
The planetary nebula _H. IV. 37 Draconis_ is of a decided pale blue
colour, and one of the most conspicuous objects of its class.
DRACONTIUS, BLOSSIUS AEMILIUS, of Carthage (according to the early
tradition, of Spanish origin), Christian poet, flourished in the latter
part of the 5th century A.D. He belonged to a family of landed
proprietors, and practised as an advocate in his native place. After the
conquest of the country by the Vandals, Dracontius was at first allowed
to retain possession of his estates, but was subsequently deprived of
his property and thrown into prison by the Vandal king, whose triumphs
he had omitted to celebrate, while he had written a panegyric on a
foreign and hostile ruler. He subsequently addressed an elegiac poem to
the king, asking pardon and pleading for release. The result is not
known, but it is supposed that Dracontius obtained his liberty and
migrated to northern Italy in search of peace and quietness. This is
consistent with the discovery at Bobbio of a 15th-century MS., now in
the Museo Borbonico at Naples, containing a number of poems by
Dracontius (the _Carmina minora_). The most important of his works is
the _De laudibus Dei_ or _De Deo_ in three books, wrongly attributed by
MS. tradition to St Augustine. The account of the creation, which
occupies the greater part of the first book, was at an early date edited
separately under the title of _Hexaemeron_, and it was not till 1791
that the three books were edited by Cardinal Arevalo. The apology
(_Satisfactio_) consists of 158 elegiac couplets; it is generally
supposed that the king addressed is Gunthamund (484-496). The _Carmina
minora_, nearly all in hexameter verse, consist of school exercises and
rhetorical declamations, amongst others the fable of Hylas, with a
preface to his tutor, the grammarian Felicianus; the rape of Helen; the
story of Medea; two epithalamia. It is also probable that Dracontius was
the author of the _Orestis tragoedia_, a poem of some 1000 hexameters,
which in language, metre and general treatment of the subject exhibits a
striking resemblance to the other works of Dracontius. Opinions differ
as to his poetical merits, but, when due allowance is made for
rhetorical exaggeration and consequent want of lucidity, his works show
considerable vigour of expression, and a remarkable knowledge of the
Bible and of Roman classical literature.
EDITIONS.--_De Deo_ and _Satisfactio_, ed. Arevalo, reprinted in
Migne's _Patrologiae cursus_, lx.; _Carmina minora_, ed. F. de Duhn
(1873). On Dracontius generally, see A. Ebert, _Allgemeine Geschichte
der Lit. des Mittelalters im Abendlande_, i. (1874); C. Rossberg, _In
D. Carmina minora_ (1878); H. Mailfait, _De Dracontii poetae lingua_
(1902). On the _Orestis tragoedia_, see editions by R. Peiper (1875)
and C. Giarratino (Milan, 1906); pamphlets by C. Rossberg (1880, on
the authorship; 1888, materials for a commentary).
DRAFTED MASONRY, in architecture, the term given to large stones, on the
face of which has been dressed round the edge a draft or sunken surface,
leaving the centre portion as it came from the quarry. The dressing is
worked with an adze of eight teeth to the inch, used in a vertical
direction and to a width of 2 to 4 in. The earliest example of drafted
masonry is found in the immense platform built by Cyrus 530 B.C. at
Pasargadae in Persia. It occurs again in the palace of Hyrcanus, known
as the Arak-el-Emir (176 B.C.), but is there inferior in execution. The
finest drafted masonry is that dating from the time of Herod, in the
tower of David and the walls of the Haram in Jerusalem, and at Hebron.
In the castles built by the Crusaders, the adze has been worked in a
diagonal direction instead of vertically. In all these examples the size
of the stones employed is sometimes enormous, so that the traditional
influence of the Phoenician masons seems to have lasted till the 12th
century.
DRAG (from the Old Eng. _dragan_, to draw; the word preserves the _g_
which phonetically developed into _w_), that which is drawn or pulled
along a surface, or is used for drawing or pulling. The term is thus
applied to a harrow for breaking up clods of earth, or for an apparatus,
such as a grapnel, net or dredge, used for searching water for drowned
bodies or other objects. As a name of a vehicle, "drag" is sometimes
used as equivalent to "break," a heavy carriage without a body used for
training horses, and also a large kind of wagonette, but is more usually
applied to a privately owned four-horse coach for four-in-hand driving.
The word is also given to the "shoe" of wood or iron, placed under the
wheel to act as a brake, and also to the "drift" or "sea-anchor,"
usually made of spars and sails, employed for checking the lee-way of a
ship when drifting. In fox-hunting, the "drag" is the line of scent left
by the fox, but more particularly the term is given to a substitute for
the hunting of a fox by hounds, an artificial line of scent being laid
by the dragging of a bag of aniseed or other strong smelling substance
which a pack will follow.
DRAGASHANI (Rumanian _Draga[s,]ani_), a town of Rumania, near the right
bank of the river Olt, and on the railway between Caracal and Ramnicu
Valcea. Pop. (1900) 4398. The town is of little commercial importance,
but the vineyards on the neighbouring hills produce some of the best
Walachian wines. Dragashani stands on the site of the Roman Rusidava. In
1821 the Turks routed the troops of Ypsilanti near the town.
DRAGOMAN (from the Arabic [Arabic: terjuman] _terjuman_, an interpreter
or translator; the same root occurs in the Hebrew word _targum_
signifying translation, the title of the Chaldaean translation of the
Bible), a comprehensive designation applied to all who act as
intermediaries between Europeans and Orientals, from the hotel tout or
travellers' guide, hired at a few shillings a day, to the chief dragoman
of a foreign embassy whose functions include the carrying on of the most
important political negotiations with the Ottoman government, or the
dragoman of the imperial divan (the grand master of the ceremonies).
The original employment of dragomans by the Turkish government arose
from its religious scruples to use any language save those of peoples
which had adopted Islamism. The political relations between the Porte
and the European states, more frequent in proportion as the Ottoman
power declined, compelled the sultan's ministers to make use of
interpreters, who rapidly acquired considerable influence. It soon
became necessary to create the important post of chief dragoman at the
Porte, and there was no choice save to appoint a Greek, as no other race
in Turkey combined the requisite knowledge of languages with the tact
and adroitness essential for conducting diplomatic negotiations. The
first chief dragoman of the Porte was Panayot Nikousia, who held his
office from 1665 to 1673. His successor, Alexander Mavrocordato,
surnamed Exaporritos, was charged by the Turkish government with the
delicate and arduous negotiation of the treaty of Carlowitz, and by his
dexterity succeeded, in spite of his questionable fidelity to the
interests of his employers, in gaining their entire confidence, and in
becoming the factotum of Ottoman policy. From that time until 1821 the
Greeks monopolized the management of Turkey's foreign relations, and
soon established the regular system whereby the chief dragoman passed on
as a matter of course to the dignity of hospodar of one of the Danubian
principalities.
In the same way, the foreign representatives accredited to the Porte
found it necessary, in the absence of duly qualified countrymen of their
own, to engage the services of natives, Greek, Armenian, or Levantine,
more or less thoroughly acquainted with the language, laws and
administration of the country. Their duties were by no means confined to
those of a mere translator, and they became the confidential and
indispensable go-betweens of the foreign missions and the Porte. Though
such dragomans enjoyed by treaty the protection of the country employing
them, they were by local interests and family ties very intimately
connected with the Turks, and the disadvantages of the system soon
became apparent. Accordingly as early as 1669 the French government
decided on the foundation of a school for French dragomans at
Constantinople, for which in later years was substituted the _Ecole des
langues orientales_ in Paris; most of the great powers eventually took
some similar step, England also adopting in 1877 a system, since
modified, for the selection and tuition of a corps of British-born
dragomans.
The duties of an embassy dragoman are extensive and not easily defined.
They have been described as partaking at once of those of a diplomatist,
a magistrate, a legal adviser and an administrator. The functions of the
first dragoman are mainly political; he accompanies the ambassador or
minister at his audiences of the sultan and usually of the ministers,
and it is he who is charged with the bulk of diplomatic negotiations at
the palace or the Porte. The subordinate dragomans transact the less
important business, comprising routine matters such as requests for the
recognition of consuls, the settlement of claims or furthering of other
demands of their nationals, and in general all the various matters in
which the interests of foreign subjects may be concerned. An important
part of the dragoman's duties is to attend during any legal proceedings
to which a subject of his nationality is a party, as failing his
attendance and his concurrence in the judgment delivered such
proceedings are null and void. Moreover, the dragoman is frequently
enabled, through the close relations which he necessarily maintains with
different classes of Turkish officials, to furnish valuable and
confidential information not otherwise obtainable. The high estimation
in which the dragomans are held by most foreign powers is shown by the
fact that they are usually and in the regular course promoted to the
most important diplomatic posts. This is the case in the Russian and
Austrian services (where more than one ambassador began his career as a
junior dragoman) and generally in the German service; the French chief
dragoman usually attains the rank of minister plenipotentiary. The value
of a tactful and efficient intermediary can hardly be over-estimated,
and in the East a personal interview of a few minutes often results in
the conclusion of some important matter which would otherwise require
the exchange of a long and laborious correspondence. The more important
consulates in the provinces of Turkey are also provided with one or more
dragomans, whose duties, _mutatis mutandis_, are of a similar though
less important nature. In the same way banks, railway companies and
financial institutions employ dragomans for facilitating their business
relations with Turkish officials.
DRAGOMIROV, MICHAEL IVANOVICH (1830-1905), Russian general and military
writer, was born on the 8th of November 1830. He entered the Guard
infantry in 1849, becoming 2nd lieutenant in 1852 and lieutenant in
1854. In the latter year he was selected to study at the Nicholas
Academy (staff college), and here he distinguished himself so much that
he received a gold medal, an honour which, it is stated, was paid to a
student of the academy only twice in the 19th century. In 1856 he was
promoted staff-captain and in 1858 full captain, being sent in the
latter year to study the military methods in vogue in other countries.
He visited France, England and Belgium, and wrote voluminous reports on
the instructional and manoeuvre camps of these countries at Chalons,
Aldershot and Beverloo. In 1859 he was attached to the headquarters of
the king of Sardinia during the campaign of Magenta and Solferino, and
immediately upon his return to Russia he was sent to the Nicholas
Academy as professor of tactics. Dragomirov played a leading part in the
reorganization of the educational system of the army, and acted also as
instructor to several princes of the imperial family. This post he held
until 1863, when, as a lieutenant-colonel, he took part in the
suppression of the Polish insurrection of 1863-64, returning to St
Petersburg in the latter year as colonel and chief of staff to one of
the Guard divisions. During the Austro-Prussian War of 1866, Dragomirov
was attached to the headquarters of the II. Prussian army. He was
present at the battles on the upper Elbe and at Koniggratz, and his
comments on the operations which he witnessed are of the greatest value
to the student of tactics and of the war of 1866.
In 1868 he was made a major-general, and in the following year became
chief of the staff in the Kiev military circumscription. In 1873 he was
appointed to command the 14th division, and in this command he
distinguished himself very greatly in the Russo-Turkish War of 1877-78.
The 14th division led the way at the crossing of the Danube at Zimnitza,
Dragomirov being in charge of the delicate and difficult operation of
crossing and landing under fire, and fulfilling his mission with
complete success. Later, after the reverses before Plevna, he, with the
cesarevich and Generals Todleben and Milutine, strenuously opposed the
suggestion of the Grand-duke Nicholas that the Russian army should
retreat into Rumania, and the demoralization of the greater part of the
army was not permitted to spread to Dragomirov's division, which
retained its discipline unimpaired and gave a splendid example to the
rest.
He was wounded at the Shipka Pass, and, though promoted
lieutenant-general soon after this, was not able to see further active
service. He was also made adjutant-general to the tsar and chief of the
53rd Volhynia regiment of his old division. For eleven years thereafter
General Dragomirov was chief of the Nicholas Academy, and it was during
this period that he collated and introduced into the Russian army all
the best military literature of Europe, and in many other ways was
active in improving the moral and technical efficiency of the Russian
officer-corps, especially of the staff officer. In 1889 Dragomirov
became commander-in-chief of the Kiev military district, and
governor-general of Kiev, Podolsk and Volhynia, retaining this post
until 1903. He was promoted to the rank of general of infantry in 1891.
His advanced age and failing health prevented his employment at the
front during the Russo-Japanese war of 1904-5, but his advice was
continually solicited by the general headquarters at St Petersburg, and
while he disagreed with General Kuropatkin in many important questions
of strategy and military policy, they both recommended a repetition of
the strategy of 1812, even though the total abandonment of Port Arthur
was involved therein. General Dragomirov died at Konotop on the 28th of
October 1905. In addition to the orders which he already possessed, he
received in 1901 the order of St Andrew.
His larger military works were mostly translated into French, and his
occasional papers, extending over a period of nearly fifty years,
appeared chiefly in the _Voienni Svornik_ and the _Razoiedschik_; his
later articles in the last-named paper were, like the general orders he
issued to his own troops, attentively studied throughout the Russian
army. His critique of Tolstoy's _War and Peace_ attracted even wider
attention. Dragomirov was, in formal tactics, the head of the "orthodox"
school. His conservatism was not, however, the result of habit and early
training, but of deliberate reasoning and choice. His model was, as he
admitted in the war of 1866, the British infantry of the Peninsular War,
but he sought to reach the ideal, not through the methods of repression
against which the "advanced" tacticians revolted, but by means of
thorough efficiency in the individual soldier and in the smaller units.
He inculcated the "offensive at all costs," and the combination of
crushing short-range fire and the bayonet charge. He carried out the
ideas of Suvarov to the fullest extent, and many thought that he pressed
them to a theoretical extreme unattainable in practice. His critics,
however, did not always realize that Dragomirov depended, for the
efficiency his unit required, on the capacity of the leader, and that an
essential part of the self-sacrificing discipline he exacted from his
officers was the power of assuming responsibility. The details of his
brilliant achievement of Zimnitza suffice to give a clear idea of
Dragomirov's personality and of the way in which his methods of training
conduced to success.
DRAGON (Fr. _dragon_, through Lat. _draco_, from the Greek; connected
with [Greek: derkomai], "see," and interpreted as "sharp-sighted"; O.H.
Ger. _tracho_, _dracho_, M.H.G. _trache_, Mod. Ger. _Drachen_; A.S.
_draca_, hence the equivalent English form "drake," "fire-drake," cf.
Low Ger. and Swed. _drake_, Dan. _drage_), a fabulous monster, usually
conceived as a huge winged fire-breathing lizard or snake. In Greece the
word [Greek: drakon] was used originally of any large serpent, and the
dragon of mythology, whatever shape it may have assumed, remains
essentially a snake. For the part it has played in the myths and cults
of various peoples and ages see the article SERPENT-WORSHIP. Here it may
be said, in general, that in the East, where snakes are large and deadly
(Chaldea, Assyria, Phoenicia, to a less degree in Egypt), the serpent or
dragon was symbolic of the principle of evil. Thus Apophis, in the
Egyptian religion, was the great serpent of the world of darkness
vanquished by Ra, while in Chaldaea the goddess Ti[=a]mat, the female
principle of primeval Chaos, took the form of a dragon. Thus, too, in
the Hebrew sacred books the serpent or dragon is the source of death and
sin, a conception which was adopted in the New Testament and so passed
into Christian mythology. In Greece and Rome, on the other hand, while
the oriental idea of the serpent as an evil power found an entrance and
gave birth to a plentiful brood of terrors (the serpents of the Gorgons,
Hydra, Chimaera and the like), the _dracontes_ were also at times
conceived as beneficent powers, sharp-eyed dwellers in the inner parts
of the earth, wise to discover its secrets and utter them in oracles, or
powerful to invoke as guardian genii. Such were the sacred snakes in the
temples of Aesculapius and the _sacri dracontes_ in that of the Bona Dea
at Rome; or, as guardians, the Python at Delphi and the dragon of the
Hesperides.
In general, however, the evil reputation of dragons was the stronger,
and in Europe it outlived the other. Christianity, of course, confused
the benevolent and malevolent serpent-deities of the ancient cults in a
common condemnation. The very "wisdom of the serpent" made him suspect;
the devil, said St Augustine, "leo et draco est; leo propter impetum,
draco propter insidias." The dragon myths of the pagan East took new
shapes in the legends of the victories of St Michael and St George; and
the kindly snakes of the "good goddess" lived on in the _immanissimus
draco_ whose baneful activity in a cave of the Capitol was cut short by
the intervention of the saintly pope Silvester I. (Duchesne, _Liber
pontificalis_, i. 109 seq.). In this respect indeed Christian mythology
found itself in harmony with that of the pagan North. The similarity of
the Northern and Oriental snake myths seems to point to some common
origin in an antiquity too remote to be explored. Whatever be the origin
of the Northern dragon, the myths, when they first become articulate for
us, show him to be in all essentials the same as that of the South and
East. He is a power of evil, guardian of hoards, the greedy withholder
of good things from men; and the slaying of a dragon is the crowning
achievement of heroes--of Siegmund, of Beowulf, of Sigurd, of Arthur, of
Tristram--even of Lancelot, the beau ideal of medieval chivalry. Nor
were these dragons anything but very real terrors, even in the
imaginations of the learned, until comparatively modern times. As the
waste places were cleared, indeed, they withdrew farther from the haunts
of men, and in Europe their last lurking-places were the inaccessible
heights of the Alps, where they lingered till Jacques Balmain set the
fashion which has finally relegated them to the realm of myth. In the
works of the older naturalists, even in the great _Historia animalium_
of so critical a spirit as Conrad Gesner (d. 1564), they still figure as
part of the fauna known to science.
[Illustration: Dragon Lizard (_Draco taeniopterus_).]
As to their form, this varied from the beginning. The Chaldaean dragon
Ti[=a]mat had four legs, a scaly body, and wings. The Egyptian Apophis
was a monstrous snake, as were also, originally at least, the Greek
_dracontes_. The dragon of the Apocalypse (Rev. xii. 3), "the old
serpent," is many-headed, like the Greek Hydra. The dragon slain by
Beowulf is a snake (worm), for it "buckles like a bow "; but that done
to death by Sigurd, though its motions are heavy and snake-like, has
legs, for he wounds it "behind the shoulder." On the other hand, the
dragon seen by King Arthur in his dreams is, according to Malory, winged
and active, for it "swoughs" down from the sky. The belief in dragons
and the conceptions of their shape were undoubtedly often determined, in
Europe as in China, by the discovery of the remains of the gigantic
extinct saurians.
The qualities of dragons being protective and terror-inspiring, and
their effigies highly decorative, it is natural that they should have
been early used as warlike emblems. Thus, in Homer (_Iliad_ xi. 36
seq.), Agamemnon has on his shield, besides the Gorgon's head, a blue
three-headed snake ([Greek: drakon]), just as ages afterwards the Norse
warriors painted dragons on their shields and carved dragons' heads on
the prows of their ships. From the conquered Dacians, too, the Romans in
Trajan's time borrowed the dragon ensign which became the standard of
the cohort as the eagle was that of the legion; whence, by a long
descent, the modern dragoon. Under the later East Roman emperors the
purple dragon ensign became the ceremonial standard of the emperors,
under the name of the [Greek: drakonteion]. The imperial fashion spread;
or similar causes elsewhere produced similar results. In England before
the Conquest the dragon was chief among the royal ensigns in war. Its
origin, according to the legend preserved in the _Flores historiarum_,
was as follows. Uther Pendragon, father of King Arthur, had a vision of
a flaming dragon in the sky, which his seers interpreted as meaning that
he should come to the kingdom. When this happened, after the death of
his brother Aurelius, "he ordered two golden dragons to be fashioned,
like to those he had seen in the circle of the star, one of which he
dedicated in the cathedral of Winchester, the other he kept by him to be
carried into battle." From Uther Dragonhead, as the English called him,
the Anglo-Saxon kings borrowed the ensign, their custom being, according
to the _Flores_, to stand in battle _inter draconem et standardum_. The
dragon ensign, which was borne before Richard I. in 1191 when on crusade
"to the terror of the heathen beyond the sea," was that of the dukes of
Normandy; but even after the loss of Normandy the dragon was the battle
standard of English kings (_signum regium quod Draconem vocant_), and
was displayed, e.g. by Henry III. in 1245 when he went to war against
the Welsh. Not till the 20th century, under King Edward VII., was the
dragon officially restored as proper only to the British race of Uther
Pendragon, by its incorporation in the armorial bearings of the prince
of Wales. As a matter of fact, however, the dragon ensign was common to
nearly all nations, the reason for its popularity being naively stated
in the romance of _Athis_ (quoted by Du Cange),
"Ce souloient Romains porter,
Ce nous fait moult a redouter:"
"This the Romans used to carry, This makes us very much to be feared."
Thus the dragon and wyvern (i.e. a two-legged snake, M.E. _wivere_,
viper) took their place as heraldic symbols (see HERALDRY).
As an ecclesiastical symbol it has remained consistent to the present
day. Wherever it is represented it means the principle of evil, the
devil and his works. In the middle ages the chief of these works was
heresy, and the dragon of the medieval church legends and mystery plays
was usually heresy. Thus the knightly order of the vanquished dragon,
instituted by the emperor Sigismund in 1418, celebrated the victory of
orthodoxy over John Huss. Hell, too, is represented in medieval art as a
dragon with gaping jaws belching fire. Of the dragons carried in effigy
in religious processions some have become famous, e.g. the Gargouille
(gargoyle) at Rouen, the Graully at Metz, and the Tarasque at Tarascon.
Their popularity tended to disguise their evil significance and to
restore to them something of the beneficent qualities of the ancient
_dracontes_ as local tutelary genii.
In the East, at the present day, the dragon is the national symbol of
China and the badge of the imperial family, and as such it plays a large
part in Chinese art. Chinese and Japanese dragons, though regarded as
powers of the air, are wingless. They are among the deified forces of
nature of the Taoist religion, and the shrines of the dragon-kings, who
dwell partly in water and partly on land, are set along the banks of
rivers.
The constellation Draco (_anguis_, _serpens_) was probably so called
from its fanciful likeness to a snake. Numerous myths, in various
countries, are however connected with it. The general character of these
may be illustrated by the Greek story which explains the constellation
as being the dragon of the Hesperides slain by Heracles and translated
by Hera or Zeus to the heavens.
See C. V. Daremberg and E. Saglio, _Dictionnaire des antiquites
grecques et romaines_ (Paris, 1886, &c.), s.v. "Draco"; Pauly-Wissowa,
_Realencyclopadie_, s.v. "Drakon"; Du Cange, _Glossarium_, s.v.
"Draco"; _La Grande Encyclopedie_ s.v. "Dragon"; J. B. Panthot,
_Histoire des dragons et des escarboucles_ (Lyons, 1691). See also the
articles EGYPT: _Religion_, and BABYLONIAN AND ASSYRIAN RELIGION.
(W. A. P.)
In zoology the name "dragon" is now applied to a highly interesting, but
very harmless, group of small flying lizards forming the genus _Draco_,
belonging to the _Agamidae_, a family of Saurian reptiles. About 20
species of "flying dragons" inhabit the various Indo-Malayan countries;
one, _D. dussumieri_, occurs in Madras. They are small creatures,
measuring about 10 in. long, including the tail, which in some cases is
more than half of the entire length. The head is small, and the throat
is provided with three pouches which are spread out when they lie on the
trunks of trees. They are, however, chiefly remarkable for the wing-like
cutaneous processes with which their sides are provided, and which are
extended and supported by greatly elongated ribs. These form a sort of
parachute by which the animals are enabled to glide from branch to
branch of the trees on which they live, but, being altogether
independent of the fore limbs, they cannot be regarded as true wings,
nor do they enable the lizard to fly, but merely to make extensive
leaps. But they have the habit of opening and folding these prettily
coloured organs, when resting upon a branch, which gives them the
appearance of butterflies. When not in use they are folded by the side
after the manner of a fan, and the dragon can then walk or run with
considerable agility. Its food consists of insects.
DRAGONETTI, DOMENICO (1763-1846), Italian double-bass player, was born
in Venice on the 7th of April 1763. Having become famous as a performer
on his instrument, he went to London in 1794, where his playing created
a furore. He was the friend of Haydn and of Beethoven, and a well-known
character in his day. He died in London on the 16th of April 1846.
DRAGON-FLY (Ger. _Wasserjungfer_; Swed. _trollslanda_; Dan. _guldsmed_;
Dutch, _scherpstekendevlieg_; Fr. _demoiselle_), the popular English
name applied to the members of a remarkable group of insects which
formed the genus _Libellula_ of Linnaeus and the ancient authors. In
some parts of the United States they appear to be known as "devil's
darning needles," and in many parts of England are termed
"horse-stingers." It is almost needless to say that (excepting to other
insects upon which they prey) they are perfectly innocuous, though some
of the larger species can inflict a momentarily painful bite with their
powerful jaws. Their true systematic position is still contested and
somewhat uncertain. By most of the older systematists they were placed
as forming part of the heterogeneous order _Neuroptera_. J. C.
Fabricius, however, elevated them to the rank of a distinct order, which
he termed _Odonata_; and whatever may be the difference of opinion
amongst authors at the present day, that term is almost universally
employed for the group. W. F. Erichson transferred all the groups of
so-called _Neuroptera_ with incomplete metamorphoses, hence including
the dragon-flies, as a division of _Orthoptera_, which he termed
_Pseudo-Neuroptera_. K. E. A. Gerstacker more recently also retains them
in the _Orthoptera_, terming those groups in which the earlier states
are subaquatic _Orthoptera amphibotica_. All entomologists are agreed in
maintaining the insects as forming a group marked by characters at once
extraordinary and isolated in their nature, and in most modern
classifications they are treated as a distinct order.
The group _Odonata_ is divided into three families, and each of these
again into two subfamilies. The families are the _Agrionidae_,
_Aeschnidae_ and _Libellulidae_--the first including the subfamilies
_Calopterygina_ and _Agrionina_, the second _Gomphina_ and _Aeschnina_,
and the third _Cordulina_ and _Libellulina_.
_Anatomy._--The structure of a dragon-fly being so very remarkable, it
is necessary to enter somewhat extensively into details. The head is
comparatively small, and excavated posteriorly, connected very
slightly with the prothorax, on which it turns almost as on a pivot.
The eyes are, as a rule, enormous, often contiguous, and occupying
nearly the whole of the upper surface of the head, but sometimes
(_Agrionidae_ and _Gomphina_) widely distant; occupied by innumerable
facets, which are often larger on the upper portion. The antennae,
which are smaller in proportion than in almost any other insects,
consist only of two short swollen basal joints and a 5 or 6-jointed
bristle-like thread. The large labrum conceals the jaws and inner
mouth parts. The lower lip, or labium (formed by the conjoined second
maxillae), is attached to a very small chin piece (or mentum), and is
generally very large, often (_Agrionidae_) divided almost to its base
into two portions, or more frequently entire or nearly so; on each
side of it are two usually enormous hypertrophied pieces, which form
the "palpi," and which are often furnished at the tips with an
articulated spine (or terminal joint), the whole structure serving to
retain the prey. Considerable diversity of opinion exists with respect
to the composition of the mouth parts, and by some authors the "palpi"
have been termed the side pieces of the lower lip. The prothorax is
extremely small, consisting of only a narrow ring. The rest of the
thorax is very large, and consolidated into a single piece with
oblique sutures on the sides beneath the wings.
The abdomen varies excessively in form, the two extremes being the
filiform structure observable in most _Agrionidae_, and the very broad
and depressed formation seen in the familiar British _Libellula
depressa_. It consists of ten distinct segments, whereof the basal two
and those at the apex are short, the others elongate, the first being
excessively short. In a slit on the under side of the second in the
male, accompanied by external protuberances, are concealed the genital
organs: on the under side of the eighth in the female is a scale-like
formation, indicating the entrance to the oviduct. The tenth is always
provided in both sexes with prominent appendages, differing greatly in
form, and often furnishing the best specific (and even generic)
characters.
The legs vary in length and stoutness, but may, as a rule, be termed
long and slender. The anterior pair probably assist in capturing and
holding insect prey, but the greatest service all the legs render is
possibly in enabling the creature to rest lightly, so that it can quit
a position of repose in chase of passing prey in the quickest possible
manner. The coxa is short and stout, followed by a still shorter
trochanter; the femora and tibiae long and slender, almost invariably
furnished on their under surface with two series of strong spines, as
also are the tarsi, which consist of three slender joints, the last
having two long and slender claws.
The wings are always elongate, and furnished with strong longitudinal
neuration and dense transverse nervules strengthening the already
strong (although typically transparent) membrane. In the _Agrionidae_
both pairs are nearly equal, and are carried vertically and
longitudinally in repose, and the neuration and membrane are less
strong; hence the species of this family are not so powerful on the
wing as are those of the other groups in which the wings are
horizontally extended in a position ready for instant service. The
neuration is peculiar, and in many respects without precise analogy in
other groups of insects, but it is not necessary here to enter into
more than some special points. The arrangement of the nervures at the
base of the wing is very singular, and slight differences in it form
useful aids to classification. In the _Aeschnidae_ and _Libellulidae_
this arrangement results in the formation of a triangular space (known
as the "triangle"), which is either open or traversed by nervules; but
in many _Agrionidae_ this space, instead of being triangular, is
oblong or elongately quadrate, or with its upper edge partly straight
and partly oblique. This fixitude of type in neuration is not one of
the least important of the many peculiarities exhibited in these
insects.
The internal structure is comparatively simple. The existence of
salivary glands, denied by L. Duprix, has been asserted by O.
Poletajewa. The rest of the digestive apparatus consists of an
elongate canal extending from mouth to anus, comprising the
oesophagus, stomach and intestine, with certain dilatations and
constrictions; the characteristic Malpighian vessels are stated to
number about forty, placed round the posterior extremity of the
stomach. Dragon-flies eat their prey completely, and do not content
themselves by merely sucking its juices; the harder portions are
rejected as elongate, nearly dry, pellets of excrement.
_Pairing._--But the most extraordinary feature in the economy--one
which has attracted the attention of naturalists from remote times--is
the position of the genital organs, and the corresponding anomalous
manner in which the pairing of the sexes and impregnation is effected.
In the male the intromittent organ is situated in a slit on the under
surface of the second abdominal segment; it is usually very crooked or
sinuous in form, and is accompanied by sheaths, and by external hooks
or secondary appendages, and also by seminal vessels. But the ducts of
the vessels connected with the testes unite and open on the under
surface of the ninth segment; hence, before copulation can take place,
it is necessary that the vessels in the second segment be charged
from this opening, and in the majority of cases this is done by the
male previously to seeking the female. In the latter sex the entrance
to the oviduct and genital organs is on the under surface of the
eighth abdominal segment. The act of pairing may be briefly stated as
follows. The male, when flying, seizes the prothorax of the female
with the strong appendages at the extremity of the abdomen, and the
abdomen of this latter sex is then curved upward so as to bring the
under side of the eighth segment into contact with the organs of the
second segment of the male. In the more powerful _Libellulidae_, &c.,
the act is of short duration, and it is probable that polygamy and
polyandry exist, for it possibly requires more than one almost
momentary act to fertilize all the eggs in the ovaries of a female.
But in many _Agrionidae_, and in some others, the male keeps his hold
of the prothorax of the female for a lengthened period, retaining
himself in flight in an almost perpendicular manner, and it may be
that the deposition of eggs and pairing goes on alternately. There is,
however, much yet to be learned on these points. The gravid female
usually lays her eggs in masses (but perhaps sometimes singly), and
the operation may be witnessed by any one in localities frequented by
these insects. She hovers for a considerable time over nearly the same
spot, rapidly dipping the apex of her abdomen into the water, or at
any rate touching it, and often in places where there are no
water-weeds, so that in all probability the eggs fall at once to the
bottom. But in some of the _Agrionidae_ the female has been often
noticed by trustworthy observers to creep down the stems of aquatic
plants several inches below the surface, emerging after the act of
oviposition has been effected; and in the case of _Lestes sponsa_, K.
T. E. von Siebold saw the male descend with the female. The same exact
observer noticed also in this species that the female makes slight
incisions in the stems or leaves of water plants with the double
serrated apparatus (vulva) forming a prolongation of the ninth segment
beneath, depositing an egg in each incision. He has seen two pairs
thus occupied beneath the surface on one and the same stem.
[Illustration: FIG. 1--The anterior portion of the body of _Aeschna
cynea_ freed from the nymph-cuticle.]
[Illustration: FIG. 2.--The tail being extricated.]
[Illustration: FIG. 3.--The whole body extricated.]
[Illustration: FIG. 4.--The perfect insect (the wings having acquired
their full dimensions) resting to dry itself, preparatory to the wings
being horizontally extended.]
_Larva and Nymph._--The duration of the subaquatic life of a dragon-fly
is no doubt variable, according to the species. In the smaller forms it
is probably less than a year, but precise evidence is wanting as to the
occurrence of two broods in one year. On the other hand, it is certain
that often a longer period is requisite to enable the creature to attain
its full growth, and three years have been stated to be necessary for
this in the large and powerful _Anax formosus._ Like all insects with
incomplete metamorphoses, there is no quiescent pupal condition, no
sharp line of demarcation between the larval and so-called "nymph" or
penultimate stage. The creature goes on eating and increasing in size
from the moment it emerges from the egg to the time when it leaves the
water to be transformed into the aerial perfect insect. The number of
moults is uncertain, but they are without doubt numerous. At probably
about the antepenultimate of these operations, the rudimentary wings
begin to appear as thoracic buddings, and in the full-grown nymph these
wings overlap about one-half of the dorsal surface of the abdomen. In
structure there is a certain amount of resemblance to the perfect
insect, but the body is always much stouter and shorter, in some cases
most disproportionately so, and the eyes are always separated; even in
those genera (e.g. _Aeschna_) in which the eyes of the imago are
absolutely contiguous, the most that can be seen in the larva is a
prolongation towards each other, and there are no ocelli. The legs are
shorter and more fitted for crawling about water plants and on the
bottom. In the mouth parts the mandibles and maxillae are similar in
form to those of the adult, but there is an extraordinary and unique
modification of the lower lip. This is attached to an elongate and
slender mentum articulated to the posterior portion of the lower surface
of the head, slightly widened at its extremity, to which is again
articulated the labium proper, which is very large, flattened, and
gradually dilated to its extremity; but its form differs according to
group as in the perfect insect. Thus in the _Agrionidae_ it is deeply
cleft, and with comparatively slender side-pieces (or palpi), and
strongly developed articulated spines; in the _Aeschnidae_ it is at the
most notched, with narrow side-pieces and very strong spines; in the
_Libellulidae_ it is entire, often triangular at its apex, and with
enormously developed palpi without spines, but having the opposing inner
edges furnished with interlocking serrations. The whole of this
apparatus is commonly termed the mask. In a state of repose it is
applied closely against the face, the elongated mentum directed backward
and lying between the anterior pair of legs; but when an approaching
victim is seen the whole apparatus is suddenly projected, and the prey
caught by the raptorial palpi; in some large species it is capable of
being projected fully half an inch in front of the head. The prey, once
caught and held by this apparatus, is devoured in the usual manner.
There are two pairs of thoracic spiracles, through which the nymph
breathes during its later life by thrusting the anterior end of the body
into the air; but respiration is mostly effected by a peculiar apparatus
at the tail end, and there are two different methods. In the
_Agrionidae_ there are three elongate flattened plates, or false gills,
full of tracheal ramifications, which extract the air from the water,
and convey it to the internal tracheae (in _Calopteryx_ these plates are
excessively long, nearly equalling the abdomen), the plates also serving
as means of locomotion. But in the other groups these external false
gills are absent, and in their place are five valves, which by their
sudden opening and closing force in the water to the rectum, the walls
of which are furnished with branchial lamellae. The alternate opening
and closing of these valves enables the creature to make quick jerks or
rushes (incorrectly termed "leaps") through the water,[1] and, in
conjunction with its mouth parts, to make sudden attacks upon prey from
a considerable distance. Well-developed Aeschnid larvae have been
observed to take atmospheric air into the rectum. The lateral angles of
the terminal abdominal segments are sometimes produced into long curved
spines. In colour these larvae are generally muddy, and they frequently
have a coating of muddy particles, and hence are less likely to be
observed by their victims. If among insects the perfect dragon-fly may be
termed the tyrant of the air, so may its larva be styled that of the
water. Aquatic insects and larvae form the principal food, but there can
be no doubt that worms, the fry of fish, and even younger larvae of
their own species, form part of the bill of fare. The "nymph" when
arrived at its full growth sallies forth from the water, and often
crawls a considerable distance (frequently many feet up the trunks of
trees) before it fixes itself for the final change, which is effected by
the thorax splitting longitudinally down the back, through which fissure
the perfect insect gradually drags itself. The figures indicate this
process as observed in _Aeschna cyanea_.
_The Complete Insect._-For a considerable time after its emergence a
dragon-fly is without any of its characteristic colours, and is flaccid
and weak, the wings (even in those groups in which they are afterwards
horizontally extended) being held vertically in a line with the abdomen.
By degrees the parts harden, and the insect essays its first flight, but
even then the wings have little power and are semi-opaque in appearance,
as if dipped in mucilage. In most species of _Calopterygina_, and in
some others, the prevailing colour of the body is a brilliant bronzy
green, blue or black, but the colours in the other groups vary much, and
often differ in the sexes. Thus in _Libellula depressa_ the abdomen of
the fully adult male is covered with a bluish bloom, whereas that of the
female is yellow; but several days elapse before this pulverulent
appearance is attained, and a comparatively young male is yellow like
the female. The wings are typically hyaline and colourless, but in many
species (especially _Calopterygina_ and _Libellulina_) they may be
wholly or in part opaque and often black, due apparently to gradual
oxydization of a pigment between the two membranes of which the wings
are composed; the brilliant iridescence, or metallic lustre, so
frequently found is no doubt due to interference--the effect of minute
irregularities of the surface--and not produced by a pigment. A
beautiful little genus (_Chalcopteryx_) of _Calopterygina_ from the
Amazon is a gem in the world of insects, the posterior wings being of
the most brilliant fiery metallic colour, whereas the anterior remain
hyaline.
These insects are pre-eminently lovers of the hottest sunshine (a few
are somewhat crepuscular), and the most powerful and daring on the wing
in fine weather become inert and comparatively lifeless when at rest in
dull weather, allowing themselves to be captured by the fingers without
making any effort to escape. Many of the larger species (_Aeschna_, &c.)
have a habit of affecting a particular twig or other resting place like
a fly-catcher among birds, darting off after prey and making long
excursions, but returning to the chosen spot. A. R. Wallace, in his
_Malay Archipelago_, states that the inhabitants of Lombok use the large
species for food, and catch them by means of limed twigs.
They are distributed over the whole world excepting the polar regions,
but are especially insects of the tropics. At the present day about 2200
species are known, dispersed unequally among the several subfamilies as
follows: Agrionina, 700 species; Calopterygina, 280; Gomphina, 320;
Aeschnina, 170; Corduliina, 130; Libellulina, 600. In Europe proper only
100 species have been observed, and about 46 of these occur in the
British islands. New Zealand is excessively poor, and can only number 8
species, whereas they are very numerous in Australia. Some species are
often seen at sea, far from land, in calm weather, in troops which are
no doubt migratory; the common _Libellula quadrimaculata_, which
inhabits the cold and temperate regions of the northern hemisphere, has
been frequently seen in immense migratory swarms. One species (_Pantala
flavescens_) has about the widest range of any insect, occurring in the
Old World from Kamtchatka to Australia, and in the New from the Southern
States to Chili, also all over Africa and the Pacific islands, but is
not found in Europe. The largest species occur in the _Aeschnina_ and
_Agrionina_; a member of the former subfamily from Borneo expands to
nearly 6-1/2 in., and with a moderately strong body and powerful form; in
the latter the Central American and Brazilian _Megaloprepus caerulatus_
and species of _Mecistogaster_ are very large, the former expanding to
nearly 7 in., and the latter to nearly as much, but the abdomen is not
thicker than an ordinary grass-stem and of extreme length (fully 5 in.
in _Mecistogaster_).
_Fossils._--Among fossil insects dragon-flies hold a conspicuous
position. Not only do they belong to what appears to have been a very
ancient type, but in addition, the large wings and strong dense
reticulation are extremely favourable for preservation in a fossil
condition, and in many cases all the intricate details can be as readily
followed as in a recent example. From the Carboniferous strata of
Commentry, France, C. Brongniart has described several genera of
gigantic insects allied to dragon-flies, but with less specialized
thoracic segments and simpler wing-neuration. These form a special
group--the Protodonata. True _Odonata_ referable to the existing
families are plentiful in Mesozoic formations; in England they have been
found more especially in the Purbeck beds of Swanage, and the vales of
Wardour and Aylesbury, in the Stonesfield Slate series, and in the Lias
and Rhaetic series of the west of England. But the richest strata appear
to be those of the Upper Miocene at Oeningen, near Schaffhausen in the
Rhine valley; the Middle Miocene at Radaboj, near Krapina in Croatia;
the Eocene of Aix, in Provence; and more especially the celebrated
Secondary rocks furnishing the lithographic stone of Solenhofen, in
Bavaria. This latter deposit would appear to have been of marine origin,
and it is significant that, although the remains of gigantic
dragon-flies discovered in it are very numerous and perfect, no traces
of their subaquatic conditions have been found, although these as a rule
are numerous in most of the other strata, hence the insects may be
regarded as having been drowned in the sea and washed on shore. Many of
these Solenhofen species differ considerably in form from those now
existing, so that Dr H. A. L. Hagen, who has especially studied them,
says that for nearly all it is necessary to make new genera. It is of
great interest, however, to find that a living Malayan genus (_Euphaea_)
and another living genus _Uropetala_, now confined to New Zealand, are
represented in the Solenhofen deposits, while a species of
_Megapodagrion_ now entirely Neotropical, occurs in the Eocene beds of
Wyoming.
A notice of fossil forms should not be concluded without the remark that
indications of at least two species have been found in amber, a number
disproportionately small if compared with other insects entombed
therein; but it must be remembered that a dragon-fly is, as a rule, an
insect of great power, and in all probability those then existing were
able to extricate themselves if accidentally entangled in the resin.
See E. de Selys-Longchamps, _Monographie des Libellulidees d'Europe_
(Brussels, 1840); _Synopses des Agrionines, Calopterygines, Gomphines,
et Cordulines_, with Supplements (Brussels, from 1853 to 1877); E. de
Selys-Longchamps and H. A. L. Hagen, _Revue des Odonates d'Europe_
(Brussels, 1850); _Monographie des Calopterygines et des Gomphines_
(Brussels, 1854 and 1858); Charpentier, _Libellulinae europeae_
(Leipzig, 1840). For modern systematic work see various papers by R.
M'Lachlan, P. P. Calvert, J. G. Needham, R. Martin, E. B. Williamson,
F. Karsch, &c.; also H. Tumpel, _Die Geradflugler Mitteleuropas_
(Eisenach, 1900); and W. F. Kirby, _Catalogue of Neuroptera Odonata_
(London, 1890). For habits and details of transformation and larval
life, see L. C. Miall, _Natural History of Aquatic Insects_ (London,
1895); H. Dewitz, _Zool. Anz._ xiii. (1891); and J. G. Needham, _Bull.
New York Museum_, lxviii. (1903). For geographical distribution, G. H.
Carpenter, _Sci. Proc. R. Dublin Soc._ viii. (1897). For British
species, W. J. Lucas, _Handbook of British Dragonflies_ (London,
1899). For wings and mechanism of flight, R. von Lendenfeld, _S.B.
Akad. Wien_, lxxxiii. (1881), and J. G. Needham, _Proc. U.S. Nat.
Mus._ xxvi. (1903). For general morphology, R. Heymons, _Abhandl. k.
preuss. Akad._ (1896), and _Ann. Hofmus. Wein_, xix. (1904).
(R. M'L.; G. H. C.)