Having already discussed the general history of butterflies at
considerable length, in a volume devoted to the illustration of
the kinds found in Britain, it is not our intention to resume the
subject in this place, further than to make a few remarks on certain
peculiarities presented by many foreign species, a selection from which
forms the subject of the present volume.
The remarkable superiority in size and beauty of most tropical
productions over those of temperate regions, is scarcely more
strikingly exemplified in any department of nature than in this. The
most richly ornamented of our native species, and we possess many of
great beauty, appear insignificant when contrasted with those of Brazil
and Eastern Asia. Various as are the modifications of form which they
present in this country, we find nothing to prepare us for the peculiar
outline and aspect which many kinds assume in the warmer regions of the
earth. Here we seldom find any having the hinder wings prolonged into a
tail, but among foreign species this is a common appendage, sometimes
long and linear, at other times broad and spatulate; and occasionally
there are not fewer than three or four on each of the hinder wings.
Along with this variety of outline, they exhibit almost every possible
shade of colour, from the most brilliant to the most obscure, combined
and blended in the most elegant and harmonious designs, rendering this
tribe of creatures one of the most ornamental to be found in nature.
Although such endless diversity of colouring is observable in this
class as a whole, it is, at the same time, worthy of remark, that
most of the principal groups are characterized by the prevalence of
particular hues, as well as considerable uniformity in their mode
of distribution; that is to say, certain modifications of structure
are generally accompanied with a certain pictorial design. Thus, the
greater proportion of the genus _Pieris_ are white; _Colias_ and
_Callidryas_ various shades of yellow, from the palest sulphur-yellow
to deep reddish-ochre. _Argynnis_ is almost invariably fulvous or
reddish brown, variegated with numerous undulating black lines or
spots; the under side more or less ornamented with silvery streaks and
spots. In the species of the European genus _Thais_, the wings are
spotted or chequered with black and red. The prevailing colour in the
genus _Argus_ is azure-blue. _Danais_, _Idæa_, and _Euplœa_, have this
character in common, that the breast and head are always punctured with
white. In _Cethosia_, hieroglyphical markings cover the under side of
the wings in such a manner as is observable in no other genus.
Many of the caterpillars of exotic butterflies offer peculiarities
in their forms and appendages, of which we find no prototype in the
kinds occurring in Britain. In the place of spines, some have the body
thickly covered with long fleshy prominences, of a corneous consistency
at the tip, and probably serving as a means of defence. In others,
spines of singular conformation and formidable size are thickly stuck
over the whole surface, making it resemble a miniature forest. A
few are provided with a long anal horn, resembling that which is so
conspicuous in the caterpillars of the Sphinges. If Madam Merian’s
delineation of the larva of _Urania Leilus_ be correct (which there is
now reason to believe is the case), it bears many slender spines, as
long as the whole body, and as stiff as iron wire. Another species
(that of _Papilio Protesilaus_), is likewise clothed with plumose
spines, two of which at the hinder extremity are much longer than the
rest, and terminate in an appendage like a star. Equally remarkable
with any of these is the caterpillar of one of the Nymphalidæ (_Adoleas
Aconthea_), which has a series of long filiform bodies projecting from
each side, thickly clothed laterally with hairs of considerable length
diminishing gradually to the extremity, which is armed with a few
minute spines.
As might be expected, great diversity likewise prevails in the
appearance of the chrysalides; but to these it will be more convenient
hereafter to refer, in the preliminary notices to the respective
genera. One of the most remarkable, however, may be mentioned, that
of _Morpho Menelaus_, which has the nasal prominence of the prothorax
produced into a long curved horn, which extends to the middle of the
abdomen. In another species of the same group, the head is obtuse,
projects considerably, and is curved upwards at the extremity, exactly
like the beak of an ancient galley.
Our acquaintance with the geographical distribution of the diurnal
lepidoptera was long very imperfect, and it may yet be said to be
very far from complete. The older naturalists seem to have been but
little alive to the importance of the subject, and even if it had
been otherwise, the means they possessed for illustrating it were
comparatively limited. Those who had opportunities of collecting
specimens in foreign countries, valued them merely as specimens, and,
in general, kept no record of their localities, or natural history
properly so called. Collections from China and the East Indies were
indiscriminately mixed, in their way homewards, with others from
the Cape of Good Hope; and American species were in like manner
mingled with such as are proper to the West Indian islands. Hence it
followed, that Fabricius and others were so often led into error when
they indicated the native country of the kinds they described: but,
indeed, the author just named did not very frequently attempt this,
but merely says, “From the Indies”--an expression which means nothing
more explicit, in his acceptation of it, than that the species in
question is exotic. Linnæus, also, when he uses the same word, means
indiscriminately either the East or West Indies. The indications
of localities in modern works are in general copious and accurate,
but they have not hitherto been made the basis of any general and
satisfactory view of the distribution of the species.
As might be expected in the case of animals endowed with considerable
power of flight, certain kinds of diurnal lepidoptera have a much
more extensive range than most other insects--than the coleoptera for
example. It is now ascertained that _Cynthia cardui_, a species well
known throughout Europe, (without confounding it, as may sometimes
have been done, with the kindred species _C. Hunteri_), occurs in
Senegal, Egypt, Barbary, Cape of Good Hope, in the islands of Bourbon
and Madagascar, in Bengal, China, Java, New Holland, Brazil, and
North America; so that it may be called a complete cosmopolite. Of the
four quarters of the globe, Europe is poorest in these insects; and
next to it is Africa. Asia, including the great islands of the Indian
Archipelago and America, are both exceedingly rich. Of the former,
the islands seem to be much more prolific than the continent; they
are the exclusive haunts of the gigantic _Ornithoptera_, several of
the largest and most richly coloured of the _Pierides_, as well as
several of the most remarkable species of the genus _Morpho_. South
America produces a greater number than any other country; and Brazil,
always preeminent for its exuberance both in animal and vegetable
life, may be said to be the richest portion of the new continent. It
has been estimated by an individual who has enjoyed the advantage of
personally examining the country, that Brazil alone affords between
600 and 700 species of diurnal lepidoptera, a calculation which seems
in no degree overcharged. Among these are many genera peculiar to
America, such as _Heliconia_, _Castnia_, _Erycina_, &c. In almost every
one of its physical properties, Africa affords a complete contrast
to the country just named; and however favourable its arid soil, and
far-extending deserts of parched and drifting sand, may be to the
existence of certain peculiar races of coleoptera, it is by no means
generally adapted to the support of creatures which derive their entire
sustenance from vegetable juices. The sea-coast, and umbrageous banks
of the larger rivers, however, are pretty abundantly supplied, and
afford many species peculiar to the country. This is the metropolitan
station of the genus _Acrea_, and it is likewise inhabited by several
peculiar groups of the genera _Papilio_, _Pieris_, &c. The neighbouring
island of Madagascar is much richer than the continent, and exemplifies
what has been observed in relation to many other islands, that their
zoological productions by no means correspond to those of the nearest
portion of the main land. Little relation exists between the diurnal
lepidoptera of Madagascar and the Cape of Good Hope, but a very close
one can be traced between the former and those inhabiting distant
parts of the continent, such as Senegal and Sierra Leone. Mauritius
and Bourbon likewise differ considerably in their lepidopterous
productions from Madagascar. In the latter, magnificent _Papilios_,
_Acrææ_, _Euplœæ_, _Danaides_, _Uraniæ_, _Cyrestes_, _and Xanthidia_,
embellish by their elegant forms and splendid colours, the marshy and
pestilential forests of that extensive island, and rival in beauty that
majestic and teeming vegetation which has always excited the admiration
of botanists[22]. New Holland is not without its peculiar species,
although this department of its zoology is not characterised by such
marked singularities as are observed among its higher animals and
vegetable productions.
A singular circumstance has been recorded by a recent traveller
regarding one of the species, _Euplœa humata_ (Mac Leay), found in the
country just referred to, namely, that it is employed as an article of
food!
He states that there is a certain mountain, called the Bugong Mountain
from multitudes of small moths, named Bugong by the natives, which
congregate at certain times upon the masses of granite which compose
it. The months of November, December, and January are quite a season
of festivity among these people, who assemble from every quarter to
collect these moths. They are stated also to form the principal summer
food of those who inhabit to the south of the Snow Mountains. To
collect these moths (improperly so called, for as above indicated, they
are true butterflies), the natives make smothered fires under the rocks
on which they congregate; and suffocating them with smoke, collect them
by bushels, and then bake them by placing them on heated ground. Thus
they separate from them the down and the wings; they are then grounded
and formed into cakes, resembling lumps of fat, and often smoked, which
preserves them for some time. When accustomed to this diet, they thrive
and fatten exceedingly upon it[23]. Millions of these butterflies were
likewise observed on the coasts of New Holland, both by Captains Cook
and King; and thus, says Mr. Kirby, has a kind Providence provided
an abundant supply of food for a race that, subsisting entirely on
hunting and fishing, must often be reduced to great straits[24].
These insects were, no doubt, the first that attracted the attention of
naturalists, in consequence of their imposing appearance and striking
metamorphoses. Collections of them began to be made at an early time,
and were valued not only by the lover of nature, but by those who
had no farther or more worthy design in view than to possess them as
objects highly ornamental. Very extensive collections exist in nearly
all the principal cities and museums of Europe; and many are to be
found throughout Britain, not only belonging to public institutions
for promoting natural history, but also in the possession of private
individuals. One of the best conditioned collections of exotic
lepidoptera in this country, is that in the possession of the East
India Company, made in Java by Dr. Horsfield. As the method followed
by that gentleman for preserving his specimens was attended with great
success, the following account of it will be interesting and useful
to those who have opportunities of making collections in foreign
countries:--“During the inquiries I made,” says Dr. Horsfield, “in
the early part of my residence in Java, to become acquainted with the
best methods for securing what I obtained in my excursions, I noticed
the plan described by Le Vaillant in his Travels in Africa, for the
preservation of entomological collections. It is the following:--Boxes
or chests carefully made of light wood, of a convenient portable size,
are provided with partitions or moveable shelves, each consisting of
a simple board; these are fitted at the distance of two inches one
from another, in grooves in the sides of the box, in which they are
made to slide with accuracy and facility, and are therefore removable
at pleasure. These boards or shelves have necessarily the exact
dimensions of the ends of the chest, and are placed in a vertical
position; a small vacancy is preserved between this lower extremity
and the floor, and any object detached by accident falls to the bottom
without causing further injury. Each board or shelf, lined with cork or
soft wood, supplies, in some measure, the place of a cabinet drawer.
When taken out of the box and placed on a table, it rests securely,
and affords a plain surface, upon which insects may be fixed and
examined with perfect ease and security: it is returned into the box
in an instant, which, if carefully made, when closed secures most
effectually the contents. A small quantity of camphor, at the bottom,
spreads its influence over the whole. One large box may conveniently
contain fourteen boards, answering the purpose of as many drawers;
and, being eighteen inches long, they have a manageable size. This
plan I resolved to adopt. In the early period of my pursuits, the
boxes which I provided were made of light wood, and to their use I
must ascribe, in a great measure, the preservation of my collection.
I found that they afforded a complete protection against the ants and
other destructive insects which abound in the island of Java, perhaps
as much as in any other tropical region. They were peculiarly useful
in travelling, and possessed the advantage of affording a ready access
to the subjects. As the ultimate object of my pursuits was to provide
an extensive and well-conditioned collection, which might be useful
and instructive in England, I had, soon after receiving the patronage
of the Honourable East India Company, directed my attention to the
provision necessary for its safety during a voyage. My residence at
Surakarta afforded me peculiar advantages in this point of view. Both
materials and workmen are here obtained, perhaps more readily than in
any other part of Java. Boxes, according to the plan described, were
therefore provided, of more substantial materials than those employed
in travelling, in proportion to the increase of the collection. The
wood of the _Bombax pentandrum_ was employed for lining the boards and
securing the pins; and I ascribe to an acquaintance with the peculiar
property of this wood--which renders it an effectual substitute for
cork--the preservation of the collection during its transportation.
After having carefully packed the subjects, every necessary precaution
that suggested itself was used in securing the boxes against accidents
during the voyage. They were individually painted and covered with
oil-cloth. Each box was then placed in an outer case, made of the same
substantial materials, and secured in the same manner. By these various
precautions, and by the care which the collection received from the
commander of the vessel during the voyage, I enjoy the satisfaction of
having brought the whole in safety to England[25].”
* * * * *
The systematic arrangement of this tribe of insects has always been
considered a task of great difficulty. So convinced of this was
Latreille, who had himself studied the subject profoundly, that he
says a classification of lepidoptera may be considered the touchstone
of entomologists. This difficulty arises chiefly from the uniformity
of organization which prevails throughout the order--a uniformity
occasioned by all of them being designed to subsist on liquid food, and
to imbibe it in the same manner. The oral organs, therefore, which are
of the first importance in classifying other tribes--the coleoptera,
for example, in which they undergo almost endless variations of form
and consistency to fit them for consuming every kind of organic
substance, from semi-fluid animal or vegetable matter to the hardest
ligneous tissue--are, in this instance, of comparatively little avail.
Recourse must be had to secondary and subordinate characters; and
even when we are convinced that, owing to a peculiar _facies_, and
the concurrence of many minute resemblances, certain groups should
be regarded as distinct, it is found difficult to define them in a
satisfactory manner. Neither has the difficulty been much lessened
by the manner in which the subject has been handled by many modern
naturalists. The numerous illustrations of lepidoptera published of
late years, have been _partial_, being either selections from the
whole class, or forming part of a local fauna. In either case, the
subject is regarded in too insulated a light. The illustrator of
foreign butterflies selects a species, and by giving prominence to all
its minute characters, proposes it with considerable plausibility as
a distinct genus. The local faunist divides his groups in reference
to his own limited sphere of observation. Neither contemplates
the possibility of being ever called upon to elaborate a general
system, and he leaves it to those who are to reconcile all existing
inconsistences. Hence it follows, that so many of the genera proposed
in local and partial works can find no place in a general one; for
however specious they may appear when standing alone, it is often
found that they will not unite into a consistent whole, and they may
therefore be said still further to embroil the very subject they were
designed to elucidate.
The Linnean distribution was vague and unsatisfactory, even at the
time when it was first produced, and soon became utterly inapplicable
when the amount of known species was increased. But it did not fail
to exercise, like every other system emanating from that gifted
mind, a powerful influence on the progress of the science, and is
interesting on account of its ingenuity and poetical elegance. “It is
an attempt,” says Dr. Shaw, “to combine, in some degree, natural and
civil history, by attaching the memory of some illustrious ancient name
to an insect of a particular cast.” The first Linnæan division consists
of _Equites_, which are distinguished by the shape of the upper
wings; these are longer, measured from their posterior angle to their
anterior extremity, than from the same point to the base; the antennæ
sometimes filiform. The _equites_ are denominated _Troes_ or Trojans,
distinguished by having blood-coloured spots on each side of the
breast: or _Achivi_, Greeks, which are without red marks on the breast,
of gayer colours, and having an eye-shaped spot on the anal angle of
the inferior wings. The second division consists of _Heliconii_, which
are distinguished by having the wings narrow and entire, often naked or
without scales; the superior oblong, the inferior very short. The third
division consists of the _Danai_, so called from the sons and daughters
of Danaus. They are divided into _Danai candidi_, or such as have
whitish wings, and _Danai festivi_, in which the ground colour is never
white, and the surface variegated. The fourth division consists of the
_Nymphales_, distinguished by the edges of the wings being scolloped or
indented; it is subdivided into _N. gemmati_, in which the wings are
marked with ocellated spots, and _N. Phalerati_, without these spots.
The fifth division contains the _Plebeii_. These are commonly smaller
than the preceding butterflies, and are subdivided into _rurales_ and
_urbicolæ_; the former having the wings marked with obscure spots, the
latter for the most part with transparent spots.
In his earlier works, _Mantissa_ and _Species_, Fabricius made no
important change on the Linnæan method; but the many additional
species which had come to his knowledge when he drew up his _Systema
glossatarum_, led him to establish many new genera, and remodel
the arrangement of the old ones. This method consists of forty-one
genera, most of which have been adopted by subsequent authors; but it
is less complete than it might otherwise have been rendered, owing
to the death of the author before it was finished. Latreille did
not deviate materially from the Fabrician method, adopting nearly
all the genera; but he did not derive the distinctive characters
exclusively from the antennæ and palpi, as the Danish entomologist
had done, but had recourse to other parts of structure, and likewise
judiciously took into account the peculiarities of the caterpillar
and chrysalis. Several arrangements were proposed subsequent to or
contemporaneous with that of Latreille, such as those of Lamarck,
Dumeril, Dalman, &c. but most of them are of little importance. The
last mentioned individual, however, appears to have been the first
to apply to actual practice, in his description of the lepidoptera
of Sweden, characters derived from the neuration of the wings, the
value of which were first pointed out by Mr. Jones, in a paper in the
Linnæan Transactions, published in 1794. Godart, without appearing to
have been acquainted with what had been done by Dalman, likewise had
recourse to the structure of the wings in his arrangement, as published
in the Encyclopédie Methodique, and Lepidoptera of France. In the
latter work, the diurnal series is classified with reference to the
appearance of the discoidal cell in the inferior wings; and by adopting
this excellent character, he has, in most instances, greatly improved
on Latreille’s method.
In 1776, an arrangement was proposed which attracted little attention
at the time, but which has since risen to considerable distinction.
It is that exhibited in the Systematic Catalogue of the Lepidoptera
found in the neighbourhood of Vienna, by MM. Denis and Schiffermüller.
This original and highly valuable system is entirely founded on the
appearance of the caterpillars. It is singular that characters almost
exclusively drawn from that state, should confirm the classifications
founded on characters afforded by the imago or complete insect. But
to such a degree does this coincidence obtain, that almost all the
families proposed by the Austrian naturalists have been adopted as
genera by those who were guided by other principles. This method
remained for a long time almost unknown to the naturalists of this
country, and even on the continent its excellence seems to have been
but inadequately appreciated, except among the Germans. The only
authors that have acted upon it are Ochsenheimer, and his continuator
Treitschke, in their valuable and extensive work on the Lepidoptera of
Europe[26].
But there can be little doubt that those arrangements are the most
accurate and philosophical which are founded on characters derived
from all the different states in which these insects exist. This
conviction seems now to be generally entertained, and most writers
of very recent date have seen the propriety of acting upon it. In
the works of Curtis, Stephens, Horsfield, &c. it has been adhered to
to a greater or less extent, and in a general work on Lepidoptera
lately published by Dr. Boisduval of Paris, nearly equal importance
is assigned to the peculiarities of the caterpillar, chrysalis, and
butterfly. As this method presents some new features, and is the last
that has been laid before the public, we shall give an account of it
along with the accompanying remarks in the authors own words:--“It is
not till after a most attentive study of the butterflies of Europe in
their different states, and after having collected a certain number
of materials on the metamorphoses of exotic species, that we have
attempted to group the lepidoptera in a manner different from that
hitherto followed, not neglecting, at the same time, the study of
those authors who have occupied themselves with this order, that we
might be enabled to combine the results of their labours with our
own. We do not flatter ourselves, however, that the combinations
which we have made are altogether free from blame, any more than
those of our predecessors. When occupied with the productions of a
single country, the classification is much more easy; the greater
number of species associate pretty well with each other, and, if we
except a few of the most anomalous, a series is obtained free from
much irregularity. In this way, the European species form a pretty
homogeneous assemblage, and the same thing holds with regard to those
of South America, New Holland, or any other country taken by itself;
but when we attempt to classify those of the whole globe, we frequently
meet with intermediate genera which interrupt this harmony. If we
even take a somewhat numerous genus belonging at the same time to
several different countries, we find species which form a passage to
other races proper to each of these countries. For example, the genus
_Pieris_ of Latreille offers species in America (genus _Leptalis_)
which bear a perfect resemblance to the _Heliconii_ in their colour,
the length of their bodies, and narrowness of the wings. Others of the
same country (genus _Euterpe_) insensibly unite with that division of
American _Papiliones_ which is of a black colour with red spots; those
of Europe, on the contrary, present certain relations to _Parnassius_,
_Pieris Cratægi_ appearing to form the passage to _P. Mnemosyne_, while
those of India gradually approach _Colias_ through _P. Judith_ and _P.
Panda_, and to _Danais_ with green spots through _P. Valeria_. All
other genera of some extent, and distributed over several countries,
are in the same condition.
“What we have just stated, applies equally to the correlation of
species with each other. If we take, for example, the genus _Satyrus_
of Latreille, we perceive that it is composed of an infinite number
of secondary groups, scarcely any of which are proper to one country.
Thus, in Europe, we have the division to which _Galatea_ belongs,
extending along the basin of the Mediterranean, even into Persia;
that of _Hermione_, which takes the same direction, and continues to
Cachmere; that of _Norna_, proper to the polar regions of the two
continents; that of _Nigres_, which inhabits mountainous countries,
and is found only at the Cape and at Chili; finally, that of the
_Satyres_, properly so called, which are connected with the species of
New Holland, some of them with those of Chili, of North America, and
Siberia. America and the East Indies, likewise, present groups which in
general appearance differ widely from our European species; while there
are others which resemble several at the same time. A collection of the
_Satyres_ of one country would, therefore, form a sufficiently natural
series; but it would appear most irregular when the species of several
countries were brought together.
“Our method is partly founded on the caterpillar, and partly on the
perfect insect. We attach the greatest importance to the caterpillar
state, and the characters which it furnishes have often more value in
our estimation, than those afforded by the butterfly; but generally
these characters confirm each other, in other words, two caterpillars
presenting the same characters produce flies which likewise partake
of the same generic characters. It will no doubt be objected to us,
that it is illogical to deduce characters except from the animals we
are attempting to classify. We reply, that by following any other plan
we must despair of attaining to a natural method. Besides, it is not
necessary to be acquainted with the caterpillars of every species; it
is sufficient to study a caterpillar and chrysalis of _Vanessa_ or
_Pieris_ to have an exact idea of those of the two genera. Even though
it should be very difficult to verify the characters taken from the
larva, this is no reason why we should abstain from employing them. It
is not merely from the fruit that botanists obtain their characters,
but likewise from the flower, and even from the first developement of
the vegetable embryo. The flower is to the plant what the caterpillar
is to the lepidopteron, and the different modes of metamorphosis have
as much value as those of inflorescence.
“It appears to us that Latreille’s three divisions, taken from
Linnæus--_Diurnal_, _Crepuscular_, and _Nocturnal_--are too inaccurate
to be retained, especially the crepuscular section. The denomination
_Diurnal_ not only applies to all the known kinds of day butterflies,
but also to an almost infinite number of others forming a part of the
two other divisions, such as _Macroglossa_, _Zygenides_, _Castniariæ,
gocerides_, &c. That of _Crepuscular_ is adapted more or less to
some sphinges, but by no means to the _Zygenides_, which fly only
in the heat of the sun. Finally, the term _Nocturnal_ is not more
properly applicable to all the species, since many belonging to this
section appear only during the day. In order to avoid these improper
denominations, we have substituted for the word _Diurnal_, that of
_Rhopaloceres_, proposed by M. Dumeril. Being unable to perceive limits
between the _Crepuscular_ and _Nocturnal_ divisions of Latreille, we
have united those two great sections under the name of _Heteroceres_.
In our method, therefore, the lepidoptera are divided into two grand
legions, _Rhopaloceres_ and _Heteroceres_[27].”
Dr. Boisduval then proceeds to explain that the first of these
divisions is characterised by antennæ thickening to a club at the
extremity; and the second, by having these organs variously shaped;
this indeed is implied by the words themselves. The first division is
subdivided into three sections, according to the manner in which the
caterpillars transform themselves into chrysalides. Such as undergo
this change by attaching themselves by the tail and a band round
the middle, form the first division, named _Succincti_; such as are
suspended by the tail only, the second, _Penduli_; while those which
form a cocoon by rolling leaves together, compose the third division,
termed _Involuti_.
Each of these three sections is then divided into _tribes_, according
to characters derived from the caterpillars and the perfect insect.
Among those furnished by the latter, the most important are considered
to be the number of ambulatory legs and the form of the palpi. The
genera are characterised by the form of the caterpillar and chrysalis,
by the dispositions of the nervures of the wings, the form of the
antennæ, legs, palpi, thorax, &c. of the perfect insect.