shall consider, first, how we are to distinguish affinities from
analogies; and then mention some of the various instances of the
latter that occur between insects and other animals, and between
different tribes of insects themselves.
To know what characters denote affinity and what are merely
analogical, it must be kept in mind that the former being predicated
of beings in a _series_ (whether that series has its gyrations that
return into themselves, or proceeds in a right line, or assumes
any other intermediate direction, it matters not), it cannot be
satisfactorily ascertained but by considering attentively the gradual
approximation or recession of the structure to or from a certain type
in any point of such series. If, therefore, you wish to ascertain
whether the characters, in which any given object resembles other
objects in certain groups, indicate affinity or only analogy, you
must first make yourself acquainted with the common features which
distinguish the animals known to belong to that group,--either those
relating to their structure, or to their habits and economy. If the
object under your eye partakes in these characters more or less, in
proportion as it approaches the type or recedes from it, the relation
it exhibits is that of _affinity_; but if, though it resembles some
members of it in several points of its structure, it differs from
the whole group in the general features and characteristic marks
that distinguish it, the relation it bears to those members is
merely that of _analogy_. Thus, for instance, _Ascalaphus italicus_
in its antennæ, the colouring of its wings, and its general aspect,
exhibits a striking resemblance to a _butterfly_; yet a closer
examination of its characters will satisfy any one that it is in
quite a different series, and has no _affinity_ whatever to that
genus. A departure, however, in only one respect from what may be
called the _normal_ characters of its group, does not annul the claim
of any tribe of insects to remain in it; since this very often only
indicates a retrocession from the type, and not a disruption of its
ties of affinity. Thus the saw-flies (_Serrifera_) differ from the
other _Hymenoptera_, though not in their pupæ, yet more or less in
their larvæ; but this alone cannot countervail their agreement with
that Order in their organs of manducation and motion, in their
ovipositor, and in the other details of their structure[1287].
I have on a former occasion pointed out many of the analogies which
take place between insects and other parts of the animal kingdom, and
even between insects and the mineral and vegetable kingdoms[1288]:
I shall now resume the subject more at large, but without recurring
to those last mentioned. In considering the analogies which connect
insects with other animals, or which they exhibit with respect to
each other, we may have recourse to _two_ methods. We may either
consider them as placed somewhere between the two extremes of a
convolving series, from which station we may trace these analogies
_upwards_ and _downwards_ towards each limit; or we may conceive them
and other animals in this respect arranged in a number of series
that are _parallel_ to each other, in which the opposite points are
analogous. The first mode will perhaps best explain the analogies
that exist between insects and other animals, and the last those
between different groups of insects themselves. I shall give an
example or two of each method, beginning with the first.
There are two tribes in the animal kingdom that seem placed in
contrast to each other, both by their habits and by their structure.
One of these is carnivorous, living by rapine and bloodshed, and can
seldom be rendered subservient to our domestic purposes; while the
other is herbivorous or granivorous, is quiet in its habits, and
easily domesticated. Amongst insects we find the representatives of
both: those of the first tribe are distinguished by their predaceous
habits, by the open attacks, or by the various snares and artifices
which they employ to entrap and destroy other insects. They may
usually be known by their powerful jaws or instruments of suction; by
their prominent or ferocious eyes; by the swiftness of their motions,
either on the earth, in the air, or in the water; by their fraud and
artifice in lying in wait for their prey. Amongst the _Coleoptera_,
the Predaceous beetles,--including the Linnean genera _Cicindela_,
_Carabus_[1289], _Dytiscus_, and _Gyrinus_,--are of this description;
and they symbolize those higher animals that by open violence attack
and devour their prey:--for instance, the sharks, pikes, &c., amongst
the fishes; the eagles, hawks, &c., amongst the birds; and the whole
feline genus amongst the beasts. Similar characters give a similar
relation of analogy to the _Mantidæ_ and _Libellulina_ amongst
the _Orthoptera_ and _Neuroptera_. The whole family of _Arachne_,
the larvæ of the _Myrmeleonina_, &c., portray those animals that
to ferocity add cunning and stratagem, or suck the blood of their
victims. The _Myriapods_ symbolize in a striking manner the Ophidian
reptiles. Look at an _Iulus_, and both in its motions and form you
will acknowledge that it represents a _living_ serpent; next turn
your eyes to a centipede or _Scolopendra_, and you will find it
nearly an exact model of the skeleton of a _dead_ one, the flat
segments of its body resembling the vertebræ, its curving legs the
ribs, and its venomous maxillæ the poison-fangs. The great body of
the _Orthoptera_, the _Homopterous Hemiptera_, the _Lepidoptera_,
and _Trichoptera_, afford no example of Predaceous insects. All the
analogies I have here particularized, ascending from the insect,
terminate in races of a corresponding character and aspect amongst
the _Mammalia_, and thus lead us towards _man_ himself, or rather to
men in whose minds those bad and malignant qualities prevail, which,
when accompanied by power, harass and lay waste mankind; and thus
ascending from symbol to symbol, we arrive at an animal who in his
own person unites both matter and spirit, and is thus the member both
of a visible and invisible world: and we are further instructed by
these symbols,--perpetually recurring under different forms,--in the
existence of evil and malignant spirits, whose object and delight is
the corporeal and spiritual ruin of the noble creature who is placed
at the head of the visible works of GOD.
The other tribe of animals that I mentioned of a milder character,
may be looked upon as represented by many herbivorous, or not
carnivorous, insects; amongst others, the Lamellicorn beetles imitate
them by their remarkable horns, so that they wear the aspect of
miniature bulls, or deer, or antelopes[1290], or rams, or goats,
whether these horns are processes of the head or of the upper
jaws. The gregarious _Hymenoptera_, some of which form part of our
domestic treasures, may be regarded in some degree as belonging to
this department. From insects the ascent upwards, with regard to
_form_, is by some of the branchiostegous fishes, which symbolize
the horns of cattle; with regard to _character_, by the various
species of _Cyprinus_ and other similar genera.--Whether any of the
_reptiles_ may be looked upon as falling into this division, I am
not sufficiently conversant with them to assert; but if any, the
_Chelonians_, or tortoise and turtle tribes, are entitled to that
distinction. Amongst the birds, the _Gallinæ_ and _Anseres_,--from
which Orders we derive our domestic poultry, whether terrestrial or
aquatic,--and our game, form the step next below the ruminants, or
cattle: and we are thus again led towards man, and are symbolically
instructed in those domestic and social qualities which endear us
to each other, best promote the general welfare, and render us most
like good spirits and the Divinity himself; of whom the perpetual
recurrence of animals exhibiting these amiable and useful qualities
is calculated to impress upon us some notion. I might mention many
more instances of ascending analogies; as from some of the _Diptera_
by the parrots, to the _Quadrumanes_ or monkey tribes--or from some
of the _Iulidæ_ that roll themselves into a ball, to the _Armadillo_;
but these are sufficient to set your mind at work upon the subject,
so that you may trace them for yourself. Nor shall I occupy your time
by pointing out how analogies may be traced from insects downwards
towards the lowest term in the scale of animal life, but proceed
to consider the analogies observable between insects themselves;
in which I shall follow the _second_ method lately mentioned, and
consider them as arranged in parallel series.
In studying the analogies that take place between insects themselves,
we should always bear in mind that our inquiry is not concerning an
_affinity_ which demands a correspondence in various particulars
that are not necessary to constitute an analogy; as, for instance,
that there should be a mutual imitation in all the states of any
two insects. Wherever we discover a marked resemblance between
two _perfect_ insects, there is a true analogy, though their
metamorphosis may differ; and where there is _not_ that resemblance,
though the metamorphosis may agree, there is no analogy. In fact,
insects are sometimes analogous in their _first_ state and _not_ in
their _last_; and at other times analogous in their _last_ and _not_
in their _first_; but the analogy is most perfect when it holds
in _all_ their states: it then, indeed, almost approaches to an
affinity. They may also be analogous to each other in their _habits_
and _economy_, when there is little or no resemblance in their
_form_; and, _vice versa_, be analogous in their _form_ and not in
their _habits_. So that different sets of analogies may be assumed
as foundations for different systems. Thus Mr. MacLeay assumes the
_metamorphosis_ as the basis of analogy between the corresponding
Orders of _Mandibulata_ and _Haustellata_[1291], while M. Savigny
compares the _perfect_ insects[1292]: the result therefore differs in
some instances. I shall now lay before you in a tabular view their
plans and my own.
SAVIGNY.
MANDIBULATA. HAUSTELLATA.
Neuroptera } { Lepidoptera
_Ascalaphus_ } { _Papilio_
Hymenoptera } { Diptera
_Eucera_ } { _Tabanus_
Orthoptera } { Homoptera
_Locusta_ L. } { _Cicada_
Aptera } { Aphaniptera
_Nirmus_ } { _Pulex_.
MACLEAY.
MANDIBULATA. HAUSTELLATA.
Trichoptera Lepidoptera
Hymenoptera Diptera
Coleoptera Aptera
Orthoptera Hemiptera
Neuroptera Homoptera.
K. AND S.
Coleoptera Hemiptera _Leach_
Orthoptera Homoptera _Leach_
Neuroptera Lepidoptera
Hymenoptera Diptera.
In these two last columns, you see, I differ little from M. Savigny:
I merely exclude the _Aphaniptera_ as forming an osculant Order,
and I have added the _Coleoptera_ and Heteropterous _Hemiptera_ for
reasons I shall soon assign. From Mr. MacLeay I differ more widely,
which has resulted from our different ideas as to the mode of tracing
analogies; his theory leading him to the _metamorphosis_, and mine
leading me[1293] to the _perfect_ insect, for the foundation of our
several systems. It remains that I show how each of the pairs in my
columns represent each other: but I must observe, that the analogies
exhibited by insects in the corresponding Orders of these columns are
not equally striking in all their respective members; but only in
certain individual species or genera, more or less numerous, by which
the nearest approach is made to the contrasted forms.
To begin with the _Coleoptera_ and Heteropterous _Hemiptera_.--Both
are distinguished by having an ample _prothorax_, a conspicuous
_scutellum_, the neuration of their wings, the substance of the hard
part of their _hemelytra_, which, as in _Coleoptera_, sometimes
imitates horn and sometimes leather, and is occasionally, like
elytra, lined with a _hypoderma_[1294]; the articulation of the
head with the trunk is likewise the same in both[1295]: and some
Heteropterous species so strikingly resemble beetles (_Lygæus_,
_brevipennis_ &c.), having little or no membrane at the end of
their hemelytra, that they might easily be mistaken for them. These
circumstances prove, I think, that this suborder is more analogous
to the _Coleoptera_ than to the _Orthoptera_, with which it agrees
in scarcely any respect but its metamorphosis. The counterparts of
this last Order indeed, instead of the _Heteropterous_, are to be
sought for amongst the _Homopterous Hemiptera_, various species of
which exhibit a most marked and multifarious analogy with numerous
_Orthoptera_. Many of both Orders (_Cicada_, _Locusta_), as you have
heard long since, are signalized by possessing the same powers of
song, and produced by an analogous organ[1296]: a large proportion
also of both are endued with wonderful saltatorious powers, and their
posterior tibiæ are similarly armed; their legs in general likewise
are longitudinally angular, and the head in both articulates with the
trunk in the same manner[1297]. In both Orders too, the upper organs
of flight are most commonly _tegmina_, but sometimes in both they are
nearly membranous, like _wings_. In _Centrotus_ and _Acrydium_, the
one _Homopterous_ and the other _Orthopterous_, the front is bilobed,
the eyes are small; there are only two stemmata between the eyes;
the prothorax is conspicuous, and behind is producted into a long
scutelliform process, under which all the parts also are analogous;
the abdomen articulates with the trunk in the same way, is similar
in shape in both, and consists of short inosculating segments. Some
_Fulgoridæ_ and _Truxalides_ agree also in their producted front.
Other analogous characters might be named between these tribes,
but these are sufficient to confirm M. Savigny's opinion. That the
_Neuroptera_ present analogies to the _Lepidoptera_, though they
differ so widely from them in their metamorphosis and habits, is
evident from the instance lately adduced of _Ascalaphus italicus_,
which was described as a butterfly by Scopoli[1298]; and many of the
_Libellulina_, by their wings, partly transparent and partly opaque,
and by the shape of those organs and of their bodies, imitate the
Heliconian butterflies: and this resemblance is much more striking
than any that occurs between the perfect insects in the _Neuroptera_
and Homopterous _Hemiptera_. With regard to the _Hymenoptera_ and
_Diptera_ the analogy is undisputed, and must strike every beholder;
and one would almost say it was a real affinity, were it not that
the resemblance is not only general between Order and Order, but
that almost every Hymenopterous tribe has its counterpart amongst
the _Diptera_; the saw-flies[1299] for instance, the ichneumons,
the various false-wasps[1300], the false-bees[1301], the bees, the
humble-bees, the ants, &c., severally find there a representative
that wears its livery and general aspect: a circumstance which
evidently proves that it was part of the plan of the CREATOR to place
them in contrast with each other. Were I to pursue this subject
further, it might not be difficult to show that were the _tribes_ of
_Mandibulata_ or of _Haustellata_ also arranged in columns, analogies
would be discoverable between their corresponding points: this seems
to be Mr. MacLeay's opinion[1302]; and it is worth your pursuing the
subject further, which cannot but prove very interesting.
But though the general analogy of these columns is that of Order
to Order, yet individual species in each Order sometimes find
their representatives in a different one from that with which they
generally are contrasted;--thus some _Diptera_, as _Culex_, by the
scales on the veins and other parts of their wings, are analogous to
_Lepidoptera_ rather than _Hymenoptera_[1303]; as is also the genus
_Psychoda_ by its form.
* * * * *
We come now to the consideration of a question not easy to be
decided,--I mean, which Order of insects is to have the _precedency_,
and which is the connecting link that unites them to Vertebrate animals.
Linné (and Mr. MacLeay seems in this to coincide with him) considered
the _Coleoptera_ as at the head of the Class of insects; De Geer
thought the _Lepidoptera_ entitled to that honour; Latreille and
Cuvier begin with the _Aptera_: Marcel de Serres favours the
_Orthoptera_[1304]; and others, on account of their admirable
economy, have made the _Hymenoptera_ the princes of the insect
world[1305]. If the claim to priority was to be decided by the
exquisiteness of instincts and the benefits conferred upon the
human race, doubtless it would be in favour of the last-mentioned
insects. If the power to do mischief carried it, and to lay waste
the earth, the _Orthoptera_ would be entitled as much as any to the
bad pre-eminence. If beauty, and grace, and gaiety, and splendour
of colours were the great requisite, and the law enjoined, _Detur
pulchriori_,--the _Lepidoptera_ would doubtless win the throne.
But if perfection and solidity of structure, as they ought, are to
regulate this point; we must, I think, with the illustrious Swede,
assign the palm to the _Coleoptera_. If we consider these in all
their parts, the organs for flight only excepted, they seem more
perfectly formed and finished than the insects of any other order.
But which of the Coleopterous tribes are entitled to the precedency?
Linné placed the Lamellicorn beetles at the head of the order,
beginning with the _Dynastidæ_, probably led by some characters
which seem to connect these with the Branchiostegous fishes. In
this he was followed by Fabricius. But Latreille and most modern
Entomologists have begun with _Cicindela_ and the other Predaceous
beetles. I am not certain what are Mr. MacLeay's sentiments on this
subject; but from what he says in the _Annulosa Javanica_[1306], it
does not appear that he is a convert to the latter opinion. Bulk
and strength seem the most striking characteristics of the former
tribe, which represent the cattle or ruminants amongst Vertebrate
animals.--Strength united with agility and a considerable portion of
grace and symmetry evidently confers a degree of pre-eminence upon
the latter, symbolizing the feline race, which seems to throw no
small weight into their scale.
There are two Classes of Vertebrate animals with which insects may
appear to claim kindred. The _fishes_, and the _reptiles_. _Fishes_
in their fins exhibit no small resemblance to insects; the pectoral
and ventral ones representing their arms and legs, and the dorsal
ones their wings: _Pegasus Draco_ in this last respect is not unlike
a butterfly[1307]. In some genera (_Ostracion_, _Pegasus_, &c.),
like insects the animal is covered with a hard shell or crust,
formed by the union of its scales. The oral _cirrhi_ of many fishes
seem analogous to the _palpi_ of insects; and in some a pair longer
than the rest represent their _antennæ_[1308]. Another circumstance
in which insects and fishes correspond, is the wonderful variety
of forms, often in the greatest degree eccentric, that occurs in
both Classes. Some of the cyclostomous fishes, as _Ammocœtus_,
_Gastrobranchus_, are supposed to connect the fishes with the
_Annulosa_, by means of the _Annelida_ as an osculant Class[1309],
which Mr. MacLeay regards as the passage to the _Chilopoda_[1310]:
his _Mandibulata_ he considers as passing into the _Anoplura_ by
means of some osculant Order as yet unknown[1311]. But I must confess
I can see no good ground for this last transition:--the _Anoplura_
appear much more nearly related to the _Psocidæ_, especially by the
apterous _Atropos pulsatoria_[1312] than to any _Coleopterous_
insect. But having stated these opinions, I shall leave you to draw
your own conclusions, as the question is still perplexed with many
difficulties. I am ready to admit that some Vertebrates approach near
to the _Annelida_; but that it is through them alone that they are
connected with insects, is not at present clear.
With regard to _reptiles_, they seem to be connected with insects
by several characters. In the _Chelonians_, the skeleton merges in
the external carapace or shell; the _Ophidians_ change their skin
like larvæ; the _Batrachians_ undergo metamorphoses; some of the
_Saurians_ also have their changes: and the _Draco volans_ has wings
somewhat analogous to those of insects[1313]. Were I to be asked
what Order of insects could connect with reptiles, I should point to
the _Orthoptera_, especially _Gryllus_ L., which by their noise and
saltatorious powers not a little resemble frogs; and the larvæ of
some strikingly imitate their form[1314]: and of others even that of
a lizard[1315]. But these resemblances, after all, may only indicate
analogies.
FOOTNOTES:
[1126] _Philos. Botan._ 97. n. 153.
[1127] _Ibid._ 98. n. 155, &c.
[1128] Μεθοδος is rendered "An _artificial_ and compendious mode of
doing any thing; a mode of _teaching_ or _learning_:" Μεθοδευω is
"To overcome by _artifice_." Συσεμα applied to music is "A _full_
and _harmonious_ assemblage of tones." So that in fact, _System_
should express the actual disposition of objects, or a _Natural_
arrangement; and _Method_, an _Artificial_ one.
[1129] Wisdom. xi. 20.
[1130] Genes. i. 31.
[1131] W. S. MacLeay in _Linn. Trans._ xiv. 54.
[1132] Linn. _Syst. Nat._ i. 11.
[1133] Qu. Whether every real species or group has not some one
or more _peculiar_ characters which it neither derives from its
predecessor nor imparts to its successor in a series?
[1134] _Œuvres_ vii. 51--.
[1135] _N. Dict. d'Hist. Nat._ xx. 485.
[1136] VOL. III. p. 11--.
[1137] W. S. MacLeay. _Hor. Entomolog._ passim; and in _Linn. Trans._
ubi supr. 53--.
[1138] _N. Dict. d'Hist. Nat._ xx. 485.
[1139] The idea of a continuous _series_ militates somewhat against
that of a circle returning into itself. The progression of the series
may be in a circle; but at the point of contact where the second
circle meets the first, the lines must cut each other; and at this
point of intersection of the two circles are of course the osculant
groups constituting the first and the last of each circle, which in
their intervention come in contact with each other, or rather forming
_transition_ groups. If each circle is regarded as _absolute_, the
_series_ is broken, though the osculant groups connect the circular
ones.
[1140] Mr. MacLeay almost admits that there are _natural_ genera.
_Hor. Ent._ 492.
[1141] _Œuvr._ vii. 52.
[1142] _N. Dict. d'Hist. Nat._ ii. 34--.
[1143] Even those animals that like the _Spongiæ_ and _Alcyonia_
are aggregate, and fixed by a common base, have a partial degree of
voluntary locomotion in their cells.
[1144] VOL. III. p. 10.
[1145] Cuv. _Anat. Comp._ i. 173.
[1146] _N. Dict. d'Hist. Nat._ ii. 25.
[1147] _Ibid._ 26--.
[1148] VOL. III. p. 12--.
[1149] _Hor. Entomolog._ 200--. See above, p. 3--.
[1150] Savigny _Mém. sur les Anim. sans Vertèbr._ II. i. 3.
[1151] MacLeay _Hor. Ent._ 204.
[1152] VOL. III. p. 46--, See above, p. 247.
[1153] See above, p. 195--.
[1154] VOL. II. p. 306--.
[1155] In this respect insects excel many reptiles, which can
reproduce some of their parts.
[1156] See MacLeay _Hor. Entomolog._ 203, 206--. 298--.
[1157] Linn. _Philos. Botan._ n. 155, 160.
[1158] VOL. III. LETTER XXVIII.
[1159] Scias Characterem non constituere Genus, sed Genus Characterem;
Characterem fluere e Genere, non Genus e Charactere; Characterem non
esse ut Genus fiat, sed ut Genus noscatur. _Philos. Botan._ m. 169.
[1160] VOL. I. p. 66. note^a.
[1161] VOL. III. p. 417.
[1162] Derived from κολεος, _a sheath_, and πτερον, _a wing_.
[1163] _Hist. Animal._ l. iv. c. 7. l. v. c. 20.
[1164] Ὁσα το πτερον εχει εν κολεῳ.
[1165] Latr. _Gen. Crust. et Ins._ i. 169. Oliv. _Ins._ i. Introd. v.
[1166] VOL. I. p. 65.
[1167] In some genera, as _Molorchus_, &c., they do not completely
cover the wings. PLATE X. FIG. 1. PLATE I. FIG. 4, 5.