Insect architecture

INSECT

ARCHITECTURE.

SECOND EDITION.

LONDON:
M. A. NATTALI, 23, BEDFORD STREET,
COVENT GARDEN.

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LONDON: WILLIAM CLOWES AND SONS, STAMFORD STREET.

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CONTENTS.

CHAPTER I.

InTRODUCTION;
nstruction derivable from common things «
Extraordinary numbers and varieties of insects

Can be studied in every situation. .
Anecdotes ° . . . ° .
Cabinets useful, but not indispensable . .
Study of insects does not narrow the mind .
Injuries and benefits caused by Insects .
Use of names in Natural History . .
Study of Insects fascinating to youth .
Anecdote of a little girl = - . “

Beauty of Insects. . . .
Varieties in the economy of Insects
States of Insects . .

Insects produced from eggs .« A
Larva, Caterpillar, Grub, Maggot
Pupa, Chrysalis, Aurelia, Nymph
Imago, perfect Insect « . .

CHAPTER II.

Structures for pretactitis Eggs .
Eggs of
Bees compared to our mechanics . . .
Mason-Wasps « . ee * . .
Curious proceedings of one at Lee « .
Her caution outwitted by aFly ~. : .
Structures of another Mason-Wasp . .
Her storing of live Caterpillars . . .

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Mason-Bees . . . . ‘| . :
Nest of one on the wall of Greenwich Park
Clay-miue of Mason-Bees at Lee .
Estimate of their labours ~- . :
Wall-Mason-Bees of France.

Proceedings of the two-horned Mason-Bee at Lee

Structures of Mason Bees. . .
Their restless disposition . . Fy .

beh . . . . . ‘ .
heir different proceedings in Britain and in France

CHAPTER IIL.

Carpenter-Bees_. . san: s : . .

a Methods of working - ‘ , . .

History of one at Lee . . e . .
Violet Carpenter-Bee of France - °

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vi CONTENTS.

Compared with our joiners .
Elder and Bramble Carpenter- Bees
Carpenter-Wasps. . . « .
Curious cocoon of ° . :
Upholsterer-Bees .
Poppy-Flower Bee of Largs and of Bercy
‘Taste of the little architects in ornament
Cotton-gathering-Bee . . . .
Rose-Leaf-Cutter Bee . . . .
Her method of working. . ° .
Anecdote of Sir Francis Xavier . .

CHAPTER Iv.
Carder-Bees .

Method of preparing and conveying their materials

Structure of their nests . . .
Lapidary-Bees .
Pertinacity in defending their nests
Humble-Bees. . . .
Structure of their nests « ‘ .
Social-Wasps. . .
Nest founded by a single femule .
Compared with the Burrowing-Owl
Materials rasped off from wood .
Different opinions of Naturalisis . .
Paper made by Wasps . . . 5
Structure of the nest .
Extraordinary number of cells *
Hornet’s nest . .
Tree-Wasps’ nests in Ayrshire .

Rose- pa ape Wasps’ nest. .
Vertical-Wasps’ nest. .
Wasp-paper compared with ours
Card-making Wasp of Cayenne

BSI, igi ia’

CHAPTER V.
Architecture of the Hive-Bee , .

Discoyeries, from Aristomachus to Maraldi and Huber

Nurse-Bees and Wax-Workers . .
Preparation of wax .

Erroneous account by the Abbé la “Pluche

Conjectures of Reaumur . . .

Discovery of John Hunter , . .

Experiments of M. Huber . .

Singular facts by Mr. Wiston .

Senses Hee TR Ss

Dissections by Madlle zaxne and M. Latreille

Propolis ‘ .
inions of old Naturalists . . :
Discovery by Huber. . .
Various uses of ropolis .
Mr, T. A. Knight's observations .
Basket for carrying on the Auphe ae aes
Process of loading a
Building ofthe cells. rs » ' ‘
Division of labour . . . .

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CONTENTS. Vil

Page
Festooned curtain of Wax-Workers . . , . 113
Commencement of the combs " . ° : » 116
Huber’s history of his experiments . . : + ib.
Secretion of wax . . . . . . . . » 116
Foundation of the firstcell . ° ° . : . Pe blr
Workers extract their own wax. aaah Sere .» 118
View of the proceedings obstructed . F * . - 119

CHAPTER VI.

Form of the cells . . . A : euteear . + 120
Mathematical problem solved by Bees . . . > oe del
Calculated by Maraldi and Kanig . . . . ib.
Reasons for the form ofthe cells . . . 4 . 122
Referred to the form of the Bee .« . . . . : ib
el ppt of Huber . . 3 . . . : 123
Cells commenced in the foundation-wall . . . « 125
Deepening of the cells . 4 ’ ac a ‘ » « 127
Polishing by Nurse-Bees . . . e . - 128
Distance of the combs from each other . . 5 ° - 129
Dr, Barclay’s discovery - ‘ . * A . 130

Irregularities iu their workmanship . . . ’ . + Il
Anecdote from Dr. Bevan. A . : ° . + ib.
Similar anecdote from Huber 5 . y . ‘ + 132
Symmetry in the architecture of Bees explained . . . 133
Curved combs , . . . . . . . - 14
Experiments of Huber . . . . : : s 4b.
Size of male cells . . . . . . . . - 136
Cells enlarged when honey is plentiful . 5 . . - ib.

The finishing of the cells si . : * é ci 7 - 137
Varnished with propolis . . . . . lee
Strengthened with pissoceros . . . . . © sibs
Discovery by Huber . a: > ae ees eee Ee
Cells strengthened by the Bee-grubs « . e mes ONE
Difficulties explained = _ ° . ; . . » 141
Mistake of an American writer . . . . ‘ - 142
Curious experiment of Huber . . . ' . » ib.

Wild-Honey Bees . . . . . . . ee - ib,
Wild-Bees of America, Ireland, Palestine . . A . 148
Honey-guide of Africa . . . . . ° ‘ - 145
Bee-hunting in America =. > . ° . . - 146

CHAPTER VII.

Carpentry of Tree-hoppers (Cicad@) . ; . . 5 - 7
Mistaken for grass-hoppers . . . . . . . ib.
Singular cutting instrament of the Tree-hopper « . - 148
Double files of. . . . . . . . . - 150
Their nests . : . . . ‘ . 5 . « WL

Saw-Flies . . . . . . . . . . - 152
Their ovipositor . fot ; < . . emer
Structure of. ‘ i . . ' . ‘ . - 154
Comb-tooth rasp, and saw . ; in Fj v ; - 166
Grooves cut by it in the rose-tree . st gee ge

CHAPTER VIII,
Leaf- rolling caterpillars . , ‘ 5 . . . - 159

Lilac Leaf-roller . . . . . . . . + 160

Vili CONTENTS.

Oak-Leaf-Roller . .
Rose-Leaf-Roller . .
Nettle-Leaf-Roller 7
Method of proceeding .
Probable mistake concerning
Sorrel-Leaf- Roller .
Admirable, and Painted Lady, Butterfl
Mallow-Butterfly of France . .

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Willow-Leaf-Bundler . . * .
Nest of Ziczac Caterpillar . . .
Nest of Glanville-Fritillary . ° .
Experiment on gregarious ‘Caterpillars by J.
Design in rolling leaves . . .

CHAPTER IX.
Habitations formed of detached leaves .

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The Pondweed Tent-Maker . ° . * . ‘ - li7
Chickweed Caterpillar’s nest P . . . < « 178
Cypress-spurge Caterpillar’s nest , ‘ . . ° . 179
Durability of these structures . 4 . . - 180
Compared with our architecture . . . . . « 18h
Moss:cell of a Wall-Caterpillar . « ° a ‘< > deo.
Caterpillar of Greenwich Park wall . . . * . 184
CHAPTER X,

Caddis-Worms . 2 . . . . « . 185
Leaf and reed nests of . . . . . . + ib.
Shell nestsof . ; > . . este - 186
Stone and sand nests of. . . . . . . « 187
Nest balanced with straws . . . . . . . 188

Carpenter-Caterpillars . A é . « . ‘ . - 189
Caterpillar of Goat-Moth . » . . . + ib.
Its winter nests . . 5 . . . . . + 190
Singular nest of . . . ° . ‘ ° . + 191
Nest of the Augeria in a sed : . . . » 192
Paper-nest of the Puss- Mot . S . : . - 193
How it escapes from its cell . ° . . . . + 195
Purple-Capricorn-Beetle —_, . . . . + 196
Bark-building Caterpillar of the oak . . . + 197

CHAPTER XI.

Earth-Mason-Caterpillars . . . . . Fy * + 200
Outside walls of their nest . a F ‘ . . + 201
Caterpillar of Ghost-Moth . . . . : . - ib.
Experiments of Réaumur , * . : . . + 203
Nests of Ephemera Grubs. . ‘ . . . + 206
Similar nests in a willow stump . . . . . - 207
Nests of the esi ane ae . . . . . ib.

The Ant-Lion < . . 5 . Praia « 209
Structure of the Grub . . . . . . + 210
Formation of its traps . . ‘ . » 211
Reflections upon the economy of Nature . . . + 214

CHAPTER XII.

Clothes-Moth Caterpillars . : . . . ‘ . + 217

Varieties in the species. 2 . ’ s . ‘ » ib.

CONTENTS., ix

Page

Methods of destroying . . . . . . . 218

Mode of building. . i . . . . 5 219

Experiments upon . . . . . . . 220

Migrations GE "se . . . . * . . - 222

‘Pent-Making Caterpillars. . . * . . . « 223

Mode of constructing these . . Celie . a, Oe eae

Experiments upon . . . . . . . « ib.

‘Tent upon a Nettle-leaf a . . . . . + 226

Stone-Mason Caterpillars | . . . . . : . » 227

Their singular proceedings .« . . . . . . 228

Colony of, at Blackheath . . . ‘ . . + 229

Foundation of their tents . . - . mi . 230

An attempted robbery - . . . . ’ . + 231

Muff-shaped Tents . . . . . . a . . + ib.

Their utility . . . . . z . . » 233

Leaf-Mining Caterpillars . . . . . . . - ib.

On the leat of the Monthly Rose-tree_ « ° . * « 234

On the leaf of the Bramble . . . . . . « 236

On the leaf of the Primtose . . . . . . » 237

Vine-leaf Miner . . . . . ° . . + 238

On the leaf of the Alder . . . . . . + ib.

Social Leaf-Miners ° . . . . . . . « ib

Bark-mining Caterpillars . . . . ° . . + 239
CHAPTER XIII.

Structures of Crickets . . . . . . . . + 241

The House-Cricket . . . i . . 5 - dbs

‘The Mole-Cricket. ° . . . . . ° + 242

The Field-Cricket . . . . . ° . . 244

Mode of depositing eggs . . . . . . » 246

Beetles. . . . . . . . . . . - AT

The Burying-Beetle + . ¥ . . . . - ib,

The Dung-Beetle . : . . . . - 249

Itscleanliness . ‘ . . ° . . . + 250

The Rose-Chafer . . . . . . . » 251

The Tumble-Dung-Beetle + . ‘ . . . » ib.

The Necklace-Beetle « . . . . . « 253
CHAPTER XIV.

Architecture of Ants — . ° . A . . ' . + 254

Their genuine history begun by Gould . . . . » ib.

Mason-Ants .« : . . . ‘ . . . . « 255

Structures of Turf-Ants A . . . . ‘ - ib.

Winter nest of Yellow-Ants . . . ‘ 5 . + 256

Sort of earth employed in building . 2 . . + 257

Proceedings of the Brown-Ants . ‘ . . . - 28

Raft formed by American-Ants . > . * . + 260

Blind-Ants . . . 5 . . ° . . + 261

Night proceedingsof Ants. .« « ee es oe a)

Proceedings during rain . . . . . . + ib.

Experiments Fe » ie . . * 5 . . 266

History of a labouring Ant, by M. Huber. . . + 267

Glazed Artificial Formicaries . . . . . + 269

Section of a Mason-Ant’s nest . . . . . » 270

Experiments by J. R. . s . . . . . . aml

x CONTENTS.

CHAPTER XV.

Structures of the Wood-Ants, or Pismires
Materials employed =. e .
Coping of their nest . . .
Interior structure ’

Glazed Formicary for ex eriments,
Their proceedings at night-fall .

Carpenter Ants. . . .
Emmets, or Jet- Ants : i 4
Their galleries in trees , .
Extremely populous anlany, at Brockley
Dusky-Ants. . . . .

Foreign Ants . .
Sugar-Ants of the ‘West Indies . .

CHAPTER XVI,

Structures of White-Ants, or'Termites .
Their extraordinary comparative height,
Their mining operations . .

The Warrior (Termes Bellicosus) . 5
Used as delicate food. .
Commencement of their nests
Royal chamber . .
Nurseries.

Galleries and covert ways .

Turret-building White-Ants .
Singular form of their nests

White-Ants of trees and timber
Death-Watch . .

CHAPTER XVII.

Spinning-Caterpillars . . ‘
Manifold advantages of 8 munaion F)
Structure of their legs and feet ~ . .
Side spiracles for urestis . . .
Internal structure. . . .
Structure of the silk- tube :

Mode of spinning Gavastha By La Pluche

Silk-Worms . . . A
Their transformations .

How they make their exit from the cocoons

Parts used in our manufactures. .
History of the introduction of silk ‘
Varioties and species of silk-worms .
Emperor-Moth .
Ingenious contrivance of the cocoon *
Bploning: Caterpillars, continued. .
Elastic cocoon of Tortrie chlorana’ .
Slender covering of the Srey -Moth .
Cocoon of the Cream-spot Tiger-Moth ,
Experiment with the Dock-Weevil . .

Nest of Puss-Moth, with cocoons of Ichnoumons

Cocoon of the Hormed Mason-Bee . a
Experiment with Hriogaster lunestris ,

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CONTENTS,

Social cl ates oa Weal = . .

inter nest of the Brown-tail Moth . ’

Winter nests of the Golden-tail Moth .
Pendulous leaf nests, from Bonnet . .
Nest of Processionary Caterpillars . .

CHAPTER XVIII.

Structures of Spiders. . . . . .
Spiders not properly insects, and why . .
Apparatus for spinning. . . . .
Extraordinary number of spinnerules . .
Attachment of the end of a thread s .

Shooting of the Lines of Spiders. . . :

1, Opinions of Redi, Swammerdam, and Kirby .

— Lister, Kirby, and White . rs

3. — La Pluche and Bingley +» «

4. D'Isjonval, Murray, and Bowman
5. Experiments of Mr. Blackwall . +

His account of the ascent of gossamer

6. Experiments by J. R. . . < mie
Thread supposed to go off double . .
Subsequent experiments . . .

Nests, Webs, and Nets of Spiders. . .
Elastic satin nest of a spider « . .
Evelyn’s account of Hunting-Spiders .
Labyrinthic Spider's nest. . .
Erroneous account of the House-Spider.
Geometric Spiders . ae) Pts .

Mason-‘Spiders . 5 . . * .
Ingenious door with a hinge - : F °
Nest from the West Indies, with spring hinge.

Raft-building Spider . . . . . .

Diving Water-Spider . . 4 .
Observations of M. Clerck . . . .

Cleanliness of Spiders . 5 . . . .

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Structure of their claws . . .
Fanciful account of them patting their webs
Proceedings of a Spider in a steam-boat.

CHAPTER XIX.

Structures of Gall-flies . x . . ‘ .
Berry-gall of the oak-leaf, &e. |. . :
Ingenious mechanism of the ovipositor . i
Opinions of Naturalists as to the cause of galls
Bedeguar of the rose. . . .
Artichoke-gall of the oak
Leaf-gall of Dyer’s broom
Rose-willow . .
Rose-hawithorn . =
Woolly-gall of the oak ,
Experiments with the Flies
Oak-apples . . .
Root-galls of the oak.
Woody-gall of the willow
Oak currant-galls .

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Xl CONTENTS,

Weevil-Galls . . . . a . .
Weevil-gall of the hawthorn « . .
Anbury on the roots of cabbages, &e. .

Semi-galls of Aphides . ° . .

ountain-ash leaf-galls ‘ . .
Poplar semi-galls of the cottony aphis .

Leaf-rolling Aphides ° A ’
Leaf of the currant-bush thus altered
Shoot of the lime-tree thus convoluted

Pseudo-Galls . 5 . . . .
Pseudo-gall of the bramble . .

hawthorn :

Scotch fir .

CHAPTER Xx,

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Animal-Galls . . . . . :
Enthusiasm of M. Réeaumur for study «
Ovipositor of Breeze-flies . .

inion of Mr. Bracey Clark on its use
Eifects produced by the fly apon cattle .

Observations of Linneus on the Rein-deer Breeze

inion of Kirby and Spence . .
Observations of Mr. B. Clark . .
Hatching oftheegg . . Py Aa
Bumps, or Wurbles, thence produced ,
Communication of the grub with the air
Final cause of these bumps . . .
The Zimb (Breeze-fly ?) of Africa ,
Human Breeze-fly eekly Me

Grub-parasite inthe Garden-Snail.
Caterpillar Parasite in thesame ,

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INSECT ARCHITECTURE.

Cuapter I.
INTRODUCTION.

Ircan never be too strongly impressed upon a mind
anxious for the acquisition of knowledge, that the
commonest things by which we are surrounded are
deserving of minute and careful attention. The
most profound investigations of Philosophy are
necessarily connected with the ordinary circum-
stances of our being, and of the world in which
our every-day life is spent. With regard to our own
existence, the pulsation of the heart, the act of respi-
ration, the voluntary movement of our limbs, the
condition of sleep, are among the most ordinary
operations of our nature ; and yet how long were the
wisest of men struggling with dark and bewildering
speculations before they could offer anything like a
satisfactory solution of these phenomena, and how
far are we still from an accurate and complete know-
ledge of them! ‘The science of Meteorology, which
attempts to explain to us the philosophy of matters
constantly before our eyes, as dew, mist, and rain,
is dependent for its illustrations upon a know-
ledge of the most complicated facts, such as the
influence of heat and electricity upon the air; and
that knowledge is at present so imperfect, that even
these common occurrences of the weather, which
B

2 INSECT ARCHITECTURE,

men have been observing and reasoning upon for
ages, are by no means satisfactorily explained, or
reduced to the precision that every science should
aspire to. Yet, however difficult it may be entirely
to comprehend the phenomena we daily witness,
every thing in nature is full of instruction. Thus
the humblest flower of the field, although, to one
whose curiosity has not been excited, and whose un-
derstanding has, therefore, remained uninformed, it
may appear worthless and contemptible, is valuable
to the botanist, not only with regard to its place in
the arrangement of this portion of the Creator’s
works, but as it leads his mind forward to the con-
sideration of those beautiful provisions for the sup-
port of vegetable life, which it is the part of the phy-
siologist to study and to admire.

This train of reasoning is peculiarly applicable to
the economy of insects. They constitute a very large
and interesting part of the animal kingdom. They are
everywhere aboutus. ‘The spider weaves his curious
web in our houses; the caterpillar constructs his silken .
cell in our gardens; the wasp that hovers over our
food has a nest not far removed from us, which she
has assisted to build with the nicest art; the beetle
that crawls across our path is also an ingenious and
laborious mechanic, andhas some curious instincts to
exhibit to those who will feel any interest in watching
his movements; and the moth that eats into our
clothes has something to plead for our pity, for he
came, like us, naked into the world, and he has de-
stroyed our garments, not in malice or wantonness,
but that he may clothe himself with the same wool
which we have stripped from the sheep. An obser-
vation of the habits of these little creatures is full of
valuable lessons, which the abundance of the examples
has no tendency to diminish. The more such observa-
tions are multiplied, the more are we led forward to the

INTRODUCTION. 3

freshest and the most delightful parts of knowledge ;
the more do we learn to estimate rightly the extraor-
dinary provisions and most abundant resources of a
creative Providence ; and the better do we appreciate
our own relations with all the infinite varieties of
Nature, and our dependence, in common with the
ephemeron that flutters its little hour in the summer
sun, upon that Being in whose scheme of existence
the humblest as well as the highest creature has its
destined purposes. ‘‘If you speak of a stone,” says
St. Basil, one of the Fathers of the Church, “if you
speak of a fly, a gnat, or a bee, your conversation
will be a sort of demonstration of His power whose
hand formed them; for the wisdom of the workman
is commonly perceived in that which is of little size.
He who has stretched out the heavens, and dug up
the bottom of the sea, is also He who has pierced a
passage through the sting of the bee for the ejection
of its poison.”

If it be granted that making discoveries is one of
the most satisfactory of human pleasures, then we may
without hesitation affirm, that the study of insects is
one of the most delightful branches of natural his-
tory, for it affords peculiar facilities for its pur-
suit, These facilities are found in the almost inex-
haustible variety which insects present to the entomo-
logical observer. As a proof of the extraordinary
number of insects within a limited field of observation,
Mr. Stephens informs us, that in the short space ot
forty days, between the middle of June and the be-
ginning of August, he found, in the vicinity of Ripley,
specimens of above two thousand four hundred species
of insects, exclusive of caterpillars and grubs,—a
number amounting to nearly a fourth of the insects
ascertained to be indigenous. He further tells us,
that among these specimens, although the ground
had, in former seasons, been frequently explored,

B2

4 INSECT ARCHITECTURE,

there were about one hundred species altogether new,
and not before in any collection which he had in-
spected, including several new genera; while many
insects reputed scarce were in considerable plenty*.
The localities of insects are, to a certain extent, con-
stintly changing; and thus the study of them has,
in this circumstance, as well as in their manifold
abundance, a source of perpetual variety. Insects,
also, which are plentiful one year, frequently become
scarce, or disappear altogether, the next—a fact
strikingly illustrated by the uncommon abundance,
in 1826 and 1827, of the seven-spot lady-bird (Coc-
cinella septempunctata), in the vicinity of London,
though during the two succeeding summers this
insect was comparatively scarce, while the small two-
spot lady-bird (Coccinella bipunctata) was plen-
tiful.

There is, perhaps, no situation in which the lover
of nature and the observer of animal life may not
find opportunities for increasing his store of facts. It
is told of a state prisoner under a crnel and rigorous
despotism, that when he was excluded from all com-
merce with mankind, and was shut out from books,
he took an interest and found consolation in the visits
of a spider; and there is no improbability in the
story. The operations of that persecuted creature
are among the most extraordinary exhibitions of
mechanical ingenuity ; and a daily watching of the
workings of its instinct would beget admiration in
a rightly constituted mind, ‘The poor prisoner had
abundant leisure for the speculations in which the
spider’s web would enchain his understanding. We
have all of us, at one period or other of our lives, been
struck with some singular evidence of contrivance in
the economy of insects, which we have seen with our

* Stephens’s Illustrations, vol. i., p. 72, note.

INTRODUCTION, 5

own eyes. Want of leisure, and probably want of
knowledge, have prevented us from following up the
curiosity which for a moment was excited. And yet
some such accident has made men Naturalists, in the
highest meaning of the term. Bonnet, evidently
speaking of himself, says, “T knew a Naturalist,
who, when he was seventeen years of age, having
heard of the operations of the ant-lion, began by
doubting them. He had no rest till he had examined
into them; and he verified them, he admired them,
he discovered new facts, and soon became the disciple
and the friend of the Pliny of France*” (Réaumur).
It is not the happy fortune of many to be able to de-
vote themselves exclusively to the study of nature,
unqnestionably the most fascinating of human em-
ployments ; but almost every one may acquire suffi-
cient knowledge to be able to derive a high grati-
fication from beholding the more common operations
of animal life. His materials for contemplation are
always before him, Some weeks ago we made an
excursion to West Wood, near Shooter's Hill, ex-
pressly for the purpose of observing the insects we
might meet with in the wood; but we had not got far
among the bushes, when heavy rain came on, We
immediately sought shelter among the boughs of
some thick underwood, composed of oak, birch, and
aspen; but we could not meet with a single insect,
not even a gnat or a fly, slieltered under the leaves,
Upon looking more narrowly, however, into the
bushes which protected us, we soon found a variety
of interesting objects of study. The oak abounded
in galls, several of them quite new to us; while the
leaves of the birch and the aspen exhibited the
curious serpentine paths of the minute mining cater-
pillars. When we had exhausted the narrow field of

* Contemplation de la Nature, part ii, chap, 42,

6 INSECT ARCHITECTURE,

observation immediately around us, we found that
we could considerably extend it, by breaking a few of
the taller branches near us, and then examining their
leaves at leisure. In this manner two hours glided
quickly and pleasantly away, by which time the *rain
had nearly ceased; and though we had been dis-
appointed in our wish to ramble through: the wood,
we did not return without adding a few interesting
facts to our previous knowledge of insect economy*.
It will appear then, from the preceding observations,
that cabinets and collections, though undoubtedly of
the highest use, are by no means indispensable, as
the observer of nature may find inexhaustible sub-
jects of study in every garden and in every hedge.
Nature has been profuse enough in affording us
materials for observation, when we are prepared to
look about us with that keenness of inquiry, which
curiosity, the first step in the pursuit of knowledge,
will unquestionably give. Nor shall we be dis-
appointed in the gratification which is thus within
our reach, Were it no more indeed than a source
of agreeable amusement, the study of insects comes
strongly recommended to the notice of the well-
educated. The pleasures of childhood are generally
supposed to be more exquisite, and to contain less
alloy, than those of riper years; and if so, it must
be because then every thing appears new and dressed
in fresh beauties: while in manhood, and old age,
whatever has frequently recurred begins to wear the
tarnish of decay. The study of nature affords us a
succession of “ever new delights,” such as charmed ~
us in childhood, when every thing had the attractions
of novelty and beauty; and thus the mind of the
naturalist may have its own fresh and vigorous

* The original observations in this volume which are marked
by the initials J. R., are by J. Rennie, A.M., A.L.S., Lee, Kent,

INTRODUCTION, 7

thoughts, even while the infirmities of age weigh
down the body.

It has been objected to the study of insects, as
well as to that of Natural History in general,
that it tends to withdraw the mind from subjects
of higher moment; that it cramps and narrows
the range of thought; and that it destroys, or
at least weakens, the finer creations of: the fancy.
Now, we should allow this objection in its fullest
extent, and even be disposed to carry it further
than is usually done, if the collecting of specimens
only, or, as the French expressively call them, chips
(échantillons), be called astudy. But the mere col-
lector is not, and cannot be, justly considered as a
naturalist ; and, taking the term naturalist in its en-
larged sense, we can adduce some distinguished in-
stances in opposition to the objection. Rousseau, for
example, was passionately fond of the Linnzan botany,
even to the driest minutie of its technicalities ; and
yet it does not appear to have cramped his mind, or
impoverished his imagination. If Rousseau, how-
ever, be objected to as an eccentric being, from
whose pursuits no fair inference can be drawn, we
give the illustrious example of Charles James Fox,
and may add the names of our, distinguished poets,
Goldsmith, Thomson, Gray, and Darwin, who were
all enthusiastic naturalists. We wish particularly to
insist upon the example of Gray, because he was
very partial to the study of insects. It may be new
to many of our readers, who are familiar with the
Elegy in a Country Church-yard, to be told that
its author was at the pains to turn the characteris-
ties of the Linnean orders of insects into Latin
hexameters, the manuscript of which is still preserved
in his interleaved copy of the “Systema Nature.”
Further, to use the somewhat exaggerated words
of Kirby and Spence, whose work on Entomology
is one of the most instructive and pleasing books on

8 INSECT ARCHITECTURE.

the science, “ Aristotle among the Greeks, and Pliny
the Elder among the Romans, may be denominated
the fathers of Natural History, as well as the greatest
philosophers of their day ; yet both these made
insects a principal object of their attention : and in
more recent times, if we look abroad, what names
greater than those of Redi, Malpighi, Vallisnieri,
Swammerdam, Leeuwenhoek, Réaumur, Linneus,
De Geer, Bonnet, and the Hubers? and at home,
what philosophers have done more honour to their
country and to human nature than Ray, Willughby,
Lister, and Derham? Yet all these made the study
of insects one of their most favourite pursuits *.”
And yet this study has been considered, by
those who have superficially examined the subject,
as belonging to a small order of minds; and the
satire of Pope has been indiscrimiuately applied
to all collectors, while, in truth, it only touches
those who mistake the means of knowledge for
the end :—
«©! would the sons of men once think their eyes

And reason given them but to study Flies!

See Nature in some partial, narrow shape,

And let the Anthor of the whole escape ;

Learn but to trifle ; or, who most observe,

To wonder at their Maker, not to serve f.”
Thus exclaims the Goddess of Dulness, sweeping
into her net all those who study nature in detail.
But if the matter were rightly appreciated, it would
be evident that no part of the works of the Creator
can be without the deepest interest to an inquiring
mind; and that a portion of creation, which exhibits
such extraordinary manifestations of design as is
shewn by insects, must have attractions for the very
highest understanding.

An accurate knowledge of the properties of insects

* Introduction to Entomology, vol. i.
+ Duneiad, book iv,

INTRODUCTION, 9

is of great importance to man, merely with relation to
his own comfort and security. The injuries which they
inflict upon us are extensive and complicated ; and the
remedies which we attempt, by the destruction of
those creatures, both insects, birds, and quadrupeds,
who keep the ravagers in check, are generally ag-
gravations of the evil, because they are directed by
an ignorance of the economy of nature. The little
knowledge which we have of the modes by which
insects may be impeded in their destruction of much
that is valuable to us, has probably proceeded from
our contempt of their individual insignificance. ‘The
security of property has ceased to be endangered by
quadrupeds of prey, and yet our gardens are ravaged
by aphides and caterpillars. It is somewhat startling
to affirm that the condition of the human race is
seriously injured by these petty annoyances; but it
is perfectly true that the art and industry of man have
not yet been able to overcome the collective force,
the individual perseverance, and the complicated
machinery of destruction which insects employ. A
small ant, according to a most careful and philo-
sophical observer, opposes almost invincible obstacles
to the progress of civilization in many parts of the
equinoctial zone. ‘These animals devour paper and
parchment; they destroy every book and manu-
script. Many provinces of Spanish America can-
not, in consequence, shew a written document of a
hundred years’ existence. ‘ What development,” he
adds, ‘‘can the civilization of a people assume, if
there be nothing to connect the present with the
past—if the depositories of human kuowledge must
be constantly renewed—if the monuments of genius
and wisdom cannot be transmitted to posterity *?”
Again, there are beetles which deposit their larve

* Humboldt, Voyage, lib. vii, ch. 20.
BS

19 INSECT ARCHITECTURE.

in trees, iu such formidable numbers, that whole
forests perish, beyond the power of remedy. The
pines of the Hartz have thus been destroyed to an
enormous extent; and in North America, at one
place in South Carolina, at least ninety trees in
every hundred, upon a tract of two thousand acres,
were swept away by asmall, black, winged bug. And
yet, according to Wilson, the historian of American
birds, the people of the United States were in the habit
of destroying the red-headed woodpecker, the great
enemy of these insects, because he occasionally spoilt
anapple*. The same delightful writer, and true natu-
ralist, speaking of the labours of the ivory-billed wood-
pecker, says, “would it be believed that the larve of
an insect, or fly, no larger than a grain of rice, should
silently, and in one season, destroy some thousand
acres of pine trees, many of them from two to three
feet in diameter, and a hundred and fifty feet high ?
In some places the whole woods, as far as you can
see around you, are dead, stripped of the bark, their
wintry-looking arms and bare trunks bleaching in
the sun, and tumbling in ruins before every blast +.”
The subterraneous larva of a species of beetle (Zabrus
gibbus) has often caused a complete failure of the
seed-corn, as in the district of Halle in 1812}. The
corn-weevil, which extracts the flour from grain,
leaving the husk behind, will destroy the contents of
the largest storehouses in a very short period. ‘The
wire-worm and the turnip-fly are dreaded by every
farmer. The ravages of the locust are too well known
not to be at once recollected, as an example of the
formidable collective power of the insect race. The
white ants of tropical countries sweep away whole
villages, with as much certainty as a fire or an inun-
dation; and ships even have been destroyed by these

* Amer. Ornith, i., p. 144. + Ib,, iii, p. 21. — ¢ Blumenbach,

INTRODUCTION, ll

indefatigable republics. Our own docks and em-
bankments have been threatened by such minute
ravagers,

The enormous injuries which insects cause to man
may thus be held as one reason for ceasing to consider
the study of them as an insignificant pursuit ; for
a knowledge of their structure, their food, their
enemies, and their general habits, may lead, as it
often has led, to the means of guarding against their
injuries. At the same time we derive from them
both direct and indirect benefits. The honey of thebee,
the dye of the cochineal, and the web of the silk-worm,
the advantages of which are obyious, may well be
balanced against the destruetive propensities of in-
sects which are offensive to man. But a philosophi-
cal study of natural history will teach us, that the
direct benefits which insects confer upon us are even
less important than their general uses in maintaining
the economy of the world. The mischiefs which
result to us from the rapid inerease and the activity
of insects, are merely results of the very principle by
which they confer upon us numberless indirect ad-
vantages. Forests are swept away by minute flies ;
but the same agencies relieve us from that extreme
abundance of vegetable matter, which would render
the earth uninhabitable, were this excess not periodi-
cally destroyed. In hot countries, the great business
of removing corrupt animal matter, which the vulture
and the hyena imperfectly perform, is effected with
certainty and speed by the myriads of insects that
spring from the eggs deposited in every carcass, by
some fly seeking therein the means of life for her
progeny. Destruction and reproduction, the great
laws of Nature, are carried on very greatly through
the instrumentality of insects; and the same princi-
ple regulates even the increase of particular species

2 INSECT ARCHITECTURE,

of insects themselves. When aphides are so abun

dant that we know not how to escape their ravages,
flocks of lady-birds instantly cover our fields and
gardens to destroy them, Such considerations as
these are thrown out to shew that the subject of
insects has a great philosophical importance-—and
what portion of the works of Nature has not?
The habits of all God's creatures, whether they are
noxious, or harmless, or beneficial, are worthy
objects of our study. If they affect ourselves, in
our health or our possessions, whether for good or
for evil, an additional impulse is naturally given to
our desire to attain a knowledge of their properties.
Such studies form one of the most interesting occu-
pations which can engage a rational and inquisitive
mind; and, perhaps, none of the employments of
human life are more dignified than the investigation
and survey of the workings and the ways of Nature
in the minutest of her productions.

The exercise of that habit of observation which
can alone make a naturalist—* an out-of-door natu-
ralist,” as Daines Barrington called himself—is well
calculated to strengthen even the most practical and
merely useful powers of the mind. One of the most
valuable mental acquirements is the power of discri-
minating among things which differ in many minute
points, but whose general similarity of appearance
usually deceives the common observer into a belief of
their identity. Entomology, in this point of view, is
a study peculiarly adapted for youth. According to
our experience, itis exceedingly difficult for persons
arrived at manhood to acquire this power of discri-
mination ; but in early life, a little care on the part of
the parent or teacher will render it comparatively easy.
In this study the knowledge of things should go
along with that of words. “If names perish,” says

INTRODUCTION, 13

Linneus, ‘‘the knowledge of things perishes also *;”
and without names, how can any one communicate
to another the knowledge he has acquired relative to
any particular fact, either of physiology, habit, utility,
or locality? On the other hand, mere catalogue
learning is as much to be rejected as the loose
generalizations of the despisers of classification and
nomenclature. ‘To name a plant, or an insect, or a
bird, or a quadruped rightly, is one step towards an
accurate knowledge of it; butit is not the knowledge
itself. It is the means, and not the end, in natural
history, as in every other science.

If the bias of opening curiosity be properly di-
rected, there is not any branch of natural history so
fascinating to youth as the study of insects. It is,
indeed, a common practice in many families, to
teach children, from the earliest infancy, to treat the
greater number of insects as if they were venomous
and dangerous, and, of course, meriting to be de-
stroyed, or, at least, avoided with horror. Associa-
tions are by this means linked with the very ap-
pearance of insects, which become gradually more
inveterate with advancing years; provided, as most
frequently happens, the same system be persisted in,
of avoiding or destroying almost every insect which
is unlucky enough to attract observation. How much
rational amusement and innocent pleasure is thus
thoughtlessly lost ; and how many disagreeable feel-
ings are thus created, in the most absurd manner !
“In order to shew,” says a writer in the Magazine
of Natural History, ‘that the study, or (if the word
be disliked) the observation of insects is peculiarly
fascinating to children, even in their early infancy,
we may refer to what we have seen in the family of a
friend, who is partial to this, as well as to all the

* Nomina si pereant, perit et cognitio rerum.

14 INSECT ARCHITECTURE,

departments of natural history. Our friend’s children,
a boy and a girl, were taught, from the moment they
could distinguish insects, to treat them as objects of
interest and curiosity, and not to be afraid even of
those which wore the most repulsive appearance.
The little girl, for example, when just beginning to
walk alone, encountered one day a large staphylinus
(Goérius olens? SrePuENS; vulgo, the devil's coach-
horse), which she fearlessly seized, and did not quit
her hold, though the insect grasped one of her fingers
in his formidable jaws. ‘The mother, who was by,
knew enough of the insect to be rather alarmed for
the consequences, though she prudently concealed
her feelings from the child, She did well; for the
insect was not strong enough to break the skin, and
the child took no notice of its attempts to bite her
finger. A whole series of disagreeable associations
with this formidable-looking family of insects was
thus ayerted, at the very moment when a different
mode of acting on the part of the mother would have
produced the contrary effect. For more than two
years after this occurrence, the little girl and her
brother assisted in adding numerous specimens to
their father’s collection, without the parents ever
having had cause, from any accident, to repent of
their employing themselves in this manner. The
sequel of the little girl’s history strikingly illustrates
the position for which we contend. The child hap-
pened to be sent to a relative in the country, where
she was not long in having carefully instilled into
her mind all the usual antipathies against ‘every-
thing that creepeth on the earth; and though she
afterwards returned to her paternal home, no persua-
sion nor remonstrance could ever again persuade her
to touch a common beetle, much less a staphylinus,
with its tail turned up in a threatening attitude, and its
formidable jaws ready extended for attack or defence.”

INTRODUCTION, 16

We do not wish that children should be encouraged
.o expose themselves to danger, in their encounters
with insects. ‘They should be taught to avoid those
few which are really noxious—to admire all—to
injure none.

The various beauty of insects—their glittering
colours, theic graceful forms—supplies an inexhaus-
tible source of attraction. Even the most formidable
insects, both in appearance and reality,—the dragon-
fly, which is perfectly harmless to man, and the wasp,
whose sting every human being almost instinctively
shuns,—are splendid in their appearance, and are
painted with all the brilliancy of natural hues. It
has been remarked, that the plumage of tropical
birds is not superior in vivid colouring to what may
be observed in the greater number of butterflies and
moths*, ‘See!’ exclaims Linneus, ‘the large,
elegant painted wings of the butterfly, four in num:
ber, covered with delicate feathery scales! With these
it sustains itself in the air a whole day, rivalling the
flight of birds and the brillianey of the peacock.
Consider this insect through the wonderful progress
of its life,—how different is the first period of its
being from the second, and both from the parent
insect! Its changes are an inexplicable enigma to
us: we see a green caterpillar, furnished with sixteen
feet, feeding upon the leaves of a plant; this is
changed into a chrysalis, smooth, of golden lustre,
hanging suspended to a fixed point, without feet, and
subsisting without food ; this insect again undergoes
another transformation, acquires wing's, and six feet,
and becomes a gay butterfly, sporting in the air, and
living by suction upon the honey of plants. What
has Nature produced more worthy of our admiration
than such an animal coming upon the stage of the

* Miss Jermyn’s Butterfly Collector, p. 11

16 INSECT ARCHITECTURE,

world, and playing its part there under so many dif-
ferent masks?” The ancients were so struck with
the transformations of the butterfly, and its revival
from a seeming temporary death, as to have consi-
dered it an emblem of the soul, the Greek word
wuxn signifying both the soul and a butterfly ; and
it is for this reason that we find the butterfly intro-
duced into their allegorical sculptures as an emblem
of immortality. Trifling, therefore, and perhaps con-
lemptible, as to the unthinking may seem the study
of a butterfly, yet when we consider the art and me-
thanism displayed in so minute a structure,—the
fluids circulating in vessels so small as almost to
escape the sight—the beauty of the wings and
covering—and the manner in which each part is
adapted for its peculiar functions,—we cannot but
be struck with wonder and admiration, and allow,
with Paley, that ‘the production of beauty was as
much in the Creator’s mind in painting a butterfly
as in giving symimetry to the human form.”

A collection of insects is to the true naturalist what
a collection of medals is to the accurate student of
history. The mere collector, who looks only to the
shining wings of the one, or the green rust of the
other, derives little kuowledge from his pursuit. But
the cabinet of the entomologist becomes rich in the
most interesting subjects of contemplation, when
he regards it in the genuine spirit of scientific
inquiry. What, for instance, can be so delightful
as to examine the wonderful variety of structure in
this portion of the creation; and, above all, to trace
the beautiful gradations by which one species runs
into another. Their differences are so minute, that an
unpractised eye would proclaim their identity; and
yet, when the species are separated, and not very
distantly, they become visible even to the ‘common |
observer. It is in examinations such as these that

INTRODUCTION. 17

the naturalist finds a delight of the highest order,
While it is thus one of the legitimate objects of his
study to attend to minute differences of structure,
form, and colouring, he is not less interested in the in-
vestigation of habits and economy ; and in this respect
the insect world is inexhaustibly rich, We find herein
examples of instinct to parallel those of all the larger
animals, whether they are solitary or social; and
innumerable others besides, altogether unlike those
manifested in the superior departments of animated
nature, ‘These instincts have various directions, and
are developed in a more or less striking manner to
our senses, according to the force of the motive by
which they are governed, Some of their instincts
have for their object the preservation of insects from
external attack; some have reference to procuring
food, and involve many remarkable stratagems ;
some direct their social economy, and regulate the
condition under which they live together either in
monarchies or republics, their colonizations, and their
migrations. but the most powerful instinct which
belongs to insects has regard to the preservation of
their species. We find, accordingly, that as the ne-
cessity for this preservation is of the utmost importance
in the economy of nature, so for this especial object
many insects, whose offspring, whether in the egg or
the larva state, are peculiarly exposed to danger,
are endued with an almost miraculous foresight, and
with an ingenuity, perseverance, and unconquerable
industry, for the purpose of avoiding those dangers,
which are not to be paralleled even by the most singu-
lar efforts of human contrivance. The same ingenuity
which is employed for protecting either eggs, or ca-
terpillars and grubs, or pupa and chrysalides, is also
exercised by many insects for their own preservation
against the changes of temperature to which they are
exposed, or against their natural enemies. Many

18 INSECT ARCHITECTURE.

species employ those contrivances during the period
of their hybernation, or winter-sleep. For all these
purposes some dig holes in the earth, and form them
into cells ; others build nests of extraneous substances,
such as bits of wood and leaves ; others roll up leaves
into cases, which they close with the most curious
art; others build a house of mud, and line it with
the cotton of trees, or the petals of the most delicate
flowers; others construct cells, of secretions from
their own bodies; others form cocoons, in which
they undergo their transformation; and others dig
subterraneous galleries, which, in complexity of ar-
rangement, in solidity, and in complete adaptation to
their purposes, vie with the cities of civilized man.
The contrivances by which insects effect these ob-
jects have been accurately observed and minutely de-
scribed, by patient and philosophical inquirers, who
knew that such employments of the instinct with
which each species is endowed by its Creator offered
the most valuable and instructive lessons, and opened
to them a wide field of the most delightful study.
The construction of their habitations is certainly
among the most remarkable peculiarities in the
economy of insects ; and it is of this subject that we
propose to treat under the general name, which is
sufficiently applicable to our purpose, of Insect
ARCHITECTURE.

INTRODUCTION. 1s

In the descriptions which we shall give of Insect
Architecture, we shall employ as few technical words
as possible; and such as we cannot well avoid, we
shall explain in their places: but, since our object
chiefly relates to the reproduction of insects, it may
be useful to many readers to introduce here a brief
description of the changes which they undergo.

It was of old believed that insects were produced
spontaneously by putrefying substances; and Virgil
gives the details of a process for creating a swarm
of bees out of the carcass of a bull: but Redi, a cele-
brated Italian naturalist, proved by rigid experiments
that they are always, in such cases, hatched from eggs
previously laid. Most insects, indeed, lay eggs, though
some few are viviparous, and some, like serpents,
propagate both ways. The eggs of insects are very
various in form, and seldom shaped like those of
birds. We have here figured those of several species,
as they appear under the microscope.

Eggs of Insects. —Magnified.

20 INSECT ARCHITECTURE,

When an insect first issues from the egg, it is called
by naturalists larva, and, popularly, a caterpillar, a
grub, ora maggot. The distinction, in popular lan=
guage, seems to be, that caterpillars ave produced
from the eggs of moths or butterflies; grubs, from
the ege's of beetles, bees, wasps, &c.; and maggots
(which are without feet), from blow-flies, house-flies,
cheese-flies, &c., though this is not very rigidly ad-
hered to in common parlance. Maggots are also
sometimes called worms, as in the instance of the
meal-worm; but the common earth-worm is not a
larva, nor is it by modern naturalists ranked among
insects.

Larve are remarkably small at first, but grow
rapidly. The full-grown caterpillar of the goat-moth
(Cossus ligniperda) is thus seventy-two thousand
times heavier than when it issues from the egg; and

Larva, Grubs, Caterpillars, or Maggots.

INTRODUCTION ; 21

the maggot of the blow-fly is, in twenty-four hours,
one hundred and fifty-five times heavier than at its
birth. Some larve have feet, others are without :
none have wings. They cannot propagate. They
feed voraciously on coarse substances; and as they
increase in size, which they do very rapidly, they cast
their skins three or four times. In defending them-
selves from injury, and in preparing for their change
by the construction of secure abodes, they manifest
great ingenuity and mechanical skill. The figures
on the preceding page, exemplify various forms of
insects in this stage of their existence.

When larve are full grown, they cast their skins
for the last time, undergo a complete change of form,
and, with a few exceptions, cease to eat, and remain
nearly motionless. When an insect, afier this change,
does not lose its legs, or continues to eat and move,
it is popularly called a Nymph; and when the inner
skin of the larva is converted into a membranous or
leathery covering, which wraps the insect closely up
like a mummy, it is termed Pupa, from its resem-

Pupa, or Chrysatides,

blance to an infant in swaddling bands. From the
pupa of many of the butterflies appearing gilt as if

22 INSECT ARCHITECTURE,

with gold, the Greeks called them Chrysalides, and
the Romans Aurelie, and hence naturalists frequently
call a pupa, chrysalis, even when it is not gilt. We
shall see, as we proceed, the curious contrivances re-
sorted to for protecting insects in this helpless state.

After a certain time. the insect which has re-
mained in its pupa-case, like a mass of jelly without
shape, is gradually preparing for its final change,
when it takes the form of a perfect insect. This
state was called by Linneus, Imago, because the
insect, having thrown off its mask, becomes a per-
fect image of its species. Of some, this last por-
tion of their existence is very short, others live

Insects in the Imago or perfect state.

INTRODUCTION, 23

through a year, and some exist for longer periods.
They feed lightly, and never increase in size. ‘The
chief object of all is to perpetuate their species, after
which the greater number quickly die. It is in this
state that they exercise those remarkable instincts for
the preservation of their race, which are exhibited in
their preparations for the shelter of their eggs, and
the nourishment of their larve. The foregoing are
examples of insects in the imago, or perfect state.

24

Cnarrer If,

STRUCTURES FOR PROTECTING EGGS.—MASON-WASPS 5
MASON-BEES ; MINING-BEES.

Tur provisions which are made by the different
species of insects for protecting their eggs, appear in
many cases to be admirably proportioned to the kind
of danger and destruction to which they may be ex-
posed. Theeggs themselves, indeed, are not so liable
to depredation and injury as the young brood hatched
from them ; for, like the seeds of plants, they are ca-
pable of withstanding greater degrees both of heat and
cold than the insects which produce them. According
to the experiments of Spallanzani, the eggs of frogs
that had been exposed to various degrees of artificial
heat, were scarcely altered in their productive powers
by a temperature of 111° of Fahrenheit, but they
became corrupted after 133°. He tried the same ex-
periment upon tadpoles and frogs, and found they
all died at 111°. Silk-worms died at a temperature
of 108°, while their eggs did not entirely cease to be
fertile till 144°. The larve of flesh-flies perished,
while the eggs of the same species continued fertile,
at about the same comparative degrees of heat as in
the preceding instances. Intense cold has a still less
effect upon eggs than extreme heat. Spallanzani ex-
posed the eggs of silk-worms to an artificial cold 23°
below zero, and yet, in the subsequent spring, they
all produced caterpillars. Insects almost inyariably
die at the temperature of 14°, that is at 18° below the
freezing point®. The care of insects for the pro-

* See Spallanzani’s Tracts, by Malyell, vol. i.

MASON-WASPS, 2

tection of their eggs is not entirely directed to their
‘preservation in the most favourable temperature for
being hatched, but to secure them against the nume-
rous enemies which would attempt their destruction,
and, above all, to protect the grubs, when they are:
first developed, from those injuries to which they are
peculiarly exposed. ‘Their prospective contrivances
for accomplishing these objects are in the highest
degree curious.

Most persons have more or less acquaintance
with the hives of the social species of bees and
wasps: but little is generally known of the nests
constructed by the solitary species, though in many
respects these are not inferior to the others in dis-
plays of ingenuity and skill. We admire the social
bees, labouring together for one common end, in the
same way that we look with delight upon the great
division of labour in a well-ordered manufactory.
As in a cotton-mill, some attend to the carding: of
the raw material, some to its formation into single
threads, some to the gathering these threads upon
spindles, others to the union of many threads into
one,—all labouring with invariable precision because
they attend to a single object ;—so do we view with
delight and wonder the successive steps by which
the hive-bees bring their beautiful work to its com-
pletion,—striving, by individual efforts, to accomplish
their general task, never impeding each other by use-
less assistance, each taking a particular department,
and each knowing its own duties. We may, how-
ever, not the less admire the solitary wasp or bee,
who begins and finishes every part of its destined
work; just as we admire the ingenious mechanic
who perfects something useful or ornamental entirely
by: the labour of his own hands,—whether he be the
patient Chinese carver, who cuts the most elaborately
decorated boxes out of a solid piece of ivory, or the

(

26 INSECT ARCHITECTURE,

turner of Europe, who produces every variety of
elegant form by the skilful application of the simplest
means.

Our island abounds with many varieties of solitary
wasps and bees; and their nests may therefore be
eusily discovered by those who, in the proper seasons,
are desirous of observing the peculiarities of their
architecture.

Mason- Wasps.

In September, 1828, a common species of solitary
mason-wasp (Odynerus, Larr.) was observed by us*

Odynerus.—Natural size,

on the east wall of a house at Lee, in Kent, very busy
in excavating a hole in one of the bricks, about five
feet from the ground. Whether there might not
have been an accidental hole in the brick, before
the wasp commenced her labours, is unknown, as
she had made considerable progress in the work
when first observed ; but the brick was one of the
hardest of the yellow sort made in this neighbourhood.
The most remarkable circumstance in the process of
hewing into the brick, was the care of the insect in
removing to a distance the fragments which from
time to time she succeeded in detaching. It did not
appear to suit her design to wear down the brick,
particle by particle, as the furniture-beetle (Anobium
pertinaz) does, in making its pin-hole galleries in
old wood. Our wasp-architect, on the contrary, by
means of her strong tranchant-toothed jaws, severed

*JR.

MASON-WASI’S, 27

Mandibles—Jaws of Mason-Wasp.—Greatly magnified.

a piece usually about the bigness of a mustard-seed.
It might have been supposed that these fragments
would have been tossed out of the hole as the
work proceeded, without further concern; as the
mole tosses above ground the earth which has been
cleared out of its subterranean gallery. The wasp
was of a different opinion; for it was possible that
a heap of brick chips, at the bottom of the wall,
might lead to the discovery of her nest by some of
her enemies, particularly by one or other of the
numerous tribe of what are called ichnewmon-flies.
This name is given to them, from the similarity of
*their habit of destroying eggs to that of the little
animal which proves so formidable an enemy to the
multiplication of the crocodile of Egypt. They may
be also denominated cuckoo-flies, because, like that
bird, they thrust their egg into the nest of another
species. These flies are continually prowling about
and prying into every corner, to find, by stealth, a
nidus for their eggs. It might have been some such
consideration as this which induced the wasp to carry
off the fragments as they were successively detached.
That concealment was the motive, indeed, was proved;
for one of the fragments which fell out of the hole by

28 INSECT ARCHITECTURE,

accident, she immediately sought for at the bottom of
the wall, and carried off like the rest. It was no easy
matter to get out one of the fragments, as may readily
be conceived, when the size of the insect is compared
with that of the entrance, of which this (@) is the
exact size, as taken from the impression of a bit of
dough upon the hole when finished. It was only by
seizing the fragment with her jaws, and retreating
backwards, that the matter could be accomplished,
though, after the interior of the excavation was barely
large enough to admit of her turning round, she more
than once attempted to make her exit head-foremost,
but always unsuccessfully. ‘The weight of the frag-
ments removed did not appear to impede her flight,
and she generally returned to her task in about two
or three minutes

Within two days the excavation was completed ;
but it required two other days to line it with a coating
of clay, to deposit the eggs, two in number, and, no
doubt, to imprison a few live spiders or caterpillars,
for the young when hatched,—a process which was
first observed by Ray and Willughby*, but which
has since been frequently ascertained, In the present
instance, this peculiarity was not seen ; but the little
architect was detected in closing up the entrance,
which was formed of a layer of clay more than
double the thickness of the interior lining. In No-
vember following, we hewed away the brick around
this nest, and found the whole excavation was rather
Jess than an inch in depth.

Notwithstanding all the precautions of the careful
parent to conceal her nest, it was found out by one of
the cuckoo-flies (Zachina larvarum?)—probably a
common species very similar to the house-fly, but

* Ray, Hist. Insect. 254,

MASON-WASPS, 29

Cuchoo-Fly—(Tachina larvarum?)—Natural size.

rather larger, which deposited an egg there; and the
grub hatched from it, after devouring one of the ‘wasp-
grubs, formed itself a cocoon (@), as did the other

Mason-Wasp’s Nest and Cocoons,—About one-third the natural size.

undevoured grub of the wasp (6). Both awaited
the return of summer to change into winged insects,
burst their cerements, and proceed as their parents
did.

Mason-Wasp—(Odynerus murarius.)—Natural size.

Another mason-wasp (Odynerus murarius, Latr.),
differing little in appearance from the former, may
often be seen frequenting sandy banks exposed to
the sun, and constructing its singular burrows.

c3

$0 INSECT ARCHITECTURE,

The sort of sand-bank which it selects is hard and
compact; and though this may be more difficult to
penetrate, the walls are not liable to fall down upon
the little miner. In such a bank, the mason-wasp
bores a tubular gallery two or three inches deep.
The sand upon which Réaumur found some of these
wasps at work was almost as hard as stone, and
yielded with difficulty to his nail; but the wasps dug
into it with ease, having recourse, as he ascertained,
to the ingenious device of moistening it by letting
fall two or three drops of fluid from their mouth,
which rendered the mass ductile, and the separation
of the grains easy to the double pickaxe of the little
ploneers.

When this wasp has detached a few grains of the
moistened sand, it kneads them together into a
pellet about the size of one of the seeds of a goose-
berry. With the first pellet which it detaches, it
lays the foundation of a round tower, as an out-
work, immediately over the mouth of its nest.
Every pellet which it afterwards carries off from
the interior is added to the wall of this outer round
tower, which advances in height as the hole in the
sand increases in depth. Every two or three minutes,
however, during these operations, it takes a short
excursion, for the purpose, probably, of replenishing
its store of fluid wherewith to moisten the sand.
Yet so little time is lost, that Réaumur has seen a
mason-wasp dig in an hour a hole the length of its
body, and at the same time build as much of its
round tower. For the greater part of its height this
round tower is perpendicular; but towards the sum-
mit it bends into a curve, corresponding to the bend
of the insect’s body, which, in all cases of insect
architecture, is the model followed. The pelleis
which form the walls of the tower are not very
nicely joined, and numerous vacuities are left be-

MASON-WASPS, 31

Nests, &c. of Mason-Vasps.—About half the nataral size—
a The tower of the nest. b The entrance after the tower is re-
moved. c The cell, d The cel, with a roll of caterpillars pre-
pared for the larva,

tween them, giving it the appearance of fillagree

work. That it should be thus slightly built is not

surprising, for it is intended as a temporary structure
for protecting the insect while it is excavating its
hole; and as a pile of materials, well arranged and
ready at hand, for the completion of the interior
building,—in the same way that workmen make a
regular pile of bricks near the spot where they are
going to build. This seems, in fact, to be the main
design of the tower, which is taken down as expedi-
tiously as it had been reared. Reéaumur thinks, that
by piling in the sand which has previously been dug
out, the wasp intends to guard its progeny for a time
from being exposed to the too violent heat of the
sun; and he has even sometimes seen that there were
not sufficient materials in the tower, in which case
the wasp had recourse to the rubbish she had thrown

32 INSECT ARCHITECTURE,

out after the tower was completed. By raising a
tower of the materials which she excavates, the wasp
produces the same shelter from external heat, as a
hnman creature would who chose to inhabit a deep
cellar of a high house. She further protects her
progeny from the ichneumon-fly, as the engineer con-
structs an outwork to render more difficult the ap~
proach of an enemy to the citadel, Réaumur has
seen this indefatigable enemy of the wasp peep into
the mouth of the tower, and then retreat, apparently
frightened at the depth of the cell which he was
anxious to invade.

The mason-wasp does not furnish the cell she has
thus constructed with pollen* and honey, like the
solitary bees, but with living caterpillars, and these
always of the same species,—being of a green colour,
and without feet. She fixes the caterpillars together
in a spiral column: they cannot alter their position,
although they remain alive. They are an easy prey
to their smaller enemy ; and when the grub has eaten
them all up, it spins a case, and is transformed into
a nymph, which afterwards becomes a wasp, The
number of caterpillars which is thus found in the
lower cavity of the mason-wasp’s nest is ordinarily
from ten to twelve. The mother is careful to lay in
the exact quantity of provision which is necessary to
the growth of the grub before he quits his retreat.
He works through his store till his increase in this
state is perfected, and he is on the point of under-
going a change into another state, in which he re-
quires no food. The careful purveyor, cruel indeed
in her choice of a supply, but not the less directed
by an unerring instinct, selects such caterpillars as
she is conscious have completed their growth, and
will remain thus imprisoned without increase or cor-

* The prolific powder o fflowers.

MASON-BEES, 33

ruption till their destroyer has gradually satisfied the
necessities of his being. ‘* All that the worm of the
wasp,” says Réaumur, “ has to do in his nest, from
his birth to his transformation, is to eat.” There is
another species of wasp which does not at once en-
close in its nest all the sustenance which its larva
will require before transformation, but which, from
time to time, imprisons a living caterpillar, and when
that is consumed opens the nest and introduces
another*,

Mason-Bees

It would not. be easy to find a more simple, and,
at the same time, ingenious specimen of insect archi-
tecture, than the nests of those species of solitary
bees which” have been justly called mason-bees
(Megachile, Larrerius.) Réaumur, who was struck
by the analogies between the proceedings of insects
and human arts, first gave to bees, wasps, and cater-
pillars those names which indicate the character
of their labours; and which, though they may he
considered a little fanciful, are at least calculated te
arrest the attention. The nests of mason-bees are
constructed of various materials; some with sand,
some with earth mixed with chalk, and some with a
mixture of earthy substances and wood

On the north-east wall of Greenwich Park, facing
the road, and about four feet from the ground, we
discoveredt, December 10th, 1828, the nest of a
mason-bee, formed in the perpendicular line of
cement between two bricks. Externally there was
an irregular cake of dry mud, precisely as if a hand-
ful of wet road-stuff had been taken from a cart-rut
and thrown against the wall; though, upon closer
inspection, the cake contained more small stones

* Bonnet, Contemplation, &c,, |. xii, c. 41. + JR.

34 INSECT ARCHITECTURG,

Mason. Bee—(Anthophora retusa),—Natural size.

than usually occur in the mud of the adjicent cart-
ruts. We should, in fact, have passed it by without
notice, had there not been a circular hole on one side
of it, indicating the perforation of some insect. This

Exterior wall of Mason-Bee's nest.

hole was found to be the orifice of a cell about an inch
deep, exactly of the form and size of a lady’s thimble,
finely polished, and of the colour of plaster of Paris,
but stained in various places with yellow.

This cell was empty ; but upon removing the cake
of mud, we discovered another cell, separated from
the former by a partition about a quarter of an inch
thick, and init a living bee, from which the preceding
figure was drawn, and which, as we supposed, had
just changed from the pupa into the winged state,
in consequence of the uncommon mildness of the
weather. The one which had occupied the adjacent cell

MASON-BEES, 35

had, no doubt, already dug its way out of its prison,

and would probably fall a victim to the first frost.
Our nest contained only two cells—perhaps from

there not being room between the bricks for more.

Cells of a Masun-Bee (Anthophora retusa),—One-third the natural size.

An interesting accountis given by Réaumur of ano-
ther mason-bee (Megachile muraria), selecting earthy
sand, grain by grain; her gluing a mass of these toge-
ther with saliva, and building with them her cells from
the foundation. But the cells of the Greenwich Park
nest were apparently composed of the mortar of the
brick wall; though the external covering seems to
have been constructed as Réaumur describes his
nest, with the occasional addition of small stones.

About the middle of May, 1829, we discovered the
mine from which all the various species of mason-bees
in the vicinity seemed to derive materials for their
nests*. It was.a bank of brown clay, facing the east,
and close by the margin of the river Ravensbourn, at
Lee, in Kent. The frequent resort of the bees to this
spot attracted the attention of some workmen, who,
deceived by their resemblance to wasps, pointed it
out as a wasp’s nest; though they were not a little
surprised to see so numerous a colony at this early
season, As the bees had dug a hole in the bank,

* JR,

36 INSECT ARCHITECTURE,

where they were incessantly entering and re-appear-
ing, we were of opinion that they were a peculiar
sort of the social earth bees (Bombus). On ap-
proaching the spot, however, we remarked that the
bees were not alarmed, and manifested none of the
irritation usual in such cases, the consequence of
jealous affection for their young. ‘This led us to ob-
serve their operations more minutely; and we soon
discovered that on issuing from the hole each bee
carried out in its mandibles a piece of clay. Still
supposing that they were social earth bees, we con-
cluded that they were busy excavating a hollow for
their nest, and carrying off the refuse to prevent dis-
covery. The mouth of the hole was overhung, and
partly concealed, by a large pebble. ‘This we removed,
and widened the entrance of the hole, intending to dig
down and ascertain the state of the operations; but
we soon found that it was of smalldepth. The bees,
being scared away, began scooping out clay from
another hole about a yard distant from the first.
Upon our withdrawing a few feet from the first hole,
they returned thither in preference, and continued as-
siduously digging and removing the clay. It became
obvious, therefore, from their thus changing place,
that they were not constructing a nest, but merely
quarrying for clayasa building material. By catching
one of the bees (Osmia bicornis) when it was loaded
with its burden, we ascertained that the clay was not
only carefully kneaded, but was also more moist than
the mass from which it had been taken. The bee, ©
therefore, in preparing the pellet, which was nearly
as large as a garden pea, had moistened it with its
saliva, or some similar fluid, to render it, we may
suppose, more tenacious, and better fitted for build-
ing. ‘The reason of their digging a hole, instead of
taking clay indiscriminately from the bank, appeared
to be for the purpose of economizing their saliva, as

MASON-BEES, 37

the weather was dry, and the clay at the surface was
parched and hard. It must have been this circum -
stance which induced them to prefer digging a hole.
as it were, in concert, though each of them had to
build a separate nest.

The distance to which they carried the clay was
probably considerable, as there was no wall near, in
the direction they all flew towards, upon which they
could build; and in the same direction also, it is
worthy of remark, they could have procured much
nearer the very same sort of clay. Whatever
might be the cause of their preference, we could
not but admire their extraordinary industry. It
did not require more than half a minute to knead
one of the pellets of clay ; and from their frequent
returns, probably not more than five minutes to
carry it to the nest, and apply it, where wanted.
From the dryness of the weather, indeed, it was in-
dispensable for them to work rapidly, otherwise the
clay could not have been made to hold together.
The extent of the whole labour of ferming a single
nest may be imagined, if we estimate that if must
take several hundred pellets of clay for its completion.
If a bee work fourteen or fifteen hours a day, there-*
fore, carrying ten or twelve pellets to its nest every
hour, it wil] be able to finish the structure in about
two or three days ; allowing some hours of extra time
for the more nice workmanship of the cells in which
the eggs are to be deposited, and the young grubs
reared.

That the construction of such a nest is not a
merely agreeable exercise to the mason-bee has been
sufficiently proved by M. Du Hamel. He has ob-
served a bee (Megachile muraria) less careful to
perform the necessary labour for the protection of
her offspring than those we have described ; but, not
less desirous of obtaining this protection, attempt to

D

38 INSECT ARCHITECTURE,

usurp the nest which another had formed. A fierce
battle was invariably the consequence of this attempt ;
for the true mistress would never give place to the
intruder. The motive for the injustice and the re-
sistance was an indisposition to further labour. The
trial of strength was probably, sometimes, of as little
use in establishing the right as it is amongst man-
kind; and the proper owner, exhausted by her
efforts, had doubtless often to surrender to the dis-
honest usurper.

The account which Réaumur has given of the opera-
tions of this class of bees differs considerably from
that which we have here detailed; from the species
being different, or from his bees not having been able
to procure moist clay. On the contrary, sand was
the chief material used by his mason-bees (Megachile
muraria) ; which they had the patience to select from
the walks of a garden, and knead into a paste or
mortar, adapted to their building. They had con-
sequently to expend a much greater quantity of
saliva, than our bees (Osmia bicornis) which worked
with moist clay. Réaumur, indeed, ascertained that
every individual grain of sand is moistened previous
to its being joined to the pellet, in order to make
it adhere more effectually. The tenacity of the
mass is besides rendered stronger, he tells us, by
adding a proportion of earth or garden mould. In
this manner, a ball of mortar is formed, about the
size of a small shot, and carried off to the nest. When
the structure of this is examined, it has all the appear-
ance externally of being composed of earth and small
stones or gravel. The ancients, who were by no means
accurate naturalists, having observed bees carrying
pellets of earth and small stones, supposed that they
employed these to add to their weight, in order to
steady their flight when impeded by the wind.

The nests thus constructed appear to have been

MASON-BEES, 39

more durable edifices than those which have fallen
under our observation;—for Réaumur says they
were harder than many sorts of stone, and could
scarcely be penetrated with a knife. Ours, on the
contrary, do not seem harder than a piece of sun-
baked clay, and by no means so hard as brick. One
circumstance appeared inexplicable to Réaumur and
his friend Du Hamel, who studied the operations of
these insects in concert. After taking a portion of
sand from one part of the garden-walk, the bees
usually took another portion from a spot almost twenty
and sometimes a hundred paces off, though the sand,
so far as could be judged by close examination, was
precisely the same in the two places. We should be
disposed to refer this more to the restless character
of the insect, than to any difference in the sand.
We have observed a wasp paring the outside of a
plank, for materials ty form its nest; and though the
plank was as uniform in the qualities of its surface,
nay, probably more so than the sand could be, the
wasp fidgeted about, nibbling a fibre from one, and
a fibre from another portion, till enough was procured
for one load. In the same way, the whole tribe of
wasps and bees flit restlessly from flower to flower,
not unfrequently revisiting the same blossom, again
and again, within a few seconds. It appears to us,
indeed, to be far from improbable, that this very rest-
lessness and irritability. may be one of the springs
of their unceasing industry.

By observing, with some care, the bees which we
found digging the clay, we discovered one of them
(Osmia bicornis) at work upon a nest, about a gun-
shot from the bank. The place it had chosen was
the inner wall of a coal-house, facing the south-west,
the brick-work of which was but roughly finished,
In an upright interstice of half an inch in width, be-
tween two of the bricks, we found the little architect

D2

40 INSECT ARCHITECTURE,

assiduously building its walls. The bricklayer’s
mortar had either partly fallen out, or been removed
by the bee, who had commenced building at the
lower end, and did not build downwards, as the
social-wasps construct their cells.

The very different behaviour of the insect here, and
at the quarry, struck us as not a little remarkable.
When digging and preparing the clay, our approach,
however near, produced no alarm; the work went
ou as if we had been at a distance; and though
we were standing close to the hole, this did not scare
away any of the bees upon their arrival to procure a
fresh load. But if we stood near the nest, or even in
the way by which the bee flew to it, she turned back
or made a wide circuit immediately, as if afraid to
betray the site of her domicile. We even observed
her turning back, when we were so distant that it
could not reasonably be supposed she was jealous of
us; but probably she had detected some prowling
insect-depredator, tracking her flight with designs
upon her provision for her future progeny. We
imagined we could perceive not a little art in her
jealous caution, for she would alight on the tiles as
if to rest herself ; and even when she had entered the
coal-house, she did not go directly to her nest, but
again rested on a shelf, and at other times pre-
tended to examine several crevices in the wall, at
some distance from the nest. But when there was
nothing to alarm her, she flew directly to the spot,
and began eagerly to add to the building.

It is in instances such as these, which exhibit the
adaptation of instinct to circumstances, that our
reason finds the greatest difficulty in explaining the
governing’ principle of the minds of the inferior ani-
mals, The mason-bee makes her nest by an inva-
riable rule; the model is in her mind, as it has been
in the mind of her race from their first creation ; they

MASON-BEES, 4}

have learnt nothing by experience. But the mode in
which they accomplish this task varies according to
the situations in which they are placed. They appear
to have a glimmering of reason, employed as an
accessary and instrument of their instinct.

The structure, when finished, consisted of a wall of
clay supported by two contiguous bricks, enclosing
six chambers, within which a mass of pollen, rather
larger than a cherry-stone, was deposited, together
with an egg, from which in due time a grub was
hatched. Contrary to what has been recorded by pre-
ceding naturalists, with respect to other mason-bees,
we found the cells in this instance quite parallel and
perpendicular; but it may also be remarked, that the

Cells of Mason-Bees, bnilt, in the firat and second figures, by
Osmia bicornis between bricks, and in the third, by Megachile
muraria in the fluting ofan old pilaster; about half the natural
size,

bee itself was a species altogether different from the
one whicli we have described above as the Antho-
phora retusa, and agreed with the figure of the one
we caught quarrying the clay—(Osmia bicornis).
There was one circumstance attending the pro-
ceedings of this mason-bee which struck us not a
little, though we could not explain it to our own

42 INSECT ARCHITECTURE,

satisfaction. Every time she left her nest for the pur-
pose of procuring a fresh supply of materials, she
paid a regular visit to the blossoms of a lilac tree
which grew near. Had these blossoms afforded a
supply of pollen, with which she could have reple-
nished her cells, we could have easily understood her
design; but the pollen of the lilac is not suitable for
this purpose, and that she had never used it was
proved by all the pollen in the cells being yellow,
whereas that of the lilac is of the same pale, purple
colour as the flowers. Besides, she did not return
immediately from the lilac tree to the building, but
always went for a load of clay. There seemed to us,
therefore, to be only two ways to explain the cireum-
stance:—she must either have applied to the lilac
blossoms to obtain a refreshment of honey, or to pro-
cure glutinous materials to mix with the clay.

When employed upon the building itself, tne bee
exhibited the restless disposition peculiar to most
hymenopterous* insects; for she did not go on with
one particular portion of her wall, but ran about from
place to place every timeshe came to work. At first,
when we saw her running from the bottom to the
top of her building, we naturally imagined that she
went up for some of the bricklayer’s mortar to mix
with her own materials ; but upon minutely examining
the walls afterwards, no lime could be discovered in
their structure, similar to that which was apparent in
the nest found in the wall of Greenwich Park.

Réaumur mentions another sort of mason-bee,
which selects a small cavity in a stone, in which she
forms her nest of garden mould moistened with glu-
ten, and afterwards closes the hole with the same
material,

* The fifth order of Linneus; insects with four transparent
veined wings,

43

Mason-Bee and Nest—From Réaumur.

Minina-BeeEs.

A very small sort of bees (Andrene), many of
them not larger than a house-fly, dig in the ground
tubular galleries little wider than the diameter of
their own bodies. Samouelle says, that all of them
seem to prefer a southern aspect; but we have found
them in banks facing the east, and even the north.
Immediately above the spot where we have described
the mason-bees quarrying the clay, we observed
several holes, about the diameter of the stalk of a
tobacco-pipe, into which those little bees were seen
passing. The clay here was very hard; and on
passing a straw into the hole asa director, and digging
down for six or eight inches, a very smooth circular
gallery was found, terminating in a thimble-shaped
horizontal chamber, almost at right angles to the
entrance, and nearly twice as wide. In this chamber

are
. ANS ANY
NUN ARRA

\

Coll of Mining-Bee (Andrena),.—About half the natural size.

44 INSECT ARCHITECTURE

there was a ball of bright yellow pollen, as round as
a garden pea, and rather larger, upon which a small
white grub was feeding ; and to which the mother
bee had been adding, as she had just entered a minute
before with her thighs loaded with pollen. That it
was not the male, the load of pollen determined; for
the male has no apparatus for collecting or trans-
porting it. The whole labour of digging the nest
and providing food for the young is performed by
the female. ‘The females of the solitary bees have
no assistance in their tasks. The males are idle; and
the females are unprovided with labourers, such as
the queens of the hive command.

Rédaumur mentions that the bees of this sort, whose
operations he had observed, piled up at the entrance
of their galleries the earth which they had scooped
out from theinterior, and when the grub was hatched,
and properly provided with food, the earth was again
employed to close up the passage, in order to prevent
the intrusion of ants, ichneumon flies, or other de-
predators. In those which we have observed, this
was not the case; but every species differs from
another in some little peculiarity, though they agree
in the general principles of their operations.

45

Cuaprter III.

DARPENTER-BEES } CARPENTER-WASPS 5 UPHOLSTERER*
BEES.

CarPENTER-BEES.

Amona the solitary bees are several British species
which come under that class called carpenter-bees by
M. Réaumur, from the circumstance of their working
in wood, as the mason-bees work in stone. We have
frequently witnessed the operations of these inge-
nious little workers, who are particularly partial to
posts, palings, and the wood-work of houses which has
become soft by beginning to decay. Wood actually
decayed, or affected by dry-rot, they seem to reject
as unfit for their purposes ; but they make no objec-
tions to any hole previously drilled, provided it be
‘not too large; and, like the mason-bees, they not
unfrequently take possession of an old nest, a few
repairs being all that in this case is necessary.

When a new nest is to be constructed, the bee
proceeds to chisel sufficient space for it out of the
wood with her jaws. We say her, because the task
in this instance, as in most others of solitary bees
and wasps, devolves solely upon the female, the male
taking no concern in the affair, and probably being
altogether ignorant that such a work is going forward.
It is, at least, certain that the male is never seen giv-
ing his assistance, and he seldom, if ever, approaches
the neighbourhood, ‘The female carpenter-bee has a
task to perform no less arduous than the mason-bee 5
for though the wood may he tolerably soft, she can

nN)

46 INSECT ARCHITECTURE.

only cut outa very small portion ata time, The suc-
cessive portions which she gnaws off may be readily
ascertained by an observer, as she carries them away
from the place. In giving the history of a mason-
wasp (Odynerus), at page 25, we remarked the
care with which she carried to a distance little frag~
ments of brick, which she detached in the progress of
excavation. We have recently watched a precisely
similar procedure in the instance of a carpenter-bee
forming a cell in a wooden post*. The only difference
was, that the bee did not fly so far away with her frag-
ments of wood as the wasp did; but she varied the
direction of her flight every time: and we could ob-
serve, that after dropping the chip of wood which she
had carried off, she did not return in a direct line to
her nest, but made a circuit of some extent before
wheeling round to go back.

On observing the proceedings of this carpenter-bee
next day, we found her coming in with balls of pollen
on her thighs; and on tracing her from the nest into
the adjacent garden, we saw her visiting every flower
which was likely to yield her a supply of pollen for
her future progeny. This was not all: we subse-
quently saw her taking the direction of the clay-
quarry frequented by the mason-bees, as we have
mentioned in page 35, where we recognized her
loading herself with a pellet of clay, and carrying it
into her cell in the wooden post. We observed her
alternating this labour for several days, at one time
carrying clay, and at another pollen; till at length
she completed her task and closed the entrance with
a barricado of clay, to preyent the intrusion of any
insectivorous depredator, who might make prey of
her young; or of some prying parasite, who might
introduce its own eggs into the nest she had taken
so much trouble to construct.

*J.R,

CARPENTER-BEES, 47

Cells of Carpenter-Bees, ewcavated in anold post.—In fig. a tne
cells contain the yonng grubs; in fig. B the cells are empty, Both
figures are shewn in section, and about half the natural size.

Some days after it was finished, we cut into the
post, and exposed this nest to view. It consisted of
six cells of a somewhat square shape, the wood
forming the lateral walls; and each was separated
from the one adjacent by a partition of clay, of the
thickness of a playing card. ‘The wood was not
lined with any extraneous substance, but was worked
as smooth as if it had been chiselled by a joiner.
There were five cells, arranged in a very singular
manner—two being almost horizontal, two perpendi-
cular, and one oblique.

The depth to which the wood was excavated, in
this instance, was considerably less than what we
have observed in other species which dig perpendi-
cular galleries several inches deep in posts and gar
den-seats ; and they are inferior in ingenuity to the
carpentry of a bee described by Réaumur (Xylocopa
violacea), which has not been ascertained to be a
native of Britain, though a single indigenous species
of the genus has been doubtingly mentioned, and is

48 INSECT ARCHITECTURE,

figured, by Kirby, in his valuable ‘Monographia.’ If
it ever be found here, its large size and beautiful
violet-coloured wings will render mistakes impos-
sible.

The violet carpenter-bee usually selects an up-
right piece of wood, into which she bores obliquely
for about an inch; and then, changing the direction,
works perpendicularly, and parallel to the sides of
the wood, for twelve or fifteen inches, and half an
inch in breadth. Sometimes the bee is contented
with one or two of these excavations; at other times,
when the wood is adapted to it, she scoops out three
or four—a task which sometimes requires several
weeks of incessant labour.

The tunnel in the wood, however, is only one part
of the work ; for the little architect has afterwaids
to divide the whole into cells, somewhat less than an
inch in depth. It is necessary, for the proper growth
of her progeny, that each should be separated from
the other, and be provided with adequate food. She
knows, most exactly, the quantity of food which each
grub will require, during its growth; and she there-
fore does not hesitate to cut it off from any additional
supply. In constructing her cells, she does not employ
clay, like the bee which we have mentioned above,
but the sawdust, if we may call it so, which she has
collected in gnawing out the gallery. It would not,
therefore, have suited her design to scatter this about,
as our carpenter-bee did. ‘The violet bee, on the
contrary, collects her gnawings into a little store-heap
for future use, at a short distance from her nest. She
proceeds thus:—At the bottom of her excavation she
deposits an egg, and over it fills a space nearly an
inch high with the pollen of flowers, made into a paste
with honey. She then covers this over with a ceiling”
composed of cemented sawdust, which also serves
for the floor of the next chamber above it. For this

CARPENTER-BEES, 49

eS

Ni

lt

|
at i A;

i i}

A, represents a part of an espalier prop, tunnelled in several
places by the violet carpenter-bee: the stick is split, and shews the
nests and passages by which they are approached. B, a portion
ot the prop, half the natural size, C, a piece of thin stick, pierced
by the carpenter-bee, and split, to shew the nests. D, Perspee-
live view of one of the partitions. E, Carpenter-bee (Xylocopa
violacra). ¥, Teeth of the carpenter-bee, greatly magnified : a, the
upper side; b, lower side,

purpose, she cements round a wall a ring of wood
chips, taken from her store-heap ; and within this ring
forms another, gradually contracting the diameter till
she has constructed a circular plate, about the thick-
ness of a crown-piece, and of considerable hardness

50 INSECT ARCHITECTURE,

This plate of course exhibits concentric circles, some-
what similar to the annual circles in the cross section
ofa tree. In the same manner she proceeds till she
has completed ten or twelve cells ; and then she closes
the main entrance with a barrier of similar materials.

Let us compare the progress of this little joiner with
a human artisan—one who has been Iong practised in
his trade, and has the most perfect and complicated
tools for his assistance. ‘The bee has learnt nothing
by practice; she makes her nest but once in her life,
but it is then as complete and finished as if she had
made a thousand. She has no pattern before her—
but the Architect of all things has impressed a plan
upon her mind, which she can realize without scale
or compasses. Her two sharp teeth are the only
tools with which she is provided for her laborious
work; and yet she bores a tunnel, twelve times the
length of her own body, with greater ease than the
workman who bores into the earth for water, with
his apparatus of augers adapted to every soil. Her
tunnel is clean and regular; she leaves no chips at
the bottom, for she is provident of her materials.
Further, she has an exquisite piece of joinery to per-
form, when her ruder labour is accomplished. ‘The
patient bee works her rings from the circumference
to the centre, and she produces a shelf, united with
such care with her natural glue, that a number of
fragments are as solid as one piece.

The violet carpenter-bee, as may be expected, oc-
eupies several weeks in these complicated labours ;
and during that period she is gradually depositing
her eggs, each of which is successively to become
a grub, a pupa, and aperfect bee. It is obvious,
therefore, as she does not lay all her eggs in the
same place—as each is separated from the other by
a laborious process—that the egg which is first laid
will be the earliest hatched ; and that the first perfect

CARPENTER-BEES, 51

insect being older than its fellows in the same tun-
nel, will strive to make its escape soener, and so on
of the rest. The careful mother provides for this
contingency. She makes a lateral opening at the
bottom of the cells; for the teeth of the young bees
would not be strong enough to pierce the outer wood,
though they can remove the cemented rings of saw-
dust in the interior. Réaumur observed these holes,
in several cases; and he further noticed another ex-
ternal opening opposite to the middle cell, which he
supposed was formed, in the first instance, to shorten
the distance for the removal of the fragments of wood
in the lower half of the building.

That bees of similar habits, if not the same spe-
cies as the violet bee, are indigenous to this country,
is proved by Grew, who mentions, in his ‘ Rarities
of Gresham College,’ having found a series of such
cells in the middle of the pith of an old elder branch,
in which they were placed lengthwise, one after an-
other, with a thin boundary between each. As he
does not, however, tell us that he was acquainted
with the insect which constructed these, it might
as probably be allied to the Ceratina albilabris, of
which Spinola has given so interesting an account
in the ‘Annales du Muséum d’Histoire Naturelle’
(x. 236). This noble and learned naturalist tells
us, that one evening he perceived a female ceratina
alight on the branch of a bramble, partly withered,
and of which the extremity had been broken; and,
after resting a moment, suddenly disappear. On
detaching the branch, he found that it was perfo-
rated, and that the insect was in the very act of exca-
vating a nidus for her eggs. He forthwith gathered
a bundle of branches, both of the bramble and the
wild-rose, similarly perforated, and took them home
to examine them at leisure. Upon inspection, he

\2 INSECT ARCHITECTURE,

found that the nests were furnished, like those of the
same tribe, with balls of pollen kneaded with honey,
as a provision for the grubs.

The female ceratina selects a branch of the bramble
or wild-rose which has been accidentally broken, and
digs into the pith only, leaving the wood and bark
untouched. Her mandibles, indeed, are not adapted
for guawing wood ; and, accordingly, he found in-
stances in which she could not finish a nest in
branches of the wild-rose, where the pith was not of
sufficient diameter.

The insect usually makes her perforation a foot in
depth, and divides this into eight, nine, or even
twelve cells, each about five lines long, and sepa-
rated by partitions formed of the gnawingss of the
pith, cemented by honey, or some similar glutinous
fluid, much in the same manner with the wylocopa
violacea, which we have already described.

Canpenter-Waspes.

As there are mason-wasps similar in economy to
mason-bees, so are there solitary carpenter-wasps
which dig galleries in timber, and partition them out
into several cells by means of the gnawings of the
wood which they have detached. ‘This sort of
wasp is of the genus Eumenes. ‘The wood se-
lected is generally such as is soft, or in a state of
decay; and the hole which is dug in it is much less
neat and regular than that of the carpenter-bees,
while the division of the chambers is nothing more
than the rubbish produced during the excavation.

The provision which is made for the grub consists
of flies or gnats piled into the chamber, but without
the nice order remarkable in the spiral columns of
green caterpillars provided by the mason-wasp
(Odynerus murarius). The most remarkable cir-
cumstance is, that in some of the species, when the

CARPENTER-WASPS, 53

AB represent sections of old wonden posts, with the cells of
the carpenter-wasp. In fig. A the young grubs are shewn feeding
on the insects placed there for their support by the parent wasp.
The cells in fig. B contain cocoons. C, carpenter-wasp, natural
size. D, cocoon of a carpenter-wasp, composed of sawdust and
wings of insects,

grub is about to go into the pupa state, it spins a
case (a cocoon), into which it interweaves the wings
of the flies whose bodies it has previously devoured.
In other species, the gnawings of the wood are em-
ployed in a similar manner.

Urnoltsterer-Bers.

In another part of this volume we shall see how
certain caterpillars construct abodes for themselves,
by cutting off portions of the leaves or bark of
plants, and uniting them by means of silk into a
uniform and compact texture; but this scarcely ap-
pears so wonderful as the prospective labours of
some species of bees for the lodgment of their pro-
geny. We allude to the solitary bees, known by the
name of the leaf-cutting bees, but which may be de-
nominated more generally wpholsterer-bees, as there
are some of them which use other materials beside
leaves.

ee

54 INSECT ARCHITECTURE,

One species of our little upholsterers has been
called the poppy-bee (Osmia papaveris, Latr.),
from its selecting the scarlet petals of the poppy as
tapestry for its cells. Kirby and Spence express
their doubts whether it is indigenous to this coun-
try: we are almost certain that we have seen the
nests in Scotland*. At Largs, in Ayrshire, a beau-
tiful sea-bathing village on the Firth of Clyde, in
July, 1814, we found in a foot-path a great num-
ber of the cylindrical perforations of the poppy-bee.
Réaumur remarked that the cells of this bee which
he found at Bercy, were situated in a northern ex-
posure, contrary to what he had remarked in the
mason-bee, which prefers the south. The cells at
Largs, however, were on an elevated bank, facing
the south, near Sir ‘Thomas Brisbane’s observatory.
With respect to exposure, indeed, no certain rule
seems applicable; for the nests of mason-bees which
we found on the wall of Greenwich Park faced the
north-east, and we have often found carpenter-bees
make choice of a similar situation. In one instance,
we found carpenter-bees working indifferently on the
north-east and south-west side of the same post.

As we did not perceive any heaps of earth near
the holes at Largs, we concluded that it must either
have been carried off piecemeal when they were
dug, or that they were old holes re-occupied—(a
circumstance common with bees), and that the rub-
bish had been trodden down by passengers. Réau-
mur, who so minutely describes the subsequent ope~
rations of the bee, says nothing respecting its exca
vations. One of these holes is about three inches
deep, gradually widening asit descends, till it assumes
the form of a small Florence flask. The interior of
this is rendered smooth, uniform, and polished, in

wks

UPHOLSTERER-BEES. 55

order to adapt it to the tapestry with which it is in-
tended to be hung, and which is the next step in the
process.

The material used for tapestry by the insect uphol-
sterer is supplied by the petals * of the scarlet field-
poppy, from which she successively cuts off small
pieces of an oval shape, seizes them between her legs,
and conveys them to the nest. She begins her work
at the bottom, which she overlays with three or four
leaves in thickness, and the sides have never less than
two. When she finds that the piece she has brought
is too large to fit the place intended, she cuts off what
is superfluous, and carries away the shreds. By cut-
ting the fresh petal of a poppy with a pair of scissors,
we may perceive the difficulty of keeping the piece
free from wrinkles and shrivelling ; but the bee knows
how to spread the pieces which she uses as smooth as

lass.

i When she has in this manner hung the little cham-
ber all round with this splendid scarlet tapestry, of
which she is not sparing, but extends it even be-
yond the entrance, she then fills it with the pollen
of flowers mixed with honey, to the height of about
half an inch, In this magazine of provisions for her
future progeny she lays an egg, and over it folds
down the tapestry of poppy petals from above. The
upper part is then filled in with earth; but Latreille
says, he has observed more than one cell constructed
ina single excavation. This may account for Réau-
mur’s describing them as sometimes seven inches
deep ; a circumstance which Latreille, however, thinks
very surprising.

it will, perhaps, be impossible ever to ascertain
beyond a doubt, whether the tapestry-bee is led to

* Petal is the term employed by botanists to denote the leaf
or division of the coloured portion of a flower.

56 INSECT ARCHITECTURE.

select the brilliant petals of the poppy from their co-
Jour, or from any other quality they may possess,
of softness or of warmth, for instance. Réaumur
thinks that the largeness, united with the flexibility
of the poppy-leaves, determines her choice. Yet it
is not improbable that her eye may be gratified by
the appearance of her nest;—that she may possess
a feeling of the beautiful in colour, and may look
with complacency upon the delicate hangings of the
apartment which she destines for her offspring.
Why should not an insect be supposed to have a
glimmering of the value of ornament? How can we
pronounce, from our limited notion of the mode in
which the inferior animals think and act, that their
gratifications are wholly bounded by the positive
utility of the objects which surround them? Why
does a dog howl at the sound of a bugle, but because
it offends his organs of hearing?—and why, there-
fore, may not a bee feel gladness in the brilliant hues
of her scarlet drapery, because they are grateful to
her organs of sight? All these little creatures work,
probably, with more neatness and finish than is
absolutely essential for comfort; and this circum-
stance alone would imply that they have something
of taste to exhibit, which produces to them a plea-
surable emotion.

The tapestry-bee is, however, content with orna-
menting the interior only of the nest which she forms
for her progeny. She does not misplace her embel-
lishments with the error of some human artists. She
desires security as well as elegance; and, therefore,
she leaves no external traces of her operations, Her’s
is not a mansion rich with columns and friezes with-
out, but cold and unfurnished within, like the deso-
late palaces of Venice. She covers her tapestry
quite round with the common earth; and leaves her
eggs enclosed in their poppy-case with a certainty

UPHOLSTERER-BEES, 5?

that the outward show of her labours will attract no
plunderer.
The poppy-bee may be known by its being rather
_ more than the third of an inch long, of a black colour,
studded on the head and back with reddish grey
hairs; the belly being grey and silky, and the rings
margined with grey above, the second and third
having an impressed transversal line.

A species of solitary bee (Anthidium manicatum,
Fasricius), by no means uncommon with us, forms
anest of a peculiarly interesting structure. Kirby and
Spence say, that it does not excavate holes, but makes
choice of the cavities of old trees, key-holes, and
similar localities ; yet itis highly prebable, we think,
that it may sometimes scoop out a suitable cavity
when it cannot find one; for its mandibles seem
equally capable of this, with those of any of the car-
penter or mason bees.

Be this as it may, the bee in question having
selected a place suitably sheltered from the weather,
and from the intrusion of depredators, proceeds to
form hey uest, the exterior walls of which she forms
of the wool of pubescent plants, such as rose-cam-
pion (Lychnis coronaria), the quince (Pyrus cydo-
nia), cats-ears (Stachys lanata), &c, “It is very
pleasant,” says Mr. White of Selborne, “ to see with
what address this insect strips off the down, running
from the top to the bottom of the branch, and shaving
it bare with all the dexterity of a hoop shaver... When
it has got a vast bundle, almost as large as itself, it
flies away, holding it secure between its chin and its
fore-leg's *.”’

The manner in which the cells of the nest are

* Naturalists’ Calendar, p. 109.

58 INSECT ARCHITECTU

made seems not to be very clearly understood. M

Latreille says, that after constructing her nest of the
down of quince leaves, she deposits her eggs, together
with a store of paste, formed of the pollen of flowers
for nourishing the grubs. Kirby and Spence, on the
other hand, tell us, that “the parent bee, after
having constructed her cells, laid an egg in each, and
filled them with a store of suitable food, plasters
them with a covering of vermiform masses, appa-
rently composed of honey and pollen; and having
done this, aware, long before Count Rumford's expe-
riments, what materials conduct heat most slowly,”
she collects the down from woolly plants, and “ sticks
it upon the plaster that covers her cells, and thus
closely envelops them with a warm coating of down,
impervious to every change of temperature.” “From
later observations,” however, they are “ inclined to
think that these cells may possibly, as in the case of
the humble-bee, be in fact formed by the larva pre-
viously to becoming a pupa, after having eaten the
provision of pollen and honey with which the parent
bee had surrounded it. The vermicular shape, how-
ever, of the masses with which the cases are sur-
rounded, does not seem easily reconcileable with this
supposition, unless they are considered as the exere=
ment of the larva *,”

Whether or not this second explanation is the true
one, we have not the means of ascertaining; but we
are almost certain the first is incorrect, as it is con-
trary to the regular procedure of insects, to begin
with the interior part of any structure, and work out-
wards. We should imagine, then, that the down is
first spread out into the form required, and afterwards
plastered on the inside to keep it in form, when pro-

* introduction to Entomology, vol, i., p. 435, 5th edit.

UPHOLSTERER-BEES. 59

bably the grub spins the vermicular cells previous to
its metamorphosis,

It might prove interesting to investigate this more
minutely; and as the bee is by no means scarce in
the neighbourhood of London, it might not be difficult
for a careful observer to witness all the details of this
singular architecture. The bee may be readily known
from its congeners, by its being about the size of the
hive-bee, but more broad and flattened, blackish
brown above, with a row of six yellow or white
spots along each side of the rings, very like the rose-
leaf cutter, and having the belly covered with yel-
lowish brown hair, and the legs fringed with long
hairs of a rather lighter colour.

A common bee belonging to the family of uphol-
sterers is called the rose-leaf cutter (Megachile cen-
tuncularis, Lavr.). The singularly ingenious habits
of this bee have long attracted the attention of na-
turalists, but the most interesting description is given
by Réaumur, So extraordinary does the construction
of their nests appear, that a French gardener having
dug up some, and believing them to be the work of
a magician, who had placed them in his garden with
evil intent, sent them to Paris to his master, for ad-
vice as to what should be done by way of exorcism.
On applying to the Abbé Nollet, the owner of the
garden was soon persuaded that the nests in question
were the work of insects; and M. Réaumur, to
whom they were subsequently sent, found them to
be the nests of one of the upholsterer-bees, and pro-
bably of the rose-leaf cutter, though the nests in
question were made of the leaves of the mountain-
ash (Pyrus aucuparia).

The rose-leaf cutter makes a cylindrical hole in a
beaten pathway, for the sake of more consolidated
earth (or in the cavities of walls or decayed: wood),

60 INSECT ARCHITECTURE,

from six to ten inches deep, and does not throw the
earth dug out from it into a heap, like the an-
drene *. In this she constructs several cells about
an inch in length, shaped like a thimble, and made
of cuttings of leaves (not petals), neatly folded to-
gether, the bottom of one thimble-shaped cell being
inserted into the mouth of the one below it, and so on
in succession.

It is interesting to observe the manner in which
this bee procures the materials for forming the ta-
pestry of her cells. The leaf of the rose-tree seems
to be that which she prefers, though she sometimes
takes other sorts of leaves, particularly those with ser-
rated margins, such as the birch, the perennial mer-
cury (Mercurialis perennis), mountain-ash, &c. She
places herself upon the outer edge of the leaf which
she has selected, so that its margin may pass between
her legs. ‘Turning her head towards the point, she
commences near the footstalk, and with her mandi-
bles cuts out a circular piece with as much expedi-
tion as we could do with a pair of scissors, and with
more accuracy and neatness than could easily be done
by us. As she proceeds, she keeps the cut portion
between her legs so as not to impede her progress ;
and using her body for a trammel, as a carpenter
would say, she cuts in a regular curved line. As she
supports herself during the operation upon the por-
tion of the leaf which she is detaching, it must be
obvious, when it is nearly cut off, that the weight of
her body might tear it away, so as to injure the accu-
racy of its curvilineal shape. To prevent any acci-
dent of this kind, as soon as she suspects that her
weight might tear it, she poises herself on her wings,
till she has completed the incision. It has been
said, by naturalists, that this manceuvre of. poising

* See p. 43.

ee ee eee

UPHOLSTERER-BEES. 61

herself on the wing, is to prevent her falling to the
ground, when the piece gives way ; but as no winged
insect requires to take any such precaution, our ex-
planation is probably the true one. :

Rose-leaf-cutter bees, and nest lined with rose-leaves:

With the piece which she has thus cut out, held in

a bent position, perpendicular to her body, she flies
off to her nest, and fits it into the interior with the ut-
most neatness and ingenuity ; and, without employing
any paste or glue, she trusts, as Réaumur ascertained,
to the spring the leaf takes, in trying to retain it inits
osition. It requires from nine to twelve pieces of
leaf to form one cell, as they are not always of pre-

62 INSECT ARCHITECTURE,

cisely the same thickness. The interior surface of
each cell consists of three pieces of leaf, of equal size,
narrow at one end, but gradually widening at the
other, where the width equals half ‘the length. One
side of each of the pieces is the serrated margin of
the leaf from which it was cut, and this margin is
always placed outermost, and the cut margin inner-
most. Like most insects, she builds from the inte-
rior, beginning with a layer of tapestry, which is
composed of three or four oval pieces, larger in
dimensions than the rest, adding a second and a
third layer proportionately smaller. In forming
these, she is careful not to place a joining opposite
to a joining, but, with all the skill of a consummate
artificer, lays the middle of each piece of leaf over the
margins of the others, so as by this means both to
cover and strengthen the junctions. By repeating
this process, she sometimes forms a fourth or fifth
layer of leaves, taking care to bend the leaves at the
narrow extremity or closed end of the cell, so as to
bring them into a convex shape.

When she has in this manner completed a cell, her
next business is to replenish it with a store of honey
and pollen, which, being chiefly collected from thistles,
forms a beautiful rose-coloured conserve, In this
she deposits a single egg, and then covers in the
opening with three pieces of leaf, so exactly circular,
that a pair of compasses could not define their mar-
gin with more accuracy. In this manner the indus-
trious and ingenious upholsterer proceeds till the
whole gallery is filled, the convex extremity of the
one fitting into the open end of the next, and serving
both as a basis and as the means of strengthening
it. If, by any accident, the labour of these insects is
interrupted or the edifice deranged, they exhibit
astonishing perseverance in setting it again to rights,

UPHOLSTE RER-BEES, 63

Insects, indeed, are not easily forced to abandon any
work which they may have begun.

The monkish legends tell us that St, Francis
Xavier, walking one day in a garden, and seeing an
insect, of the Mantis genus, moving along in its
solemn way, holding up its two fore-legs as in the
act of devotion, desired it to sing the praises of God.
The legend adds that the saint immediately heard
the insect carol a fine canticle with a loud emphasis.
We want no miraculous voice to record the wonders
of the Almighty hand, when we regard the insect
world. The little rose-leaf cutter, pursuing her work
with the nicest mathematical art—using no artificial
instruments to form her ovals and her circles—know-
ing that the elastic property of the leaves will retain
them in their position—making her nest of equal
strength throughout, by the most rational adjustment
of each distinct part—demands from us something
more than mere wonder; for such an exercise of
instinctive ingenuity at once directs our admiration
to the great Contriver, who has so admirably pro-
portioned her knowledge to her necessities.

64

CuapTer iV.
CARDER-BEES ; HUMBLE-BEES } SOCIAL-WABPS.

Tue bees and wasps, whose ingenious architecture
we have already examined, are solitary in their la-
bours. Those we are about to describe live in so-
ciety. The perfection of the social state among this
class of insects is certainly that of the hive-bees,
They are the inhabitants of a large city, where the
arts are carried to a higher excellence than in small
districts, enjoying little communication of intelli-
gence. But the bees of the villages, if we may follow
up the parallel, are not without their interest. Such
are those which are called carder-bees and humble-
bees.

Carver-BeeEs.

The nests of the bees which Réaumur denomi-
nates carders (Bombus muscorum, Lar.) are by no
means uncommon, and are well worth the study of
the naturalist. During the hay harvest, they are fre-
quently met with by mowers in the open fields and
meadows ; but they may sometimes be discovered in
hedge-banks, the borders of copses, or among moss-
grown stones, ‘The description of the mode of build-
ing adopted by this bee has been copied by most of our
writers on insects from Réaumur ; though he is not a
little severe on those who write, without having ever
had a single nest in their possession. We have been
able to avoid such areproach ; for we have now before

CARDER-BEES, 65

us a very complete nest of carder-bees, which differs
from those described by Réaumur, in being made, not
of moss, but withered grass. With this exception,
we find that his account agrees accurately with our
own observations*,

The carder-bees select for their nest a shallow ex-
cavation about half a foot in diameter; but when they
cannot find one to suit their purpose, they under-
take the Herculean task of digging one themselves.
They cover this hollow with a dome of moss—some-
times, as we have ascertained, of withered grass.
They make use, indeed, of whatever materials may be
within their reach ; for they do not attempt to bring
any thing froma distance, not even when they are
deprived of the greater portion by an experimental
naturalist. Their only method of transporting ma-
terials to the building is by pushing them along the
ground—the bee, for that purpose, working back-
wards, with its head turned from the nest. If there
is only one bee engaged in this labour, as usually
happens in the early spring, when a nest fs founded
by a solitary female who has outlived the winter, she
transports her little bundles of moss or grass by suc-
cessive backward pushes, till she gets them home.

In the latter part of the season, when the hive is
populous and can afford more hands, there is an in-
genious division of this labour. A file of bees, tothe
number sometimes of half a dozen, is established,
from the nest to the moss or grass which they intend
to use, the heads of all the file of bees being turned
from the nest and towards the material. The last
bee of the file lays hold of some of the moss with
her mandibles, disentangles it from the rest, and
having carded it with her fore-legs into a sort of felt
or small bundle, she pushes it under her body to the

¥ JiR,
E3

66 INSECT ARCHISECTURE,

next bee, who passes it in the same manner to the
next, and so on till it is brought to the border of the
uest,—in the same way as we sometimes see sugar-
loaves conveyed from a cart to a warehouse, by a file
of porters throwing them fiom one to another.

Fig. A represents two carder-bees heckling moss for their nests.
B, Exte: or view of the nest of the carder-bee.

The elevation cf the dome, which is all built from
the interior, is fiom four to six inches above the
level of the field. Beside the moss or grass, they
frequently employ coarse wax to form the ceiling of
the vault, for the purpose of keeping out rain, and

CARDER-BEES, 67

preventing high winds from destroying it. Before
this finishing is given to the nest, we have re-
marked, that on a fine sunshiny day, the upper
portion of the dome was opened to the extent of
more than an inch, in order, we suppose, to forward
the hatching of the eggs in the interior; but on the
approach of night this was carefully covered in again.
It was remarkable that the opening which we have
just mentioned was never used by the bees for either
their entrance or their exit from the nest, though
they were all at work there, and, of course, would
haye found it the readiest and easiest passage. But
they invariably made their exit and their entrance
through the covert-way or gallery which opens at
the bottom of the nest, and, in some nests, is about a
foot long and half an inch wide. This is, no doubt,
intended for concealment, from field-mice, polecats,
wasps, and other depredators.

On removing a portion of the dome and bringing
the interior of the structure into view, we find little
of the architectural regularity so conspicuous in the .
combs of a common bee-hive; instead of this sym-
metry, there are only a few eg@-shaped, dark-coloured
cells, placed somewhat irregularly, but approaching
more to the horizontal than to the vertical position,
and connected together with small amorphous *
columns of brown wax. Sometimes there are two or
three of these oval cells placed one above another,
without anything to unite them. :

These cells are not, however, the workmanship of
the old bees, but of their young grubs, who spin
them when they are about to change into nymphs.
But, from these cases, when they are spun, the en-
closed insects have no means of escaping, and they
depend for their liberation on the old bees gnawing

* Shape ess,

68 INSECT ARCHITECTURE.

off the covering, as is done also by ants in the same
circumstances. The instinet with which they know
the precise time when it is proper to do this is truly
wonderful. It is no less'so, that these cocoons are
by no means useless when thus untenanted, for they
subsequently serve for honey-pots, and are indeed
the only store-cells in the nest. For this purpose the
edge of the cell is repaired and strengthened with a
ting of wax.

Breeding-Cells.

The true breeding-cells are contained in several
amorphous masses of brown-coloured wax, varying
in dimensions, but of a somewhat flat and globular
shape. On opening any of these, a number of eggs
or grubs are found, on whose account the mother
bee has collected the masses of wax, which also: con-
tain a supply of pollen moistened with honey, for
their subsistence.

The number of eggs or grubs found in one sphe-
roid of wax varies from three to thirty, and the bees
in a whole nest seldom exceed sixty. ‘There are
three sizes of bees, of which the females are the
largest ; but neither these nor the males are, as in
the case of the hive-bee, exempt from labour. The
females, indeed, always found the nests, since they
alone survive the winter, all the rest perishing with
cold. In each nest, also, are several females, that
live in harmony together.

CARDER-BEES, 69

Interior views of Carder-Bee's Nest,

The carder-bees may be easily distinguished from
their congeners (of the same genus), by being not
unlike the colour of the withered moss with which
they build their nests, having the fore part of their
back a dull orange, and hinder part ringed with dif-
ferent shades of greyish yellow. They are not so
large as the common humble-bee (Bombus terrestris,
Larr.), but rather shorter and thicker in the body
than the common hive-bee (Apis mellifica).

70 INSECT ARCHITECTURE,

Lapipary-Bees.

A bee still more common, perhaps, than the carder,
is the orange-tailed bee, or lapidary (Bombus lapi-
daria), readily known by its general black colour and
reddish orange tail. It builds its nest sometimes in
stony ground, but prefers a heap of stones such as
are gathered off grass fields, or are piled up near
quarries. Unlike the carder, the lapidary carries to its
nest bits of moss, which are very neatly arranged into
a regular oval. These insects associate in their
labours ; and they make honey with great industry.
The individuals of a nest are more numerous than
the carders, and likewise more pertinaciously vin-
dictive. About two years ago, we discovered a nest
of these bees at Compton-Basset, in Wiltshire, in the
centre of a heap of limestone rubbish; but owing
to the brisk defensive warfare of their legionaries,
we could not obtain a view of the interior. It was
not even safe to approach within many yards of the
place, and we do not exaggerate when we say that
several of them pursued us most pertinacious!y about
a quarter of a mile*.

Humsue-BeEes.

The common humble-bee (Bombus terrestris) is
precisely similar in its economy to the two preceding
species, with this difference, that it forms its nest
underground like the common wasp, in an excavated
chamber, to which a winding passage leads, of from
one to two feet, and of diameter sufficient to allow
of two bees passing. ‘The cells have no covering
beside the vault of the excavation and patches of
coarse wax similar to that of the carder-bee.

*J.R.

SOCIAL-WASPS. 71

Socia-Wasps.

The nest of the common wasp (Vespa vulgaris)
attracts more or less the attention of everybody; but
its interior architecture is not so well known as it
deserves to be, for its singular ingenuity, in which it
rivals even that of the hive-bee (Apis mellifica).
In their general economy, the sociak or republican
wasps, closely resemble the humble-bee (Bombus),
every colony being founded by a single female who
has survived the winter, to the rigours of which all
her summer associates of males and working wasps
uniformly fall victims. Nay, out of three hundred
females which may be found in one vespiary, or
wasp’s nest, towards the close of autumn, scarcely ten
or a dozen survive till the ensuing spring, at which
season they awake from their hybernal lethargy, and
begin with ardour the labours of colonization.

It may be interesting to follow one of these mo-
ther wasps through her several operations, in which
she merits more the praise of industry than the queen
of a bee-hive, who does nothing, and never moves
without a numerous train of ‘obedient retainers, al-
ways ready to execute her commands and to do her
homage. The mother wasp, on the contrary, is at
first alone, and is obliged to perform every species
of drudgery herself.

Her first care, after being roused to activity by the
returning warmth of the season, is to discover a
place suitable for her intended colony; and, ac-
cordingly, in the spring, wasps may be seen prying
into every hole of a hedge-bank, particularly where
field-mice have burrowed. Some authors report
that she is partial to the forsaken galleries of the
mole, but this does not accord with our observations,
as we have never met wilh a single vespiary in any
situation likely to have been frequented by moles,

72 INSECT ARCHITECTURE,

But though we cannot assert the fact, we think it
highly probable that the deserted nest of the field-
mouse, which is not uncommon in hedge-banks, may
be sometimes appropriated by a mother wasp as an
excavation convenient for her purpose. Yet, if she
does make choice of the burrow of a field-mouse, it
requires to be afterwards considerably enlarged in
the interior chamber, and the entrance gallery very
much narrowed.

The desire of the wasp to save herself the labour
of excavation, by forming her nest where other ani-
mals have burrowed, is not without a parallel in the
actions of quadrupeds, and even of birds. In the
splendid continuation of Wilson’s American Orni-
thology, by Charles L. Bonaparte (whose scientific
pursuits have thrown round that name a beneficent
lustre, pleasingly contrasted with his uncle’s glory),
there is an interesting example of this instinctive
adoption of the labours of others. ‘In the Trans-
Mississippian territories of the United States, the
burrowing-owl resides exclusively in the villages
of the marmot, or prairie-dog, whose excavations
are so commodious, as to render it unnecessary
that the owl should dig for himself, as he is
said to do where no burrowing animals exist*.
The villages of the prairiedog are very nume-
rous and variable in their extent, — sometimes
covering only a few acres, and at others spreading
over the surface of the country for miles together.
They are composed of slightly-elevated mounds,
having the form of a truncated cone, about two feet
in width at the base, and seldom rising as high as
eighteen inches from the surface of the soil. ‘The

* The owl observed by Vieillot in St. Domingo digs itself a
burrow two feet in depth, at the bottom of which it deposits its
eggs upon a bed of moss. :

SOCIAL-WASPS. 73

entrance is placed either at the top or on the side,
and the whole mound is beaten down externally,
especially at the summit, resembling a much-used
footpath. From the entrance, the passage into the
_mound descends vertically for one or two feet, and
is thence continued obliquely downwards until it ter-
minates in an apartment, within which the industrious
prairie-dog constructs, on the approach of cold
weather, a comfortable cell for his winter’s sleep.
The cell, which is composed of fine dry grass, is
globular in form, with an opening at top, capable of
admitting the finger; and the whole is so firmly
compacted, that it might, without injury, be rolled
over the floor™.”

In case of need, the wasp is abundantly fur-
nished by nature with instruments for excavating a
burrow out of the solid ground, as she no doubt
most commonly does,—digging the earth with her
strong mandibles, and carrying it off or pushing it
out as she proceeds. The entrance-gallery is about
an inch or less in diameter, and usually runs in a
winding or zigzag direction, from one to two feet in
depth. Jn the chamber to which this gallery leads,
and which, when completed, is from one to two feet
in diameter, the mother wasp lays the foundations of
her city, beginning with the walls.

The building materials employed by wasps were
long a matter of conjecture to scientific inquirers; for
the bluish-grey papery substance of the whole struc-
ture has no resemblance to any sort of wax employed
by bees for a similar purpose. Now that the discovery
has been made, we can with difficulty bring our-
selves to believe that a naturalist so acute and inde-
fatigable as M. Réaumur should have, for twenty
years, as he tells us, endeavoured, without success,

* American Ornithology, by Charles Lucien Bonaparte, Vol. i,

p- 69
¥

74 INSECT ARCHITECTURE,

to find out the secret. At length, however, his per+
severance was rewarded. He remarked a female
wasp alight on the sash of his window, and begin to
gnaw the wood with her mandibles; and it struck
him at once that she was procuring materials for
building. He saw her detach from the wood a
bundle of fibres about a tenth of an inch in length,
and finer than a hair; and as she did not swallow
these, but gathered them into a mass with her feet,
he could not doubt that his first idea was correct.
In a short time she shifted to another part of the
window-frame, carrying with her the fibres she had
collected, and to which she continued to add, when
he caught her, in order to examine the nature of her
bundle; and he found that it was not yet moistened
nor rolled into a ball, as is always done before em-
ploying it in building. In every other respect it
had precisely the same colour and fibrous texture
as the walls of a vespiary. It struck him as remark-
able that it bore no resemblance to wood gnawed
by other insects, such as the goat-moth caterpillar,
which is granular like sawdust. This would not
have suited the design of the wasp, who was well
aware that fibres of some length form a stronger
texture. He even discovered, that before detaching
the fibres, she bruised them (Jes charpissoit) into a
sort of lint (charpie) with her mandibles. All this
the careful naturalist imitated by bruising and paring
the same wood of the window-sash with his pen-knife,
till he succeeded in making a little bundle of fibres
scarcely to be distinguished from that collected by the
‘wasp.

We have ourselves frequently seen wasps em-~
ployed in procuring their materials in this manner,
and have always observed that they shift from one
part to another more than once in preparing a single
load,—a circumstance which we ascribe entirely to

SOCIAL-WASPS 75

the restless temper peculiar to the whole order of
hymenopterous insects. Réaumur found that the
wood which they preferred was such as had been
long exposed to the weather, and is old and dry.
White of Selborne, and Kirby and Spence, on the
contrary, maintain that wasps obtain their paper
from sound timber, hornets only from that which is
decayed*. Our own observations, however, confirm
the statement of Réaumur, with respect to wasps, as,
in every instance which has fallen under our notice,
the wood selected was very much weathered ; and in
one case an old oak post in a garden at Lee, in
Kent, half destroyed by dry-rot, was seemingly the
resort of all the wasps in the vicinity. In another
case, the deal bond in a brick wall, which had been
built thirty years, is at this moment (June, 1829)
literally striped with the gnawings of wasps, which
we have watched at the work for hours together f.

The bundles of ligneous fibres thus detached, are
moistened, before being used, with a glutinous liquid,
which causes them to adhere together, and are then
kneaded into a sort of: paste, or papier maché,
Having prepared some of this material, the mother
wasp begins first to line with it the roof of her
chamber, for wasps always build downwards. ‘The
round ball of fibres which she has previously kneaded
up with glue, she now forms into a leaf, walking
backwards, and spreading it out with her mandibles,
her tongue, and her feet, till it is as thin almost as
tissue paper.

One sheet, however, of such paper as this would
form but a fragile ceiling, quite insufficient to-pre-
vent the earth from falling down into the nest. The
wasp, accordingly, is not satisfied with her work

* Réaumur, vol. vi. bottom of page 182; Hist. of Selb. it,
228; and Introd, to Entomol. i. 504, 5th edition.
dp kts
P2

76 INSECT ARCHITECTURE,

till she has spread fifteen or sixteen layers one above
the other, rendering the wall altogether nearly two
inches thick. The several layers are not placed in
contact like the layers of a piece of pasteboard, but
with small intervals or open spaces between, ap-
pearing somewhat like a grotto built with bivalve
shells, particularly when looked at on the outside.
This is probably caused by the insect working in a
curvilineal manner,

Section of the Sovial-/Vasp's Nest.—a a, the external wal ;
¢ ¢, five small terraces of ceils for the nenter wasps; dd, ea,
three rows of larger cells for the males and females,
Having finished the ceiling, she next begins to
build the first terrace of her city, which, under its

SOCIAL-WASPS, 77

protection, she suspends horizontally, and not like
the combs in a bee-hive, in a perpendicular position.
The suspension of which we speak is also light and
elegant, compared with the more heavy union of the
hive-bees’ combs. It is in fact a hanging floor,
immoveably secured by rods of similar materials
with the roof, but rather stronger. From twelve to
thirty of these rods, about an inch or less in length,
and a quarter of an inch in diameter, are constructed

A, represents one % the rods from which the terraces are sus-
,

pended. a portion of the external crust.

for the suspension of the terrace. They are elegant
in form, being made gradually narrower towards the
middle, and widening at each end, in order, no doubt,
to render their hold the stronger.

The terrace itself is circular, and composed of an
immense number of cells, formed of the paper al-
ready described, and of almost the same size and
form as those of a honey-comb, each being a perfect
hexagon, mathematically exact, and every hair's
breadth of the space completely filled. ‘These cells,
howeyer, are never used as honey-pots by wasps, as
they are by bees; for wasps make no honey, and
the cells are wholly appropriated to the rearing of
their young. Like other hymenopterous insects, the
grubs are placed with their heads downwards; and
the openings of the cells are also downwards: while

78 INSECT ARCHITECTURE.

their united bottoms form a nearly uniform level
upon which the inhabitants of the nest may walk.
We have seen, in describing the economy of the
carder-bee, that when a young bee had escaped from
its cradle-cell, and so rendered it empty, that cell was
subsequently appropriated to the storing of honey.
But in the case of wasps, a cell thus evacuated is
immediately cleaned out and repaired for the recep-
tion of another grub—an egg being laid in it by a
female wasp as soon as it is ready.

When the foundress wasp has completed a certain
number of cells, and deposited eggs in them, she
soon intermits her building operations, in order to
procure food for the young eruhs, which now require
all her care. Ina few weeks these become perfect
wasps, and lend their assistance in the extension of
the edifice; enlarging the original coping of the
foundress by side walls, and forming another plat-
form of cells, suspended to the first by columns, as
that had been suspended to the ceiling.

In this manner several platforms of combs are
constructed, the outer walls being extended at the
same time; and, by the end of the summer, there is
generally from twelve to fifteen platforms of cells.
Each contains about 1060 cells—forty-nine being
contained in an inch anda half square, and, of course,
making the enormous number of about 16,000 cells
inone colony. Réeaumur, upon these data, calculates
that one vespiary may produce every year more than
30,000 wasps, reckoning only 10,000 cells, and each
serving successively for the cradle of three genera-
tions. But, although the whole structure is built at
the expense of so much labour and ingenuity, it has
scarcely been finished before the winter sets in, when
it becomes nearly useless, and serves only for the
abode of a few benumbed females, who abandon it
on the approach of spring, and never return for

SOCIAL-WASPS, 79

wasps do not, like mason-bees, ever make use of the
same nest for more than one season.

Both Réaumur and the younger Huber studied
the proceedings of the common wasp in the manner
which has been so successful in observing bees—by
means of glazed hives, and other contrivances. In
this, these naturalists were greatly aided by the ex-
treme affection of wasps for their young ; for though
their nest is carried off, or even cut in various direc-
tions, and exposed to the light, they never desert it,
uor relax their attention to their progeny. When a
wasp’s nest is removed from its natural situation, and
covered with a glass hive, the first operation of the
inhabitants is to repair the injuries it has suffered.
They carry off with surprising activity all the earth
or other matters which have fallen by accident into
the nest; and when they have got it thoroughly
cleared of everything extraneous, they begin to se-
cure it from further derangement, by fixing it to the
glass with papyraceous columns, similiar to those
which we have already described. The breaches
which the nest may have suffered are then repaired,
and the thickness of the walis is augmented, with
the design, perhaps, of more effectually excluding
the light.

The nest of the hornet is nearly the same in struc-
ture with that of the wasp; but the materials are
considerably coarser, and the columns to which the
platforms of cells are suspended are larger and
stronger, the middle one being twice as thick as any
of the others. The hornet, also, does not build
under ground, but in the cavities of trees or in
the thatch or under the eaves of barns. Réaumur
once found upon a wall a hornet’s nest which had
not been long begun, and had it transferred to the
outside of his study window; but in consequence,

60 INSECT ARCHITECTURE,
as he imagined, of the absence of the foundress
hornet at the time it was removed, he could not get
the other five hornets, of which the colony consisted,
either to add to the building or repair the damages
which it had sustained.

Hornet's Nest inits first stage.

M. Réaumur differs from our English naturalists,
White, Kirby, and Spence, with respect to the ma-
terials employed by the hornet for building. The
latter say that it employs decayed wood ; the former,
that it uses the bark of the ash-tree, but takes less
pains to split it into fine fibres than wasps do; not,
however, because it is destitute of skill; for in con-
structing the suspensory columns of the platforms, a
paste is prepared little inferior to that made by wasps,
We cannot, from our own observations, decide which

SOCIAL-WASPS, 81.

of the above statements is correct, as we have only
once seen a hornet procuring materials, at Compton-
Bassett, in Wiltshire ; and in that case it gnawed the
inner bark of an elm which had been felled for seve-
ral months, and was, consequently, dry and tough.
Such materials as this would account for the common
yellowish-brown colour of a hornet’s nest*.

When hornets make choice of a tree for their
domicile, they select one which is in a state of decay,
and already partly hollowed: but they possess the
means, in their sharp and strong mandibles, of ex-
tending the excavation to suit their purposes; and
Réaumur frequently witnessed their operations in
mining into a decayed tree, and carrying off what
they had gnawed. He observed, also, that in such
cases they did not make use of the large hole of the
tree for an entrance, but went to the trouble of dig-
ging a gallery, sufficient for the passage of the largest
hornet in the nest, through the living and undecayed
portion of the tree. As this is perforated in a wind-
ing direction, it is no doubt intended for the purpose
of protecting the nest from the intrusion of depre-
dators, who could more easily effect an entrance if
there was not such a tortuous way to pass through.

One of the most remarkable of our native social-
wasps is the Vespa Britannica, or tree-wasp, which is
not uncommon in the northern, but is seldom to be
met with in the southern parts of the island. Instead
of burrowing in the ground like the common wasp
(Vespa vulgaris), or in the hollows of trees like the
hornet (Vespa crabro), it boldly swings its nest from
the extremity of a branch, where it exhibits some
resemblance, in size and colour, to a Welsh wig,
hung out to dry. We have seen more than one of
these nests on the same tree, at Catrine, in Ayrshire,

*J.R.
FS

82 INSECT ARCHITECTURE,

and at Wemyss Bay, in Renfrewshire. The tree
which the Britannie wasp prefers is the silver fir,
whose broad flat branch serves as a protection to the
suspended nest both from the sun and the rain. The
materials and structure are nearly the same as those
employed by the common wasp, and which we have
already described*.

A singular nest of a species of wasp is figured by
Réaumur, but is apparently rare in this country, as
Kirby and Spence mention only a single nest of similar
construction, found in a garden at Hast-Dale. This
nest is of a flattened globular figure, and composed
of a great number of envelopes, so as to assume a
considerableresemblance to a half-expanded Provence
rose. The British specimen mentioned by Kirby and
Spence had only one platform of cells; Réaumur's
had two; but there was a large vacant space, which
would probably have been filled with cells, had the
nest not been taken away asaspecimen. The whole

Wasp's Nest.
*J, R.

SOCIAL-WASPS, 8s

nest was not much larger than a rose, and was com-
posed of paper exactly similar to that employed by
the common ground-wasp.

There is another species of social-wasp (Epipone
nidulans, Ltr.) meriting attention from the singu-
lar construction of its nest. It forms one or more
terraces of cells, similar to those of the common wasp,
but without the protection of an outer wall, and quite
exposed to the weather. Swammerdam found a nest
of this description attached to the stem of a nettle.
Réaumur says they are sometimes attached to the
branch of a thorn or other shrub, or to stalks of grass;
—peculiarities which prove that there are several
species of these wasps.

The most remarkable circumstance in the archi»

Wasp s Cells attached to a branch.

&4 INSECT ARCHITECTURE,

tecture of this species of vespiary is, that it is
not horizontal, like those formerly described, but
neariy vertical, The reason appears to be, that
if it had been horizontal, the cells must have
been frequeutly filled with rain; whereas, in the
position in which it is placed, the rain runs off
without lodging. It is, besides, invariably placed
so as to face the north or the east, and conse-
quently is less exposed to rains, which most fre-
quently come with southerly or westerly winds. It
is another remarkable peculiarity, that, unlike the nests
of other wasps, it is covered with a shining coat of
varnish, to prevent moisture from soaking into the
texture of the wadsp's paper. The laying on this
varnish, indeed, forms a considerable portion of the
labour of the colony, and individuals may be seen
employed for hours together spreading it on with
their tongues.

Few circumstances are more striking with regard
to insects, as Kirby and Spence justly remark, than
the great and incessant labour which maternal
affection for their progeny leads them to undergo.
Some of these exertions are so disproportionate to
the size of the insect, that nothing short of ocular
conviction could attribute them to such an agent. A
wild bee, or a wasp, for instance, as we have seen,
will dig a hole in a hard bank of earth some inches
deep, and five or six times its own size, labouring
unremittingly at this arduous task for several days in
succession, and scarcely allowing itself a moment for
eating or repose. It will then occupy as much time
in searching for a store of food; and no sooner is
this finished, than it will set about repeating the pro-
cess, and before it dies, will have completed five or
six similar cells, or even more.

We shall have occasion more particularly to dwell

SOCIAL-WASPS, 86

upon the geometrical arrangement of the cells, both
of the wasp and the social-bee, in our description
of those interesting operations, which have long at-
tracted the notice, and commanded the admiration,
of mathematicians and naturalists. A few observa-
tions may here be properly bestowed upon the ma-
terial with which the wasp-family construct the in-
terior of their nests.

The wasp is a paper-maker, and a most perfect
and intelligent one. While mankind were arriving,
by slow degrees, at the art of fabricating this valu-
able substance, the wasp was making it before their
eyes, by very much the same process as that by
which human hands now manufacture it with the
best aid of chemistry and machinery. While some
nations carved their records on wood, and stone, and
brass, and leaden tablets,—others, more advanced,
wrote with a style on wax,—others employed the inner
bark of trees, and others the skins of animals rudely
prepared,—the wasp was manufacturing a firm and
durable paper. Even when the papyrus was rendered
more fit, by a process of art, for the transmission of
ideas in writing, the wasp was a better artisan than
the Egyptians; for the early attempts at paper-
making were so rude, that the substance produced
was almost useless, from being extremely friable.
The paper of the papyrus was formed of the leaves
of the plant, dried, pressed, and polished; the wasp
alone knew how to reduce vegetable fibres to a
pulp, and then unite them by a size or glue, spread-
ing the substance out into a smooth and delicate
leaf. This is exactly the process of paper-making.
Tt would seem that the wasp knows, as the modern
paper-makers now know, that the fibres of rags,
whether linen or cotton, are not the only materials
that can be used in the formation of paper; she em
ploys other vegetable matters, converting them into

86 INSECT ARCHITECTURE,

a proper consistency by her assiduous exertions. In
some respects she is more skilful even than our
paper-makers, for she takes care to retain her fibres
of sufficient length, by which she renders her paper
as strong as she requires. Many manufacturers of
the present day cut their material into small bits, and
thus produce a rotten article. One great distinction
between good and bad paper is its tonghness ; and
this difference is invariably produced by the fibre of
which it is composed being long, and therefore tough ;
or short, and therefore friable.

The wasp has been labouring at her manufacture
of paper, from her first creation, with precisely the
same instruments and the same materials ; and her
success has been unvarying. Her machinery is
very simple, and therefore it is never out of order.
She learns nothing, and she forgets nothing. Men,
from time to time, lose their excellence in particular
arts, aud they are slow in finding out real improve-
ments. Such improvements are often the effect of ac-
cident. Paper is now manufactured very extensively
by machinery, in all its stages ; and thus, instead of
a single sheet being made by hand, a stream of paper
is poured out, which would form a roll large enough
to extend round the globe, if such a length were de-
sirable. The inventors of this machinery, Messrs.
Fourdrinier, it is said, spent the enormous sum
of 40,000/. in vain attempts to render the machine
capable of determining with precision the width of
the roll; and, at last, accomplished their object,
at the suggestion of a bystander, by a strap re-
volving upon an axis, at a cost of three shillings
and sixpence. Such is the difference between the
workings of human knowledge and experience, and
those of animal instinct. We proceed slowly and in
the dark—but our course is not bounded by a nar-
row line, for it seems difficult to say what is the per-

SOCIAL-WASPS. 87

fection of any art; animals go clearly to a given
point—but they can go no further. We may, how
ever, learn something from their perfect knowledge
of what is within their range. It is not improbable
that if man had attended in an earlier state of society
to the labours of wasps, he would have sooner known
how to make paper. We are still behind in our
arts and sciences, because we have uot always been
observers. If we had watched the operations of in-
sects, and the structure of animals in general, with
more care, we might have been far advanced in the
knowledge of many arts, which are yet in their in-
fancy, for nature has given us abundance of patterns.
We have learnt to perfect some instruments of sound,
by examining the structure of the human ear; and
the mechanism of an eye has suggested some valu~
able improvements in achromatic glasses.

Réaumur has given a very interesting account of the
wasps of Cayenne, which hang their nests in trees *.
Like the bird of Africa called the Loxia, they fabricate
a perfect house, capable of containing many hundreds
of their community, and suspend it on high out of
the reach of attack. But the Cayenne wasp is a
more expert artist than the bird. He is a card-
maker ;—and travellers of veracity agree that the
card with which he forms the exterior covering of his
abode is so smooth, so strong, so uniform in its
texture, and so white, that the most skilful manu-
facturer of this substance might be proud of the
work.

The nest of the card-making wasp is impervious
to water. It hangs upon the branch of a tree, as
represented in the engraving ; and those rain-drops

® Mémoires sur les Insectes, tom. vi., mem. vii. See also Bonne.
ol. ix.

88 INSECT ARCHITECTURE,

which penetrate through the leaves never rest upon
its hard and polished surface. A small opening for
the entrance of the insects terminates its funnel-
shaped bottom. It is impossible to unite more per-
fectly the qualities of lightness and strength.

New.) the Card-maher Wasp, with part removed to shew the arrangement
of the Cells,

89

CuaprTer V.

ARCHITECTURE OF THE HIVE-BEE,

Part of a honeycomb, and bees at work.

Aurnouan the hive-bee (Apis mellifica) has engaged
the attention of the curious from the earliest ages,
recent discoveries prove that we are yet only begin-
ning to arrive at a correct knowledge of its wonderful
proceedings. Pliny informs us that Aristomachus,
of Soles, in Cilicia, devoted fifty-eight years to the
study ; and that Philiscus the Thracian spent his
whole life in forests for the purpose of observing
them. But in consequence (as we may naturally
infer) of the imperfect methods of research, as-

90 INSECT AROHITECTURE,

suming that what they did discover was known to
Aristotle, Columella, and Pliny, we are justified in
pronouncing the statements of these philosophers, as
well as the embellished poetical pictures of Virgil, to
be nothing more than conjecture, almost in every par-
ticular erroneous. It was not indeed till 1712, when
glass hives were invented by Maraldi, a mathema-
tician of Nice, that what we may call the in-door
proceedings of bees could be observed. This im-
portant invention was soon afterwards taken advan-
tage of by M. Réaumur, who laid the foundation of
the more recent discoveries of John Hunter, Schi-
rach, and the Hubers. ‘The admirable architecture
which bees exhibit in their miniature cities has, by
these and other naturalists, been investigated with
great care and accuracy. We shall endeavour to
give as full an account of their wonderful structures
as our limits will allow. In this we shall chiefly
follow M. Huber, the elder, whose researches appear
almost miraculous when we consider that he was
blind.

At the early age of seventeen this remarkable man
lost his sight by gutta serena, “ the drop serene” of
our own Milton. But, though eut off from the sight of
Nature’s works, he didiakad himself to their study.
He saw them through the eyes of the admirable
woman whom he married: his philosophical reason-
ings pointed out to her all that he wanted to ascer-
tain; and as she reported to him from time to time
the results of his ingenious experiments, he was en-
abled to complete, by diligent investigation, one
of the most accurate and satisfactory accounts of
the habits of bees which has ever been produced.
This venerable naturalist is, we believe, still alive.

It had long been known that the bees of a hive
consist of three sorts, which were ascertained by

HIVE-BEES, 91

M. Réaumur to be distinguished as workers or
neuters, constituting the bulk of the population ;
drones or males, the least numerous class; and a sin-
gle female, the queen and mother of the colony. Schi-
rach subsequently discovered the very extraordinary
fact, which Huber and others have proved beyond
doubt, that when a hive is accidentally deprived of a
queen, the grub of a worker can be and is fed in
a particular manner, so as to become a queen and
supply the loss*. But another discovery of M. Hu-
ber is of more importance to the subject of archi-
tecture now before us. By minute research he ascer-
tained, that the workers, which had been considered
by former naturalists to be all alike, are divided
into two important classes, nurse-bees and wax-
makers,

The nurse-bees are rather smaller than the wax-
workers, and even when gorged with honey their
belly does not, as in the others, appear distended.
Their business is to collect honey, and impart it to
their companions ; to feed and take care of the young
grubs, and to complete the combs and cells which
have been founded by the others; but they are not
charged with provisioning the hive.

The wax-workers on the other hand are not only
a little larger, but their stomach, when gorged with
honey, is capable of considerable distension, as M.
Huber proved by repeated experiments. He also
ascertained that neither of the species can alone
fulfil all the functions shared among the workers of
a hive. He painted those of each class with different
colours, in order to study their proceedings, and their
labours were not interchanged. Jn another experi-

*Tt is right to remark that Huish and others have suggested
that the grubs thus royalized may originally be misplaced queens ;
yet this admission is not necessary, since Madlle. Jurine has
proved, by dissection, the workers to be imperfect females.

92 INSECT ARCHITECTURE,

ment, after supplying a hive deprived of a queen with
brood and pollen, he saw the nurse-bees quickly oc-
cupied in the nutrition of the grubs, while those of
the wax-working class neglected them. When hives
are full of combs, the wax-workers disgorge their
honey into the ordinary magazines, making no wax:
but if they want a reservoir for its reception, and if
their queen does not find cells ready made wherein
to lay her egas, they retain the honey in the stomach,
and in twenty-four hours they produce wax. Then
the labour of constructing combs begins.

It might perhaps besupposed that, when the country
does not afford honey, the wax-workers consume
the provision stored up in the hive. But they are
not permitted to touch it. A portion of honey is
carefully preserved, and the cells containing it are
protected by a waxen covering, which is never re-
moved except in case of extreme necessity, and
when honey is not to be otherwise procured. 'The
cells are at no time opened during summer ;
other reservoirs, always exposed, contribute to the
daily use of the community; each bee, however, sup-
plying itself from them with nothing but what is
required for present wants. Wax-workers appear
with large bellies at the entrance of their hive, only
when the country affords a copious collection of
honey. From this it may be concluded, that the
production of the waxy matter depends on a con-
currence of circumstances not invariably subsisting.
Nurse-bees also produce wax, but in a very inferior
quantity to what is elaborated by the real wax-workers.
Another characteristic whereby an attentive observer
can determine the moment of bees collecting sufficient
honey to produce wax, is the strong odour of both
these substances from the hive, which is not equally
intense at any other time. From such data, it was
easy for M. Huber to discover whether the bees

HIVE-BERES, 93

worked in wax in his own hives, and in those of the
other cultivators of the district.

There is still another sort of bees, first observed
by Huber in 1809, which appear to be only casual
inmates of the hive, and which are driven forth to
starve, or are killed in conflict. They closely re-
semble the ordinary workers, but are less hairy, and
of a much darker colour. These have been called
black bees, and are supposed by Huber to be defective
bees*; but Kirby and Spence conjecture that they
are toil-worn superannuated workers, of no farther
use, and are therefore sacrificed, because burdensome
to a community which tolerates no unnecessary in-
mates. The very great numbers of black bees, how-
ever, which sometimes appear, does not well accord
with such an opinion. The subject remains, there-
fore, still in uncertainty.

PrePaRATION OF Wax.

In order to build the beautiful combs, which every
one must have repeatedly seen and admired, it is
indispensable that the architect-bees should be pro-
vided with the materials—with the wax, in short, of
which they are principally formed. Before we follow
them, therefore, to the operation of building, it may
be necessary to inquire how the wax itself is pro-
cured. Here the discoveries of recent inquirers have
been little less singular and unexpected than in other
departments of the history of these extraordinary in-
sects. Now that it has been proved that wax is
secreted by bees, it is not a little amusing to read
the accounts given by our elder naturalists, of
its being collected from flowers. Our countryman,

* Huber on Bees, p, 238,

94 INSECT ARCHITECTURE,

Thorley *, appears to have been the first who sus-
pected the true origin of wax, and Wildman (1769)
seems also to have been aware of it; but Réaumur, |
and particularly Bonnet, though both of them in
general shrewd and accurate observers, were par-
tially deceived by appearances.

The bees, we are erroneously told, search for wax
“upon all sorts of trees and plants, but especially
the rocket, the single poppy, and in general all kinds
of flowers. They amass it with their hair, with
which their whole body is invested. It is something
pleasant to see them roll in the yellow dust which
falls from the chives to the bottom of the flowers,
and then return covered with the same grains; but
their best method of gathering the wax, especially
when it is not very plentiful, is to carry away all the
little particles of it with their jaws and fore feet, to
press the wax upon them into little pellets, and slide
them, one at a time, with their middle feet, into a
socket or cavity, that opens at their hinder feet, and
serves to keep the burden fixed and steady till they
return home. They are sometimes exposed to incon-
veniences in this work by the motion of the air, and
the delicate texture of the flowers which bend under
their feet, and hinder them from packing up their
booty, on which occasions they fix themselves in some
steady place, where they press the wax into a mass,
and wind it round their legs, making frequent re-
turns to the flowers; and when they have stocked
themselves with a sufficient quantity, they imme-
diately repair to their habitation. 'Two men, in the
compass of a whole day, could not amass so much
as two little balls of wax; and yet they are no more
than the common burthen of a single bee, and the
produce of one journey. ‘Those who are employed

* Melisselogia, or Female Monarchy, 8vo.,-Lond, 1744,

HIVE-BEES, 95

in collecting the wax from flowers are assisted by
their companions, who attend them at the door of
the hive, ease them of their load at their arrival,
brush their feet, and shake out the two balls of wax;
upon which the others return to the fields to gather
new treasure, whilst those who disburthened them
convey their charge to the magazine. But some bees,
again, when they have brought their load home,
carry it themselves to the lodge, and there deliver it,
laying hold of one end by their hinder feet, and with
their middle feet sliding it out of the cavity that con-
tained it; but this is evidently a work of superero-
gation which they are not obliged to perform. The
packets of wax continue a few moments in the lodge,
till a set of officers come, who are charged with a
third commission, which is to knead this wax with
their feet, and spread it out into different sheets, laid
one above another. This is the unwrought wax,
which is easily distinguished to be the produce of
different flowers, by the variety of colours that appear
on each sheet, When they afterwards come to work,
they knead it over again, they purify and whiten,
and then reduce it to a uniform colour. They use
this wax with a wonderful frugality; for it is easy to
observe that the whole family is conducted by pru-
dence, and all their actions regulated by good go-
vernment. Everything is granted to necessity, but
nothing to superfluity; not the least grain of wax is
neglected, and if they waste it, they are frequently
obliged to\provide more; at those very times when
they want to get their provision of honey, they take
off the wax that closed the cells, aud carry it to the
magazine*.” 8

Réaumur hesitated in believing that this was a

* Pluche, Spectacle de Ja Nature, vol. i.

96 INSECT ARCHITECTURE,

correct view of the subject, from observing the great
difference between wax and pollen; but he was in-
clined to think the pollen might be swallowed, par-
tially digested, and disgorged in the form of a kind
of paste. Schirach also mentions, that it was re-
marked by a certain Lusatian, that wax comes from
the rings of the body, because, on withdrawing a bee
while it is at work, and extending its body, the wax
may be seen there in the form of scales.

The celebrated John Hunter shrewdly remarked
that the pellets of pollen seen on the thighs of bees
are of different colours on different bees, while the
shade of the new-made comb is always uniform; and
therefore he concluded that pollen was not the origin

_of wax. Pollen also, he observed, is collected with
greater avidity for old hives, where the comb is com-
plete, than for those where it is only begun, which
would hardly be the case were it the material of wax.
He found that when the weather was cold and wet
in June, so that a young swarm was prevented from
going abroad, as much comb was constructed as had
been made in an equal time when the weather was
favourable and fine.

The pellets of pollen on the thighs being thence
proved not to be wax, he came to the conclusion
that it was an external secretion originating between
the plates of the belly. When he first observed this,
he felt not a little embarrassed to explain the phe-
nomenon, and doubted whether new plates were
forming, or whether bees cast the old ones as lob-
sters do their shells. By melting the scales, he ascer-
tained at least that they were wax; and his opinion
was confirmed by the fact, that the scales are only to
be found during the season when the combs are
constructed. But he did not succeed in completing
the discovery by observing the bees actually detach the

HIVE-BEES, 97

scales, though he conjectured they might be taken
up by others, if they were once shaken out from
between the rings”.

We need not be so much surprised at mistakes
committed upon this subject, when we recollect that
honey itself was believed by the ancients to be an
emanation of the air—a dew that descended upon
flowers, as if it had a limited commission to fall only
on them. The exposure and correction of error is
one of the first steps to genuine knowledge ; and
when we are aware of the stumbling-blocks which
have interrupted the progress of others, we can
always travel more securely in the way of truth.

That wax is secreted, is proved both by the wax
pouches within the rings of the abdomen, and by
actual experiment t+. Huber and others fed bees
entirely upon honey or sugar, and, notwithstanding,
wax was produced and combs formed as if they had
been at liberty to select their food. ‘* When bees
were confined,” says M. Huber, ‘ for the purpose of
discovering whether honey was sufficient for the
production of wax, they supported their captivity
patiently, and shewed uncommon perseverance in
rebuilding their combs as we removed them. Our
experiments required the presence of grubs; honey
and water had to be provided; the bees were to be
supplied with combs containing brood, and at the
same time it was necessary to confine them, that they
might not seek pollen abroad, Having a swarm by
chanee, which had become useless from sterility of
the queen, we devoted it for our investigation in one
of my leaf hives, which was glazed on both sides.
We removed the queen, and substituted combs con-
taining eggs and young grubs, but no cell with
farina; even the smallest particle of the substance

* Philosophical Trans. for 1792, p. 143. + See p. 103.
S

98 INSECT ARCHITECTURE,

which John Hunter conjectured to be the basis of
the nutriment of the young, was taken away.

“ Nothing remarkable occurred during the first and
second day: the bees brooded over the young, and
seemed to take an interest in them; but at sun-set,
on the third, a loud noise was heard in the hive.
Impatient to discover the reason, we opened a, shut-
ter, and saw all in confusion; the brood was aban-
doned ; the workers ran in disorder over the combs ;
thousands rushed towards the lower part of the hive;
and those about the entrance gnawed at its grating.
Their design was not equivocal; they wished to quit
their prison. Some imperious necessity evidently
obliged them to seek elsewhere what they could not
find in the hive; and apprehensive that they might
perish if I restrained them longer from yielding to
their instinct, I set them at liberty. The whole
swarm escaped ; but the hour being unfavourable for
their collections, they flew around the hive, and did
not depart far from it. Increasing darkness and the
coolness of the air compelled them very soon to re-
turn. Probably these circumstances calmed their
agitation ; for we observed them peaceably remount-
ing their combs; order seemed re-established, and
we took advantage of this moment to close the
hive.

“ Next day, the 19th of July, we saw the rudiments
of two royal cells, which the bees had formed on one
of the brood combs, ‘This evening, at the same hour
as on the preceding, we again heard a loud buzzing
in the closed hive; agitation and disorder rose to the
highest degree, and we were again obliged to let the
swarm escape. ‘The bees did not remain long absent
from their habitation; they quieted and returned as
before. We remarked on the 20th, that the royal
cells had not been continued, as would have been the
case in the ordinary state of things. A great tumult

HIVE-BEES. 99

took place in the evening; the bees appeared to be in
a delirium; we set them at liberty, and order was
restored on their return. Their captivity having
endured five days, we thought it needless to protract
it farther; besides, we were desirous of knowing,
whether the brood was in a suitable condition, and if
it had made the usual progress; and we wished also
to try to discover what might be the cause of the
periodical agitation of the bees. M. Burnens (the
assistant of Huber) having exposed the two brood
combs, the royal cells were immediately recognized ;
but it was obvious that they had not been enlarged.
Why should they? Neither eggs, grubs, nor that
kind of paste peculiar to the individuals of their
species were there! ‘The other cells were vacant like-
wise; no brood, not an atom of paste was in them.
Thus, the worms had died of hunger. Had we pre-
cluded the bees from all means of sustenance by
removing the farina? ‘To decide this point, it was
necessary to confide other brood to the care of the
same insects, now giving them abundance of pollen.
They had not been enabled to make any collections
while we examined their combs. On this occasion
they escaped in an apartment where the windows
were shut; and after substituting young worms for
those they had allowed to perish, we returned them
to their prison. Next day we remarked that they had
resumed courage; they had consolidated the combs,
and remained on the brood. ‘They were then provided
with fragments of combs, where other workers had
stored up farina ; and to be able to observe what they
did with it, we took this substance from some of their
cells, and spread it on the board of the hive. ‘The
bees soon discovered both the farina in the combs
and what we had exposed to them. ‘They crowded to
the cells, and also descending to the bottom of the
hives, took the pollen grain by grain in their teeth,

100 INSECT ARCHITECTURE,

and conveyed it to their mouths. Those that had
eaten it most greedily, mounted the combs before the
rest, and stopping on the cells of the young worms,
inserted their heads, and remained there for a certain
time. M. Burnens opened one of the divisions of
the hive gently, and powdered the workers, for the
purpose of recognizing them when they should
ascend the combs. He observed them during several
hours, and by this means ascertained that they took
so great a quantity of pollen only to impart it to
their young. Then withdrawing the portions of
comb which had been placed by us on the board of
the hive, we saw that the pollen had been sensibly
diminished in quantity. They were returned to the
bees, to augment their provision still farther, for the
purpose of extending the experiment. The royal,
as well as several common cells were soon closed ;
and, on opening the hive, all the worms were found
to have prospered. Some still had their food before
them; the cells of others that had spun were shut
with a waxen covering.

‘“« We witnessed these facts repeatedly, and always
with equal interest. ‘They so decisively prove the
regard of the bees towards the grubs which they are
intrusted with \rearing, that we shall not seek for
any other explanation of their conduct. Another
fact, no less extraordinary, and much more difficult
to be accounted for, was exhibited by bees constrained
to work in wax, several times successively, from the
syrup of sugar. ‘Towards the close of the experiment
they ceased to feéd the young, though in the begin-
ning these had received the usual attention. They
even frequently dragged them from their cells, and
carried them out of the hive *.”

Mr. Wiston, of Germantown, in the United States,

* Huber on Bees,

HIVE-BEES, 10

mentions a fact conclusive on this subject. “ I had,”
says he, ‘‘a late swarm last summer, which, ip eon-
sequence of the drought, filled only one box with
honey. As it was late in the season, and the food
collected would not enable the bees to subsist for
the winter, I shut up the hive, and gave them halt
a pint of honey every day. They immediately set to
work, filled the empty cells, and then constructed
new cells enough to fill another box, in which they
deposited the remainder of the honey.”

A more interesting proof is thus related by the
same gentleman. ‘‘ In the summer of 1824, I traced
some wild bees, which had been feeding on the
flowers in my meadow, to their home in the woods,
and which I found in the body of an oak tree, exactly
fifty feet above the ground. Having caused the
entrance to the hive to be closed by an expert climber,
the limbs were separated in detail, until the trunk
alone was left standing. ‘To the upper extremity of
this, a tackle-fall was attached, so as to connect it
with an adjacent tree, and, a saw being applied be-
low, the naked trunk was cut through. When the
immense weight was lowered nearly to the earth, the
ropes broke, and the mass fell with a violent crash.
The part of the tree which contained the hive, sepa-
rated by the saw, was conveyed to my garden, and
placed in a vertical position. On being released, the
bees issued out by thousands, and though alarmed,
soon became reconciled to the change of situation.
By removing a part of the top of the block, the inte-
rior of the hive was exposed to view, and the comb
itself, nearly six feet in height, was observed to have
fallen down two feet below the roof of the cavity.
To repair the damage was the first object of the
labourers; in doing which, a large part of their store
of honey was expended, because it was at too late a
season to obtain materials from abroad. In the fol-

6¢

102 INSECT ARCHITECTURE,

lowing February, these industrious, but unfortunate
insects, issuing in a confused manner from the hive,
fell dead in thousands, around its entrance, the vic-
tims of a poverty created by their efforts to repair the
ruins of their habitation*,”

In ‘another experiment, M. Huber confined a
swarm so that they had access to nothing beside
honey, and five times successively removed the
combs with the precaution of preventing the escape
of the bees from the apartment. On each occasion
they produced new combs, which puts it beyond dis-
pute that honey is sufficient to effect the secretion of
wax without the aid of pollen. Instead of supplying
the bees with honey, they were subsequently fed,
exclusively, on pollen and fruit; but though they
were kept in captivity for eight days under a bell-
glass, with a comb containing nothing but farina,
they neither made wax, nor was any secreted under the
rings. In another series of experiments, in which bees
were fed with different sorts of sugar, it was found
that nearly one-sixth of the sugar was converted into
wax, dark-coloured sugar yielding more than double
the quantity of refined sugar.

It may not be out of place to subjoin the few
anatomical and physiological facts which have been
ascertained by Huber, Madlle. Jurine, and Latreille.

The first stomach of the worker-bee, according to
Latreillet, is appropriated to the reception of honey,
but this is never found in the second stomach, which
is surrounded with muscular rings, and from one
end to the other very much resembles a cask covered
with hoops. It is within these rings that the wax is
produced, but the secreting vessels for this purpose
have hitherto escaped the researches of the acutest

* American Quarterly Review for June, 1828, p. 382.
+ Latreille, Mem. Acad. des Sciences, 1821.

HIVE-BEES, 103

naturalists. Huber, however, plausibly enough conjec-
tures that they are contained in the internal lining of
the wax pockets, which consists of a cellular substance
reticulated with hexagons, ‘The wax pockets them-
selves, which are concealed by the over-lapping of the
rings, may be seen by pressing the abdomen of a
worker-bee so as to lengthen it, and separate the rings
further from each other. When this has been done,
there may be seen on each of the four intermediate
hoops of the belly, and separated by what may be
called the keel (carina), two whitish-coloured
pouches, of a soft texture, and in the form of a
trapezium. Within, the little scales or plates of wax

Work r-bee, magnified—shewing the position of the scales of wax.

are produced from time to time, and are removed and
employed as we shall presently see. We may remark
that it is chiefly the wax-workers which produce the
wax, for though the nurse-bees are furnished with
wax pockets, they secrete it only in very small quan-
tities, while in the queen bee, and the males or drones,
no pockets are discoverable.

104 ; INSECT ARCHITECTURE

Abdomen of Wax-worker Bea.

“ All the scales,” says Huber, “are not alike in
every bee, for a difference is perceptible in consist-
ence, shape, and thickness; some are so thin and
transparent, as to require a magnifier to be recog-
nised, or we have been able to discover nothing but
spicule similar to those of water freezing. Neither the
spiculz nor the scales rest immediately on the mem-
brane of the pocket, a slight liquid medium is inter-
posed, serving to lubricate the joinings of the rings,
or to render the extraction of the scales easier, as
otherwise they might adhere too firmly to the sides
of the pockets.” M. Huber has seen the scales so
large as to project beyond the rings, being visible
without stretching the segments, and of a whitish-
yellow, from greater thickness lessening their trans-
parency. These shades of difference in the scales of
various bees, their enlarged dimensions, the fluid in-
terposed beneath them, the correspondence between
the scale, and the size and form of the pockets, seem
to infer the oozing of this substance through the mem-

HIVE-BEES, 105

branes whereon it is moulded. He was confirmed
in this opinion by the escape of a transparent fluid,
on piercing the membrane, whose internal surface
seemed to be applied to the soft parts of the belly.
This he found coagulated in cooling, when it re-
sembled wax, and again liquefied on exposure to heat.
The scales themselves, also, melted and coagulated
like wax*.

By chemical analysis, however, it appears that the
wax of the rings is a more simple substance than that
which composes the celis; for the latter is soluble
in ether, and in spirit of turpentine, while the former
is insoluble in ether, and but partially soluble in spirit
of turpentine. It should seem to follow, that if the
substance found lying under the rings be really the
elements of wax, it undergoes some subsequent pre-
paration after it is detached; and that the bees, in
short, are capable of impregnating it with matter,
imparting to it whiteness and ductility, whereas in its
unprepared state it is only fusible.

Propotis.

Wax is not the only material employed by bees in
their architecture. Besides this, they make use of a
brown, odoriferous, resinous substance, called pro-
polis, more tenacious and extensible than wax, and
well adapted for cementing and varnishing. It was
strongly suspected by Réaumur, that the bees col-
lected the propolis from those trees which are known te
produce a similar gummy resin, such as the poplar,
the birch, and the willow; but he was thrown into
doubt by not being able to detect the bees in the
act of procuring it, and by observing them to collect

* Huber on Bees, p. 325.
+ From two Greek words xo roAis, meaning before the city, as

ae substance is principally applied to the projecting parts of the
jive,

106 INSECT ARCHITECTURE,

it where none of those trees, nor any other of the
same description, grew. His bees also refused to
make use of bitumen and other resinous substances,
with which he supplied them, though Mr. Knight, as
we shall afterwards see, was more successful*.

Long before the time of Réaumur, however, Mouf-
fet, in his Insectarum Theatrum, quotes Cordus for
the opinion, that propolis is collected from the buds
of trees, such as the poplar and birch ; and Reim
says it is collected from the pine and firt. Huber
at length set the question at rest; and his experi-
ments and observations are so interesting, that we
shall give them in his own words :—

“For many years,” says he, “I had fruitlessly en-
deavoured to find them on trees producing an ana-
Jogous substance, though multitudes had been seen
returning laden with it.

“ fn July, some branches of the wild poplar, which
had been cut since spring, with very large buds, full
of a reddish, viscous, odoriferous matter, were brought
to me, and I planted them in vessels before hives, in
the way of the bees going out to forage, so that they
could not be insensible of their presence, Within a
quarter of an hour, they were visited by a bee, which
separating the sheath of a bud with its teeth, drew
out threads of the viscous substance, and lodged a
pellet of it in one of the baskets of its limbs: from
another bud it collected another pellet for the oppo-
site limb, and departed to the hive. A second bee
took the place of the former in a few minutes, fol-
lowing the same procedure. Young shoots of poplar,
recently cut, did not seem to attract these insects, as
their viscous matter had less consistence than the
formert.

* Phil. Trans. for 1807, p. 242.

+ Schirach, Hist. des Abeilles, p. 241.
} Kirby and Spence observed bees very busy in collecting

HIVE-BEES. 109

“ Different experiments proved the identity of this
substance with propolis; and now, having only to
discover how the bees applied it to use, we peopled
a hive, so prepared as to fulfil our views. ‘The bees,
building upwards, soon reached the glass above;
but, unable to quit their habitation, on account
of rain, they were three weeks without bringing
home propolis. Their combs remained perfectly
white until the beginning of July, when the state of
the atmosphere became more favourable for our ob-
servations. Serene warm weather engaged them to
forage, and they returned from the fields laden with
a resinous gum, resembling a transparent jelly, and
having the colour and lustre of the garnet. It was
easily distinguished from the farinaceous pellets then
collected by other bees. The workers bearing the
propolis ran over the clusters suspended from the
roof of the hive, and rested on the rods supporting
the combs, or sometimes stopped on the sides of their
dwelling, in expectation of their companions coming
to disencumber them of their burden. We actually
saw two or three arrive, and carry the propolis from
off the limbs of each with their teeth. ‘The upper
part of the hive exhibited the most animated spec-
tacle: thither a multitude of bees resorted from all
quarters, to engage in the predominant occupation
of the collection, distribution, and application of the
propolis. Some conveyed that of which they had
unloaded the purveyors in their teeth, and deposited
it in heaps ; others hastened, before its hardening, to
spread it out like a varnish, or formed it into strings,
proportioned to the interstices of the sides of the
hive to be filled up. Nothing could be more diver-
sified than the operations carried on.

“The bees, apparently charged with applying the

propolis from the tacamahaca tree ( Popudus balsamifera).—
Lotrod., ii. 186.

108 INSECT ARCHITECTURE,

propolis within the cells, were easily distinguished
from the multitude of workers, by the direction of
their heads towards the horizontal pane forming the
roof of the hive, and on reaching it, they deposited
their burden nearly in the middle of intervals sepa-
rating the combs: then they conveyed the propolis
to the real place of its destination. They suspended
themselves by the claws of the hind legs to points of
support, afforded by the viscosity of the propolis on
the glass; and, as it were, swinging themselves back-
wards and forwards, brought the heap of this substance
nearer to the cells at each impulse. Here the bees em-
ployed their fore feet, which remained free, to sweep
what the teeth had detached, and to unite the frag-
ments scattered over the glass, which recovered all
its transparency when the whole propolis was brought
to the vicinity of the cells.

“ After some of the bees had smoothed down and
cleaned out the glazed cells, feeling the way with
their antenne, one desisted, and having approached
a heap of propolis, drew out a thread with its teeth.
This being broken off, it was taken in the claws of the
fore feet, and the bee, re-entering the cell, imme-
diately placed it in the angle of two portions that
had been smoothed, in which operation the fore feet
and teeth were used alternately ; but probably proving
too clumsy, the thread was reduced and polished ;
and we admired the accuracy with which it was ad-
justed when the work was completed. The insect
did not stop here: returning to the cell, it prepared
other parts of it to receive a second thread, for which
we did not doubt that the heap would be resorted to,
Contrary to our expectation, however, it availed
itself of the portion of the thread cut off on the
former occasion, arranged it in the appointed place,
and gaye it all the solidity and finish of which it was
susceptible. Other bees concluded the work which
the first had begun; and the sides of the cells were

HIVE-BUES, 109

speedily secured with threads of propolis, while some
were also put on the orifices; but we could not seize
the moment when they were varnished, though it
may be easily conceived how it is done *.”

This is not the only use to which bees apply the
propolis. They are extremely solicitous to remove
such insects or foreign bodies as happen to get ad-
mission into the hive. When so light as not to
exceed their powers, they first kill the insect with
their stings, and then drag it out with their teeth.
But it sometimes happens, as was first observed by
Maraldi, and since by Réaumur and others, that an
ill-fated snail creeps into the hive: this is no sooner
perceived than it is attacked on all sides, and stung
to death. But how are the bees to carry out so
heavy a burthen? Such a labour would be in vain.
To prevent the noxious smell which would arise from
its putrefaction, they immediately embalm it, by co-
vering every part of its body with propolis, through
which no effluvia can escape. When a snail with a
shell gets entrance, to dispose of it gives much less
trouble and expense to the bees. As soon as it re-
ceives the first wound from a sting, it naturally
retires within its shell. In this case, the bees, instead
of pasting it all over with propolis, content them-
selves with gluing all round the margin of the shell,
which is sufficient to render the animal for ever im-
moveably fixed.

Mr. Knight, the learned and ingenious President of
the Horticultural Society, discovered by accident an
artificial substance, more attractive than any of the
resins experimentally tried by Réaumur. Having
caused the decorticated part of a tree to be covered
with a cement, composed of bees’-wax and turpentine,
he observed that this was frequei ted by hive-bees,
who, finding it to be a very good propolis ready made,

* Huber on Bees, p. 408,
He

110 INSECT ARCHITECTURE,

detached it from the tree by their mandibles, and
then, as usual, passed it from the first leg to the
second, and soon, When one bee had thus collected
its load, another often came behind and despoiled
it of all it had collected ; a second and a third load
were frequently lost in the same manner ; and yet
the patient insect pursued its operations without
manifesting any signs of anger”. Probably the
latter circumstance, at which Mr. Knight seems to
have been surprised, was nothing more than an instance
of the division of labour so strikingly exemplified in
every part of the economy of bees.

It may not be out of place here to describe the
apparatus with which the worker-bees are provided
for the purpose of carrying the propolis as well as
the pollen of flowers to the hive, and which has just
been alluded to in the observations of Mr. Knight.
The shin or middle portion of the hind pair of legs is
actually formed into a triangular basket, admirably
adapted to this design. The bottom of this basket

Structure of the legs of the Bee for carrying propolis and pollen, magnijies,
* Philosophical Trans. for 1807, p. 242.

Lo? ihe.

HIVE BEES. lt

ie composed of a smooth, shining, horn-like sub-
stance, hollowed out in the substance of the limb,
and surrounded with a margin of strong and thickly-
set bristles. Whatever materials, therefore, may be
placed by the bee in the interior of this basket, are
secured from falling out by the bristles around it,
whose elasticity will even allow the load to be heaped
beyond their points without letting it fall.

In the case of propolis, when the bee is loading
her singular basket, she first kneads the piece she
has detached with her mandibles, till it becomes
somewhat dry and less adhesive, as otherwise it would
stick to her limbs. This preliminary process some-
times occupies nearly half an hour. She then passes
it backwards by means of her feet to the cavity of her
basket, giving it two or three pats to make it adhere;
and when she adds a second portion to the first, she
often finds it necessary to pat it still harder. When
she has procured as much as the basket will conve-
niently hold, she flies off with it to the hive.

Tae Burpine or tHe CeLts.

The notion commonly entertained respecting glass
hives is altogether erroneous. Those who are un-
acquainted with bees imagine, that, by means of a
glass hive, all their proceedings may be easily watched
and recorded; but it is to be remembered that bees
are exceedingly averse to the intrusion of light, and
their first operation in such cases is to close up every
chink by which light can enter to disturb them,
either by clustering together, or by a plaster com-
posed of propolis. It consequently requires con-
siderable management and ingenuity, even with the
aid of a glass hive, to see them actually at work.
M. Huber employed a hive with leaves, which opened
in the manner of a book; and for some purposes he

H2

112 INSECT ARCHITECTURE.

used a glass box, inserted in the body of the hive,
but easily brought into view by means of serews.

But no invention hitherto contrived is sufficient to
obviate every difficulty. ‘The bees are so eager to
afford mutual assistance, and for this purpose so
many of them crowd together in rapid succession,
that the operations of individuals can seldom be
traced. Though this crowding, however, appears
to an observer to be not a little confused, it is all
regulated with admirable order, as has been ascer-
tained by Reaumur and other distinguished natu-
ralists,

When bees begin to build the hive, they divide
themselves into bands, one of which produces mate-
rials fur the structure ; another works upon these, and
forms them into a rough sketch of the dimensions and
partitions of the cells. All this is completed by the
second band, who examine and adjust the angles,
remove the superfluous wax, and give the work its
necessary perfection; and a third band brings pro-
visions to the labourers, who cannot leave their work.
But no distribution of food is made to those whose
charge, in collecting propolis and pollen, calls them
to the field, because it is supposed they will hardly
forget themselves; neither is any allowance made to
those who begin the architecture of the cells. Their
province is very troublesome, because they are obliged
to level and extend, as well as cut and adjust the wax
to the dimensions required; but then they soon ob-
tain a dismission from this labour, and retire to the
fields to regale themselves with food, and wear off
their fatigue with a more agreeable employment.
Those who succeed them, draw their mouth, their
feet, and the extremity of their body, several times
over all the work, and never desist till the whole is
polished and completed; and as they frequently need
vefreshments, and yet are not permitted to retire,

HIVE-BEES, 113

there are waiters always attending, who serve them
with provisions when they require them. The labourer,
who has an appetite, bends down his trunk before the
caterer, to intimate that he has au inclination to eat,
upon which the other opens his bag of honey, and
pours out a few drops; these may be distinctly seen
rolling through the whole of his trunk, which in-
sensibly swells in every part the liquor flows through.
When this little repast is over, the labourer returns to
his work, and his body and feet repeat the same mo-
tions as before*.

Before they can commence building, however,
when a colony or swarm migrates from the original
hive to a new situation, it is necessary first to collect
propolis, with which every chink and cranny in the
place where they mean to build may be carefully
stopped up; and, secondly, that a quantity of wax be
secreted by the wax-workers to form the requisite
cells. The secretion of wax, it would appear, goes
on best when the bees are in a state of repose ; and
the wax-workers, accordingly, suspend themselves
in the interior in an extended cluster, like a curtain
which is composed of a series of intertwined festoons
or garlands, crossing each other in all directions,—
the uppermost bee maintaining its position by laying
hold of the roof with its fore legs, and the succeeding
one by laying hold of the hind legs of the first.

“ A person,” says Réaumur, “ must have been
born devoid of curiosity not to take interest in the
investigation of such wonderful proceedings.” Yet
Réaumur himself seems not to have understood that
the bees suspended themselves in this manner to
secrete wax, but merely, as he imagined, to recruit
themselves by rest for renewing their labours. The
bees composing the festooned curtain are individu-
ally motionless; but this curtain is, notwithstanding,

* Spectacle de la Nature, tom, i.

114 INSECT ARCHITECTURE,

kept moving by the proceedings in the interior; for
the nurse-bees never form any portion of it, and
continue their activity—a distinction with which
Réaumur was unacquainted.

Curtain of Vaw-workers secreting Vax,

Although there are many thousand labourers in 3
hive, they do not commence foundations for combs

err At Pe

HIVE-BEES, 115

in several places at once, but wait till an individua.
bee has selected a site, and laid the foundation of. a
comb, which serves as a directing mark for all that
are to follow. Were we not expressly told by so
accurate an observer as Huber, we might hesitate to
believe that bees, though united in what appears to
be a harmonious monarchy, are strangers to sub-
ordination, and subject to no discipline. Hence it
is, that though many bees work on the same comb,
they do not appear to be guided by any simultaneous
impulse. The stimulus which moves them is suc-
cessive. An individual bee commences each opera-
tion, and several others successively apply themselves
to accomplish the same purpose, Hach bee appears,
therefore, to act individually, either as directed by the
bees preceding it, or by the state of advancement in
which it finds the work it has to proceed with. If
there be anything like unanimous consent, it is the
inaction of several thousand workers while a single
individual proceeds to determine and lay down the
foundation of the first comb. Reéaumur regrets, that,
though he could by snatches detect a bee at work in
founding cells or perfecting their structure, his ob-
servations were generally interrupted by the crowding
of other bees between him and the little builder.
He was therefore compelled rather to infer the dif
ferent'steps of their procedure from an examination
of the cells when completed, than from actual ob-
servation. The ingenuity of Huber, even under all
the disadvantages of blindness, succeeded in tracing
the minutest operations of the workers from the first
waxen plate of the foundation. We think the narra-
tive of the discoverer’s experiments, as given by him-
self, will be more interesting than any abstract of it
which we could furnish.

« Having taken a large bell-shaped glass receiver,
we glued thin wooden slips to the arch at certain in-

116 INSECT ARCHITECTURE,

tervals, because the glass itself was too smooth to
admit of the bees supporting themselves on it. A
swarm, consisting of some thousand workers, several
hundred males, and a fertile queen, was introduced,
and they soon ascended to the top. Those first
gaining the slips, fixed themselves there by the fore
feet; others scrambling up the sides, joined them,
by holding their legs with their own, and they thus
formed a kind of chain, fastened by the two ends to
the upper parts of the receiver, and served as ladders
or a bridge to the workers enlarging their number.
The latter were united in a cluster, hanging like an
inverted pyramid from the top to the bottom of the hive.

“ The country then affording little honey, we pro-
vided the bees with syrup of sugar, in order to hasten
their labour. They crowded to the edge of a vessel
containing it; and, having satisfied themselves, re-
turned to the group. We were now struck with the
absolute repose of this hive, contrasted with the usual
agitation of bees. Meanwhile, the nurse-bees alone
went to forage in the country: they returned with
pollen, kept guard at the entrance of the hive,
cleansed it, and stopped up its edges with propolis.
The wax-workers remained motionless above fifteen
hours: the curtain of bees, consisting always of the
same individuals, assured us that none replaced them,
Some hours later, we remarked that almost all these
individuals had wax scales under the rings; and
next day this phenomenon was still more general.
The bees forming the external layer of the cluster,
having now somewhat altered their position, enabled
us to see their bellies distinctly. By the projection
of the wax scales, the rings seemed edged with
white. ‘The curtain of bees became rent in several
places, and some commotion began to be observed
in the hive,

“ Convinced that the combs would originate in

HIVE-BEES, 117

the centre of the swarm, our whole attention was
then directed towards the roof of the glass. A worker
at this time detached itself from one of the central
festoons of the cluster, separated itself from the
crowd, and, with its head, drove away the bees at
the beginning of the row in the middle of the arch,
turning round to form a space an inch or more in
diameter, in which it might move freely. It then
fixed itself in the centre of the space thus cleared.
“The worker now employing the pincers at the
joint of one of the third pair of its limbs, seized a
scale of wax projecting from a ring, and brought it
forward to its mouth with the claws of its fore legs,

Wax-worker laying the foundation of the first Cell,

where it apppeared in a vertical position. We re-
marked, that, with its claws, it turned the wax in
every necessary direction; that the edge of the scale
was immediately broken down, and the fragments
having been accumulated in the hollow of the mandi-
bles, issued forth like a very narrow ribbon, impreg-
nated with a frothy liquid by the tongue. The
tongue itself assumed the most varied shapes, and
executed the most complicated operations,—being
sometimes flattened like a trowel, and at other times
pointed like a pencil; and, after imbuing the whole
substance of the ribbon, pushed it forward again
into the mandibles, whence it was drawn out a
second time, but in an opposite direction.

“ At length the bee applied these particles of wax
to the vault of the hive, where the saliva impreg-
nating them promoted their adhesion, and also coms

H 5

118 INSECT ARCHITECTURE,

municated a whiteness and opacity, which were want-
ing when the scales were detached from the rings,
Doubtless, this process was to give the wax that
ductility and tenacity belonging to its perfect state.
The bee then separated those portions not yet
applied to use with its mandibles, and with the same
organs afterwards arranged them at pleasure. The
founder bee, a name appropriate to this worker,
repeated the same operation, until all the fragments,
worked up and impregnated with the fluid, were
attached to the vault, when it repeated the preceding
operations on the part of the seale yet kept apart,
and again united to the rest what was obtained from
it, A second and third scale were similarly treated
by the same bee; yet the work was only sketched;
for the worker did nothing but accumulate the par-
ticles of wax together. Meanwhile, the founder,
quitting its position, disappeared amidst its com-
panions. Another, with wax under the ring’s, suc-
ceeded it, which, suspending itself to the same spot,
withdrew a scale by the pincers of the hind legs, and
passing it through its mandibles, prosecuted the
work ; and taking care to make its deposit in a line
with the former, it united their extremities. A third
worker, detaching itself from the interior of the
cluster, now came and reduced some of the scales
to paste, and put them near the materials accu-
mulated by its companions, but not in a straight line.
Another bee, apparently sensible of the defect, removed
the misplaced wax before our eyes, and carrrying it
to the former heap, deposited it there, exactly in the
order and direction pointed out.

“ From all these operations was produced a block
of a rugged surface, hanging down from the arch,
without any perceptible angle, or any traces of cells,
Tt was a simple wall, or ridge, running in a straight
line, and without the least inflection, two-thirds of

HIVE-BEES, 119

an inch in length, about two-thirds of a cell, or two
lines, high, and declining towards the extremities.
We have seen other foundation walls from an inch
to an inch and a half long, the form being always
the same; but none ever of greater height.

“The vacuity in the centre of the cluster had per-
mitted us to discover the first mancnyres of the
bees, and the art with which they laid the foundations
of their edifices. However, it was filled up too soon
for our satisfaction ; for workers collecting on both
faces of the wall obstructed our view of their further
operations *.”

Curtain of Wax-workers.—(See p, 114,)
p- 358,

120

Cuarter VI.

ARCHITECTURE OF THE HIVE-BEE CONTINUED.—FORM
OF THE CELLS.

Tur obstruction of which M. Huber complains only
operated as a stimulus to his ingenuity in contriving
how he might continue his interesting observations.
From the time of Pappus to the present day, mathe-
maticians have applied the principles of geometry to
explain the construction of the cells of a bee-hive;
but though their extraordinary regularity, and won-
derfully selected form, had so often been investigated
by men of the greatest talent, and skilled in all the
refinements of science, the process by which they are
constructed, involving also the causes of their regu-
larity of form, had not been traced till M. Huber
devoted himself to the inquiry.

As the wax-workers secrete only a limited quantity
of wax, it is indispensably requisite that as little as
possible of it should be consumed, and that none of it
should be wasted, Bees, therefore, as M. Réaumur
well remarks*, have to solve this difficult geometrical
problem :—A quantity of wax being given, to form
of it similar and equal cells of a determinate capa-
city, but of the largest size in proportion to the
quantity of matter employed, and disposed in such a
manner as to occupy the least possible space in the
hive. This problem is solved by bees in all its con-
ditions. "The cylindrical form would seem to be best
adapted to the shape of the insect ; but had the cells
been cylindrical, they could not have been applied to

* Reaumur, vol. y., pr. 380,

HIVE-BEES, 121

each other without leaving a vacant and superfluous
space between every three contiguous cells, Had the
cells, on the other hand, been square or triangular, they
might have been constructed without unnecessary
vacancies; but these forms would have both required
more material and been very unsuitable to the shape
of a bee’s body. The six-sided form of the cells
obviates every objection ; and while it fulfils the con-
ditions of the problem, it is equally adapted with a
cylinder to the shape of the bee.

M. Réaumur further remarks, that the base of
each cell, instead of forming a plane, is usually com-
posed of three pieces in the shape of the diamonds
on playing cards, aud placed in such a manner as to
form a hollow pyramid. This structure, it may be
observed, imparts a greater degree of strength, and,
still keeping the solution of the problem in view,
gives a great capacity with the smallest expenditure of
material. This has actuaily, indeed, been ascertained
by mathematical measurement and calculation. Ma-
raldi, the inventor of glass hives, determined, by
minutely measuring these angles, that the greater
were 109° 28’, and the smaller, 70° 32’; and M.
Réaumur, being desirous to know why these parti-
cular angles are selected, requested M. Koenig, a
skilful mathematician, (without informing him of his
design, or telling him of Maraldi’s researches,) to
determine, by calculation, what ought to be the angle
of a six-sided cell, with a concave pyramidal base,
formed of three similar and equal rhomboid plates,
so that the least possible matter should enter into its
construction. By employing what geometricians de-
nominate the infinitesimal calculus, M. Koenig found
that the angles should be 109° 26’ for the greater,
and 70° 34’ for the smaller, or about two-sixtieths of
a degree, more or less, than the actual angles made
choice of by bees. The equality of inclination in the

122 INSECT ARCHITECTURE,

angles has also been said to facilitate the construction
of the cells.

M. Huber adds to these remarks, that the cells of
the first row, by which the whole comb is attached
to the roof of a hive, are not like the rest; for
instead of six sides they have only five, of which the
roof forms one. The base, also, is in these different,
consisting of three pieces on the face of the comb,
and on the other side of two: one of these only is
diamond-shaped, while the other two are of an irre-
gular four-sided figure. ‘This arrangement, by bring-
ing the greatest number of points in contact with the
interior surface, ensures the stability of the comb.

It may, however, be said not to be quite certain,
that Réaumur and others have not ascribed to bees
the merit of ingenious mathematical contrivance and
selection, when the construction of the cells may more
probably originate in the form of their mandibles and
other instruments employed in their operations. In
the case of other insects, we have, both in the preced-
ing and subsequent pages of this volume, repeatedly
noticed, that they use their bodies, or parts thereof,
as the standards of measurement and modelling; and
it is not impossible that bees may proceed on a
similar principle, M, Huber replies to this objection,

HIVE-BEES, 123

that bees are not provided with instruments corre-
sponding to the angles of their cells; for there is no
more resemblance between these and the form of
their mandibles, than between the chisel of the
sculptor and the work which he produces. The
head, he thinks, does not furnish any better explana-
tion. He admits that the antenne are very flexible,
so as to enable the insects to follow the outline of
every object; but concludes that neither their struc-
ture, nor that of the limbs and mandibles, are ade-
quate to explain the form of the cells, though all
these are employed in the operations of building,—
the effect, according to him, depending entirely on
the object which the insect proposes.

We shall now follow M. Huber in the experiments
which he contrived, in order to observe the operations
of the bees subsequent to their laying a foundation
for the first cell; and we shall again quote from his
own narrative :—

“Tt appeared to me,” he says, “that the only
method of isolating the architects, and bringing
them individually into view, would be to induce
them to change the direction of their operations, and
work upwards.

“JT had a box made twelve inches square and nine
deep, with a moveable glass lid. Combs full of
brood, honey, and pollen, were next selected from
one of my leaf hives, as containing what might in-
terest the bees, and being cut into pieces a foot long,
and four inches deep, they were arranged vertically
at the bottom of the box, at the same intervals as
the insects themselves usually leave between them.
A small slip of wooden lath covered the upper edge
of each. It was not probable that the bees would
attempt to found new combs on the glass roof of the
box, because its smoothness precluded the swarm
from adhering to it; therefore, if disposed to build,

124 INSECT ARCHITECTURE,

they could do so over the slips resting on the combs,
which left a vacuity five inches high above them. As
we had foreseen, the swarm with which this box was
peopled established itself among the combs below.
We then observed the nurse-bees displaying their
natural activity. ‘They dispersed themselves through-
out the hive, to feed the young grubs, to clear out
their lodgment, and adapt it for their convenience.
Certainly, the combs, which were roughly cut to fit
the bottom of the box, and in some parts damaged,
appeared to them shapeless and misplaced ; for they
speedily commenced their reparation. ‘They beat
down the old wax, kneaded it between their teeth, and
thus formed binding materials to consolidate them.
We were astonished beyond expression by such a
multitude of workers employed at once in labours
to which it did not appear they should have been
called, at their coincidence, their zeal, and their pru-
dence,

“ But it was still more wonderful, that about half
the numerous population took no part in the pro-
ceedings, remaining motionless, while the others ful-
filled the functions required. The wax-workers, in
a state of absolute repose, recalled our former obser-
vations, Gorged with the honey we had put within
their reach, and continuing in this condition during
twenty-four hours, wax was formed under their rings,
and was now ready to be put in operation. To our
great satisfaction, we soon saw a little foundation
wall rising on one of the slips that we had prepared
to receive the superstructure. No obstacle was of-
fered to the progress of our observations ; and for the
second time, we beheld both the undertaking of the
founder bee, and the successive labours of several
wax-workers, in forming the foundation wall, Would
that my readers could share the interest which the
view of these architects inspired !

HIVE-BEES, 125

“This foundation, originally very small, was en-
larged as the work required; while they excavated
on one side a hollow, of about the width of a com-
mon cell, and on the opposite surface two others
somewhat more elongated. The middle of the single
cell corresponded exactly to the partition separating
the latter; the arches of these excavations, projecting
by the accumulation of wax, were converted into
ridges in a straight line ; whence the cells of the first
row were composed of five sides, considering the
slip as one side, and those of the second row, of six
sides.

Foundation-wall enlarged, and the cells commenced,

“The interior conformation of the cavities, ap-
parently, was derived from the position of their re-
spective outlines, It seemed that the bees, endowed
with an admirable delicacy of feeling, directed their
teeth principally to the place where the wax was
thickest; that is, the parts where other workers on
the opposite side had accumulated it; and this ex-
plains why the bottom of the cedl is excavated in an
angular direction behind the projection on the sides
of which the sides of the corresponding cells are to
rise. The largest of the excavations, which was op-
, site to three others, was divided into three parts,
while the excavations of the first row on the other
face, applied against this one, were composed of only
two.

Tn consequence of the manner in which the ex-
cavations were opposed to each other, those of the
second row, and all subsequent, partially applied to
three cavities, were composed of three equal diamonds

126 INSECT ARCHITECTURE,

shaped lozenges. I may here remark, that each part
of the labour of bees appears the natural result of
what has preceded it; therefore, chauce has no share
in these admirable combinations.

“A foundation wall rose above the, slip like a
minute vertical partition, five or six lines long, two
lines high, but only half a line in thickness; the edge
circular, and the surface rough. Quitting the cluster
among the combs, a nurse-bee mounted the slip,
turned around the block, and visiting both sides,
began to work actively in the middle. It removed
as much wax with its teeth as might equal the
diameter of a common cell; and after kneading and
moistening the particles, deposited them on the edge
of the excavation. his insect, having laboured
Some seconds, retired, and was soon replaced by
another; a third continued the work, raising the
margin of the edges, now projecting from the cavity,
and with assistance of its teeth and feet fixing the
particles, so as to give these edges a straighter form.
More than twenty bees successively participated in
the same work ; and when the cavity was little above
a line and a half in height, though equalling a cell in
width, a bee left the swarm, and after encircling the
block, commenced its operations on the opposite face,
where yet untouchetl. But its teeth acting only on
one half of this side, the hollow which it formed was
Opposite to ouly one of the slight prominences bor-
dering the first cavity. Nearly at the same time
another worker began on the right of the face that
had been untouched, wherein both were occupied in
forming cavities, which may be designed the second
and third; and they also were replaced by substi-
tutes. ‘These two latter cavities were separated only
by the common margin, framed of particles of wax
withdrawn from them; which margin corresponded
with the centre of the cavity on the opposite surface.

HIVE-BEES, 127

The foundation wall itself was still of insufficient
dimensions to admit the full diameter of a cell; but
while the excavations were deepened, wax-workers
extracting their scales of wax applied them in en-
larging its circumference; so that it rose nearly two
,ines further around the circular arch. The nurse-
bees, which appeared more especially charged with
sculpturing the cells, being then enabled to continue
their outlines, prolonged the cavities, and heightened
their margins on the new addition of wax.

“The arch, formed by the edge of each of these
cavities, was next divided as by two equal chords, in
the line of which the bees formed stages or project-
ing borders, or margins meeting at an obtuse angle ;
the cavities now had four margins, two lateral and
perpendicular to the supporting slip, and two oblique,
which were shorter.

“ Meantime, it became more difficult to follow the
operations of the bees, from their frequently inter-
posing their heads between the eye of the observer
and the bottom of the cell; but the partition, whereon
their teeth laboured, had become so transparent, as
to expose what passed on the other side.

“The cavities of which we speak, formed the
bottom of the first three cells; and while the bees
engaged were advancing them to perfection, other
workers commenced sketching a second row of cells
above the first, and partly behind those in front—
for in general, their labour proceeds by combination.
We cannot say, ‘ When bees have finished this cell,
they will begin new ones;’ but, ‘ while particular
workers advance a certain portion, we are certain
that others will carry on the adjacent cells.’ Farther,
the work begun on one face of the comb is already
the commencement of that which is to follow on the
reverse. All this depends on a reciprocal relation,
or a mutual connexion of the parts, rendering the

128 INSECT ARCHITECTURE.

whole subservient to each other. It is undoubted,
therefore, that slight irregularities on the front will
affect the form of the cells on the back of the comb *,”

When they have in this manner worked the bot-
tom of the first row of cells into the required forms,
some of the nurse-bees finish them by imparting a
sort of polish, while others proceed to cut out the
rudiments of a second row from the fresh wall of
wax which has been built in the meanwhile by the
wax-workers, and also on the opposite side of this
wall; for a comb of cells is always double, being
arranged in two layers, placed end to end. ‘The cells
of this second row are engrafted on the borders of
cavities hollowed out in the wall, being founded by
the nurse-bees, bringing the contour of all the bot-
toms, which is at first unequal, to the same level ;
and this level is kept uniform in the margins of the
cells till they are completed. At first sight, nothing
appears more simple, than adding wax to the mar-
gins; but from the inequalities occasioned by the
shape of the bottom, the bees must accumulate wax
on the depressions, in order to bring them to a level.
It follows accordingly that the surface of a new
comb is not quite flat, there being a progressive slope
produced as the work proceeds, and the comb being
therefore in the form of a lens, the thickness decreasiug
towards the edge, and the last formed cells being
shallower or shorter than those preceding them. So
long as there is room for the enlargement of the
comb, this thinning of its edge may be remarked ;
but as soon as the space within the hive prevents its
enlargement, the cells are made equal, and two flat
and level surfaces are produced.

M. Huber observed, that while sketching the
bottom of a cell, before there was any upright mar-
gin on the reverse, their pressure on the still soft

* Huber on Bees, p. 368,

HIVE-BEES, 129

and flexible wax gave rise to a projection, which
sometimes caused a breach of the partition. This,
however, was soon repaired, but a slight prominence
always remained on the opposite surface, to the right
and left of which they placed themselves, to begin a
new excavation; and they heaped up part of the
materials between the two flutings formed by their
labour. The ridge thus formed becomes a guide to
the direction which the bees are to follow for the
vertical furrow of the front cell.

We have already seen that the first cell determines
the place of all that succeed it, and two of these are
never in ordinary circumstances begun in different
parts of the hive at the same time, as is alleged by
some earlier writers. When some rows of cells,
however, have been completed in the first comb, two
other foundation walls are bezun, one on each side of
it, at the exact distance of one-third of an inch, which
is sufficient to allow two bees employed on the op-
posite cells to pass each other without jostling. These
new walls are also parallel to the former; and two
more are afterwards begun exterior to the second,
and at the same parallel distance. The combs are
uniformly enlarged, and lengthened in a progression
proportioned to the priority of their origin ; the
middle comb being always advanced beyond the two
adjoining ones by several rows of cells, and these
again beyond the ones exterior to them. Did the
bees lay the foundations of all their combs at the
same time, they would not find it easy to preserve
parallelism and an equality in their distances. It may
be remarked further, that beside the vacancies of
half an inch between the cells, which form what we
may call the highways of the community, the combs
are pierced in several places with holes, which serve
as postern-gates for easy communication from one to
another, to prevent loss of time in going round. The

130 INSECT ARCHITECTURE,

equal distance between the combs is of more impor
tance to the welfare of the hive than might at first
appear; for were they too distant, the bees would be
so scattered and dispersed, that they could not re-
ciprocally communicate the heat indispensable for
hatching the eggs and rearing the young. If the
combs, on the other hand, were closer, the bees
could not traverse the intervals with the freedom
necessary to facilitate the work of the hive. On the
approach of winter, they sometimes elongate the
cells which contain honey, and thus contract the
intervals between the combs. But this expedient is
in preparation for a season when it is important to
have copious magazines, and when their activity
being relaxed, it is unnecessary for their communi+
cations to be so spacious and free. On the return of
spring, the bees hasten to contract the elongated
cells, that they may become fit for receiving the
eggs which the queen is about to deposit, and in
this manner they re-establish the regular distance *.

We are indebted to the late Dr. Barclay of Edin-
burgh, well known as an excellent anatomist, for
the discovery that each cell in a honeycomb is not
simply composed of one wall, but consists of two.
We shall give the aceount of his discovery in his own
words :—

“ Having inquired of several naturalists whether
or not they knew any author who had mentioned
that the partitions between the cells of the honey-
comb were double, and whether or not they had ever
remarked such a structure themselves, and they hav-
ing answered in the negative; I now take the liberty
of presenting to the Society pieces of honeycomb
in which the young bees had been reared, upon
breaking which it will be clearly seen that the par-
titions between different cells, at the sides and the

* Huber on Bees, p, 220,

HIVE-BEES, 1381

base, are all dowble; or, in other words, that each
cell is a distinct, separate, and in some measure an
independent structure, agglutinated only to the neigh-
bouring cells ; and that when the agglutinating sub-
stance is destroyed, each cell may be entirely sepa-
rated from the rest.

‘« T have also some specimens of the cells formed
by wasps, which shew*that the partitions between
them are also double, and that the agglutinating sub-
stance between them is more easily destroyed than
that between the cells of the bee*.”

TRREGULARITIES IN THEIR WoRKMANSHIP.

Though bees, however, work with great uniformity
when circumstances favour their operations, they may
be compelled to vary their proceedings. M. Huber
made several ingenious experiments of this kind.
The following, mentioned by Dr. Bevan, was acci-
dental, and occurred to his friend Mr. Walond.
“ Tnspecting his bee-boxes at the end of October,
1817, he perceived that a centre comb, burdened
with honey, had separated from its attachments, and
was leaning against another comb, so as to prevent
the passage of the bees between them. This acci-
dent excited great activity in the colony; but its
nature could not be ascertained at the time. At the
end of a week, the weather being cold, and the bees
clustered together, Mr. Walond observed, through
the window of the box, that they had constructed
two horizontal pillars betwixt the combs alluded to;
and had removed so much of the honey and wax
from the top of each, as to allow the passage of a
bee: in about ten days more, there was an unin-
terrupted thoroughfare ; the detached comb at its
upper part had been secured by a strong barrier, and

* Memoirs of the Wernerian Nat. Hist, Soc., vol.ii. p. 260.

132 INSECT ARCHITECTURE,

fastened to the window with the spare wax. This
being accomplished, the bees removed the horizontal
pillars first constructed as being of no further use*.”

A similar anecdote is told by M. Huber. “ Dur-
ing the winter,” says he, ““a comb in one of my
bell-glass hives, having been originally insecure, fell
down, but preserved its position parallel to the rest.
The bees were unable to fill*up the vacuity left above
it, because they do not build combs of old wax, and
none new could be then obtained. Ata more favour-
able season they would have ingrafted a new comb
on the old one; but now their provision of honey
could not be spared for the elaboration of this sub-
stance, which induced them to ensure the stability
of the comb by another process.

“ Crowds of bees taking wax from the lower part
of other combs, and even gnawing it from the sur-
face of the orifices of the deepest cells, they con-
structed so many irregular pillars, joists, or but-
tresses, between the sides of the fallen comb, and
others on the glass of the hive, All these were arti-
ficially adapted to localities. Neither did they con-
fine themselves to repairing the accidents which their
works had sustained. 'lhey seemed to profit by the
warning, to guard against a similar casualty.

“The remaining combs were not displaced ; there-
fore, while solidly adhering by the base, we were
greatly surprised to see the bees strengthen their
principal fixtures with old wax, They rendered
them much thicker than before, and fabricated a
number of new connexions, to unite them more
firmly to each other, and to the sides of their dwelling.
All this passed in the middle of January, a time that
these insects commonly keep in the upper part ot
their hive, and when work is no longer seasonablet.”

M. Huber the younger shrewdly remarks, that

* Bevan on Bees, p. 326. + Huber on Bees, p. 416,

HIVE-BEES, 133

the tendency to symmetry, observable in the archi-
tecture of bees, does not hold so much in small de-
tails as in the whole work, because they are some-
times obliged to adapt themselves to particular loca-
lities. One irregularity leads on to another, and it
commonly arises from mere accident, or from design
on the part of the proprietor of the bees. By allow-
ing, for instance, too little interval between the spars
for receiving the foundation of the combs, the struc-
ture has been continued in a particular direction.
The bees did not at first appear to be sensible of the
defect, though they afterwards began to suspect their
error, and were then observed to change their line of
work till they gained the customary distance. The
cells having been by this change of direction in some
degree curved, the new ones which were commenced
on each side of it, by being built every where parallel
to it, partook of the same curvature. But the bees
did not relish such approaches to the “line of beauty,”
and exerted themselves to bring their buildings again
into the regular form.

In consequence of several irregularities which they
wished to correct, the younger Huber has seen bees
depart from their usual practice, and at once lay on
a spar two foundation walls not in the same line.
They could consequently neither be enlarged without
obstructing both, nor from their position could the
edges unite had they been prolonged. ‘The little
architects, however, had recourse to a very ingenious
contrivance : they curved the edges of the two combs,
and brought them to unite so neatly that they could
be both prolonged in the same line with ease; and
when carried to some little distance, their surface
became quite uniform and level.

“* Having seen bees,” says the elder Huber, “ work
both up and down, I wished to try to investigate
whether we could compel them to construct their

i

134 INSECT ARCHITECTURE.

combs in any other direction. We endeavoured to
puzzle them with a hive glazed above and below, so
that they had no place of support but the upright
sides of their dwelling; but, betaking themselves to
the upper angle, they built their combs perpendicular
to one of these sides, and as regularly as those
which they usually build under a horizontal surface.
The foundations were laid on a place which does not
serve naturally for the base, yet, except in the dif
ference of direction, the first row of cells resembled
those in ordinary hives, the others being distributed
on both faces, while the bottoms alternately corre-
sponded with the same symmetry. I put the bees to
a still greater trial. As they now testified their in-
clination to carry their combs, by the shortest way,
to the opposite side of the hive (for they prefer
uniting them to the wood, or a surface rougher than
glass), I covered it with a pane. Whenever this
smooth and slippery substance was interposed be-
tween them and the wood, they departed from the
straight line hitherto followed, and bent the struc-
ture of their comb at a right angle to what was al-
ready made, so that the prolongation of the extremity
might reach another side of the hive, which had been
lefi free.

“Varying this experiment in several ways, I saw
the bees constantly change the direction of their
combs when [ presented to them a surface too
smooth to admit of their clustering on it. They al-
ways sought the wooden sides. I thus compelled
them to curve the combs in the strangest shapes, by
placing a pane at a certain distance from their edges.
These results indicate a degree of instinct truly
wonderful. They denote even more than instinct:
for glass is not a substance against which bees can
be warned by nature. In trees, their natural abode,
there is nothing that resembles it, or with the same

71" = ve

HLVE-BEES, 135

polish. The most singular part of their proceeding
is changing the direction of the work before arriving
at the surface of the glass, and while yet at a dis-
tance suitable for doing so. Do they anticipate the
inconvenience which would attend any other mode
of building? No less curious is the plan adopted
by the bee for producing an angle in the combs: the
wonted fashion of their work, and the dimensions of
the cells, must be altered. Therefore, the cells on
the upper or convex side of the combs are enlarged ;
they are constructed of three or four times the width
of those on the opposite surface. How can so many
insects, occupied at once on the edges of the combs,
concur in giving them a common curyature from one
extremity to the other? How do they resolve on
establishing cells so small on one side, while dimen-
sions so enlarged are bestowed on those of the other?
And is it not still more singular, that they have the
art of making a correspondence between cells of
such reciprocal discrepance? The bottom being com-
mon to both, the tubes alone assume a taper form.
Perhaps no other insect has afforded a more decisive
proof of the resources of instinct, when compelled to
deviate from the ordinary course.

“ But let us study them in their natural state, and
there we shall find that the diameter of their cells
must be adapted to the individuals which shall be
bred in them, The cells of males have the same
‘igure, the same number of lozenges and sides as
lose of workers, and angles of the same size.
Their diameter is 34 lines, while those of workers
are only 2%.

“Tt is rarely that the cells of males oceupy the
higher part of the combs. They are generally in
the middle or on the sides, where they are not iso-
lated. The manner in which they are surrounded
by other cells alone can explain how the transition

136 ~ INSECT ARCHITECTURE,

in size is effected. When the cells of males are to be
fabricated under those of workers, the bees make
several rows of intermediate cells, whose diameter
augments progressively, until gaining that ‘propor-
tion proper to the cells required; and, in returning
to those of workers, a lowering is observed in a
manner corresponding.

“ Bees, in preparing the cells of males, previously
establish a block or lump of wax on the edge of their
comb, thicker than is usually employed for those of
workers. It is also made higher, otherwise the same
order and symmetry could not be preserved on a
larger scale.

“ Several naturalists notice the irrezularities in the
cells of bees as so many defects. What would have
been their astonishment had they observed that part of
them are the result of calculation? Had they followed
the imperfection of their organs, some other means
of compensating them would have been granted to the
insects. It is much more surprising that they know
how to quit the ordinary route, when circumstances
demand the construction of enlarged cells; and, after
building thirty or forty rows of them, to return to the
proper proportions from which they have departed, by
successive reductions. Bees also augment the dimen-
sions of their cells when there is an opportunity for
a great collection of honey. Not only are they then
constructed of a diameter much exceeding that of the
common cells, but they are elongated throughout the
whole space admitting it. A great portion of irre-
gular comb contains cells an inch, or even an inch
and a half, in depth. ;

“ Bees, on the contrary, sometimes are induced
to shorten their cells. When wishing to prolong an
old comb, whose cells have received their full dimen-
sions, they gradually reduce the thickness of its edges,
hy gnawing down the sides of the cells, until they

HIVE-BEES, 137

restore it to its original lenticular form. They add
a waxen block around the whole circumference, and
on the edge of the comb construct pyramidal bottoms,
such as those fabricated on ordinary occasions. It is
a certain fact, that a comb never is extended in any
direction unless the bees have thinned the edges,
which are diminished throughout a sufficient space
to remove any angular projection.

“The law which obliges these insects partly to de-
molish the cells on the edges of the comb before en-
larging it, unquestionably demands more profound in-
vestigation. How can we account for instinct leading
them to undo what they have executed with the utmost
care? The wonted regular gradation, which may be
necessary for new cells, subsists among those ad-
joining the edges of a comb recently constructed.
But afterwards, when those on the edge are deepened
like the cells of the rest of the surface, the bees no
longer preserve the decreasing gradation which is
seen in the new combs*.”

Tue FInisHine or tHe Cevis.

While the cells are building, they appear to be of
a dull white colour, soft, even, though not smooth,
and translucent: but in a few days they become
tinged with yellow, particularly on the interior sur-
face; and their edges, from being thin, uniform, and
yielding, become thicker, less regular, more heavy,
and so firm that they will bend rather than break.
New combs break on the slightest touch. There is
also a glutinous substance observable around the
orifices of the yellow cells, of reddish colour, unctuous,
and odoriferous. Threads of the same substance are
applied all around the interior of the cells, and at the
summit of their angles, as if it were for the purpose

“ Huber on Bees, p. 391.
13

138 INSECT ARCHITECTURE,

of binding and strengthening the walls. These
yellow cells also require a much higher temperature
of water to melt them than the white ones.

It appeared evident, therefore, that another sub-
stance, different from wax, had been employed- in
varnishing the orifices and strengthening the in-
terior of the cells. M. Huber, by numerous ex-
periments, ascertained the resinous threads lining
the cells, as well as the resinous substance around
their orifice, to be propolis; for he traced them,
as we mentioned in our account of propolis, from
the poplar buds where they collected it, and saw
them apply it to the cells; but the yellow colour is
not imparted by propolis, to which it bears no ana-
logy. We are, indeed, by no means certain what
it is, though it was proved by experiment not to
arise from the heat of the hives, nor from emanations
of honey, nor from particles of pollen. Perhaps
it may be ascribed to the bees rubbing their teeth,
feet, and other parts of their body on the surfaces
where they seem to rest; orto theirtongue (haustellum)
sweeping from right to left like a fine pliant pencil,
when it appears to leave some sprinkling of a trans-
parent liquid.

Beside painting and varnishing their cells in this
manner, they take care to strengthen the weaker parts
of their edifice by means of a mortar composed of
propolis and wax, and named pissoceros* by the an-
cients, who first observed it, though Réaumur was
somewhat doubtful respecting the existence of such
a composition. We are indebted to the shrewd ob-
servations of Huber for a reconcilement of the Roman
and the French naturalists. The details which he
has given of his discovery are perhaps the most in-
teresting in his delightful book.

“Soon,” he says, ‘‘ after some new combs had been

* From two Greek words, signifying pitch and waa.

HIVE-BEES, 139

finished ina hive, manifest disorder and agitation pre-
vailed among the bees. ‘They seemed to attack their
own works. The primitive cells, whose structure we
had admired, were scarcely recognizable, Thick and
massy walls, heavy shapeless pillars, were substituted
for the slight partitions previously built with such regue
larity. The substance had changed along with the form,
being composed apparently of wax and propolis. From
the perseverance of the workers in their devastations,
we suspected that they proposed some useful alteration
of their edifices; and our attention was directed to the
cells least injured. Several were yet untouched; but
the bees soon rushed precipitately on them, destroyed
the tubes, broke down the wax, and threw all the
fragments about, But we remarked, that the bottom
of the cells of the first row was spared; neither were
the corresponding parts on both faces of the comb
demolished at the same time. ‘The bees laboured at
them alternately, leaving some of the natural sup-
ports, otherwise the comb would have fallen down,
which was not their object; they wished, on the con-
trary, to provide it a more solid base, and to secure
its union to the vault of the hive, with a substance
whose adhesive properties infinitely surpassed those
of wax. The propolis employed on this occasion
had been deposited in a mass over a cleft of the hive,
aud had hardened in drying, which probably ren-
dered it more suitable for the purpose. But the bees
experienced some difficulty in makiag any impression
on it; and we thought, as also had appeared to M.
de Réaumur, that they softened it with the same
frothy matter from the tongue which they use to ren-
der wax more ductile.

“We very distinctly observed the bees mixing
fragments of old wax with the propolis, kneading the
two substances together to incorporate them; and.
the compound was employed in rebuilding the cells

140 INSECT ARCHITECTURE,

that had been destroyed. But they did not now fol-'
low their ordinary rules of architecture, for they were
oecupied by the solidity of their edifices alone.
Night intervening, suspended our observations, but
next morning confirmed what we had seen.

“ We find, therefore, that there is an epoch in the ~
labour of bees, when the upper foundation of their
combs is constructed simply of wax, as Réaumur
believed; and that after all the requisite conditions
have been attained, it is converted to a mixture of wax
and propolis, as remarked by Pliny so many ages
before us. Thus is the apparent contradiction be-
tween these two great naturalists explained. But
this is not the utmost extent of the foresight of these
insects. When they have plenty of wax, they make
their combs the full breadth of the hive, and solder
them to the glass or wooden sides, by structures
more or less approaching the form of cells, as
circumstances admit. But should the supply of wax
fail before they have been able to give suflicient
diameter to the combs whose edges are rounded,
large intervals remain between them and the upright
sides of the hive, and they are fixed only at the top.
Therefore, did not the bees provide against it, by con-
structing great pieces of wax mixed with propolis in
the intervals, they might be borne down by the
weight of the honey. ‘These pieces are of irregular
shape, strangely hollowed out, and their cavities void
of symmetry*.”

It 1s remarked by the lively Abbé La Pluche, that
the foundations of our houses sink with the earth on
which they are built, the walls begin to stoop by de-
grees, they nod with age, and bend from their per-
pendicular ;—lodgers damage everything, and time is
continually introducing some new decay. The man-
sions of bees, on the contrary, grow stronger the

* Huber on Bees, p. 415,

HIVE-BEES, 141

oftener they change inhabitants. Every bee-grub
before its metamorphosis into a nymph, fastens its
skin to the partitions of its cell, but in such a man-
ner as to make it correspond with the lines of the
angles, and without in the least disturbing the regula-
rity of the figure. During summer, accordingly, the
same lodging may serve for three or four grubs in
succession; and in the ensuing season it may accom-
modate an equal number. Each grub never fails to
fortify the panels of its chamber by arraying them
with its spoils, and the contiguous cells receive a
similar augmentation from its brethren *. Réaumur
found as many as seven or eight of these skins
spread over one another: so that all the cells being
incrusted with six or seven coverings, well dried and
cemented with propolis, the whole fabric daily ac-
quires a new degree of solidity.

It is obvious, however, that by a repetition of this
process the cell might be rendered too contracted ;
but in such a case the bees know well how to pro-
ceed, by turning the cells to other uses, such as
magazines for bee-bread and honey. It has been
remarked, however, that in the hive of a new swarm,
during the months of July and August, there are
fewer small bees, or nurse-bees, than in one that has
been tenanted four or five years. The workers, in-
deed, clean out the cell the moment that a young
bee leaves its cocoon, but they never detach the
silky film which it has previously spun on the walls
of its cell. But though honey is deposited after the
young leave the cells, the reverse also happens; and
accordingly, when bees are bred in contracted cells.
they are by necessity smaller, and constitute, in fact,
the important class of nurse-bees.

We are not disposed, however, to go quite so far as
an American periodical writer, who says, “Thus we

* Spectacle de la Nature, vol. i

1142 INSECT ARCHITECTURE,

see that the contraction of the cell may diminish the
size of a bee, even to the extinction of life, just as the
contraction of a Chinese shoe reduces the foot even to
uselessness *.” We know, on the contrary, that the
queen-bee will not deposit eges ina cell either too -
small or too large for the proper rearing of the young.
In the case of large cells, M. Huber took advantage
of a queen that was busy depositing the ers of work-
ers, to remove all the common cells adapted for their
reception, and left only the large cells appropriated for
males. As this was done in June, when bees are most
active, he expected that they would have immediately
repaired the breaches he had made, but to his great
surprise they did not make the slightest moyement
for that purpose. In the meanwhile the queen being
oppressed by her eggs, was obliged to drop them
about at random, preferring this to depositing
them in the male cells which she knew to be too
large. At length she did deposit six eggs in the
large cells, which were hatched, as usual, three days
after. ‘The nurse-bees, however, seemed to be aware
that they could not be reared there, and, though they
supplied them with food, did not attend to them re-
gularly. M. Huber found that they had been all re-
moved from the cells during the night, and the busi-
ness both of laying and nursing was at a complete
stand for twelve days, when he supplied them again
with a comb of small cells, which the queen almost
immediately filled with eggs, and in some cells she
laid five or six.

The architecture of the hive, which we have thus
detailed, is that of bees receiving the aid of human
care, and having external coverings of a convenient
form, prepared for their reception. In this country
bees are not found in a wild state; though it is not

* North American Rev, Oct, 1828, p. 355,

NI VE-BEES, 143

uncommon for swarms to stray from their proprietors,
But these stray swarms do not spread colonies
through our woods, as they are said to do in America.
In the remoter parts of that continent there are no wild
bees. They precede civilization ; and thus when the
Indians observe a swarm they say ‘ the white man is
coming.” ‘There is evidence of bees having abounded
in these islands, in the earlier periods of our history ;
and Ireland is particularly mentioned by the Venerable
Bede as being ‘rich in milk and honey*.” ‘The hive-
bee has formed an object of economical culture in
Europe at least for two thousand years; and Varro
describes the sort of hives used in his time, 1870
years ago. We are not aware, however that it is
now to be found wild in the milder clime of Southern
Europe, any more than it is in our own island,

The wild bees of Palestine principally hived in
rocks. ‘“ He made him,” says Moses, “to suck
honey out of the rockt.” ‘ With honey out of the
rock,” says the Psalmist, “should I have satisfied
theet.” In the caves of Salsette and Elephanta, at
the present day, they hive in the clefts of the rocks,
and the recesses among the fissures, in such num-
bers, as to become very troublesome to visiters,
Their nests hang in innumerable clusters].

We are told of a little black stingless bee found in
the island of Guadaloupe, which hives in hollow trees
or in the cavities of rocks by the sea side, and lays
“up honey in cells about the size and shape of
pigeons’ eges. These cells are of a black or deep
violet colour, and so joined together as to leave no
space between them. They hang in clusters almost
like a bunch of grapes.” The following are men-
tioned by Lindley as indigenous to Brazil. “On an

* “ Hibernia dives lactis ac med/is insula.”’—Beda, Hist. Ree
oles. i,, 7. + Deut. xxxii. 13. { Psalm Ixxxi. 16,

{| Forbes, Orien. Mem. i. @ Amer. Q. Rev, iii. p. 383.

144 INSECT ARCHITECTURE.

excursion towards Upper Tapagippe,” says he, “ and
skirting the dreary woods which extend to the interior,
T observed the trees more loaded with bees’ nests
than even in the neighbourhood of Porto Seguro.
They consist of a ponderous shell of clay cemented.
similarly to martins’ nests, swelling from high trees
about a foot thick, and forming an oval mass full
two feet in diameter. When broken, the wax is
arranged as in our hives, and the honey abundant *.”

Captain Basil Hall found in South America the
hive of a honey-bee very different from the Brazilian,
but nearly allied to, if not the same, as that of
Guadaloupe. ‘‘ The hive we saw opened,” he says,
«was only partly filled, which enabled us to see the
economy of the interior to more advantage. The
honey is not contained in the elegant hexagonal cells
of our hives, but in wax-bags, not quite so large as
anegg. ‘These bags or bladders are hung round the
sides of the hive, and appear about half full; the
quantity being probably just as great as the strength
of the wax will bear without tearing. Those near
the bottom, being better supported, are more filled
than the upper ones. In the centre of the lower part
of the hive we observed an irregularly-shaped mass of
comb, furnished with cells like those of our bees, all
containing young ones in such an adyanced state,
that, when we broke the comb, and let them out, they
flew merrily away.”

Clavigero, in his History of Mexico, evidently de
scribing the same species of bee, says it abounds in
Yucatan, and makes the honey of Estabentum, the
finest in the world, and which is taken every two
months. He mentioned another species of bee,
smaller in size, and also without a sting, which forms
its nest of the shape of a sugar-loaf, and as large or
larger. ‘These are suspended from trees, particularly

* Roy. Mil. Chron, quoted in Kirby and Spence.

¢ HIVE-BEES, 145

from the oak, and are much more populous than our
common hives.

Wild honey-bees of some species appear also to
abound in Africa. Mr. Park, in his second volume
of travels, tells us that some of his associates im-
prudently attempted to rob a numerous hive of its
honey, when the exasperated bees, rushing out to
defend their property, attacked their assailants with
great fury, and quickly compelled the whole com
pany to fly.

At the Cape of Good Hope the bees themselves
must be less formidable, or more easily managed, as
their hives are sought for with avidity. Nature has
there provided man with a singular and very effi-
cient assistant in a bird, most appropriately named
the Honey-guide (Indicator major, Vir1tu0T; Cu-
culus indicator, Latuam). ‘The honey-guide, so far
from being alarmed at the presence of man, appears
anxious to court his acquaintance, and flits from
tree to tree with an expressive note of invitation,
the meaning of which is well known both to the
colonists and the Hottentots. A person invited by
the honey-guide seldom refuses to follow it on-
wards till it stops, as it is certain to do, at some
hollow tree containing a bee-hive, usually well stored
with honey and wax. It is probable chat the bird
finds itself inadequate to the attack of a legion of
bees, or to penetrate into the interior of the hive, and
is thence led ,to invite an agent more powerful than
itself. ‘The person invited, indeed, always leaves the
bird a share of the spoil, as it would be considered
sacrilege to rob it of its due, or in any way to injure
so useful a creature.

The Americans, who have not the African honey-
guide, employ several well-known methods to track
bees to their hives. One of the most common,
though ingenious modes, is to place a piece of bee-

K

‘146 INSECT ARCHITECTURE,

bread on a flat surface, a tile for instance, surround
ing it with a circle of wet white paint. The bee,
whose habit it is always to alight on the edge of any
plane, has to travel through the paint to reach the
bee-bread. When, therefore, she flies off, the ob-
server can track her by the white on her body. The_
same operation is repeated at another place, at some
distance from the first, and at right angles to the bee-
line, just ascertained. The position of the hive is
easily determined, for it lies in the angle made by the
intersection of the bee-lines. Another method is
described in the Philosophical Transactions for 1721.
The bee-hunter decoys, by a bait of honey, some of
the bees into his trap, and when he has secured as
many as he judges will suit his purpose, he incloses
one in a tube, and letting it fly, marks its course by
a pocket compass. Departing to some distance, he
liberates another, observes its course, and in this
manner determines the position of the hive, upon the
principle already detailed. These methods of bee-
hunting depend upon the insect’s habit of always
flying in a right line to its home. Those who have
read Cooper's tale of the ‘ Prairie’ must well remem-
ber the expression of ‘‘ lining a bee to its hive.”

In reading these and similar accounts of the
bees of distant parts of the world, we must not
conclude that the descriptions refer to the same
species as the common honey-bee. There are nu-
Mmerous species of social-bees which, while they differ
in many circumstances, agree in the practice of
storing up honey, in the same way as we have nu-
merous species of the mason-bee and of the humble-
bee. Of the latter Mr. Stephens enumerates no less
than forty-two species indigenous to Britain.

: 147

Cuarter VIi.
CARPENTRY OF TREE-HOPPERS AND SAW-FLIES.

Tux operations of an insect in boring into a leaf ot
a bud to form a lodgment for its eggs appear very
simple. The tools, however, by which these effects
are performed are very complicated and curious. In
the case of gull-flies (Cynips), the operation itself is
aot so remarkable as its subsequent chemical effects.
These effects are so different from any others that may
be classed under the head of Insect Architecture, that
we shall reserve them for the latter part of this
volume—although, with reference to the use of galls,
the protection of eggs and larve, they ought to find
a place here. We shall, however, at present confine
ourselves to those which simply excavate a nest, with-
out producing a tumour,

The first of these insects which we shall mention
is celebrated for its song, by the ancient Greek poets,
under the name of Terreé The Romans called it
Cicada, which we sometimes, but erroneously, trans-
late “grasshopper ;” for the grasshoppers belong to
an entirely different order of insects. We shall, there-
fore, take the liberty of calling the Cicade, Tree-
hoppers, to which the cuckoo-spit insect (Tettigonia
spumaria, Oxtv.) is allied; but there is only one of
the true cicade hitherto ascertained to be British,
namely, the Cicada hematodes (Linn.), which was
taken in the New Forest, Hampshire, by Mr. Daniel
Bydder.

M. Réaumur was exceedingly anxious to study the
economy of those insects; but they not being indi-
genous in the neighbourhood of Paris, he commis-

K2

148 INSECT ARCHITECTURE,

sioned his friends to send him some from more
southern latitudes, and he procured in this way spe-
cimens not only from the South of France and
from Italy, but also from Egypt. From these
specimens he has given the best account of them

yet published ; for though, as he tells us, he had ~

never had the pleasure of seeing one of them alive,
the more interesting parts of their structure can
be studied as well in dead as in living specimens.
We ourselves possess several specimens from New
Holland, upon which we have verified some of the
more interesting observations of Réaumur.

Virgil tells us, that in his time ‘ the cicade burst
the very shrubs with their querulous music* ;” but
we may well suppose that he was altogether unac-
quainted with the singular instrument by means of
which they can actually (not poetically) cut grooves
in the branches they select for depositing their eggs.
It is the male, as in the case of birds, which fills
the woods with his song; while the female, though
mute, is no less interesting to the naturalist on ac-
count of her curious ovipositor. This instrument,
like all those with which insects are furnished by
nature for cutting, notching, or piercing, is com-
posed of a horny substance, and is also considerably
larger than the size of the tree-hopper would pro-
portionally indicate. It can on this account be par-
tially examined without a microscope, being, in some
of the larger species, no less than five linest in length.

The ovipositor, or auger (tariére) as Réaumur calls
it, is lodged in a sheath which lies in a groove of the
terminating ring of the belly. It requires only a very
slight pressure to cause the instrument to protrude
from its sheath, when it appears to the naked eye to
be of equal thickness throughout except at the point,

* Cantu querule rumpent arbusta cicadw, Georg, iii, 328,
+ A line is about the twelfth part of an inch,

TREE-HOPPERS. 149

where it is somewhat enlarged and angular, and on
both sides finely indented with teeth. A more mi-
nute examination of the sheath demonstrates that it
is composed of two horny pieces slightly curved, and
ending in the form of an elonyated spoon, the concave
part of which is adapted to receive the convex end of
the ovipositor.

When the protruded instrument is further examined
with a microscope, the denticulations, nine in number
on each side, appear strong, and arranged with great
symmetry, increasing in fineness towards the point,
where there are three or four very small ones, beside
the nine that are more obvious. The magnifier also
shews that the instrument itself, which appeared sim-
ple to the naked eye, is in fact composed of three

_ different pieces, two exterior armed with the teeth
before mentioned, denominated by Reaumur files
(limes), aud another pointed like a lancet, and not
denticulated. 'The denticulated pieces moreover are
capable of being moved forwards and backwards,
while the centre one remains stationary, and as this
motion is effected by pressing a pin or the blade of a
knife over the muscles on either side at the origin of
the ovipositor, it may be presumed that those mus-
cles are destined for producing similar movements
when the insect requires them. By means of a finely
pointed pin carefully introduced between the pieces,
and pushed very gently downwards, they may be,
with no great difficulty, separated in their whole ex-
tent.

The contrivance by which those three pieces are
held united, while at the same time the two files can
be easily put in motion, are similar to some of our
own mechanical inventions, with this difference, that
no human workman could construct an instrument of
this description so small, fine, exquisitely polished,
and fitting so exactly. We should have been apt to

150 INSECT ARCHITECTURE,

form the grooves in the central piece, whereas they
are scooped out in the handles of the files, and play
upon two projecting ridges in the central piece, by
which means this is rendered stronger. M. Réaumur
discovered that the best manner of shewing the play
of this extraordinary instrument is to cut it off with a
pair of scissors near its origin, and then, taking it
between the thumb and the finger at the point of
section, work it gently to put the files in motion.

Ovipositors, with files, of Tree-hopper, magnified.

Beside the muscles necessary for the movement
of the files, the handle of each is terminated by a
curve of the same hard horny substance as itself,
which not only furnishes the muscles with a sort of
lever, but serves to press, as with a spring, the two
files close to the central piece, as is shewn in the
lower figure.

M. Pontedera, who studied the economy of the
tree-hoppers ,with some care, was anxious to see the

TREE-HOPPERS, 151

insect itself make use of the ovipositor in forming
grooves in wood, but found that it was so shy and
easily alarmed, that it took to flight whenever he
approached; a circumstance of which Réaumur takes
advantage, to soothe his regret that the insects were
not indigenous in his neighbourhood. But of their
workmanship when completed, he had several speci-
mens sent to him from Provence and Languedoc by
the Marquis de Caumont.

The gall-flies, when about to deposit their eggs,
select growing plants and trees ; but the tree-hoppers,
on the contrary, make choice of dead, dried branches,
for the mother seems to be aware that moisture
would injure her progeny. The branch, commonly
a small one, in which eggs have been deposited, may
be recognized by being covered with little oblong
elevations caused by small splinters of the wood, de-
tached at one end, but left fixed at the other by the
insect. These elevations are for the most part in a
line, rarely in a double line, nearly at equal distances
from each other, and form a lid to a cavity in the
wood about four lines in length, containing from

Excavations for eggs of Tree-hopper, with lids raised.

four to ten eggs. It is to be remarked, that the
insect always selects a branch of such dimensions,
that it can get at the pith, not because the pith is
more easily bored, for it does not penetrate into it at
all, but to form a warm and safe bed for the eggs.
M. Pontedera says, that when the eggs have been
deposited, the insect closes the mouth of the hole
with a gum capable of protecting them from the wea-
ther; but M. Réaumur thinks this only a fancy, as

be

152 INSECT ARCHITECTURE,

out of a great number which he examined, he could
discover nothing of the kind. Neither is such a pro-
tection wanted; for the woody splinters above men-
tioned furnish a very good covering. -

The grubs hatched from these eggs (of which, M.
Pontedera says, one female will deposit from five to
seven hundred) issue from the same holes through
which the eggs have been introduced, and betake
themselves to the ground to feed on the roots of
plants. ‘They are not transformed into chrysalides,
but into active nymphs, remarkable for their fore
limbs, which are thick, strong, and furnished with
prongs for digging ; and when we are told by Dr. Le
Fevre, that they make their way easily into hard stiff
clay, to the depth of two or three feet, we perceive
how necessary to them such a conformation must be.

Saw-F .1&s.

An instrument for cutting grooves in wood, still
more ingeniously contrived than that of the tree-
hopper, was first observed by Vallisnieri, an eminent
Italian naturalist, in a four-winged fly, most appro-
priately denominated by M, Réaumur the saw-/ly
(Tenthredo), of which many sorts are indigenous to
Great Britain. The grubs from which those flies
originate are indeed but too well known, as they fre-
quently strip our rose, gooseberry, raspberry, and red
currant trees of their leaves, and are no less destruc-
tive to birch, alder, and willows ; while turnips and
wheat suffer still more seriously by their ravages.
These grubs may readily be distinguished from the
caterpillars of moths and butterflies, by having from
sixteen to twenty-eight feet, by which they usually
hang to the leaf they feed on, while they coil up the
hinder part of their body in a spiral ring, The perfect
flies are distinguished by four transparent wings; and

SAW-FLIES, 153

some of the most common have a flat body of a
yellow or orange colour, while the head and shoulders
are black.

In order to see the ovipositor to which we shall
for the present turn our chief attention, a female saw-
fly must be taken, and her belly gently pressed, when
a narrow slit will be observed to open at some dis-
tance from the anus, and a short, pointed, and some-
what curved body, of a brown colour and horny sub-:
stance, will be protruded. ‘The curved plates which
form the sides of the slit, are the termination of the
sheath, in which the instrument lies concealed till it
is wanted by the insect. The appearance of this in-
strument, however, and its singular structure, cannot
be well understood without the aid of a microscope.

a, Ovipositor of Saw-fly, protruded from its Sheath, magnified.

The instrument thus brought into view, is a very
finely contrived saw, made of horn, and adapted
for penetrating branches and other parts of plants
where the eggs are to be deposited. The ovipo-
sitor-saw of the insect is much more complicated
than any of those employed by our carpenters. The
teeth of our saws are formed in a line, but in such
@ manner as to cut in two lines parallel to, and at
a small distance from each other. ‘his is effected
by slightly bending the points of the alternate teeth
right and left, so that one halt of the whole teeth

kD

154 INSECT ARCHITECTURE,

stand a little to the right, and the other half a little
to the left. ‘The distance of the two parallel lines
thus formed is called the course of the saw, and it
is only the portion of wood which lies in the course
that is cut into sawdust by the action of the instru-
ment. It will follow, that in proportion to the thin-
ness of a saw there will be the less destruction of
wood which may be sawed. When cabinet-makers
have to divide valuable wood into very thin leaves,
they accordingly employ saws with a narrow course;
while sawyers who cut planks, use one with a broad
course. The ovipositor-saw being extremely fine, does
not require the teeth to diverge much, but from the
manner in which they operate, it is requisite that they
should not stand like those of our saws in a straight
line. The greater portion of the edge of the instru-
ment, on the contrary, is towards the point some-
what cancave, similar to a scythe, while towards the
base it becomes a little convex, the whole edge being
nearly the shape of an Italie /f-

Svipositor-saw of Sawfly, with rasps shewn in the oross lines.

SAW-FLIES. 155

The ovipositor-saw of the fly is put in motion in
the same way as a carpenter's hand-saw, supposing
the tendons attached to its base to form the handle,
and the muscles which put it in motion to be the
band of the carpenter. But the carpenter can only
work one saw at a time, whereas each of these flies
is furnished with two, equal and similar, which it
works at the same time—one being advanced and
the other retracted alternately. The secret, indeed,
of working more saws than one at once is not un-
known to our mechanics; for two or three are some-
times fixed in the same frame. These, however, not
only all move upwards and downwards simultane-
ously, but cut the wood in different places; while
the two saws of the ovipositor work in the same cut,
and, consequently, though the teeth are extremely
fine, the effect is similar to asaw with a wide set.

It is important, seeing that the ovipositor-saws
are so fine, that they be not bent or separated while
in operation—and this, also, nature has provided for,
by lodging the backs of the saws in a groove, formed
by two membranous plates, similar to the structure
of a clasp-knife. These plates are thickest at the
base, becoming gradually thinner as they approach
the point which the form of the saws require, Ac-
cording to Vallisnieri, it is not the only use of this
apparatus to form a back for the saws, he having
discovered, between the component membranes, two
canals, which he supposes are employed to conduct
the eggs of the insect into the grooves which it has
hollowed out for them*,

The teeth of a carpenter’s saw, it may be remarked,
are simple, whereas the teeth of the ovipositor-saw
are themselves denticulafed with fine teeth. The
latter, also, combines at the same time the properties
of asaw and of arasporfile. So far as we are aware,

* Réaumur, Mem. des Insectes, y., p. iii.

156 INSECT ARCHITECTURE,

these two properties have never been combined in
any of the tools of our carpenters. The rasping
part of the ovipositor, however, is not constructed
like our rasps, with short teeth thickly studded to-
gether, but has teeth almost as long as those of the
saw, and placed contiguous to them on the back of
the instrument, resembling in their form and setting
the teeth of a comb, as may be seen in the figure.
Of course, such observations are conducted with the
aid of a microscope.

Portion of Saw-fly’s comb-touthed rasp, una Saw

When a female saw-fly has selected the branch of
arose-tree, or any other, in which to deposit her eggs,
she may be seen bending the end of her belly inwards,
in form of a crescent, and protruding her saw, at the
same time, to penetrate the bark or wood. She main-
tains this recurved position so long as she works in
deepening the groove; but when she has attained the
depth required, she unbends her body into a straight
line, and in this position works upon the place
lengthways, by applying the saw more horizontally.
When she has rendered the groove as large as she
wishes, the motion of the tendons ceases, and an
egg is placed in the cavity. The saw is then with-
drawn into the sheath for about two-thirds of its
length, and at the same moment, a sort of frothy
liquid, similar to a lather made with soap, is
dropped over the egg, either for the purpose of glu-
ing it in its place, or sheathing it from the action of
the juices of the tree. She proceeds in the same
manner in sawing out a second groove, and so on in

SAW-FLIES, 157

succession till she has deposited all her eggs, some-
times to the number of twenty-four. The grooves
are usually placed in a line, at a small distance from
one another, on the same branch; but sometimes the
mother-fly shifts to another, or to a different part of
the branch, when she is either scared or finds it un-
suitable. She commonly, also, takes more than one
day to the work, notwithstanding the superiority of
her tools. Reéaumur has seen a saw-fly make six
grooves in succession, which occupied her about ten
hours and a half.

The grooves, when finished, have externally little
elevation above the level of the bark, appearing like
the puncture of a lancet in the human skin; but in
the course of a day or two the part becomes first
brown and then black, while it also becomes more
and more elevated. This increased elevation is not
owing to the growth of the bark, the fibres of which,
indeed, have been destroyed by the ovipositor-saw,
but to the actual growth of theegg ; for, whenanew-
laid egg of the saw-fly is compared with one which
has been several days enclosed in the groove, the
latter will be found to be very considerably the larger.
This growth of the egg is contrary to the analogy
observable in the eggs of birds, and even of most
other insects; but it has its advantages. As it
continues to increase, it raises the bark more and
more, and consequently widens, at the same time,
the slit at the entrance; so that, when the grub is
' hatched, it finds a passage ready for its exit. The
mother-fly seems to be aware of this growth of her
eggs, for she takes care to deposit them at such
distances as may prevent their disturbing one another
by their development.

Another species of saw-fly, with a yellow body and
deep violet-coloured wings, which also selects the
rose-tree, deposits her eges in a different manner.
Instead of making a groove for each egg, like the

158 INSECT ARCHITECTURE,

preceding, she forms a large single groove, sufficient
for about two dozen eggs. These eggs are all ar-
ranged in pairs, forming two straight lines parallel
to the sides of the branch. The eggs, however, though
thus deposited in a common groove, are carefully
kept each in its place; fora ridge of the wood is left
to prevent those on the right from touching those on
the left—and not only so, but between each ege ofa
row a thin partition of wood is left, forming a shallow
cell.

Nest of e998 of Saw-fly, in rose-tree.

The edges of this groove, it will be obvious, must
be farther apart than those which only contain a
single egg, and, in fact, the whole is open to inspec-
tion; but the eggs are kept from falling out, both
by the frothy glue before mentioned, and by the walls
of the cells containing them. They were observed
also, by Vallisnieri, to increase in size like the prex
ceding.

149

Cuapter VIII.
LEAF-ROLLING CATERPILLARS,

Tur labours of those insect-architects, which we have
endeavoured to describe in the preceding pages, have
been chiefly those of mothers to form a secure nest
for their eggs, and the young hatched from them,
during the first stage of their existence. Butamuch
more numerous, and not less ingenious class of
architects, may be found among the newly-hatched
insects themselves, who, untaught by experience, and
altogether unassisted by previous example, manifest
the most marvellous skill in the construction of
tents, houses, galleries, covert-ways, fortifications,
and eyen cities, not to speak of subterranean caverns
and subaqueous apartments, which no human art
could rival.

The caterpillars, which are familiarly termed leaf-
rollers, are perfect hermits. Each lives in a cell,
which it begins to construct almost immediately after
it is hatched ; and the little structure is at once a
house which protects the caterpillar from its enemies,
and a store of food for its subsistence while it remains
shut up in its prison. But the insect only devours
the inner folds. The art which these caterpillars
exercise, although called into action but once,
perhaps, in their lives, is perfect. ‘They accomplish
their purpose with a mechanical skill, which is re-
markable for its simplicity and unerring success.
The art of rolling leaves into a secure and immoveable

160 INSECT ARCHITECTURE.

cell may not appear very difficult ;—nor would it
be so if the caterpillars had fingers, or any parts ~
which were equivalent to those delicate and admirable
natural instruments with which man accomplishes his
most elaborate works. And yet the human fingers
could not roll a rocket-case of paper more regularly
than the caterpillar rolls his house of leaves. A leaf
is not a very easy substance to roll. In some trees
‘t is very brittle. It has also a natural elasticity,—
a disposition to spring back if it be bent,—which is
caused by the continuity of its threads, or nervures.
This elasticity is speedily overcome by the ingenuity
with which the caterpillar works; and the leaf is
thus retained in its artificial position for many weeks,
under every variety of temperature. We will examine,
in detail, how these little leaf-rollers accomplish their
task.

One of the most common as well as the most
simple fabrics constructed by caterpillars, may be dis-
covered during summer on almost every kind of
bush and tree. We shall take as examples those
which are found on the lilac, and on the oak.

A small but very pretty chocolate-coloured moth,

Lilac-tree Moth. (Lazotenia Ribeana, Sternens ?) a

abundant in every garden, but not readily seen from
its frequently alighting on the ground which is so
nearly of its own colour, deposits its eggs on the
leaves of the lilac, and of some other trees, appro-
priating a leaf to each egg. As soon as the cater-
pillar is hatched, it begins to secure itself from birds
and predatory insects by rolling up the lilac leaf into

CATERPILLARS. 161

the form of a gallery, where it may feed in safety
We have repeatedly seen one of them when just
escaped from the egg, and only a few lines long,
fix several silk threads from one edge of a leaf to
the other, or from the edge to the mid-rib. Then
going to the middle of the space, he shortened the
tureads by bending them with his feet, and conse-
quently pulled the edges of the leaves into a circular
form; and he retained them in that position by glu-
ing down each thread as he shortened it. In their
younger state, those caterpillars seldom roll more
than a small portion of the leaf; but when farther
advanced, they unite the two edges together in their
whole extent, with the exception of a small opening
at one end, by which an exit may be made in case
of need.

\\
\\

IRAN

uy

wd

Nest of a Lilac-leaf Roller.

Another species of caterpillar, closely allied to this,
rolls up the lilac-leaves in a different form, beginning
at the end of a leaf, and fixing and pulling its threads
till it gets it nearly into the shape of a scroll of
parchment. ‘To retain this form more securely, it is

162 INSECT ARCHITECTURE.

not contented, like the former insect, with threads
fixed on the inside of the leaf; but has also recourse
to a few cables which it weaves on the outside,

Another Nest of Lilac-tree Rollers.

Another species of moth, allied to the two pre-
ceding, is of a pretty green colour, and lays its eggs

Small green Oak-moth. (Tortrix Viridana.)

upon the leaves of the oak. The caterpillar folds
them up in a similar manner, but with this difference,
that it works on the under surface of the leaf, pulling
the edge downwards and backwards, instead of for-
wards and upwards. ‘This species is very abundant,

CATERPILLARS, 163

Wests of oak-leaf-rolling Caterpillars,

and may readily be found as soon as the leaves
expand. In June, when the perfect insect has ap-
peared, by beating a branch of an oak, a whole shower
of these pretty green moths may be shook into the air.

Among the leaf-rolling caterpillars, there is a
small dark-brown one, with a black head and six
feet, very common in gardens on the currant-bush,
or the leaves of the rose-tree. (Lozotenia Rosana,
Stepuens.) It is exceedingly destructive to the
flower-buds. ‘The eggs are deposited in the summer,
and probably also in the autumn or in spring, in
little oval or circular patches of a green colour. The
grub makes its appearance with the first opening of
the leaves, of whose structure in the half-expanded
state it takes advantage to construct its summer tent.
It is not, like some of the other leaf-rollers, contented

164 INSECT ARCHITECTURE,

with a single leaf, but weaves together as many as
there are in the bud where it may chance to have been
hatched, binding their discs so firmly with silk, that
all the force of the ascending sap, and the increasing
growth of the leaves cannot break through; a farther
expansion is of course prevented. The little inha-
bitant in the meanwhile banquets securely on the
partitions of its tent, eating door-ways from one
apartment into another, through which it can escape
in case of danger or disturbance.

The leafits of the rose, it may be remarked, expand
in nearly the same manneras a fan, and the operations
of this ingenious little insect retain them in the form
of a fan nearly shut. Sometimes, however, it is not
contented with one bundle of leafits, but by means of
its silken cords unites all which spring from the same
bud into a rain-proof canopy, under the protection of
which it can feast on the flower-bud, and prevent it
from ever blowing.

In the instance of the currant leaves, the proceed
ings of the grub are the same, but it cannot unite the
plaits so smoothly as in the case of the rose leafits,
and it requires more labour also, as the nervures
being stiff, demand a greater effort to bend them.
When all the exertions of the insect prove unavailing
in its endeavours to draw the edges of a leaf together,
it bends them inwards as far as it can, and weaves
a close web of silk over the open space between.
This is well exemplified in one of the commonest
of our leaf-rolling caterpillars, which may be found
as early as February on the leaves of the nettle and
the white archangel (Lamium album), It is of a
light dirty-green colour, spotted with black, and
covered with a few hairs. In its young state it
confines itself to the bosom of a small leaf, near the
insertion of the leaf-stalk, partly bending the edges
inwards, and covering in the interval with a silken

CATERPILLARS. 165

curtain. As this sort of covering is not sufficient for
concealment when the animal advances in growth, it
abandons the base of the leaf for the middle, where
it doubles up one side in a very secure and ingenious
manner.

Nest of the nettle-leaf-rolling Caterpillar.

We have watched this little architect begin and
finish his tent upon a nettle in our study, the whole
operation taking more than half an hour*. He began
by walking over the plant in all directions, examining
the leaves severally, as if to ascertain which was best
fitted for his purpose by being pliable, and bending
with the weight of his body. Having found one to
his mind, he placed himself along the mid-rib, to the
edge of which he secured himself firmly with the
pro-legs of his tail; then stretching his head to the
edge of the leaf, he fixed a series of parallel cables
between it and the mid-rib, with another series cross-
ing these at an acute angle. The position in which
he worked was most remarkable, for he did not, as
might have been supposed, spin his cables with his
face to the leaf, but throwing himself on his back,
which was turned towards the leaf, he hung with his
whole weight by his first-made cables. This, by
drawing them into the form of a curve, shortened
them, and consequently pulled the edge of the leaf
down towards the mid-rib. The weight of his body
was not, however, the only power which he employed ;

. for, using the anal pro-legs as a point of support, he

*J.R,

166 INSECT ARCHITECTURE,

exerted the whole muscles of his body to shorten his
threads, and pull down the edge of the leaf. When
he had drawn the threads ‘as tight as he could, he
held them till he spun fresh ones of sufficient strength
to retain the leaf in the bent position into which he
had pulled it. He then left the first series to hang
loose while he shortened the fresh spun ones as be-
fore. ‘This process was continued till he had worked
down about an inch and a‘half of the leaf, as much
as he deemed sufficient for his habitation. This was
the first part of the architecture.

By the time he had worked to the end of the fold
he had brought the edge of the leaf to touch the
mid-rib; but it was only held in this position by a
few of the last spun threads, for all the first spun
ones hung loose within. Apparently aware of this,
the insect protruded more than half of its body
through the small aperture left at the end, and spun
several bundles of threads on the outside precisely
similar to those ropes of a tent which extend beyond
the canvass, and are pegged into the ground. Un-
willing to trust the exposure of his whole body on
the outside, lest he should be seized by the first sand-

wasp (odynerus) or sparrow which might descry him, »

he now withdrew to complete the internal portion of
his dwelling, where the threads were hanging loose
and disorderly. For this purpose he turned his head
about, and proceeded precisely as he had done at the
beginning of his task, but taking’ care to spin his new

threads so a& to leave the loose ones on the outside,
and make his apartment smooth and neat. When he. —

again reached the opposite end, he constructed there ~

also a similar series of cables on the outside, and
then withdrew to give some final touches to the in-
terior.
It is said by Kirby and Spence *, that when these
* Introd, vol. i. p. 457.

Az
7.)

'

ws

a.

CATERPILLARS, 167

leaf-rolling insects find that the larger nervures of
the leaves are so strong as to prevent them from
bending, they “weaken it by gnawing it here and
there half through.” We have never observed the
circumstance, though we have witnessed the process
in some hundreds of instances; and we doubt the
statement, from the careful survey which the insect
makes of the capabilities of the leaf before the opera-
tion is begun, If she found upon examination that
a leaf would not bend, she would reject it, as we have
often seen happen, and pass to another *,

A species of leaf-roller, of the most diminutive size,
merits particular mention, although it is not remark-
able in colour or figure. It is without hair, of a
greenish white, and has all the vivacity of the other
leaf-rollers. Sorrel is the plant on which it feeds;
and the manner in which it rolls a portion of the leaf
is very ingenious.

The structure which it contrives is a sort of conical
pyramid, composed of five or six folds lapped round
each other. From the position of this little cone the
caterpillar has other labours to perform, beside that
of rolling the leaf. It first cuts across the leaf, its
teeth acting as a pair of scissors; but it does not
entirely detach this segment. It rolls it up very
gradually, by attaching threads of silk to the plane
surface of the leaf, as we have before seen; and
then, having cut in a different direction, sets the cone
upright, by weaving other threads, attached to the

~centre of the roll and the plane of the leaf, upon
which it throws the weight of its body. ‘This, it
will be readily seen, is a somewhat complicated effort
of mechanical skill. It has been minutely described
‘by M. Réaumur; but the following representation

| WOR.

~

168 INSECT ARCHITECTURE.

will perhaps make the process clearer than a more
detailed account.

Leaf-rolling Caterpillars of the Sorrel.

This caterpillar, like those of which we have
already spoken, devours all the interior of the roller.
It weaves, also, in the interior, a small and thin
cocoon of white silk, the tissue of which is made
compact and close. it is then transformed into a
chrysalis. '

The caterpillars of two of our largest and hand-
somest butterflies, the Painted Lady (Cynthia cardui,
SrepHens), and the Admirable, or Alderman of the
London fly-fanciers (Vanessa atalanta), are also leaf-
rollers. ‘I'he first selects the leaves of the great spear-
thistle, and sometimes those of the stemless, or star-
thistle, which might be supposed rather difficult to
bend; but the caterpillar is four times as large and
strong as those which we have been hitherto de~
scribing. In some seasons it is plentiful ; in others
it is rarely to be met with: but the Admirable is
seldom scarce in any part of the country; and by

CATERPILLARS, 169

- examining the leaves of nettles which appear folded
edge to edge, in July and August, the caterpillar may
be readily found.

Nests of the Hesperia Malva, with Caterpillar, Chrysalis, and Butterflies,

Another butterfly (Hesperia malve) is met with
on dry banks where mallows grow, in May, or even
earlier, and also in August, but is not indigenous.
The caterpillar, which is grey, with a black head,
and four sulphur-coloured spots on the neck, folds
around it the leaves of the mallow, upon which
it feeds. There is nothing, however, peculiarly
different in its proceedings from those above de-
scribed; but the care with which it selects ‘and rolls
up one of the smaller leaves, when it is about to be
_ transformed into a chrysalis, is worthy of remark ; it
L

170 INSECT ARCHITECTURE,

joins it, indeed, so completely round and round, that
it has somewhat the resemblance of an eee. Within
this green cell it lies secure, till the time arrives
when it is ready to burst its cerements, and trust to
the quickness of its wings for protection against its
enemies.

Among the nests of caterpillars which roll up par-
cels of leaves, we know none so well contrived as
those which are found upon willows and a species
of osier. The long and narrow leaves of -these
plants are naturally adapted to be adjusted pa-
rallel to each other; for this is the direction which

% i}
iM i i!

Nest of Willow-leaf Roller,

CATERPILLARS, 171

they have at the end of each stalk, when they are not
entirely developed. One kind of small smooth cater-
pillar (Tortrix chlorana), with sixteen feet, the
under part of which is brown, and streaked with
white, fastens these leaves together, and makes them
up into parcels. There is nothing particularly strik-
ing in the mechanical manner in which it constructs
them. It does precisely what we should do in a
similar case: it winds a thread round those leaves
which must be kept together, from a little above their
termination to a very short distance from their ex-
treme point; and as it finds the leaves almost con-
stantly lying near each other, it has little difficulty in
bringing them together, as is shewn in the cut, a.

The prettiest of these parcels are those which are
made upon a kind of osier, the borders of whose
leaves sometimes form columnar bundles before they
are become developed. A section of these leaves has
the appearance of filagree work.—(See b, p. 170.)

A caterpillar which feeds upon the willow, and
whose singular attitudes have obtained for it the trivial
name of Ziczac, also constructs for itself an arbour
of the leaves, by drawing them together in an inge-
nious manner. M. Roesel* has given a tolerable
representation of this nest, and of the caterpillar.
The caterpillar is found in June; and the moth (No-
todonta ziczac) from May to July in the following
year.—(See cut, p. 172.)

Beside those caterpillars which live solitary in the
folds of a leaf, there are others which associate, em-
ploying their united powers to draw the leaves of the
plants they feed upon into a covering for their com-
mon protection. Among these we may mention the
caterpillar of a small butterfly, the plantain or Glan+

* Roesel, cl. ii, Pap. Nocturn,, tab. xx,, fig. 1, 2, 3, 4, 5, 6.

172 INSECT ARCHITECTURE,

ville fritillary (Melitea cinzia), which is very scarce
in this country.

Ziczac Caterpillar and Nest.

Although a colony of these caterpillars is not nu-
merous, seldom amounting toa hundred individuals,
the place which they have selected is not hard to dis-
cover. Their abode may be seen in the meadow in
form of a tuft of herbage covered with a white web,
which may readily be mistaken, at first view, for that
of a spider, but closer inspection soon corrects this
notion. It is, in fact, a sort of common tent, in
which the whole brood lives, eats, and undergoes the
usual transformations. 'The shape of this tent, for

CATERPILLARS, 173

the most part, approaches the pyramidal, though that
depends much upon the natural growth of the her-
bage which composes it. 'The interior is divided into
compartments formed by the union of several small
tents, as it were, to which others have been from time
to time added according to the necessities of the com-
munity.

When they have devoured all the leaves, or at
least those which are most tender and succulent,
they abandon their first camp, and construct another
contiguous to it under a tuft of fresh leaves. Several
of these encampments may sometimes be seen within
the distance of a foot or two, when they can find
plantain (Plantago lanceolata) fit for their purpose ;
but though they prefer this plant, they content them-
selves with grass if it is not to be procured.

When they are about to cast their skins, but par-
ticularly when they perceive the approach of winter,
they construct a more durable apartment in the inte-
rior of their principal tent. The ordinary web is
thin and semi-transparent, permitting the leaves to
be seen through it; but their winter canvass, if we
may call it so, is thick, strong, and quite opaque,
forming a sort of circular hall without any partition,
where the whole community lie coiled up and huddled
together.

Early in spring they issue forth in search of fresh
food, and again construct tents to protect them from
cold and rain, and from the mid-day sun.

M. Réaumur found upon trial, that it was not only
the caterpillars hatched from the eggs of the same
mother which would unite in constructing the com-
mon tent; for different broods, when put together,
worked in the same social and harmonious manner,
We ourselves ascertained, during the present sum-
mer (1829), that this principle of sociality is not
confined to the same species, nor even to the same

L3

174 INSECT ARCHITECTURE,

genus. The experiment which we tried was to. con-
fine two broods of different species to the same branch
by placing it in a glass of water to prevent their
escape. ‘The caterpillars which we experimented on
were several broods of the brown-tail moth (Porthesia
aurifilua), and the lackey (Clisiocampa neustria).
These we found to work with as much industry and
harmony in constructing the common tent as if they
had been at liberty on their native trees; and when
the lackeys encountered the brown-tails they mani-
fested no alarm nor uneasiness, but passed over the
backs of one another as if they had made only a por-
tion of the branch. In none of their operations did
they seem to be subject to any discipline, each indi-
vidual appearing to work, in perfecting the structure,
from individual instinct, in the same manner as was
remarked by M. Huber, in the case of the hive-bees*,
In making such experiments, it is obvious, that the
species of caterpillars experimented with must feed
upon the same sort of plant-f.

The design of the caterpillars in rolling up the
leaves is not only to conceal themselves from birds
and predatory insects, but also to protect them-
selves from the cuckoo-flies, which lie in wait in every
quarter to deposit their eggs in their bodies, that their
progeny may devour them. ‘Their mode of conceal-
ment, however, though it appear to be cunningly
contrived and skilfully executed, is not always suc-
cessful, their enemies often discovering their hiding-
place. We happened to see a remarkable instance of
this last summer (1828), in the case of one of the
silac caterpillars which had changed into a chrysalis
within the closely-folded leaf. A small cuckoo-fly,
aware, it should seem, of the very spot where the
chrysalis lay within the leaf, was seen boring through

* See p. 115. +) R.

CATERPILLARS. 175

it with her oyipositor, and introducing her eggs
through the punctures thus made into the body of the
dormant insect. We allowed her to lay all her egos,
about six in number, and then put the leaf under an
inverted glass. Ina few days the eggs of the cuckoo-
fly were hatched, the grubs devoured the lilac chry-
salis, and finally changed into pup in a case of yele
low silk, and into perfect insects like their parent *,

*J.R,

176

Cuarrer IX.
INSECTS FORMING HABITATIONS OF DETACHED LEAVES.

Tue habitations of the insects which we have just
described consist of growing leaves, bent, rolled,
or pressed together, and fixed in their positions by
silken threads. But there are other habitations of a
similar kind which are constructed by cutting out
and detaching a whole leaf, or a portion of a leaf. We
have already seen how dexterously the upholsterer-
bees cut out small parts of leaves and petals with
their mandibles, and fit them into their cells. Some
of the caterpillars do not exhibit quite so much neat-
ness and elegance as the leaf-cutting bees, though
their structures answer all the purposes intended ;
but there are others, as we shall presently see, that
far excel the bees, at least, in the delicate minutie
of their workmanship. We shall first advert to
those structures which are the most simple.

Not far from Longchamps, in a road through the
Bois de Bologne, is a large marsh, which M. Réau-
mur never observed to be in a dry state even during
summer. This marsh is surrounded with very lofty
oaks, aud abounds with pondweed, the water plant
named by botanists Potamogeton. ‘The shining
leaves of this plant, which are as large as those of
the laurel or orange-tree, but thicker and more
fleshy, are spread upon the surface of the water.
Having pulled up several of these, about the middle
of June, M. Réaumur observed, beneath one of the

PONDWEED TENT-MAKER. 177

first which he examined, an elevation of an oyal
shape, which was formed out of a leaf of the same
plant. He carefully examined it, and discovered
that threads of silk were attached to this elevation
Breaking the threads, he raised up one of the ends,
and saw a cavity in which a caterpillar (Hydrocampa
Potamogata) was lodged. An indefatigable ob-
server, such as M, Réaumur, would naturally follow
up this discovery; and he has accordingly given us a
memoir of the pondweed tent-maker, distinguished
by his usual minute accuracy.

In order to make a new cocoon, the caterpillar
fastens itself on the underside of a leaf of the Pota-
mogeton. With its mandibles it pierces some part of
this leaf, and afterwards gradually gnaws a curve
line, marking the form of the piece which it wishes to
detach. When the caterpillar has cut off, as from a piece
of cloth, a patch of leaf of the size and shape suited
to its purpose, it is provided with half of the mate-
rials requisite for making a tent, It takes hold of
this piece by its mandibles, and conveys it to the
situation on the underside of its own, or another
leaf, whichever is found most appropriate. It is there
disposed, in such a manner, that the underpart of
the patch—the side which was the underpart of the
entire leaf—is turned towards the underpart of the
new leaf, so that the inner walls of the cocoon are
always made by the underpart, of two portions of
leaf. The leaves of the potamogeton are a little con-
cave on the underside; and thus the caterpillar pro-
duces a hollow cell, though the rims are united.

The caterpillar secures the leaf in its position by
threads of white silk. It then weaves a cocoon in
the cavity, which is somewhat thin, but of very close
tissue. ‘There it shuts itself up to appear again only
in the form of the perfect insect, and is soon trans-
formed into a chrysalis. In this cocoon of silk no

‘ea : it:

178 INSECT ARCHITECTURE,

point touches the water; whilst the cocoon of leaves,
lined with silk, has been constructed underneath the
water. This fact proves that the caterpillar has a
particular art by which it repels the water from be-
tween the leaves.

When the caterpillar, which has thus conveyed and
disposed a patch of leaf against another leaf, is not
ready to be transformed into a chrysalis, it applies
itself to make a cocoon—a habitation which it ma
varry everywhere about with it. It begins by slightly
fixing the piece against the whole leaf, leaving inter-
vals all round, between the piece and leaf, at which
it may project its head. The piece which it has
fixed serves as a model for cutting out a similar
piece in the other leaf. ‘The caterpillar puts them
accurately together, except at one end of the oval,
where an opening is left for the insect to project its
head through. When the caterpillar is inclined to
change its situation, it draws itself forward by means
of its sealy limbs rivetted upon the leaf. The mem-
branous limbs which are rivetted against the inner
sides of the cocoon, oblige it to follow the anterior
part of the body, as it advances. The caterpillar,
also, puts its head out of the cocoon every time it
desires to eat.

There is found on the common chick-weed (Stéel-
laria media), towards the end of July, a middle-sized
smooth green caterpillar, having three brown spots
bordered with white on the back, and six legs and
ten pro-legs, whose architecture is worthy of observa-
tion. When it is about to go into chrysalis, towards
the beginning of August, it gnaws off, one by one, a
number of the leaves and smaller twigs of the chick-
weed, and adjusts them into an oval cocoon, some-
what rough and unfinished, externally, but smooth,
uniform, and finely tapestried with white silk within.
Here it undergoes its transformations securely, and

CYPRESS-SPURGE CATERPILLAR. 179

when the period of its pupa trance has expired in the
following July, it makes its exit in the form of a
yellowish moth, with several brown spots above, and
a brown band on each of its four wings below. It is
also furnished with a sort of tail.

On the cypress spurge (Euphorbia cyparissias),
a native woodland plant, but not of very common
occurrence, may be found, towards the end of Octo-
ber, a caterpillar of a middle size, sparely tufted with
hair, and striped with black, white, red, and brown.
The leaves of the plant, which are in the form of
short narrow blades of grass, are made choice of by
the caterpillar to construct its cocoon, which it does
with great neatness and regularity, the end of each
leaf, after it has been detached from the plant, being
fixed to the stem, and the other leaves placed parallel,
as they are successively added. The other ends of
all these are bent inwards, so as to form a uniformly
rounded oblong figure, somewhat larger at one end
than at the other.

SRI
Wee Hee Tee Th

Cypress-Spurge Caterpillar—(Acronycta Euphrasia?)—with a Cocoon,
on a branch,

A caterpillar, which builds a very similar cocoon

to the last mentioned, may be found upon a more

common plant—the yellow snap-dragon or toad-flax

180 INSECT ARCHITECTURE,

(Antirrhinum linaria)—which is to be seen in almost
every hedge. It is somewhat shaped like a leech, is
of a middle size, and the prevailing colour pearl-grey,
but striped with yellow and black. It spins up about
the beginning of September, forming the outer coat-
ing of pieces of detached leaves of the plant, and
sometimes of whole leaves placed longitudinally, the
whole disposed with great symmetry and neatness.
The moth appears in the following June.

It is worthy of remark, as one of the most
striking instances of instinctive foresight, that the
caterpillars which build structures of this substantial
description, are destined to lie much longer in their
chrysalis trance, than those which spin merely a
flimsy web of silk. For the most part, indeed, the
latter undergo their final transformation in a few
weeks ; while the former continue entranced the larger
portion of a year, appearing in the perfect state the
summer after their architectural Jabours have been
completed*. ‘This is a remarkable example of the
instinct which leads these little creatures to act with
a foresight in many cases much clearer than the
dictates of human prudence. In the examples be-
fore us, the instinct is more delicate and complex
than that which directs other animals to provide a
burrow for their winter sleep. It is not unreasonable
to suppose that the one caterpillar is aware, while it
is building the cocoon, that the moth into which it
is about to be changed will not be in a fit state to
appear before the succeeding summer. The other,
pursuing a similar course of thought, may feel that
the moth will see the light in a few weeks. The
comparative distances of time certainly appear most
difficult to be understood by an insect ; for, as far as
we know, quadrupeds do not carry their intelligence
to such an extent. And yet in the solitary case of

*JLR

CYPRESS-SPURGE CATERPILLAR. isi

provision for a future progeny, the instinct is ins
variably subtle and extraordinary. What, for ins
stance, is more remarkable than that the insect should
always place her eggs where her progeny will find

\ the food which is best suited to their nature? In
almost no case does the perfect insect eat that
food, so that the parent cannot judge from her own
habits. The Contriver of the mechanism by which
insects work also directs the instinct by which they
use their tools.

It is exceedingly difficult, with our very limited
knowledge of the springs of action in the inferior
animals, to determine the motives of their industry—
that is, whether they see clearly the end and object
of their arrangements, A human architect, in all his
plans, has regard, according to the extent of his skill,
to the combination of beauty and convenience ; and
in most cases he has adaptations peculiar to the cir-
cumstances connected with the purpose of the struc-
ture. In the erection of a common dwelling- house,
for instance, one family requires many sleeping-
rooms, another few—one wants its drawing-rooms
in a suite, another detached. The architect knows all
these wants, and provides for them. But all insects
build their habitations upon the same general model,
although they can slightly vary them according to
circumstances, ‘Thus, according as the uniformity,
or the occasional adaptation of their work to particu-
lar situations, has been most regarded by those who
speculate upon their actions, they have been held to
be wholly governed by instinct or by intelligence—
have been called machines or free agents. ‘There are
difficulties in either conclusion ; and the truth perhaps
lies between the two opinions, Their actions may
entirely result from their organization ; they are cer-
tainly in conformity with it. ‘Those who would deny
the animal all intelligence, by which we mean a power,

M

Ne

182 INSECT ARCHITECTURE.

resulting from selection, of deviating in smal] matters
from a precise rule of action, are often materialists,
who shut their eyes to the creating and preserving
economy of Providence. But even this belief in the
infallible results of organization does not necessarily
imply the disbelief of a presiding Power. ‘The
same wisdom,” says Bonnet, * which has constructed.
and arranged with so much art the various organs
of animals, and has made them concur towards
one determined end, has also provided that the dif
ferent operations which are the natural results of the
economy of the animal should concur towards the
same end, The creature is directed towards his ob-
ject by an invisible hand; he executes with precision,
and by one effort, those works which we so much
admire; he appears to act as if he reasoned, to
return to his labour at the proper time, to change
his scheme in case of need. But in all this he only
obeys the secret influence whieh drives him on. He
is but an instrument which cannot judge of each
action, but is wound up by that adorable Intel-
ligence, which has traced out for every insect. its
proper labours, as he has traced the orbit of each
planet. When, therefore, I see an insect working at
the construction of a nest, or a cocoon, I am im-
pressed with respect, because it seems to me that I
am at a spectacle where the Supreme Artist is hid
behind the curtain *.”

There is a small sort of caterpillar which may be
found on old walls, feeding upon minute mosses and
lichens, the proceedings of which are well worthy of
attention. They are similar, in appearance and size,
to the caterpillar of the small cabbage-butterfly
(Pontia rape), and are smooth and bluish. ‘The
material which they use in building their cocoons is

* Contemplation de la Nature, part xv. chap. 38.

MOSS-BUILDING CATERPILLAR. 183

composed of the leaves and branchlets of green moss,
which they cut into suitable pieces, detaching at the
same time along with them a portion of the earth in
which they grow. ‘They arrange these upon the
walls of their building with the moss on the outside,
and the earth on the inside, making a sort of vault
of the tiny bits of green moss turf, dug from the
surface of the wall. So neatly, also, are the several
pieces joined, that the whole might well be supposed
tobe a patch of moss which had grown in form of
an oval tuft, a little more elevated than the rest
growing on the wall. When these caterpillars are
shut up in a box with some moss, without earth,
they construct with it cells in form of a hollow ball,
very prettily plaited and interwoven.

Moss-Cell of Small Caterpillar (Bryophila perla ?)

In May last (1829), we found on the walls of
Greenwich Park, a great number of caterpillars
whose manners bore some resemblance to those of
the grub described by M. Réaumur*. ‘They were
of middle size, with a dull orange stripe along the
back ; the head and sides of the body black, and the
belly greenish. Their abodes were constructed with
ingenuity and care. A caterpillar of this sort ap-
pears to choose either a part where the mortar con-
tains a cavity, or it digs one suited to its design.
Over the opening of the hollow in the mortar, it

*J.R,
M2

184 INSECT ARCHITECTURE,

builds an arched wall so as to form a chamber con-
siderably larger than is usual with other architect
caterpillars. It selects grains of mortar, brick, or
lichen, fixing them, by means of silk, firmly into the
structure. As some of these vaulted walls were
from an inch to an inch and a half long, and about a
third of an inch wide and deep, it may be well
imagined that it would require no little industry and
labour to complete the work. Yet it does not de-
mand more than a few hours for the insect to raise it
from the foundation. Like all other insect architects,
this caterpillar uses its own body for a measuring
rule, and partly for a mould, or rather a block or
centre to shape the walls by, curving itself round and
round concentrically with the arch which it is building.

We afterwards found one of these caterpillars,
which had dug a cell in one of the softest of the
bricks, covering itself on the outside with an arched
wall of brick-dust, cemented with silk, As this brick
was of a bright red colour, we were thereby able to
ascertain that there was not a particle of lichen em-
ployed in the structure.

The neatness mentioned by Réaumur, as remark-
able in his moss-building caterpillars, is equally ob-
servable in that which we have just described ; for, on
looking at the surface of the wall, it would be impos-
sible for a person unacquainted with these structures
to detect where they were placed, as they are usually,
on the outside, level with the adjoining brick-work, and
it is only when they are opened by the entomologist,
that the little architect is perceived lying snug in his
chamber. If a portion of the wall be thus broken
down, the caterpillar loses no time in repairing the
breach, by piecing in bits of mortar and fragments of
lichen, till we can scarcely distinguish the new por
tion from the old.

Cuaprer X.
CADDIS-WORMS AND CARPENTER-CATERPILLARS,

Tuere is a very interesting class of grubs which .
live under water, where they construct for themselves
moveable tents of various materials as their habits
direct them, or as the substances they require can be
conveniently procured. Among the materials used
by these singular grubs, well known to fishermen by
the name of caddis-worms, and to naturalists as the
larve of the four-winged flies in the order T'richop-
tera, we may mention sand, stones, shells, wood, and
leaves, whichare skilfully joined and strongly cemented.
One of these grubs forms a pretty case of leaves
glued together longitudinally, but leaving an aper-
ture sufficiently large for the inhabitant to put out its
head and shoulders when it wishes to look about for

Leaf Nest of Caddis-Worm,

food. Another employs pieces of reed cut into con-
venient lengths, or of grass, straw, wood, &c., care-
fully joining and cementing each piece to its fellow
as the work proceeds; and he frequently finishes the

a

Reed Nest of Caddis-Worm,

186 INSECT ARCHITECTURE.

whole by adding a broad piece longer than the rest
to shade his door-way over-head, so that he may not
be seen from above. A more laborious structure is
reared by the grub of a beautiful caddis-fly (Phry-
ganea), which weaves together a group of the leaves
of aquatic plants into a roundish ball, and in the
interior of this forms a cell for its abode. The fol-
lowing figure from Roesel will give a more precise
notion of this structure than a lengthened description.

Another of these aquatic architects makes choice
of the tiny shells of young fresh-water mussels and
snails (Planorbis), to form a moveable grotto, and
as these little shells ave for the most part inhabited,
he keeps the poor animals close prisoners, and drags

Shell Nests of Caddis-JVorms.

eT lrlt— 7 cect Ore

CADDIS-WORMS, 187

them without mercy along with him. These grotto-
building grubs are by no means uncommon in ponds ;
and in chalk districts, such as the country about
Woolwich and Gravesend, they are very abundant.
One of the most surprising instances of their
skill occurs in the structures of which small stones
are the principal material. The problem is to make
a tube about the width of the hollow of a wheat
straw or a crow quill, and equally smooth and
uniform. Now the materials being small stones full
of angles and irregularities, the difficulty of per-
forming this problem will appear to be considerable,
if not insurmountable; yet the little architects, by
patiently examining their stones and turning them
round on every side, never fail to accomplish their
plans. ‘This, however, is only part of the pro-

"Stone Nest of Caddis-Worm,
blem, which is complicated with another condition,
and which we have not found recorded by former
observers, namely, that the under surface shall be
flat and smooth, without any projecting angles which
might impede its progress when dragged along the
bottom of the rivulet where it resides. The selection
of the stones, indeed, may be accounted for, from this
species living in streams where, but for the weight of
its house, it would to a certainty be swept away. For
this purpose, it is probable that the grub makes
choice of larger stones than it might otherwise want ;
and therefore also it is that we frequently find a case
composed of very small stones and sand, to which,

Sand Nest balanced with a Stone.

es ES OE el

7» *

188 INSECT ARCHITECTURE,

when nearly finished, a large stone 1s added by way
of ballast. In other instances, when the materials
are found to possess too great specific gravity, a bit
of light wood, or a hollow straw, is added to buoy
up the case.

Nest of Caddis-WVorm balanced with Straws.

It is worthy of remark, that the cement, used
in all these cases, is superior to pozzolana* in stand-
ing water, in which it is indissoluble. The grubs
themselves are also admirably adapted for their
mode of life, the portion of their bodies which is always
enclosed in the case being soft like a meal-worm, or
garden caterpillar, while the head and shoulders,
which are for the most part projected beyond the
door-way in search of food, are firm, hard, and con-
sequently less liable to injury than the protected por-
tion, should it chance to be exposed.

We have repeatedly tried experiments with the in-
habitants of those aquatic tents, to ascertain their
mode of building, We have deprived them of their
little houses, and furnished them with materials for
constructing new ones, watching their proceedings
from their laying the first stone or shell of the struc-
ture. They work at the commencement in a very
clumsy manner, attaching a great number of chips
to whatever materials may be within their reach with
loose threads of silk, and many of these they never
use at all in their perfect building, ‘They act, indeed,
much like an unskilful workman trying his hand be-
fore committing himself upon an intended work of
difficult execution. Their main intention is, however,
to have abundance of materials within reach: for
after their dwelling is fairly begun, they shut them-

* A cement prepared of volcanic earth, or lava.

GOAT-MOTH, 189

selves up in it, and do not again protrude more than
half of their body to procure materials; and even
when they have dragged a stone, a shell, or a chip ot
reed within building reach, they have often to reject it
as unfit*.

CARPENTER-CATERPILLARS.

Insects, though sometimes actuated by an instinct
apparently blind, unintelligent, or unknown to them-
selves, manifest in other instances a remarkable adap-
tation of meansto ends. We have it in our power to
exemplify this in a striking manner by the proceed-
ings of the caterpillar of a goat-moth (Cossus ligni-
perda) which we kept till it underwent its final
change.

Caterpillar of Goat-Moth in a Willow Tree.

This caterpillar, which abounds in Kent and many
other parts of the island, feeds on the wood of
willows, oaks, poplars, and other trees, in which it
eats extensive galleries; but it is not contented with
the protection afforded by these galleries during

eR,

M5

190 INSECT ARCHITECTURE,

the colder months of winter, before the arrival of
which it scoops out a hollow in the tree, if it do not
find one ready prepared, sufficiently large to contain
its body in a bent or somewhat coiled up position.
On sawing off a portion of an old poplar in the
winter of 1827, we found such a cell with a cater-
pillar coiled up in it.

AZZ

i

Winter Nest of the Goat-Caterpillar,

It had not, however, been contented with the bare
walls of the retreat which it had hewn out of the tree,
for it had lined it with a fabric as thick as coarse
broad-cloth, and equally warm, composed of the rasp-
ings of the wood scooped out of the cell, united with the
strong silk which every species of caterpillar can spin.
In this snug retreat our caterpillar, if it had not been
disturbed, would have spent the winter without eat-
ing; but upon being removed into a warm room and
placed under a glass along with some pieces of wood,
which it might eat if so inclined, it was roused for a
time from its dormant state, and began to move
about. It was not long, however, in constructing a
new cell for itself, no less ingenious than the former.
It either could not gnaw into the fir plank, where it
was now placed witha glass above it, or it did not
choose to do so; for it left it untouched, and made it
the basis of the edifice it began to construct. It

GOAT-MOTH, 191

formed, in fact, a covering for itself precisely like the
one from which we had dislodged it,—composed of
raspings of wood detached for the purpose from
what had been given it as food,—the largest piece of
which was employed as a substantial covering and
protection for the whole. It remained in this retreat,
motionless, and without food, till revived by the
warmth of the ensuing spring, when it gnawed its
way out, and began to eat voraciously, to make up
for its long fast.

These caterpillars are three years in arriving at
their final change into the winged state; but as the
one just mentioned was nearly full grown, it began,
in the month of May, to prepare a cell, in which it
might undergo its metamorphosis. Whether it had
actually improved its skill in architecture by its pre-
vious experience we will not undertake to say, but its
second cell was greatly superior to the first. In the
first there was only one large piece of wood em-
ployed; in the second, two pieces were placed in
such a manner as to support each other, and beneath
the angle thus formed, an oblong structure was made,
composed, as before, of wood-raspings and silk, but
much stronger in texture than the winter cell. In a
few weeks (four, if we recollect aright) the moth
came forth*.

Nest of Goat-Moth.—Figured from specimen, and raised to shew the Pupa,
sola! (oR CS

> ‘s «192 - INSECT ARCHITECTURE,

A wood-boring caterpillar, of a species of moth
much rarer than the preceding (geria asiliformis,
SrepuHens), exhibits great ingenuity in construct-
ing a cell for its metamorphosis. We observed
above a dozen of them during this summer (1829)
in the trunk of a poplar, one side of which had
been stripped of its bark. It was this portion of
the trunk which all the caterpillars selected for
their final retreat, not one having been observed
where the tree was covered with bark, The inge-
nuity of the little architect consisted in scooping its
cell almost to the very surface of the wood, leaving
only an exterior covering of unbroken wood, as thin
as writing paper. Previous, therefore, to the chry-
salis making its way through this feeble barrier, it
could not have been suspected that an insect was
lodged under the smooth wood. We observed more
than one of these in the act of breaking through this
covering, within which there is besides a round move-
able lid of a sort of brown wax *,

Another arehitect caterpillar, frequently to be met
with in July on the leaves of the willow and the
poplar, is, in the fly state, called the Puss-Moth
(Cerura vinula). The caterpillar is produced from °
brown-coloured shining eggs, about the size of a
pin’s head, which are deposited—one, two, or
more together—on the upper surface of a_ leaf,
In the course of six or eight weeks (during which
time it casts its skin thrice) it arrives at its full

Eqs of the Puss-Moth,
we

PUSS-MOTH, 193

growth, when it is about as thick, and nearly as
long, as a man’s thumb, and begins to prepare a
structure in which the pupa may sleep securely
during the winter. As we have, oftener than once,
seen this little architect at work, from the foundation
till the completion of its edifice, we are thereby ena-
bled to give the details of the process.

The puss, it may be remarked, does not depend
for protection on the hole of a tree, or the shelter of
an overhanging branch, but upon the solidity and
strength of the fabric which it rears. The material
it commonly uses is the bark of the tree upon which
the cell is constructed; but when this cannot be pro-
cured, it is contented to employ whatever analogous
materials may be within reach. One which we had
shut up in a box substituted the marble paper
it was lined with, for bark, which it could not pro-
eure*, With silk it first wove a thin web round the

* It is justly remarked by Réaumur, that when caterpillars
are left at liberty among their native plants, it is only by lucky
chance they can be observed building their cocoons, because the
greater number abandon the plants upon which they have been
feeding, to spin up in places at some distance. In order to see
their operations they must be kept in confinement, particularly in
boxes, with glazed doors, where they may be always under the eye
of the uaturalist. In such circumstances, however, we may be
ignorant what building materials we ought to provide them with
for their structures. A red caterpillar, with a few tufts of hair,
which Réaumur found in July feeding upon the flower bunches
of the nettle, and refusing to touch the leaves, began in a few days
to prepare ils cocoon, by gnawing the paper lid of the box in
which & was placed. This, of course, was a material which it
could not have procured in the fields, but it was the nearest in
properties that it could procure, for though it had the leaves and
stems of nettles, it never used a single fragment of either. When
Réaumur found that it was likely to gnaw through the paper lid
of the box, and might effect its escape, he furnished it with bits
of rumpled paper, fixed to the lid by means of a pin; and these
it chopped down into such pieces as it judged convenient for its
structure, which it took a day to complete. The moth appeared

194 INSECT ARCHITECTORE,

edges of the place which it marked out for its edi-
fice; then it ran several threads in a square manner
from side to side, and from end to end, but very
irregularly in point of arrangement: these were in-
tended for the skeleton or frame-work of the building.

Rudiments of the Cell of the Puss-Moth

When this outline was finished, the next step was to
strengthen each thread of silk, by adding several
(sometimes six or eight) parallel ones, all of which
were then glued together into a single thread, by
the insect running its mandibles, charged with
gluten, along the line. The meshes, or spaces,
which were thus widened by the compression of the
parallel threads, were immediately filled up with
fresh threads, till at length only very small spaces
were left. It was in this stage of the operation that.
the paper came into requisition, small portions of it
being gnawed off the box and glued into the meshes,
It was not, however, into the meshes only that the
bits of paper were inserted; for the whole fabric was
in the end thickly studded over with them. In about
half a day from the first thread of the frame-work
being spun the building was completed. It was at
first, however, rather soft, and yielded to slight pres-
sure with the finger; but as soon as it became

four weeks after, of a brownish- black coiour, mottled with white,
or rather grey, in the manner of lace,

Bonnet also mentions more than one instance in which he
observed caterpillars making use of paper, when they could not
procure other materials,

PUSS-MOTH, 195

thoroughly dry, it was so hard that it could with
difficulty be penetrated with the point of a penknife*

Coll built by the Larva of the Puss-Moth.

A question will here suggest itself to the curious
inquirer, how the moth, which is not, like the cater-
pillar, furnished with mandibles for gnawing, can find
its way through s0 hard a wall. To resolve this
question, it is asserted by recent naturalists (see Kirby
and Spence, vol. iii. p. 15), that the moth is furnished
with a peculiar acid for dissolving itself a passage. We
have a specimen of the case of a puss-moth, in which,
notwithstanding its strength, one of the ichneumons
had contrived to deposit its eggs. In the beginning
of summer, when we expected the moth to appear, and
felt anxious to observe the recorded effects of the
acid, we were astonished to find a large orange
cuckoo-fly make its escape; while another, which at-
tempted to follow, stuck by the way and died. On
detaching the cell from the box, we found several
others, which had not been able to get out, and had
died in their cocoons f.

Ichneumon (Ophion luteum) figured from the one mentioned.

* JR, + J.R.

196 INSECT ARCHITECTURE,

Among the carpenter-grubs may be mentioned
that of the purple capricorn-beetle (Callidium viola
ceum), of which the Rev. Mr. Kirby has given an
interesting account in the fifth volume of the Lin-
nean Transactions. This insect feeds principally
on fir timber, which has been felled some time with
out having had the bark stripped off; but it is often
found on other wood. Though occasionally taken in
this kingdom, it is supposed not to have been ori-
ginally a native. The circumstance of this destruc-
tive little animal attacking only such timber as had
not been stripped of its bark ought to be attended
to by all persons who have any concern in this article;
for the bark is a temptation not only to this, but
to various other insects; and much of the injury
done in timber might be prevented, if the trees were
all barked as soon as they were felled. ‘The female
is furnished, at the posterior extremity of her body,
with a flat retractile tube, which she inserts between
the bark and the wood, to the depth of about a quar-
ter ofan inch, and there deposits a single egg. By
stripping off the bark, it is easy to trace the whole
progress of the grub, from the spot where it is
hatched, to that where it attains its full size, It first
proceeds in a serpentine direction, filling the space
whichit leaves with its excrement, resembling sawdust,
and so stopping all ingress to enemies from without.
When it has arrived at its utmost dimensions, it does
not confine itself to one direction, but works in a kind
of labyrinth, eating backwards and forwards, which
gives the wood under the bark a very irregular sur-
face; by this means its paths are rendered of con-
siderable width. The bed of its paths exhibits, when
closely examined, a curious appearance, occasioned
by the gnawings of its jaws, which excavate an infinity
of little ramified canals, When the insect is about to
assume its chrysalis state, it bores down obliquely

OAK-BARK CATERPILLAR. 197

into the solid wood, to the depth sometimes of three
inches, and seldom if ever less than two, forming
holes, nearly semi-cylindrical, and of exactly the form
of the grub which inhabits them. At first sight one
would wonder how so small and seemingly so weak
an animal could have strength to excavate so deep a
mine; but when we examine its jaws our wonder
ceases, ‘These are large, thick, and solid sections of a
cone divided longitudinally, which, in the act of
chewing, apply to each other the whole of their inte-
rior plane surface, so that they grind the insect’s
food like a pair of millstones. Some of the grubs
are hatched in October; and it is supposed that about
the beginning of March they assume their chrysalis
state. At the place in the bark, opposite to the hole
from whence they descended into the wood, the per-
fect insects gnaw their way out, which generally takes
place betwixt the middle of May and the middle of
June. These insects are supposed to fly only in
the night, but during the day they may generally be
found resting on the wood from which they were
disclosed, The grubs are destitute of feet, pale, folded,
somewhat hairy, conyex above, and divided into thir-
teensegments. Their head is large and convex *.

It would not be easy to find a more striking ex-
ample of ingenuity than occurs in a small caterpillar
which may be found in May, on the oak, and is sup-
posed, by Kirby and Spence, to be that of the Pyralis
strigulalis. It is of a whitish yellow colour, tinged
with a shade of carnation, and studded with tufts of
red hairs, on each segment, and two brown spots
behind the head. It has fourteen feet, and the upper
part of its body is much flatter than is common in
caterpillars. When this ingenious little insect begins
to form its cell, it selects a smooth young branch

* Kirby in Linn, Trans, vol. v, p, 246, and Introd, ii.

198 INSECT ARCHITECTURE,

of the oak, near an offwoing of the branchlets whose
angle may afford it some protection. It then measures
out, with its body for a rule, the space destined for
its structure, the basement of which is of a triangular
form, with the apex at the lower end. ‘The building
itself is composed of small rectangular strap-shaped
pieces of the outer bark of the branch cut out from
the immediate vicinity; the insect indeed never tra-
vels farther for materials than the length of its own
body. Upon the two longest sides of the triangular
base it builds uniform walls, also of a triangular
shape, and both gradually diverging from each other
as they increase in height. ‘These are formed with
so much mathematical precision, that they fit exactly
when they are afterwards brought into contact. As
soon as the little architect has completed these walls,
which resemble very much the feathers of an arrow,

Magnified Cells of Pyralis Strigulalis?

a, The walls before they are joined, 6, Walls joined, but not
closed at top. o, Side view of structure complete.

OAK-BARK CATERPILLAR, 199
it proceeds to draw them together in a manner si-
milar to that which the leaf-rolling caterpillars employ
in constructing their abodes, by pulling them with
silken cords till they bend and converge. Even
when the two longest sides are thus joined, there is
an opening left at the upper end, which is united in
a similar manner. When the whole is finished, it
requires close inspection to distinguish it from the
branch, being formed of the same materials, and
having consequently the same colour and gloss.
Concealment, indeed, may be supposed, with some
justice, to be the final object of the insect in pro-
ducing this appearance, the same principle being ex«
tensively exemplified in numerous other instances,

200

Cuapter XI.
EARTH-MASON CATERPILLARS

Many species of caterpillars are not only skilfu.
in concealing themselves in their cocoons, but also
in the concealment of the cocoon itself; so that
even when that is large, as in the instance of the
death’s-head hawk-moth (Acherontia atropos), it is
almost impossible to find it. We allude to the
numerous class of caterpillars which, previous to
their changing into the pupa state, bury themselves
in the earth. This circumstance would not be sur-
prising, were it confined to those which are but too
well known in gardens, from their feeding upon and
destroying the roots of lettuce, chicory, and other
plants, as they pass a considerable portion of their
lives under ground ; nor is it surprising that those
which retire under ground during the day, and come
abroad to feed in thenight, should form their cocoons
where they have been in the habit of concealing
themselves. But it is very singular and unexpected,
that caterpillars, which pass the whole of their life on
plants, and even on trees, should afterwards bury
themselves in the earth. Yet, the fact is, that per-
haps a greater number make their cocoons under
than above ground, particularly those which are not
clothed with hair.

Some of those caterpillars, which go into the
ground previous to their change, make no cocoon at
all, but are contented with a rude masonry of earth
as a nest for their pup: into the details of their
operations it will not be so necessary for us to
go, as into those which exhibit more ingenuity

EARTH-MASON CATERPILLARS. 201

and care. When one of the latter is dug up, it
has the appearance of nothing more than a small
clod of earth, of a roundish or oblong shape, but,
generally, by no means uniform. The interior, how-
ever, when it is laid open, always exhibits a cavity,
smooth, polished, and regular, in which the cocoon, or
the chrysalis lies secure. (Fig. p. 202, 8.) The polish
of the interior is precisely such as might be given to
soft earth by moistening and kneading it with great
care, But beside this, it is usually lined with a tapes-
try of silk, more or less thick, though this cannot always
be discovered without the aid of a magnifying glass.
This species of caterpillars, as soon as they have
completed their growth, go into the earth, scoop out,
as the cossus does in wood, a hollow cell of an oblong
form, and live it with pellets of earth, from the
size of a grain of sand to that of a pea—united, by
silk or gluten, into a fabric more or less compact,
according to the species, but all of them fitted for
protecting the inhabitant, during its winter sleep,
against cold and moisture.

Outside View of Nests of Earth-mason Caterpillars,

One of the examples of this occurs in the ghost-
moth (Hepialus humuli), which, before it retires into
the earth, feeds upon the roots of the hop or the
burdock. Like other insects which construct cells
under ground, it lines the cemented earthen walls
of its cell with a smooth tapestry of silk, as closely
woven as the web of the house-spider.

Inaccurate observers have inferred that these

202 INSECT ARCHITECTURE,

Nests, &c., of an Earth-mason Caterpillar,

earthen structures were formed by a very rude and
unskilful process—the caterpillar, according to them,
doing nothing more than roll itself round, while the
mould adhered to the gluey perspiration with which
they describe its body to be covered. This is a
process as far from the truth, as Aristotle’s account
of the spider spinning its web from wool taken from
its body. Did the caterpillar do nothing more than
roll itself in the earth, the cavity would be a long
tube fitted exactly to its body (fig. c): it is essentially
different,

It does not indeed require very minute observation
to perceive, that every grain of earth in the structure
is united to the contiguous grains by threads of silk ;
and that consequently, instead of the whole having been
done at once, it must have required very considerable

EARTH-MASON CATERPILLARS, 203

time and labour. ‘This construction is rendered
more obvious by throwing one of these earthen cases
into water, which dissolves the earth, but does not
act on the silk which binds it together. To under-
stand how this is performed, it may not be uninterest-
ing to follow the little mason from the beginning of
his task.

When one of those burrowing caterpillars has
done feeding, it enters the earth to the depth of
several inches, till it finds mould fit for its purpose.
Having nowhere to throw the earth which it may dig
out, the only means in its power of forming a cavity
is to press it with its body; and, by turning round
and round for this purpose, an oblong hollow is soon
made. But were it left in this state, as Réaumur
well remarks, though the vault might endure the
requisite time by the viscosity of the earth alone,
were no change to take place in its humidity, yet, as
a great number are wanted to hold out for six, eight,
and ten months, they require to be substantially built,
a mere lining of silk, therefore, would not be suffi-
cient, and it becomes necessary to have the walls
bound with silk to some thickness.

When a caterpillar cannot find earth sufficiently
moist to bear kneading into the requisite consistence,
it has the means of moistening it with a fluid which
it ejects for the purpose ; and as soon as it has thus
prepared a small pellet of earth, it fits it into the wall
of the vault, and secures it with silk. As the little
mason, however, always works on the inside of the
building, it does not, at first view, appear in what
manner it can procure materials for making one or
two additional walls on the inside of the one first built.
As the process takes place under ground, it is not
easy to discover the particulars, for the caterpillars
will not work in glazed boxes. The difficulty was
completely overcome by M. Réaumur, in the instance

204 INSECT ARCHITECTURE,

of the caterpillar of the water-betony moth (Cu-
cullia scrophularie, Scuravux), which he permitted
to construct the greater part of its under-ground
building, and then dug it up and broke a portion off
from the end, leaving about a third part of the whole
to be rebuilt. ‘Those who are unacquainted with the
instincts of insects might have supposed that, being
disturbed by the demolition of its walls, it would
have left off work; but the stimulus of providing for
the great change is so powerful, that scarcely any
disturbance will interrupt a caterpillar in this species
of labour.

The little builder accordingly was not long in re-
commencing its task for the purpose of repairing the
disorder, which it accomplished in about four hours.
At first it protruded its body almost entirely beyond
the breach which had been made, to reconnoitre the
exterior for building materials. Earth was put within
its reach, of the same kind as it had previously
used, and it was not long in selecting a grain adapted
to its purpose, which it fitted into the wall and secured
with silk. It first enlarged the outside of the wall
by the larger and coarser grains, and then selected
finer for the interior. But before it closed the aper-
ture, it collected a quantity of earth on the inside,
wove a pretty thick network tapestry of silk over the
part which remained open, and into the meshes of
this, by pushing and pressing, it thrust grains of
earth, securing them with silk till the whole was ren~
dered opaque; and the further operations of the
insect could no longer be watched, except that it was
observed to keep in motion, finishing, no doubt, the
silken tapestry of the interior of its little chamber.
When it was completed, M. Réaumur ascertained
that the portion of the structure which had been
built under his eye was equally thick and compact
with the other, which had been done under ground.

' EARTH-MASON CATERPILLARS. 205

Ying

sth

if
SS
Sr

Earth-Mason Caterpillars’ Nests, with the perfect Moth, §c.

The grubs of several of the numerous species of
may-fly (Ephemera) excavate burrows for themselves
in soft earth, on the banks of rivers and canals, under

N

206 INSECT ARCHITECTURE,

the level of the water, an operation well described by
Scopoli, Swammerdam, and Réaumur. The excava-
tions are always proportioned to the size of the in=
habitant; and consequently, when it is young and
small, the hole is proportionally small, though, with
respect to extent, it is always at least double the
length ofits body, The hole, being under the level
of the river, is always filled with water, so that the
grub swims in its native element, and while it is se-
cure from being preyed upon by fishes, it has its own
food within easy reach. It feeds, in fact, if we may
judge from its egesta, upon the slime or moistened
clay with which its hole is lined.

i

Mi i)

>@ 3.\ ff
jh >

WN tl
wo
ay

Nests of the Grubs of Ephemera.

A, The grub. B, Perforations in a river bank. ©, One laid
open to shew the parallel structure.

In the bank of the stream at Lee in Kent, we had
occasion to take up an old willow stump, which, pre-
vious to its being driven into the bank, had been per-
forated in numerous places by the caterpillar of the

—- - — = _— ” ss a al

EARTH-MASON CATERPILLARS 207

goat-moth (Cossus ligniperda). From having been
driven amongst the moist clay, these perforations be-
came filled with it, and the grubs of the ephemerse
found them very suitable for their habitation ; for the
wood supplied a more secure protection than if their
galleries had been excavated in the clay. In these
holes of the wood we found several empty, and some
in which were full grown grubs*.

Wests of Ephemera in holes of Cussus.

The architecture of the grub of a pretty genus of
beetles, known to entomologists by the name of Ci-
cindela, is peculiarly interesting, It was first made
known by the eminent French naturalists, Geoffroy,
Desmarest, and Latreille. This grub, which may
be met with during spring, and also in summer
and autumn, in sandy places, is long, cylindric, soft,
whitish, and furnished with six brown scaly feet. The
head is of a square form, with six or eight eyes,
and very large in proportion to the body. They have
strong jaws, and on the eighth joint of the body there
are two fleshy tubercles, thickly clothed with reddish
hairs, and armed with a recurved horny spine, the
whole giving to the grub the form of the letter Z.

With their jaws and feet they dig into the earth to
the depth of eighteen inches, forming a cylindrical
cavity of greater diameter than their body, and fur-
nished with a perpendicular entrance. In construct:

* J.

208 INSECT ARCHITECTURE,

ing this, the grub first clears away the particles o1
earth and sand by placing them on its broad trape-
zoidal head, and carrying the load in this manner be-
yond the area of the excavation. When it gets deeper
down, it climbs gradually up to the surface with simi-
lar loads by means of the tubercles on its back, above
described. This process is a work of considerable
time and difficulty, and in carrying its loads, the in-
sect has often to rest by the way to recover strength
for a renewed exertion. Not unfrequently, it finds
the soil so ill adapted to its operations, that it aban-
dons the task altogether, and begins anew in another
situation. When it has succeeded in forming a com-
plete den, it fixes itself at the entrance by the hooks
of its tubercles, which are admirably adapted for the
purpose, forming a fulcrum or support, while the
broad plate on the top of the head exactly fits the
aperture of the excavation, and is on a level with the
soil. In this position, the grub remains immovyeable,
with jaws expanded, and ready to seize and devour
every insect which may wander within its reach, par-
ticularly the smaller beetles; and its voracity is so
great, that it does not spare even its own species. It
precipitates its prey into the excavation, and in case
of danger, it retires to the bottom of its den, a cir-
cumstance which renders it not a little difficult to
discover the grub. The method adopted by the French
naturalists was to introduce a straw or pliant twig
into the hole, while they dug away, by degrees and
with great care, the earth around it, and usually found
the grub at the bottom of the cell, resting in a zig-
zag position, like one of the caterpillars of the geo
metric moths.

When it is about to undergo its tranformation
into the pupa, it carefully closes the mouth of the den,
and retires to the bottom in security.

It does not appear that the grub of the genus

THE ANT-LION. 209

Cicindela uses the excavation just described for the
purpose of a trap or pitfall, any further than that it
can more effectually secure its prey by tumbling them
down into it; but there are other species of grubs
which construct pitfalls for the express purpose of
traps. Among these is the larva of a fly (Rhagio
vermileo), not unlike the common flesh maggot.
The den which it constructs is in the form of a
funnel, the sides of which are composed of sand or
loose earth. It forms this pitfall of considerable
depth, by throwing out the earth obliquely on all
sides; and when its trap is finished, it stretches
itself along the bottom, remaining stiff and motion-
less, like a piece of wood. The last segment of the
body is bent at an angle with the rest, so as to form
a strong point of support in the struggles which it
must often have to encounter with vigorous prey.
The instant that an insect tumbles into the pitfall, the
grub pounces upon it, writhes itself round it like a
serpent, trausfixes it with its jaws, and sucks its
juices at its ease. Should the prey by any chance
escape, the grub hurls after it jets of sand and earth,
with astonishing rapidity and force, and not unfre-
quently succeeds in again precipitating it to the bot-
tom of its trap.

Tue Ant-Lion.

The observations of the continental naturalists
have made known to us a pitfall constructed by an
insect, the details of whose operations are exceed-
ingly curious—we refer to the grub of the ant-lion
(Myrmeleon formicarius), which, though marked by
Dr. Turton and Mr. Stewart as British, has not (at
least of late years) been found in this country. As
it is not, however, uncommon in France and Swit-

n3

~

210 INSECT ARCHITECTURE.

zerland, it is probable it may yet be discovered in
some spot hitherto unexplored, and if so, it will well
reward the research of the curious.

The ant-lion grub being of a grey colour, and hay-
‘ing its body composed of rings, isnot unlike a wood-
louse (Oniscus), though it is larger, more triangular,
has only six legs, and most formidable jaws, in form
of a reaping-hook, or a pair of calliper compasses.
These jaws, however, are not for masticating, but
are perforated and tubular, for the purpose of suck-
ing the juices of ants, upon whichit feeds. Vallisnieri
was therefore mistaken, as Réaumur well remarks,
when he supposed that he had discovered its mouth.
Its habits require that it should walk backwards, and
this is the only species of locomotion which it can
perform. Even this sort of motion it executes very
slowly; and were it not for the ingenuity of its
stratagems, it would fare but sparingly, since its
chief food consists of ants, whose activity and swift-
ness of foot would otherwise render it impossible
for it to make a single capture. Nature, however,
in this, as in nearly every other case, has given a
compensating power to the individual animal, to
balance its privations. The ant-lion is slow—but it
is extremely sagacious ; it cannot follow its prey—but
it can entrap it.

The snare which the grub of the ant-lion employs
consists of a funnel-shaped excavation formed in
loose sand, at the bottom of which it lies in wait for
the ants that chance to stumble over the margin, and
cannot, from the looseness of the walls, gain a suffi-
cient footing to effect their escape. When the pit-
fall is intended to be small, it only thursts its body
backwards into the sand as far as it can, throwing
out at intervals the particles which fall in upon it,
till it is rendered of the requisite depth.

By shutting up one of these grubs in a box with

THE ANT-LION, 211

Grub of the Ant-Lion magnified, with one perfect Trap,
and another begun.

loose sand, it has been repeatedly observed construct-
ing its trap of various dimensions, from one to three
inches in diameter, according to circumstances, When
it intends to make one of considerable diameter, it
proceeds as methodically as the most skilful architect
or engineer amongst ourselves. It first examines
the nature of the soil, whether it be sufficiently dry
and fine for its purpose, and if so, it begins by
tracing out a circle, where the mouth of its funnel-
trap is intended to be. Having thus marked the
limits of its pit, it proceeds to scoop out the interior.
Getting within the circle, and using one of its legs
as a shovel, it places therewith a load of sand on
the flat part of its head, and it throws the whole
with a jerk some inches beyond the circle. It 1s
worthy of remark that it only uses one leg in this

212 ' INSECT ARCHITECTURE,

operation—the one, namely, which is nearest the
centre of the circle. Were it to employ the others
in digging away the sand, it would encroach upon the
regularity of its plan. Working with great industry
and adroitness in the manner we have just described,
it quickly makes the round of its circle, and as it
works backwards it soon arrives at the point where
it had commenced. Instead, however, of proceed-
ing from this point in the same direction as before,
it wheels about and works a round in the contrary
direction, and in this way it avoids throwing all the
fatigue of the labour on one leg, alternating them
every round of the circle.

Ant-Lion's Pitfalls, in an experimenting-box.

Were there nothing to scoop out but sand or loose
earth, the little engineer would have only to repeat
the operations we have described, till it had completed
the whole. But it frequently happens in the course
of its labours, sometimes even when they are near a
close, that it will meet with a stone of some size which
would, if suffered to remain, injure materially the
perfection of its trap. But such obstacles as this do
not prevent the insect from proceeding ; on the con-
trary, it redoubles its assiduity to remove the obstruc-
tion, as M. Bonnet repeatedly witnessed. If the
stone be small, it can manage to jerk it out in the
same manner as the sand; but when it is two or

THE ANT-LION, ‘ 213

three times larger and heavier than its own body, it
must have recourse to other means of removal. The
larger stones it usually leaves till the last, and when
it has removed all the sand which it intends, it then
proceeds to try what it can do with the less manage-
able obstacles. For this purpose, it crawls backwards
to the place where a stone may be, and thrusting its
tail under it, is at great pains to get it properly
balanced on its back, by an alternate motion of the
rings composing its body. When it has succeeded
in adjusting the stone, it crawls up the side of the
pit with great care and deposits its burden on the
outside of the circle. Should the stone happen to be
round, the balance can be kept only with the greatest
difficulty, as it has to travel with its load upon a
slope of loose sand, which is ready to give way at
every step; and often when the insect has carried it to
the very brink it rolls off its back and tumbles down
to the bottom of the pit. This accident, so far from
discouraging the ant-lion, only stimulates it to more
persevering efforts. Bonnet observed it renew these
attempts to dislodge a stone, five or six times. It
is only when it finds it utterly impossible to succeed,
that it abandons the design and commences another
pit in a fresh situation. When it succeeds in getting
a stone beyond the line of its circle, it is not contented
with letting it rest there ; but to prevent it from again
‘rolling in, it goes on to push it to a considerable
distance.

The pitfall, when finished, is usually about three
inches in diameter at the top, about two inches deep,
and gradually contracting into a point in the manner
of a cone or funnel. In the bottom of this pit the
aut-lion stations itself to watch for its prey. Should an
ant or any other insect wander within the verge of the
funnel, it can scarcely fail to dislodge and roll down
some particles of sand, which will give notice to the

214 INSECT ARCHITECTURE,

_ant-lion below to be on the alert. In order to secure
the prey, Réaumur, Bonnet, and others have observed
the ingenious insect throw up showers of sand by
jerking it from his head in quick succession, till the
luckless ant is precipitated within reach of the jaws
of its concealed enemy. It feeds only on the blood
or juice of insects; and as soon as it has extracted
these, it tosses the dry carcass out of its den. Its
next care is to mount the sides of the pitfall and re-
pair any damage it may have suffered ; and when this
is accomplished, it again buries itself among the sand
at the bottom, leaving nothing but its jaws above the
surface, ready to seize the next victim.

When it is about to change into a pupa, it pro-
ceeds in nearly the same. manner as the caterpillar of
the water-betony moth (Cucullia scrophularie). It
first builds a ease of sand, the particles of which are
secured by threads of silk, and then tapestries the
whole with a silken web. Within this it undergoes
its transformation into a pupa, and in due time, it
emerges in form of a four-winged fly, closely resem-
bling the dragon-flies (Libellule), vulgarly and erro-
neously called horse-stingers.

The instance of the ant-lion naturally leads us to
consider the design of the Author of Nature in so
nicely adjusting, in all animals, the means of de-
struction and of escape. As the larger quadrupeds
of prey are provided with a most ingenious machinery
for preying on the weaker, so are these furnished
with the most admirable powers of evading their
destroyers. In the economy of insects, we constantly
observe, that the means of defence, not only of the
individual creatures, but of their larve and pupa,
against the attacks of other insects, and of birds, is
proportioned, in the ingenuity of their arrangements,
to the weakness of the insect employing them. Those
species which multiply the quickest have the greatest

THE ANT-LION, 215

number of enemies. Bradley, an English naturalist,
has calculated that two sparrows carry, in the course
of a week, above three thousand caterpillars to the
young in their nests. But though this is, probably,
much beyond the truth, it is certain that there is a
great and constant destruction of individuals going
forward; and yet the species is never destroyed. In
this way a balance is kept up, by which one portion
of animated nature cannot usurp the means of life
and enjoyment which the world offers to another
portion. In all matters relating to reproduction,
Nature is prodigal in her arrangements. Insects
have more stages to pass through before they attain
their perfect growth than other creatures. The con-
tinuation of the species is, therefore, in many cases,
provided for by a much larger number of eggs being
deposited than ever become fertile. How many
larve are produced, in comparison with the number
which pass into the pupa state; and how many pupe
perish before they become perfect insects! Every
garden is covered with caterpillars; and yet how
few moths and butterflies, comparatively, are seen,
even in the most sunny season! Insects which lay
few egos are, commonly, most remarkable in their
contrivances for their preservation. ‘The dangers to
which insect life is exposed are manifold; and there-
fore are the contrivances for its preservation of the
most perfect kind, and invariably adapted to the
peculiar habits of each tribe. The same wisdom
determines the food of every species of insect; and
thus some are found to delight in the rose-tree, and
some in the oak. Had it been otherwise, the balance
of vegetable life would not have been preserved. It
is for this reason that the contrivances which an
insect employs for obtaining its food are curious, in
proportion to the natural difficulties of its structure.
The ant-lion is carnivorous, but he has not the quick-

216 INSECT ARCHITECTURE,

ness of the spider, nor can he spread a net over
a large surface, and issue from his citadel to seize a
victim which he has caught in his outworks. He is
therefore taught to dig a trap, where he sits, like the
unwieldy giants of fable, waiting for some feeble one
to cross his path. How laborious and patient are
his operations—how uncertain the chances of success!
Yet he never shrinks from them, because his instinet
tells him that by these contrivances alone can he
preserve his own existence, and continue that of his
species,

217

Cuarrer XII.

Clothes-Moth, and other Tent-making Caterpillars.—Leaf
and Bark-Miners.

Tere are at least five different species of moths
similar in manners and economy, the caterpillars of
which feed upon animal substances, such as furs,
woollen cloths, silk, leather, and, what to the natu-
ralist is no less vexing, upon the specimens of insects
and other animals preserved in his cabinet. The
moths in question are of the family named Tinea by
entomologists, such as the tapestry-moth (Tinea ta-
petzella), the fur-moth (Tinea pellionella), the wool-
moth (Ztnea vestianella), the cabinet-moth (Tinea
destructor, SrrruEns), &c.

The moths themselves are, in the winged state,
small, and well fitted for making their way through
the most minute hole or chink, so that it is scarcely
possible to exclude them by the closeness of a ward-
robe or acabinet.* If they cannot effect an entrance
when a drawer is out, or a door open, they will con-
trive to glide through the key-hole; and if they once
get in, it is no easy matter to dislodge or destroy
them, for they are exceedingly agile, and escape out
of sight ina moment. Moufet is of opinion that the
ancients possessed an effectual method of preserving
stuffs from the moth, because the robes of Servius
Tullius were preserved up to the death of Sejanus,
a period of more than five hundred years, On turning
to Pliny to learn this secret, we find him relating that
stuff laid upon a coffin will be ever after safe from
moths ; in the same way as a person once stung by a

* See fig. d. p, 221.
)

218 INSECT ARCHITECTURE.

scorpion will never afterwards be stung by a bee, ora
wasp, ora hornet! Rhasis again says, that cantha-
rides suspended in a house drive away moths; and,
he adds, that they will not touch anything wrapped in
a lion’s skin!—the poor little insects, says Réaumur
sarcastically, being probably in bodily fear of so ter-
rible an animal.* Such are the stories which fill the
imagination even of philosophers, till real science
entirely expels them.

The effluvium of camphor or turpentine, or fumiga-
tion by sulphur or chlorine may sometimes kill them,
when in the winged state, but this will have no effect
upon their eggs, and seldom upon the caterpillars ;
for they wrap themselves up too closely to be easily
reached by any agent except heat. This, when it can
be conveniently applied, will be certain either to dis-
lodge or to kill them. When the effluyium of tur-
pentine, however, reaches the caterpillar, Bonnet
says it falls into convulsions, becomes covered with
livid blotches, and dies.+

The mother insect takes care to deposit her eggs
on or near such substances as she instinctively fore-
knows will be best adapted for the food of the young,
taking care to distribute them so that there may be
a plentiful supply and enough of room for each, We
have found, for example, some of those caterpillars
feeding upon the shreds of cloth used in training
wall-fruit trees; but we never saw more than two
caterpillars on one shred. This scattering of the
eggs in many places renders the effects of the cater-
pillars more injurious, from their attacking many
parts of a garment or a piece of stuff at the same
time.t

When one of the caterpillars of this family issues

* Réaumur, Mem. Hist. Insectes, iii. 70.
+ Contemplation de la Nature, part xii, chap. x. note.
{ JR.

+o

MOTH CATERPILLARS. 219

from the egg, its first care is to provide itself with a
domicile, which indeed seems no less indispensable
to it than food; for, like all caterpillars that feed
under cover, it will not eat while it remains unpro-
tected. Its mode of building is very similar to that
which is employed by other caterpillars that make
use of extraneous materials. The foundation or
frame-work is made of silk secreted by itself, and
into this it interweaves portions of the material
upon which it feeds. It is said by Bingley, that
“after having spun a fine coating of silk immediately
around tts body, it cuts the filaments of the wool or
fur close by the thread of the cloth, or by the skin,
with its teeth, which act in the manner of scissors,
into convenient lengths, and applies the bits, one by
one, with great dexterity, to the outside of its silken
case.”* This statement, however, is erroneous,
and inconsistent with the proceedings not only of
the clothes-moth, but of every caterpillar that con-
structs a covering. None of these build from within
outwards, but uniformly commence with the exterior
wall, and finish by lining the interior with the finest
materials. Réaumur, however, found that the newly-
hatched caterpillars lived at first in a case of silk.

We have repeatedly witnessed the proceedings of
these insects from the very foundation of their struc-
tures ; and, at the moment of writing this, we turned
out one from the carease of an “old lady moth”
(Mormo maura, Ocusenuerm.) in our cabinet, and
placed it on a desk covered with green cloth, where
it might find materials for constructing another
dwelling. It wandered about for half a day before
it began its operations; but it did not, as is asserted
by Bonnet, and Kirby and Spence, “in moving from
place to place, seem to be as much incommoded by
the long hairs which surround it, as we are by

* Animal Biography, vol. iii. p. 330, 3rd ed.
02

220 INSECT ARCHITECTURE.

walking amongst high grass,” nor, ‘“ accordingly,
marching scythe in hand,” did it, “* with its teeth, cut
out a smooth road.’”’* On the contrary, it did not
cut a single hair, till if selected one for the founda-
tion of its intended structure. This it cut very near
the cloth, in order, we suppose, to have it as long as
possible ; and placed it on a line with its body. It
then immediately cut another, and placing it parallel
to the first, bound both together with a few threads of
- its own silk. The same process was repeated with
other hairs, till the little creature had made a fabric of
some thickness, and this it went on to extend till it
was large enough to cover its body; which (as is
usual with caterpillars) it employed as a model and
measure for regulating its operations. _Weremarked
that it made choice of longer hairs for the outside
than for the parts of the interior, which it thought
necessary to strengthen by fresh additions; but the
chamber was ultimately finished by a fine and closely
woven tapestry of silk. Wecould see the progress of
its work, by looking into the opening at either of the
ends; for at this stage of the structure the walls are
quite opaque, and the insect concealed. It may be
thus observed to turn round, by doubling itself and
bringing its head where the tail had just been; of
course, the interior is left wide enough for this pur-
pose, and the centre, indeed, where it turns, is always
wider than the extremities.

When the caterpillar increases in length, it takes
care to add to the length of its house, by working-in
fresh hairs at either end; andif it be shifted to stuffs
of different colours, it may be made to construct a
party-coloured tissue, like aScotch plaid, Réaumur
cut off with scissors a portion at each end, to compel
the insect to make up the deficiency. But the cater-
pillar increases in thickness as well as in length, so

* Bonnet, xi, p. 204, Kirby and Spence, Intro. i. 464. 5th ed.
{ IR.

MOTH=CATERPILLARS. 221

that its first house becoming too narrow, it must
either enlarge it, or build anewone. It prefers the for-
mer as less troublesome, and accomplishes its purpose
“as dexterously,” says Bonnet, ‘as any tailor, and
sets to work precisely as we should do, slitting the
case on the two opposite sides, and then adroitly in-
serting between them two pieces of the requisite size.

ec
Sav
AKA em, di

Cases, &c. of the Clothes-Moth (Tinea Ya eae caterpillar
e)

feeding ina case, which has been lengthened by ovals of different

colours. 6, case cut atthe ends for experiment. ¢, case cut open,

by the insect, for enlarging it. d, e, the clothes-moths in their

perfect state, when, as they cease to eat, they do no further injury.
It does not, however, cut open the case from one end
to the other at once; the sides would separate too
far asunder, and the insect be leftnaked. It therefore
first cuts each side about half way down, beginning
sometimes at the centre and sometimes at the end,
(Fig. c.) and then, after haying filled up the fissure,
proceeds to cut the remaining half; so that, in fact,
four enlargements are made, and four separate pieces
inserted. The colour of the case is always the same
as that of the stuff from which it is taken. Thus, if
its original colour be blue, and the insect, previously
to enlarging it, be put upon red cloth, the circles at

222 INSECT ARCHITECTURE.

the end, and two stripes down the middle, will be
red.”’* Réaumur found that they cut these enlarge-
ments in no precise order, but sometimes continuously,
and sometimes opposite each other, indifferently.
The same naturalist says he neyer knew one leave
its old dwelling in order to build anew, though, when
once ejected by force from its house, it would never
enter it again, as some other species of caterpillars
will do, but always preferred building another. We,
on the contrary, have more than once seen them leave
an old habitation. ‘The yery caterpillar, indeed, whose
history we have above given, first took up its abode
in a specimen of the ghost-moth (Hepialus humuli),
where, finding few suitable materials for building, it
had recourse to the cork of the drawer, with the
chips of which it made a structure almost as warm
as it would have done from wool. Whether it took
offence at our disturbing it one day, or whether it
did not find sufficient food in the body of the ghost-
moth, we know not; but it left its cork house, and
travelled about eighteen inches, selected “the old
lady,” one of the largest insects in the drawer, and built
a new apartment composed partly of cork as before,
and partly of bits clipt out of the moth’s wings.}
We have seen these caterpillars form their habita-
tions of every sort of insect, from a butterfly to a
beetle; and the soft feathery wings of moths answer
their purpose very well: but when they fall in with
such hard materials as the musk-beetle (Cerambyx
moschatus) or the large scolopendra of the West
Indies, they find some difficulty in the building.
When the structure is finished, the insect deems
itself secure to feed on the materials of the cloth or
other animal matter within its reach, provided it
is dry and free from fat or grease, which Réaumur

* Bonnet, vol. ix. p. 203. + JR.

TENT-MAKING CATERPILLARS. 223

found it would not touch. This may probably be the
origin of the practice of putting a bit of candle with
furs, &c., to preserve them from the moth. For
building, it always selects the straightest and loosest
pieces of wool, but for food it prefers the shortest and
most compact; and to procure these it eats into the
body of the stuff, rejecting the pile or nap, which it
necessarily cuts across at the origin, and permits to
fall, leaving it threadbare, as if it had been much:
worn. It must have been this circumstance which
induced Bonnet to fancy (as we have already men-
tioned) that it cut the hairs to make itself a smooth
comfortable path to walk upon. It would be equally
correct to say that an ox or a sheep dislikes walking
amongst long grass, and therefore eats it down in
order to clear the way.

TENT-MAKING CATERPILLARS.

The caterpillars of a family of small moths (Tinei-
de), which feed on the leaves of various trees, such as
the hawthorn, the elm, the oak, and most fruit-trees,
particularly the pear, form habitations which are
exceedingly ingenious and elegant. They are so
very minute that they require close inspection to
discover them; and to the cursory observer, unac-
quainted with their habits, they will appear more like
the withered leaf-scales of the tree, thrown off when
the buds expand, than artificial structures made by
insects, It is only indeed, by seeing them move
about upon the leaves, that we discover they are in-
habited by a living tenant, who carries them as the
snail does its shell.

These tents are from a quarter of an inch to an
inch in length, and usually about the breadth of an
oat-straw. That they are of the colour of a withered
leaf is not surprising ; for they are actually composed
of a piece of leaf; not, however, cut out from the

224 INSECT ARCHITECTURE.

whole thickness, but artfully separated from the
upper layer, as a person might separate one of the
leaves of paper from a sheet of pasteboard.

A caterpillar's tent upon a leafof the elm, a, a, the part of the
leaf from which the tent has been cut out. 5, the tent itself.

The tents of this class of caterpillars, which are
found on the elm, the alder, and other trees with ser-
rated leaves, are much in the shape of a minute

old-fish. They are convex on the back, where the
indentations of the leaf out of which they have
been cut add to the resemblance, by appearing like
the dorsal fins of the fish. By depriving one of those
caterpillars common on the hawthorn of its tent,
for the sake of experiment, we put it under the ne-
cessity of making another; for, as Pliny remarks of
the clothes-moth, they will rather die of hunger than
feed unprotected. When we placed it on a fresh
hawthorn leaf, it repeatedly examined every part of it,
as if seeking for its lost tent, though, when this was
put in its way, it would not again enter it; but, after
some delay, commenced a new one.*

For this purpose, it began to eat through one of
the two outer membranes which compose the leaf
and enclose the pulp (parenchyma), some of which,
also, it deyoured, and then thrust the hinder part
of its body into the perforation. The cavity, how-
eyer, which it had formed, being yet too small for
its reception, it immediately resumed the task of
making it larger. By continuing to gnaw into the

*J.R.

TENT-MAKING CATERPILLARS. 225

pulp between the membranes of the leaf (for it took
the greatest care not to puncture or injure the mem-
branes themselves), it soon succeeded in mining out
a gallery rather larger than was sufficient to contain
its body. We perceived that it did not throw out as
rubbish the pulp it dug into, but devoured it as food,
—a circumstance not the least remarkable in its pro-
‘ceedings.

As the two membranes of leaf thus deprived of the
enclosed pulp appeared white and transparent, every
movement of the insect within could be distinctly
seen; and it was not a little interesting to watch its
ingenious operations while it was making its tent from
the membranes prepared as we have just described.
These, as Réaumur has remarked, are in fact to the
insect like a piece of cloth in the hands of a tailor;
and no tailor could cut out a shape with more neat-
ness and dexterity than this little workman does. As
the caterpillar is furnished in its mandibles with an
excellent pair of scissors, this may not appear to be
a difficult task ; yet when we examine the matter
more minutely, we find that the peculiar shape of the
two extremities requires different curvatures, and this,
of course, renders the operation no less complex, as
Réaumur subjoins, than the shaping of the pieces of
cloth for a coat.* The insect, in fact, shapes the mem-
branes slightly convex on one side and concaye on the
other, and at one end twice as large as at the other.
In the instance which we observed, beginning at the
larger end, it bent them gently on each side by press-
ing them with its body thrown into a curve. We
haye not said it cuts, but shapes its materials; for it
must be obvious that if the insect had cut both the
membranes at this stage of its operations, the pieces
would have fallen and carried it along with them.

To obviate such an accident, it proceeded to join

* Mem, Hist, Insect. iii, p. 106.
03

226 INSECT ARCHITECTURE.

the two edges, and secure them firmly with silk,
befor it made a single incision to detach them.
When it had in this manner joined the two edges
along one of the sides, it inserted its head on the
outside of the joining, first at one end and then at the
other, gnawing the fibres till that whole side was
separated. It proceeded in the same manner with
the other side, joining the edges before it cut them;
and when it arrived at the last fibre, the only remain-
ing support of its now finished tent, it took the pre-
caution, before snipping it, to moor the whole to the
uncut part of the leaf by a cable of its own silk,
Consequently, when it does cut the last nervure, itis
secure from falling, and can then travel along the leaf,
carrying its tent on its back, as a snail does its shell.*

a, the caterpillar occupying the space ithas eaten between the
cuticle of the leaf. b, a portion of the upper cuticle, ent out for
the formation of the tent. c, the tent nearly completed. d, the
perfect tent, with the caterpillar protruding its head.

We have just discovered (Nov. 4th, 1829), upon
the nettle a tent of a very singular appearance, in
consequence of the materials of which it is made.
The caterpillar seems, indeed, to have proceeded ex-
actly in the same manner as those which we have
described, mining first between the two membranes
of the leaf, and then uniting these and cutting out

UES

STONE-MASON CATERPILLARS. 227

his tent. But the tent itself looks singular from being
all over studded with the stinging bristles of the
nettle, and forming ano less formidable coat of mail
to the little inhabitant, than the spiny hide of the
hedgehog. In feeding, it does not seem to have
mined into the leaf, but to have eaten the whole of
the lower membrane, along with the entire pulp,
leaving nothing but the upper membrane untouched.*
During the summer of 1830, we discovered a very
large tent which had been formed out of a blade of
grass ; and another stuck all over with chips of leaves
upon the common maple.

Tents or Stonr-Mason CATERPILLARS.

The caterpillar ofa small moth (Tinea), which feeds
upon the lichens growing on walls, builds for itself a
moveable tent of a very singular kind. M. dela Voye
was the first who described these insects ; but though
they are frequently overlooked, from being very small,
they are by no means uncommon on old walls.
Réaumur observed them regularly for twenty years
together, on the terrace-wall of the Tuileries at Paris;
and they may be found in abundance in similar situ-
ations in this country. This accurate observer refuted
by experiment the notion of M. de la Voye, that the
caterpillars fed upon the stones of the wall ; but he
satisfied himself that they detached particles of the
stone for the purpose of building their tents or sheaths
(fourreaux), as he calls their dwellings. In order
to watch their mode of building, Réaumur gently
ejected half a dozen of them from their homes, and
observed them detach grain after grain from a piece
of stone, binding each into the wall of their building
with silk, till the cell acquired the requisite magnitude,
the whole operation taking about twenty-four hours
of continued labour. M. de la Voye mentions small

* oR.

228 INSECT ARCHITECTURE.

granular bodies of a greenish colour, placed irregu-
larly on the exterior of the structure, which he calls
eggs; but we agree with Réaumur in thinking it
more probable that they are small fragments of moss
or lichen intermixed with the stone: in fact, we have
ascertained that they are so.*

When these little architects prepare for their
change into chrysalides before becoming moths, they
attach their tents securely to the stones over which
they have hitherto rambled, by spinning a strong
mooring of silk, so as not only to fill up every inter-
stice between the main entrance of the tent and the
stone, but also weaving a close thick curtain of the
same material, to shut up the entire aperture.

Lichen-Tents and Caterpillars, both of their natural size and magnified.

It is usual for insects which form similar struc-
tures, to issue, when they assume the winged state,
from the broader end of their habitation ; but our
little stone-mason proceeds ina different manner. It
leaves open the apex of the cone from the first, for
the purpose of ejecting its excrements, and latterly
it enlarges this opening a little, to allow of a free
exit when it acquires wings; taking care, however,
to spin over it a canopy of silk, as a temporary pro-
tection, which it can afterwards burst through with-

*ILR.

STONE-MASON CATERPILLARS. 229

out difficulty. The moth itself is very much like the
common clothes-moth in form, but is of a gilded
bronze colour, and considerably smaller.

In the same locality, M. de Maupertuis found a
numerous brood of small caterpillars, which employed
grains of stone, not, like the preceding, for building
feeding-tents, but for their cocoons. ‘This caterpillar
was of a brownish-grey colour, with a white line
along the back, on each side of which were tufts of
hair. The cocoons which it built were oval, and
less in size than a hazel nut, the grains of the stone
being skilfully woven into irregular meshes of silk.

In June, 1829, we found a numerous encampment
of the tent-building caterpillars described by MM.
de la Voye and Réaumur, on the brick wall of a gar-
den at Blackheath, Kent.* They were so very small,
however, and so like the lichen on the wall, that, had
not our attention been previously directed to their
habits, we should have considered them as portions of
the wall; for not one of them was in motion, and it
was only by the neat, turbinated, conical formin which
they had constructed their habitations, that we detected
them. We tried the experiment above-mentioned, of
ejecting one of the caterpillars from its tent, in order
to watch its proceedings when constructing another ;
but probably its haste to procure shelter, or the arti-
ficial circumstances into which it was thrown, influ-
enced its operations, for it did not form so good a
tent as the first, the texture of the walls being much
slighter, while it was more rounded at the apex, and
of course not so elegant. Reéaumur found, in all his
similar experiments, that the new structure equalled
the old; but most of the trials of this kind which we
have made correspond with the inferiority which we
haye here recorded. The process indeed is the same,
but it seems to be done with more hurry and less

*J.R,

230 INSECT ARCHITECTURE.

care. It may be, indeed, in some cases, that the
supply of silk necessary to unite the bits of stone,
earth, or lichen employed, is too scanty for perfect-
ing a second structure.

We remarked a very singular circumstance in
the operations of our little architect, which seems
to have escaped the minute and accurate attention
of Réaumur. When it commenced its structure, it
was indispensable to lay a foundation for the walls
about to be reared; but as the tent was to be moveable
like the shell of a snail, and not stationary, it would
not have answered its end to cement the foundation
to the wall. We had foreseen this difficulty, and felt
not a little interested in discovering how it would be
got over. Accordingly, upon watching its move-
ments with some attention, we were soon gratified
to perceive that it used its own body as the pri-
mary support of the building. It fixed a thread
of silk upon one of its right feet, warped it over to the
corresponding left foot, and upon the thread thus
stretched between the two feet, it glued grains of
stone and chips of lichen, till the wall was of the re-
quired thickness. Upon this, as a foundation, it
continued to work till it had formed a small portion
in form of a parallelogram ; and, proceeding in a
similar way, it was not longin making a ring a very
little wider than sufficient to admit its body. It ex-
tended this ring in breadth, by working on the inside
only, narrowing the diameter by degrees, till it began
to take the form of a cone, he apex of this cone
was not closed up, but left as an aperture through
which to eject its excrements,

It is worthy of remark, that one of the caterpillars
which we deprived of its tent attempted to save itself
the trouble of building a new one, by endeavouring
to unhouse one of its neighbours. For this purpose,
it got upon the outside of the inhabited tent, and

MUFF-MAKING CATERPILLARS. 231

sliding its head down to the entrance, tried to make
its way into the interior. But the rightful owner
did not choose to give up his premises so easily ; and
fixed his tent down so firmly upon the table where
we had placed it, that the intruder was forced to
abandon his attempt. The instant, however, that
the other unmoored his tent and began to move about,
the invader renewed his efforts to eject him, per-
severing in the struggle for several hours, but with-
out a chance of success. At one time we imagined
that he would have accomplished his felonious in-
tentions; for he bound down the apex of the tent to
the table with cables of silk. But he attempted his
entrance at the wrong end. He ought to have tried
the aperture in the apex, by enlarging which a
little he would undoubtedly have made good his
entrance; and as the inhabitant could not have
turned upon him for want of room, the castle must
have been surrendered. This experiment, however,
was not tried, and there was no hope for him at the
main entrance.

Murr-sHaPED TENTS,

The ingenuity of man has pressed into his service
not only the wool, the hair, and even the skins of
animals, but has most extensively searched the vege-
table kingdom for the materials of his clothing. In
all this, however, he is rivalled by the tiny inhabi-
tants of the insect world, as we have already seen;
and we are about now to give an additional instance
of the art of a species of caterpillars which select a
warmer material for their tents than even the cater-
pillar of the clothes-moth. It may have been remarked
by many who are not botanists, that the seed-catkins
of the willow become, as they ripen, covered with a
species of down or cotton, which, however, is too
short in the fibre to be advantageously employed in

232 ' INSECT ARCHITECTURE.

our manufactures. But the caterpillars to which we
have alluded find it well adapted for their habita-
tions.

The muff-looking tent in which we find these in-
sects does not require much trouble to construct 4
for the caterpillar does not, like the clothes-moth
caterpillar, join the willow-cotton together, fibre by
fibre—it is contented with the state in which it
finds it on the seed. Into this it burrows, lines the
interior with a tapestry of silk, and then detaches the
whole from the branch where it was growing, and
carries it about with it as a protection while it is
feeding.*

ITA
7

4, branch of the willow, with seed spikes covered with cotton,
b, muil-vents made of this cotton by ¢, the caterpillar,

* Réaumur, iii, p. 130,

MINING CATERPILLARS. 235

An inquiring friend of Réaumur having found
one of these insects floating about in its muff-tent
upon water, concluded that they fed upon aquatic
plantss but he was soon convinced that it had only
been blown down by an accident, which must fre-
quently happen, as willows so often hang over water.
May it not be that the buoyant materials of the tent
were intended to furnish the little inhabitant with a
life-boat, in which, when it chanced to be blown into
the water, it might sail safely ashore and regain its
native tree ?

LEAr-MINING CATERPILLARS.

The process of mining between the two mem-
branes of a leaf is carried on to more extent by mi-
nute caterpillars allied to the tent-makers above
described. The tent-maker never deserts his house,
except when compelled, and therefore can only mine
to about half the length of his own body ; but the
miners now to be considered make the mine itself
their dwelling-place, and as they eat their way they
lengthen and enlarge their galleries. A few of
these mining caterpillars are the progeny of small
weevils (Curculionide), some of two-winged flies
(Diptera), but the greater number are produced from
a genus of minute moths (Gcophora, Larr.), which,
when magnified, appear to be amongst the most
splendid and brilliant of nature’s productions, vying
even with the humming-birds and diamond-beetles
of the tropics, in the rich metallic colours which be-
spangle their wings. Well may Bonnet call them
“tiny miracles of nature,” and regret that they are
not en grand.*

There are few plants or trees whose leaves may not,
at some season of the year, be found mined by these

* Bonnet, Contempl. de la Nature, Part xii.

234 INSECT ARCHITECTURE.

caterpillars, the track of whose progress appears on
the upper surface in winding lines. Let us take one
of the most common of these for an example,—that
of the rose-leaf, produced by the caterpillar of Ray’s
golden-silyer spot (Argyromiges Rayella? Curris),
of which we have just gathered above a dozen speci-
mens from one rose-tree.*

Leaf of the Monthly Rose Roa Indica), mined by Caterpillars
of Argyromiges ?

It may be remarked, that the winding line is
black, closely resembling the tortuous course of a
river on a map,—beginning like a small brook, and
gradually increasing in breadth as it proceeds. This
representation of a river exhibits, besides, a narrow
white valley on each side of it, increasing as it goes,
till it terminates in a broad delta. The valley is the
portion of the inner leaf from which the caterpillar
has eaten the pulp eg while the river
itself nas been formed by the liquid ejectamenta of
the insect, the watery part becoming evaporated. In
other species of miners, however, the dung is hard

*J.R.

MINING CATERPILLARS. 235

and dry, and consequently these only exhibit the
yalley without the river. (See p. 231.)

On looking at the back of the leaf, where the wind-
ing line begins, we uniformly find the shell of the
very minute egg from which the caterpillar has been
hatched, and hence perceive that it digs into the leaf
the moment it escapes from the egg, without wan-
dering a hair’s breadth from the spot; as if afraid
lest the air should visit it too roughly. The egg is,
for the most part, placed upon the midrib of the rose-
leaf, but sometimes on one of the larger nervures.
When once it has got within the leaf, it seems to
pursue no certain direction, sometimes working to
the centre, sometimes to the circumference, some-
times to the point, and sometimes to the base, and
even, occasionally, crossing or keeping parallel to
its own previous track.

The most marvellous circumstance, however, is
the minuteness of its workmanship; for though a
rose leaf is thinner than this paper, the insect finds
room to mine a tunnel to live in, and plenty of food,
without touching the two external membranes. Let
any one try with the nicest dissecting instruments to
separate the two plates of a rose leaf, and he will
find it impossible to proceed far without tearing one
or other. The caterpillar goes still further in mi-
nute nicety; for it may be remarked, that its track
can only be seen on the upper, and not on the under
surface of the leaf, proving that it eats as it pro-
ceeds only half the thickness of the pulp, or that
portion of it which belongs to the upper membrane
of the leaf.

We have found this little miner on almost every
sort of rose-tree, both wild and cultivated, including
the sweet-briar, in which the leaf being very small,
it requires nearly the whole parenchyma to feed one
caterpillar. They seem, however, to prefer the foreign

236 INSECT ARCHITECTURE.

monthly rose to any of our native species, and there are
few trees of this where they may not be discovered.*

Tunnels, very analogous to the preceding, may be
found upon the common bramble (Rubus Sruticosus) ;
and on the holly, early in spring, one which is in form
of an irregular whitish blotch. But in the former
case, the little miner seems to proceed more regularly,
always, when newly hatched, making directly for the
circumference, upon or near which also the mother-
moth deposits her egg, and winding along for half
the extent of the leaf close upon the edge, following,
in some cases, the very indentations formed by the
terminating nervures.

Leaf of the Dew-berry Bramble (Rubus cesius), mined by Cater-
pillars.

The bramble-leaf miner seems also to differ from
that of the rose-leaf, by eating the pulp both from
the upper and under surface, at least the track is
equally distinct above and below; yet this may arise
from the different consistence of the leaf pulp, that
in the rose being firm, while that of the bramble is
soft and puffy.

On the leaves of the common primrose (Primula
veris), as well as on the garden variety of it, the

_™* See Insect Transformations, p. 70.

MINING CATERPILLARS. 237

polyanthus, one of those mining-caterpillars may very
frequently be found. It is, however, considerably
different from the preceding, for there is no black
trace—no river to the valley which it excavates: its
ejectamenta, being small and solid, are seen, when the
leaf is dried, in little black points like grains of sand.
This miner, also, seems more partial than the pre-
ceding to the midrib and its vicinity, in consequence
of which its path is seldom so tortuous, and often
appears at its extremity to terminate in an area, com-
paratively extensive, arising from its recrossing its
previous tracks,*

Leaf of the Primrose (Primula veris), mined by a caterpillar.

Swammerdam describes a mining caterpillar which
he found on the leaves of the alder, though it did
not, like those we have just described, excavate a
winding gallery; it kept upon the same spot, and
formed only an irregular area. A moth was pro-
duced from this, whose upper wings, he says,
“shone and glittered most gloriously with crescents
of gold, silver, and brown, surrounded by borders of
delicate black.” Another area miner which he found
on the leaves of willows, as many as seventeen on
one leaf, producing what appeared to be rusty spots,
was metamorphosed into a very minute weevil
(Curculio Rhinoc.). He says he has been informed,

SLR,

238 INSECT ARCHITECTURE.

that, in warm climates, worms an inch long are found
in leaves, and adds, with great simplicity, ‘on these
many fine experiments might have been made, if
the inhabitants had not laboured under the cursed
thirst of gold.”’*

The vine-leaf miner, when about to construct its
cocoon, cuts, from the termination of its gallery, two
pieces of the membrane of the leaf, deprived of their
pulp, in a similar manner to the tent-makers de-
scribed above, uniting them and lining them with
silk. This she carries to some distance before she
lays herself up to undergo her change. Her mode
of walking under her burthen is peculiar, for, not
contented with the security of a single thread of silk,
she forms, as Bonnet says, “little mountains (mon-
ticules) of silk, from distance to distance, and seizing
one of these with her teeth, drags herself forward, and
makes it a scaffolding from which she can build
another.’”’+ Some of the miners, however, do not
leave their galleries, but undergo their transforma-
tions there, taking the precaution to mine a cell, not
in the upper, but in the under surface; others only
shift to another portion of the leaf.

SociaL Lear-Miners.

The preceding descriptions apply to caterpillars
who construct their mines in solitude, there being
seldom more than one ona leaf or leaflet, unless
when two mother-flies happen to lay their eggs on the
same leaf; but there are others, such as the miners
of the leaves of the henbane (Hyoscyamus niger),
which excavate a common area in concert—from four
to eight forming a colony. These are very like flesh-
maggots, being larger than the common miners; the

* Swammerd. Book of Nature, vol. ii. p. 84.
+ Contempl. de la Nature, part xii. p. 197.

MINING CATERPILLARS. 239

leaves of this plant, from being thick and juicy,
giving them space to work and plenty to eat,

Most of the solitary leaf-miners either cannot or
will not construct a new mine, if ejected by an ex-
perimenter from the old, as we have frequently
proved; but this is not the case with the social
miners of the henbane leaf. Bonnet ejected one of
these, and watched it with his glass till it com-
menced a new tunnel, which it also enlarged with
great expedition ; and in order to verify the assertion i
of Réaumur, that they neither endeavour nor fear to
meet one another, he introduced’a second. Neither
of them manifested any knowledge of the other’s
contiguity, but both worked hard at the gallery, as
did a third and a fourth which he afterwards intro-
duced ; for though they seemed uneasy, they never
attacked one another, as the solitary ones often do
when they meet,*

BaRK-MINING CATERPILLARS.

A very different order of mining caterpillars are
the progeny of various beetles, which excavate their
galleries in the soft inner bark of trees, or between
it and the young wood (Alburnum). Some of these,
though small, commit extensive ravages, as may rea-
dily be conceived when we are told that as many as
eighty thousand are occasionally found on one tree.
In 1783 the trees thus destroyed by the printer-beetle
(Tomicus typographus, Lavr.), so called from its
tracks resembling letters, amounted to above a mil-
lion and a half in the Hartz forest. It appears there
periodically, and confines its ravages to the fir. This
insect is said to have been found in the neighbour-
hood of London.

On taking off the bark of decaying poplars and
willows, we have frequently met with the tracks of

Bonnet, Observ. sur les Insectes, vol. ii. p. 425.

—_— -- TT, = =” Tee

240 " INSECT ARCHITECTURE.

a miner of this order, extending in tortuous path-
ways, about a quarter of an inch broad, for several
feet and even yards in length. The excavation is
not circular, but a compressed oval, and crammed
throughout with a dark-coloured substance like saw-
dust—the excrement no doubt of the little miner,
who is thereby protected from the attacks of staphy-
linide, and other predaceous insects, from behind.
But though we haye found a great number of these
subcortical tracks, we have never discovered one of
the miners, though they are very probably the grubs
of the pretty musk-beetle (Cerambyx moschatus),
which are so abundant in the neighbourhood of the
trees in question, that the very air in summer is per-
fumed with their odour.*

Another capricorn-beetle of this family is no less
destructive to bark in its perfect state, than the above
are when grubs, as from its habit of eating round a

tree, it cuts the course of the returning sap, and de~
stroys it,

Capricorn Beetle (Cerambyx Lamia arputator), rounding off the
bark of a tree. bh

wi. Re

241

Cuarrter XIII.

Structures of Grasshoppers, Crickets, and Beetles.

Grassnorrers, locusts, crickets, and beetles are, in
many respects, no less interesting than the insects
whose architectural proceedings we have already de-
tailed. They do not, indeed, build any edifice for
the accommodation of themselves or their progeny ;
but most, if not all of them, excavate retreats in walls
or in the ground.

The house-cricket (Acheta domestica) is well
known for its habit of picking out the mortar of
ovens and kitchen fire-places, where it not only
enjoys warmth, but can procure abundance of food.
It is usually supposed that it feeds on bread. M.
Latreille says it only eats insects, and it certainly
thrives well in houses infested by the cockroach ;
but we have also known it eat and destroy lamb’s-
wool stockings, and other woollen stuffs, hung near
a fire to dry. It is evidently not fond of hard labour,
but prefers those places where the mortar is already
loosened, or at least is new, soft, and easily scooped
out; and in this way it will dig covert ways from
room to room. In summer, crickets often make ex-
cursions from the house to the neighbouring fields,
and dwell in the crevices of rubbish, or the cracks
made in the ground by dry weather, where they chirp
as merrily as in the snuggest chimney-corner. Whe-
ther they ever dig retreats in such circumstances, we
have not ascertained; though it is not improbable
they may do so for the purpose of making nests,

P

242 INSECT ARCHITECTURE,

M. Bory St. Vincent tells us, that the Spaniards are so
fond of crickets, that they keep them in cages like
singing-birds.*

Tur Mour-Crickert.

The insect called, from its similarity of habits to
the mole, the mole-cricket (Gryllotalpa vulgaris,
Larr.), is but too well known in gardens, corn-fields,
and the moist banks of rivers and ponds, in some
parts of England, such as Wiltshire and Hampshire,
though it is comparatively rare or unknown in others,
It burrows in the ground, and forms extensive gal-
leries similar to those of the mole, though smaller ;
and these may always be recognized by a slightly-
elevated ridge of mould; for the insect does not
throw up the earth in hillocks like the mole, but
gradually, as it digs along, in the manner of the field-
mouse, In this way it commits great ravages, in hot-
beds and in gardens, upon pease, young cabbages, and
other vegetables, the roots of which it is said to devour.
It is not improbable, we think, that, like its congener,
the house-cricket, it may also prey upon underground
insects, and undermine the plants to get at them, as
the mole has been proved to do. Mr. Gould, indeed,
fed a mole-cricket for several months upon ants,

The structure of the mole-cricket’s arms and hands
fe we may call them so) is admirably adapted for
these operations, being both very strong, and moved
by a peculiar apparatus of muscles. The breast is
formed of a thick, hard, horny substance, which is
further strengthened within by a double frame-work
of strong gristle, in front of the extremities of which
the shoulder-blades of the arms are firmly-jointed; a
structure evidently intended to prevent the breast
from being injured by the powerful action of the

* Dict. Classique d’Hist, Nat. Art. Grillon.

MOLE-CRICKET. 243

muscles of the arms in digging. The arms them-
selves are strong and broad, and the hand is furnished
with four large sharp claws, pointing somewhat ob-
liquely outwards, this being the direction in which
it digs, throwing the earth on each side of its course.
So strongly, indeed, does it throw out its arms, that
we find it can thus easily support its own weight
when held between the finger and thumb, as we have
tried upon half a dozen of the living insects now in
our possession.

The Mole Cricket, with a separate outline of one of its hands,

The nest which the female constructs for her eggs,
in the beginning of May, is well worthy of attention,
The Rev. Mr. White, of Selborne, tells us that a
gardener, at a house where he was on a visit, while
mowing grass by the side of a canal, chanced to
strike his scythe too deep, and pared off a large piece
of turf, laying open to view an interesting scene of
domestic economy. There was a pretty chamber dug
in the clay, of the form and about the ec it

P

244 INSECT ARCHITECTURE.

would have had if moulded by an egg, the walls
being neatly smoothed and polished. In this little
cell were deposited about a hundred eggs, of the
size and form of caraway-comfits, and of a dull tar-
nished white colour, The eggs were not very deep,
but just under a little heap of fresh mould, and with-
in the influence of the sun’s heat.* The dull tar-
nished white colour, however, scarcély agrees with
a parcel of these eggs now before us, which are
translucent, gelatinous, and greenish.
Like the eggs and young of other insects, however,
those of the mole-cricket are exposed to depredation,
and particularly to the ravages of a black beetle
which burrows in similar localities. 'The mother-
insect, accordingly, does not think her nest secure
till she has defended it, like a fortified town, with
labyrinths, intrenchments, ramparts, and covert ways.
In some part of these outworks, she stations herself
as an advanced guard, and when the beetle ventures
within her circumvallations, she pounces upon him
and kills him

\\
\

\ \ “

\\

LOM

Nest of the Mole Cricket.

Tue Prevp-Cricxer,

Another insect of this family, the field-cricket
( Acheta campestris), also forms burrows in the
ground, in which it lodges all day, and comes out
chiefly about sun-set to pipe its evening song. It is

* Nat. Hist. of Selborne, ii. 82,

FIELD-CRICKET. 245

so very shy and cautious, however, that it is by no
means easy to discover either the insect or its burrow.
“The children in France amuse themselves with
hunting after the field-cricket; they put into its hole
an ant fastened by a long hair, and as they draw it
out the cricket does not fail to pursue it, and issue
from its retreat, Pliny informs us it might be cap-
tured in a much more expeditious and easy manner.
If, for instance, a small and slender piece of stick
were to be thrust into the burrow, the insect, he says,
would immediately get upon it for the purpose of
demanding the occasion of the intrusion: whence
arose the proverb stultior grillo (more foolish than a
cricket), applied to one who, upon light grounds,
provokes his enemy, and falls into the snares which
might have been laid to entrap him.’”’*

The Rey. Mr. White, who attentively studied
their habits and manners, at first made an attempt to
dig them out with a spade, but without any great
success; for either the bottom of the hole was inac-
cessible, from its terminating under a large stone, or
else, in breaking up the ground, the poor creature
was inadvertently squeezed to death. Out of one
thus bruised, a great number of eggs was taken,
which were long and narrow, of a yeilow colour, and
covered with avery tough skin, More gentle means
were then used, and these proved successful. A pliant
stalk of grass, gently insinuated into the caverns, will
probe their windings to the bottom, and bring out
the inhabitant; and thus the humane inquirer may
gratify his curiosity without injuring the object of it.

When the males meet, they sdmetimes fight very
fiercely, as Mr. White found by some that he put into
the crevices of a dry stone wall, where he wished to
haye them settle. For though they seemed distressed
by being taken out of their knowledge, yet the first

* Entomologie, par R. A. E, 18mo., Paris, 1826, p. 168,

r3

246 INSECT ARCHITECTURE

that got possession of the chinks seized on all the
others that were obtruded upon him with his large
row of serrated fangs. With their strong jaws toothed
like the shears of a lobster’s claws, they perforate and
round their curious regular cells, having no foreclaws
to dig with like the mole-cricket, When taken into
the hand, they never attempt to defend themselves,
though armed with such formidable weapons. Of
such herbs as grow about the mouths of their burrows
they eat indiscriminately, and never in the day-time
seem to stir more than two or three inches from home.
Sitting in the entrance of their caverns, they chirp all
night as well as day, from the middle of the month
of May to the middle of July. In hot weather, when
they are most vigorous, they make the hills echo,

Acrida verrucivora depositing her eggs.
The usual position of the ovipositor is represented by dots.

BURYING-BEETLE. 247

and in the more still hours of darkness, may be heard
to a very considerable distance. ‘Not many sum-
mers ago,” says Mr. White, “ I endeavoured to trans-
plant a colony of these insects to the terrace in my
garden, by boring deep holes in the sloping turf.
The new inhabitants staid some time, and fed and
sang ; but they wandered away by degrees, and were
heard at a greater distance every morning; so it ap-
pears that on this emergency they made use of their
wings in attempting to return to the spot from which
they were taken,’”’* The manner in which these in-
sects lay their eggs is represented in the preceding
figure; which is that of an insect nearly allied to
the crickets, though of a different genus.

A more laborious task is performed by an insect by
no means uncommon in Britain, the Burying-Beetle
(Necrophorus vespillo), which may be easily recog-
nised by its longish body, of a black colour, with two
broad and irregularly-indented bands of yellowish-
brown. A foreign naturalist, M. Gleditsch, gives a
very interesting account of its industry. He had
“often remarked that dead moles, when laid upon
the ground, especially if upon loose earth, were al-
most sure to disappear in the course of two or three
days, often of twelve hours. To ascertain the cause
he placed a mole upon one of the beds in his garden.
It had vanished by the third morning; and on dig-
ging where it had been laid, he found it buried to the
depth of three inches, and under it four beetles,
which seemed to have been the agents in this sin-
gular inhumation. Not perceiving anything par-
ticular in the mole, he buried it again; and on ex-
amining it at the end of six days, he found it swarm-
ing with maggots, apparently the issue of the beetles,
which M. Gleditsch now naturally concluded had
buried the carcase for the food of their future young.

* Nat. Hist. Selborne.

248 INSECT ARCHITECTURE.

To determine these points more clearly, he put four
of these insects into a glass vessel, half filled with
earth and properly secured, and upon the surface of
the earth two frogs. In less than twelve hours one
of the frogs was interred by two of the beetles; the
other two ran about the whole day, as if busied in
measuring the dimensions of the remaining corpse,
which on the third day was also found buried. He
then introduced a dead linnet, A pair of the beetles
were soon engaged upon the bird. They began their
operations by pushing out the earth from under the
body, so as to form a cayity for its reception ; and it
was curious to see the efforts which the beetles made
by dragging at the feathers of the bird from below,
to pull it into its grave. The male, having driven
the female away, continued the work alone for five
hours. He lifted up the bird, changed its place,
turned it and arranged it in the grave, and from time
to time came out of the hole, mounted upon it, and
trod it under foot, and then retired below, and pulled
it down. At length, apparently wearied with this
uninterrupted labour, it came forth, and leaned its
head upon the earth beside the bird without the
smallest motion, as if to rest itself, for a full hour,
when it again crept under the earth. The next day,
in the morning the bird was an inch and a half under
ground, and the trench remained open the whole day,
the corpse seeming as if laid out upon a bier sur-
rounded with a rampart of mould. In the evening
it had sunk half an inch lower, and in another day
the work was completed, and the bird coyered. M.
Gleditsch continued to add other small dead animals,
which were all sooner or later buried ; and the result
of his experiment was, that in fifty days four beetles
had interred, in the very small space of earth allotted
to them, twelve carcasses: viz., four frogs, three
small birds, two fishes, one mole, and two grasshop-

DUNG-BEETLE. 249

pers, besides the entrails of a fish, and two morsels
of the lungs of an ox. In another experiment, a
single beetle buried a mole forty times its own bulk
and weight in two days.’’*

In the summer of 1826, we found on Putney
Heath, in Surrey, four of these beetles, hard at work
in burying a dead crow, precisely in the manner
described by M. Gleditsch.+

Dunc-BeEetve.

A still more common British insect, the Dorr,
Clock, or Dung-Beetle (Geotrupes stercorarius) uses
different materials for burying along with its eggs.
“It digs,” to use the words of Kirby and Spence,
‘a deep cylindrical hole, and carrying down a mass
of the dung to the bottom, in it deposits its eggs.
And many of the species of the genus Afeuchus roll
together wet dung into round pellets, deposit an Riis
in the midst of each, and when dry push them back-
wards by their hind-feet, to holes of the surprising
depth of three feet, which they have previously dug
for their reception, and which are often several yards
distant. The attention of these insects to their eggs
is so remarkable, that it was observed in the earliest
ages, and is mentioned by ancient writers, but with
the addition of many fables, as that they were all of
the male sex; that they became young again every
year; and that they rolled the pellets containing their
eggs from sunrise to sunset every day, for twenty-
eight days without intermission.’’t

“ We frequently notice in our evening walks,” says
Mr. Knapp, “the murmuring passage, and are often
stricken by the heedless flight of the great dorr-
beetle (Geotr-upes stercorarius), clocks, as the boys
call them. But this evening my attention was called

* Act. Acad. Berolin. 1752, et Gleditsch, Phys. Botan.
quoted by Kirby and Spence, ii. 353.

tJ RK } Moufet, 153 Kirby and Spence, ij. 350.

250 INSECE ARCHITECTURE.

to then in particular, by the constant passing of such
a number as to constitute something like a little
stream; and I was led to search into the object of
their direct flight, as in general it is irregular and
seemingly inquisitive. I soon found that they dropped
on some recent nuisance; but what powers of per-
ception must these creatures possess, drawn from all
distances and directions by the very little fetor which,
in such a calm evening, could be diffused around,
and by what inconceivable means could odours reach
this beetle in such a manner as to rouse so inert an
insect into action? But it is appointed one of the
pont scavengers of the earth, and maryellously en-

owed with powers of sensation, and means of effect-
ing this purpose of its being. Hxquisitely fabricated
as it is to receive impressions, yet probably it is not
more highly gifted than any of the other innumer-
able creatures that wing their way around us, or
creep about our paths, though by this one perceptible
faculty, thus ‘dimly seen,’ it excites our wonder and
surprise. How wondrous then the whole!

“The perfect cleanliness of these creatures is a
very notable circumstance, when we consider that
nearly their whole lives are passed in burrowing in
the earth, and removing nuisances; yet such is the
admirable polish of their coating and limbs, that we
very seldom find any soil adhering to them. ‘The
meloe, and some of the scarabei, upon first emerging
from their winter’s retreat, age commonly found with
earth clinging to them ; but the removal of this is
one of the first operations of the creature; and all
the beetle race, the chief occupation of which is
crawling about the soil, and such dirty employs, are,
notwithstanding, remarkable for the glossiness of their
covering, and freedom from defilements of any kind.
But purity of vesture seems to be a principal precept
of nature, and observable throughout creation.
Fishes, from the nature of the element in which they

ROSE-BEETLE. 251

reside, can contract but little impurity. Birds are
unceasingly attentive to neatness and lustration of
their plumage. All the slug race, though covered
with slimy matter calculated to collect extraneous
things, and reptiles, are perfectly free from soil. The
fur and hair of beasts, in a state of liberty and health,
is never filthy, or sullied with dirt. Some birds roll
themselves in dust, and, occasionally, particular beasts
cover themselves with mire; but this is not from any
liking or inclination for such things, but to free them-
selves from annoyances, or to prevent the bites of
insects. Whether birds in preening, and beasts in
dressing themselves, be directed by any instinctive
faculty, we know not; but they evidently derive
pleasure from the operation, and thus this feeling of
enjoyment, even if the sole motive, becomes to them
an essential source of comfort and of health.’”’*

The rose or green chafer (Cetonia aurata), which
is one of our prettiest native insects, is one of the bur-
rowers, and, for the purpose of depositing her eggs,
digs, about the middle of June, into soft light ground.
When she is seen at this operation, with her broad
and delicate wings folded up in their shining green
cases, speckled with white, it could hardly be ima-
gined that she had but just descended from the air,
or dropped down from some neighbouring rose.

The proceedings of the Tumble-Dung Beetle of
America (Scarabeus pilularius, Linn.) are described
in a very interesting manner by Catesby, in his
‘Carolina,’ ‘I have,” says he, “ attentively admired
their industry, and mutual assisting of each other in
rolling their globular balls from the place where they
made them to that of their interment, which is usually
the distance of some yards, more or less. ‘This they
perform breech foremost, by raising their hind parts,
and forcing along the ball with their hind feet. Two

* Journal of a Naturalist, p. 311.

252 INSECT ARCHITECTURE.

or three of them are sometimes engaged in trundling
one ball, which, from meeting with impediments on
account of the unevenness of the ground, is sometimes
deserted by them. It is, however, attempted by others
with success, unless it happens to roll into some deep
hollow or chink, where they are constrained to leave
it ; but they continue their work by rolling off the next
ball that comes in their way. None of them seem
to know their own balls, but an equal care for the
whole appears to affect all the community. They
form these pellets while the dung remains moist, and
leave thein to harden in the sun before they attempt
to roll them. In their moving of them from place to
place, both they and the balls may frequently be seen
tumbling about the little eminences that are in their
way. They are not, however, easily discouraged ;
and, by repeating their attempts, usually surmount
the difficulties.”

He further informs us that they “find out their
subsistence by the excellency of their noses, which
direct them in their flight to newly fallen dung, on
which they immediately go to work, tempering it with
a proper mixture of earth. So intent are they always
upon their employment, that, though handled or
otherwise interrupted, they are not to be deterred,
but immediately, on being freed, persist in their
work without any apprehension of danger. They
are said to be so exceedingly strong and active as to
move about, with the greatest ease, things that are
many times their own weight.* Dr. Brichell was
supping one evening in a planter’s house of North
Carolina, when two of them were conveyed, without
his knowledge, under the candlestick. A few blows
were struck on the table, and, to his great surprise,
the candlestick began to move about, apparently
without any agency ; and his surprise was not much

* Sce some still more curious instances in Insect Transforma-
tions, pages 179-185.

NECKLACE-BEETLE. 2538

lessened when, on taking one of them up, he dis-
covered that it was only a chafer that moved.”

We have often found the necklace-beetle (Carabus
monilis) inhabiting a chamber dug out in the earth
of a garden, just sufficient to contain its body, and
carefully smoothed and polished. From the form of
this little nest, it would seem as if it were constructed,
not by digging out the earth and removing it, but
chiefly by the insect pushing its body forcibly against
the walls. The beetles which we have found nestling
in this manner have been all males; and therefore it
cannot be intended for a breeding cell; for male
insects are never, we believe, sufficiently generous
to their mates to assist them in such labours. The
beetle in question appears to be partial to celery
trenches ;* probably from the loose earth of which
they are composed yielding, without much difficulty,
to the pressure of its body.

*J,R.

( 254 )

Cuarrer XIV.
Architecture of Ants.—Mason-Ants.

Aut the species of ants are social. There are none
solitary, as is the case with bees and wasps. They are
all more or less skilful in architecture, some employ-
ing masonry, and others being carpenters, wood-
carvers, and miners. They consequently afford much
that is interesting to naturalists who observe their
operations. The genuine history of ants has only
been recently investigated, first by Gould in 174’,
and subsequently by Linneeus, De Geer, Huber, and
Latreille. Previous to that time their real industry
and their imagined foresight were held up as moral
lessons, without any great accuracy of observation ;
and it is probable that, even now, the mixture of
truth and error in Addison’s delightful papers in the
Guardian (Nos. 156, 157) may be more generally _
attractive than the minute relation of careful natu-
ralists. Gould disproved, most satisfactorily, the
ancient fable of ants storing up corn for winter pro-
Vision, no species of ants ever eating grain, or feed

ing in the winter upon anything. It is to Huber the
younger, however, that we are chiefly indebted for
our knowledge of the habits and economy of ants ;
and to Latreille for a closer distinction of the species.
Some of the more interesting species, whose singular
economy is described by the younger Huber, have
not been hitherto found in this country. We shall,
however, discover matter of very considerable interest
in those which are indigenous ; and as our principal
object is to excite inquiry and observation with re-
gard to those insects which may be easily watched
in our own gardens and fields, we shall chiefly con-

MASON-ANTS. 255

fine ourselves to the ants of these islands. We shall
begin with the labours of those native ants which
may be called earth-masons, from their digging in
the ground and forming structures with pellets of
moistened loam, clay, or sand.

Mason-Ants.

We have used, in the preceding pages, the terms
mason-bees and mason-wasps, for insects which build
their nests of earthy materials. On the same prin-
ciple, we have followed the ingenious M. Huber the
younger, in employing the term mason-ants for those
whose nests on the exterior appear to be hillocks of
earth, without the admixture of other materials,
whilst in the interior they present a series of laby-
rinths, lodges, vaults, and galleries, constructed with
considerable skill. Of these mason-ants, as of the
mason-wasps and bees already described, there are
several species, differing from one another in their
skill in the art of Architecture,

One of the most common of the ant-masons is the
turf-ant (Formica cespitum, Latr.), which is very
small, and of a blackish brown colour. Its architec-
ture is not upon quite so extensive a scale as some of
the others; but, though slight, it is yery ingenious.
Sometimes they make choice of the shelter of a flat
stone or other covering, beneath which they hollow
out chambers and communicating galleries; at other
times they are contented with the open ground; but
most commonly they select a tuft of grass or other
herbage, the stems of which serye for columns to
their earthen walls.

We had a small colony of these ants accidentally
established in a flower-pot, in which we were rearing
some young plants of the tiger-lily (Lidium tigrinum),
the stems of which being stronger than the grass
where they usually build, enabled them to rear their

Q2

256 INSECT ARCHITECTURE,

edifice higher, and also to make it more secure, than
they otherwise might. It was wholly formed of
small grains of moist earth, piled up between the
stems of the lily without any apparent cement; in-
deed, it has been ascertained by Huber, as we shall
afterwards see, that they use no cement beside water.
This is not always to be procured, as they depend
altogether on rains and dew; but they possess the art
of joining grains of dry sand so as to support one
another, on some similar principle, no doubt, to that
of the arch.

The nest which our turf-ants constructed in the
flower-pot was externally of an imperfect square form,
in consequence of its situation; for they usually
prefer a circular plan. The principal chambers were
placed under the arches, and, when inspected, con-
tained a pile of cocoons and pupx. Beneath those
upper chambers there were others dug out deeper
down, in which was also a numerous collection of
eggs and cocoons in various stages of advancement.*

Mr. Knapp describes a still more curious structure
of another species of ant common in this country :—
“One year,” says he, “on the third of March, my
labourer being employed in cutting up ant-hills, or
tumps, as we call them, exposed to view multitudes
of the yellow species (Mormica flava) in their
winter’s retirement. They were collected in numbers
in little cells and compartments, communicating with
others by means of narrow passages. In many of
the cells they had deposited their larvee, which they
were surrounding and attending, but not brooding
over or covering. Being disturbed by our rude ope-
rations, they removed them from our sight to more
hidden compartments. The larvee were small. Some
of these ant-hills contained multitudes of the young
of the wood-louse (Oniscus armadillo), inhabiting

*JIR.

' MASON-ANTS. 257

with perfect familiarity the same compartments as
the ants, crawling about with great activity with
them, and perfectly domesticated with each other.
They were small and white; but the constant yibra-
tion of their antennz, and the alacrity of their mo-
tions, manifested a healthy vigour. The ants were
in a torpid state; but on being removed into a tem-
perate room, they assumed much of their summer’s
animation. How these cxeatures are supported
during the winter season it is difficult to compre-
hend; as in no one instance could we perceive any
store or provision made for the supply of their
wants. The minute size of the larve manifested
that they had been recently deposited; and conse-
quently that their parents had not remained during
winter in a dormant state, and thus free from the
calls of hunger. The preceding month of February,
and part of January, had been remarkably severe ;
the frost had penetrated deep into the earth, and long
held it frozen; the ants were in many cases not more
than four inches beneath the surface, and must have
been enclosed in a mass of frozen soil for a long
period; yet they, their young, and the onisci, were
perfectly uninjured by it: affording another proof
of the fallacy of the commonly received opinion, that
cold is universally destructive to insect life.’’*

The earth employed by mason-ants is usually
moist clay, either dug from the interior parts of their
city, or moistened by rain. The mining-ants and the
ash-coloured (Formica fusca) employ earth which is
probably not selected with so much care, for it forms
a much coarser mortar than what we see used in the
structure of the yellow ants (F. flava) and the
brown ants (F. brunnea). We have never observed
them bringing their building materials of this kind
from a distance, like the mason-bees and like the
wood or hill-ant (#. rufa) ; but they take care, before

* Journal of a Naturalist, page 304,

7

258 INSECT ARCHITECTURE.

they fix upon a locality, that it shall produce them
all that they require. We are indebted to Huber
the younger for the most complete account which
has hitherto been given of these operations, of which
details we shall make free use.

“To form,” says this shrewd observer, “a correct
judgment of the interior arrangement or distribution
of an ant-hill, it is necessary to select such as have
not been accidentally spoiled, or whose form has
not been too much altered by local circumstances; a
slight attention will then suffice to show, that the ha-
bitations of the different species are not all constructed
after the same system. Thus, the hillock raised by
the ash-coloured ants will always present thick walls,
fabricated with coarse earth, well-marked stories, and
large chambers, with vaulted ceilings, resting upon
a solid base. We never observe roads, or galleries,
properly so called, but large passages, of an oval
form, and all around considerable cavities and exten-
sive embankments of earth. We further notice,
that the little architects observe a certain proportion
between the large arched ceilings and the pillars that
are to support them.

“The brown-anit (Formica brunnea), one of the
smallest of the ants, is particularly remarkable for
the extreme finish of its work. Its body is of a red-
dish shining brown, its head a little deeper, and the
antenne: and feet a little lighter in colour. The ab-
domen is of an obscure brown, the scale narrow, of
asquare form, and slightly scolloped. The body is
one line and two-fifths in length.*

’ “ This ant, one of the most industrious of its tribe,
forms its nest of stories, four or five lines in height,
The partitions are not more than half a line in thick-
ness; and the substance of which they are composed
is so finely grained, that the inner walls present one

* A line is the twelfth part of the old Frenchinch. See Com-
panion to the Almanac for 1830, ». 114.

MASON-ANTS. 259

smooth unbroken surface. These stories are not
horizontal ; they follow the slope of the ant-hill, and
lie one upon another to the ground-floor, which com-
municates with the subterranean lodges. ‘They are
not always, however, arranged with the same regu-
larity, for these ants do not follow an invariable
plan; it appears, on the contrary, that nature has
allowed them a certain latitude in this respect, and
that they can, according to circumstances, modify
them to their wish; but, however fantastical their
habitations may appear, we always observe they have
been formed by concentrical stories. On examining
each story separately, we observe a number of cavi-
ties or halls, lodges of narrower dimensions, and long
galleries, which serve for general communication.
The arched ceilings covering the most spacious
places are supported either by little columns, slender
walls, or by regular buttresses. We also notice cham-
bers, that have but one entrance, communicating with
the lower story, and large open spaces, serving as a
kind of cross-road (carrefour), in which all the
streets terminate.

“Such is the manner in which the habitations of
these ants are constructed. Upon opening them, we
commonly find the apartments, as well as the large
open spaces, filled with adult ants; and always ob-
served their pupe collected in the apartments more
or less near the surface. This, however, seems re-
gulated by the hour of the day, and the temperature :
for in this respect these ants are endowed with great
sensibility, and know the degree of heat best adapted
for their young. The ant-hill contains, sometimes,
more than twenty stories in its upper portion, and at
least as many under the surface of the ground. By
this arrangement the ants are enabled, with the
greatest facility, to regulate the heat. When a too
burning sun overheats their upper apartments, they
withdraw their little ones to the bottom of the ant-

260 INSECE ARCHITECTURE.

hill. The ground-floor becoming, in its turn, unin-
habitable during the rainy season, the ants of this
species transport what most interests them to the
higher stories;"and it is there we find them more
usually assembled, with their eggs and pupa, when
the subterranean apartments are submerged.” *

Ants have a great dislike to water, when it exceeds
that of a light shower to moisten their building-ma-
terials, One species, mentioned by Azara as indige-
nous to South America, instinctively builds a nest
from three to six feet high,t to provide against the
inundations during the rainy season, Even this,
however, does not always save them from submer-
sion; and, when that occurs, they are compelled,
in order to prevent themselves from being swept
away, to form a group, somewhat similar to the cur-
tain of the wax-workers of hive-bees (see page 114).
The ants constituting the basis of this group lay
hold of some shrub for security, while their compa-
nions hold en by them; and thus the whole colony,
forming an animated raft, floats on the surface of the
water till the inundation (which seldom continues
longer than a day or two) subsides. We confess,
however, that we are somewhat sceptical respecting
this story, notwithstanding the very high character of
the Spanish naturalist.

It is usual with architectural insects to employ
some animal secretion, by way of mortar or size, to
temper the materials with which they work ; but the
whole economy of ants is so different, that it would
be wrong to infer from analogy a similarity in this
respect, though the exquisite polish and extreme de-
licacy of finish in their structures lead, naturally, to
such a conclusion. M. P. Huber, in order to resolve
this question, at first thought of subjecting the ma-
terials of the walls to chemical analysis, but wisely

* M. P, Huber on Ants, page 20.
} Stedman’s Surinam, vol. i, p. 160,

MASON-ANTS. 261

(as we think) abandoned it for the surer method of
observation. The details which he has given, as the
result of his researches, are exceedingly curious and
instructive. He began by observifg an ant-bill till
he could perceive some change in its form.

“The inhabitants,’ says he, “of that which I
selected kept within during the day, or only went out
by subterranean galleries which opened at some feet
distance inthe meadow. There were, however, two or
three small openings on the surface of the nest; but
I saw none of the labourers pass out this way, on
account of their being too much exposed to the sun,
which these insects greatly dread. This ant-hill,
which had a round form, rose in the grass, at the
border of a path, and had sustained no injury. I soon
perceived that the freshness of the air and the dew
invited the ants to walk over the surface of their
nest ; they began making new apertures; several
ants might be seen arriving at the same time, thrust-
ing their heads from the entrances, moving about
their antennz, and at length adventuring forth to
visit the environs.

“This brought to my recollection a singular opi-
nion of the ancients. ‘They believed that ants were
occupied in their architectural labours during the
night, when the moon was at its full.’’*

M. Latreille discovered a species of ants which
were, so far as he could ascertain, completely blind,+
and of course it would be immaterial to them whether
they worked by night or during the day. All ob-
servers indeed agree that ants labour in the night,
and a French naturalist is therefore of opinion that
they never sleep,—a circumstance which is well as-
certained with respect to other animals, such as the
shark, which will track a ship in full sail for weeks

* M. P. Huber on Ants, p. 23.
} Latreille, Hist. Nat. des Fourmis.
qa 3

262 INSECT ARCHITECTURE.

together.* The ingenious historian of English ants,
Gould, says they never intermit their labours by night
or by day, except when compelled by excessive rains.
It is probable the*ancients were mistaken in asserting
that they only work when the moon shines; ‘+ for,
like bees, they seem to find no difficulty in building
in the dark, their subterranean apartments being as
well finished as the upper stories of their buildings.
But to proceed with the narrative of M. P. Huber.

“Having thus noticed the movements of these
insects during the night, I found they were almost
always abroad and engaged about the dome of their
habitation after sunset. This was directly the reverse
of what I had observed in the conduct of the wood-
ants (F. rufa), who only go out during the day, and
close their doors in the evening. The contrast was
still more remarkable than I had previously supposed ;
for upon visiting the brown ants some days after,
during a gentle rain, I saw all their architectural
talents in full play.

“As soon as the rain commenced, they left in
great numbers their subterranean residence, re-entered
it almost immediately, and then returned, bearing
between their teeth pellets of earth, which they de-
posited on the roof of their nest. I could not at first
conceive what this was meant for, but at length I
saw little walls start up on all sides with spaces left.
between them, Inseveral places, columns, ranged at
regular distances, announced halls, lodges, and pas-
sages, which the ants proposed establishing; in a
word, it was the rough beginning of a new story.

“J watched with a considerable degree of interest

* Dr. Cleghorn, Thesis de Somno.

+ Aristotle, Hist. Animal. ix. 38. Pliny says “ Operantur et
noctu plend luni; eadem interlunio cessaut,” 7. e. they work in
the night at full moon, but they leave off between moon and
moon. It is the latter that we think doubtful.

MASON-ANTS. 263

the most trifling movements of my masons, and
found they did not work after the manner of wasps
and humble-bees, when occupied in constructing a
covering to their nest. The latter sit, as it were,
astride on the border or margin of the covering, and
take it between their teeth to model and attenuate it
according to their wish. The wax of which it is
composed, and the paper which the wasp employs,
moistened by some kind of glue, are admirably
adapted for this purpose, but the earth of which the
ants make use, from its often possessing little tena-
city, must be worked up after some other manner.

“Bach ant, then, carried between its teeth the
pellet of earth it had formed by scraping with the end
of its mandibles the bottom of its abode, a cireum-
stance which I have frequently witnessed in open day.
This little mass of earth, being composed of particles
but just united, could be readily kneaded and moulded
as the ants wished; thus, when they had applied it
to the spot where they had to rest, they divided and
pressed against it with their teeth,so as to fill up the
little inequalities of their wall. The antenne followed
all their movements, passing over each particle of
earth as soon as it was placed in its proper position.
The whole was then rendered more compact, by
pressing it lightly with the fore-feet. This work
went on remarkably fast. After having traced out
the plan of their masonry, in laying here and there
foundations for the pillars and partitions they were
about to erect, they raised them gradually higher, by
adding fresh materials. It often happened that two
little walls, which were to form a gallery, were raised
opposite, and at a slight distance from each other.
When they had attained the height of four or five
lines, the ants busied themselves in covering-in the
space left between them by a vaulted ceiling.

“ Asif they judged all their partitions of sufficient

—_

264 INSECT ARCHITECTURE.

elevation, they then quitted their labours in the
upper part of the building ; they affixed to the interior
and upper part of each wall fragments of moistened
earth, in an almost horizontal direction, and in such
a way as to form a ledge, which, by extension, would
be made to join that coming from the opposite wall.
These ledges were about half a line in thickness ;
and the breadth of the galleries was, for the most
part, about a quarter of an inch. On one side several
vertical partitions were seen to form the scaffolding
of a lodge, which communicated with several corri-
dors, by apertures formed in the masonry; on an-
other, a regularly-formed hall was constructed, the
vaulted ceiling of which was sustained by numerous
pillars ; further off, again, might be recognised the
rudiments of one of those cross-roads of which I haye
before spoken, and in which several avenues terminate.
These parts of the ant-hill were the most spacious ;
the ants, however, did not appear embarrassed in
constructing the ceiling to cover them in, although
they were often more than two inches in breadth.

“In the upper part of the angles formed by the
different walls, they laid the first foundations of this
ceiling, and from the top of each pillar, as from so
many centres, a layer of earth, horizontal and slightly
convex, was carried forward to meet the several
portions coming from different points of the large
public thoroughfare.

“TJ sometimes, however, laboured under an ap-
prehension that the building could not possibly re-
sist its own weight, and that such extensive ceilings,
sustained only by a few pillars, would fall into ruin
from the rain which continually dropped upon them ;
but I was quickly convinced of their stability, from
observing that the earth, brought by these insects,
adhered at all points, on the slightest contact ; and
that the rain, so far from lessening the cohesion of

MASON-ANTS. 265

its particles, appeared even to increase it. Thus,
instead of injuring the building, it even contributed
to render it still more secure.

“These particles of moistened earth, which are
only held together by juxtaposition, require a fall of
rain to cement them more closely, and thus varnish
over, as it were, those places where the walls and
galleries remain uncoyered. All inequalities in the
masonry then disappear. The upper part of these
stories, formed of several pieces brought together,
presents but one single layer of compact earth. They
require for their complete consolidation nothing but
the heat of thesun. It sometimes, however, happens
that a violent rain will destroy the apartments,
especially should they be but slightly arched; but
under these circumstances the ants reconstruct them
with wonderful patience.

“These different labours were carried on at the
same time, and were so closely followed up in the
different quarters, that the ant-hill received an addi-
tion story in the course of seven or eight hours.
All the vaulted ceilings being formed upon a regular
plan, and at equal distances from one. wall to the
other, constituted, when finished, but one single
roof. Scarcely had the ants finished one story than
they began to construct another; but they had not
time to finish it—the rain ceasing before the ceiling
was fully completed. They still, however, continued
their work for a few hours, taking advantage of the
humidity of the earth; but a keen north wind soon
sprung up, and hastily dried the collected fragments,
which, no longer possessing the same adherence,
readily fell into powder, ‘he ants, finding their
efforts ineffectual, were at length discouraged, and
abandoned their employment; but what was my
astonishment when I saw them destroy all the apart-
ments that were yet uncovered, scattering here and

266 INSECT ARCHITECTURE.

there over the last story the materials of which they
had been composed! ‘These facts incontestably
prove that they employ neither gum, nor any kind
of cement, to bind together the several substances
of their nest; but in place of this avail themselves
of the rain, to work or knead the earth, leaving the
sun and wind to dry and consolidate it.””*

Dr, Johnson of Bristol observed very similar pro-
ceedings in the case of a colony of red ants (Myr-
mica rubra ?), the roof of whose nest was formed
by a flat stone. During dry weather, a portion of
the side walls fell in; but the rubbish was quickly
removed, though no repairs were attempted till a
shower of rain enalled them to work. As soon as
this occurred, they worked with extraordinary rapi-
dity, and in a short time the whole of the fallen parts
were rebuilt, and rendered-as smooth as if polished
with a trowel.

When a gardener wishes to water a plot of ground
where he has sown seeds that require nice manage-
ment, he dips a strong brush into water, and passes
his hand backwards and forwards over the hairs for
the purpose of producing a fine artificial shower.
Huber successfully adopted the same method to excite
his ants to recommence their labours, which had been
interrupted for want of moisture. But sometimes,
when they deem it unadvisable to wait for rain, they
dig down (as we remarked to be the practice of the
mason-bees) till they arrive at earth sufficiently moist
for their purpose. They do not, however, like these
bees, merely dig for materials ; for they use the exca-
vations for apartments, as well as what they construct
with the materials thence derived. They appear, in
short, to be no less skilful in mining than in building.

Such is the general outline of the operations of

* M, P. Huber on Ants, p, 31.

MASON-ANTS. 267

this singular species ; but we are still more interested
with the history which M. P. Huber has given of the
labours of an individual ant. “One rainy day,”
he says, “I observed a labourer of the dark ash-
coloured species (Formica fusca) digging the ground
near the aperture which gave entrance to the ant-
hill. It placed ina heap the several fragments it
had scraped up, and formed them into small pellets,
which it deposited here and there upon the nest.
It returned constantly to the same place, and ap-
peared to have a particular design, for it laboured
with ardour and perseverance. I remarked a slight
furrow, excavated in the ground ina straight line,
representing the plan of a path or gallery. The
labourer (the whole of whose movements fell under
my immediate observation) gave it greater depth and
breadth, and cleared out its borders; and I saw, at
length—in which I could not be deceived—that it
had the intention of establishing an avenue which
was to lead from one of the stories to the under-
ground chambers. This path, which was about two
or three inches in length, and formed by a single
ant, was opened above, and bordered on each side
by a buttress of earth. Its concavity, in the form of
a pipe (gouttiére), was of the most perfect regu-
larity ; for the architect had not left an atom too
much. The work of this ant was so well followed
and understood, that I could almost to a certainty
guess its next proceeding, and the very fragment it
was about to remove. At the side of the opening
where this path terminated was a second opening,
to which it was necessary to arrive by some road.
The same ant began and finished this undertaking
without assistance. It furrowed out and opened
another path, parallel to the first, leaving between
each a little wall of three or four lines in height.”
Like the hive-bees, ants do not seem to work

268 INSECT ARCHITECTURE.

in concert, but each individual separately. There
is, consequently, an occasional want of coincidence
in the walls and arches; but this does not much
embarrass them, for a worker, on discovering an
error of this kind, seems to know how to rectify it,
as appears from the following observations.

“A wall,’ says M. Huber, “had been erected,
with the view of sustaining a vaulted ceiling, still
incomplete, that had been projected towards the wall
of the opposite chamber. The workman who began
constructing it had given it too little elevation to
meet the opposite partition, upon which it was to
rest. Had it been continued on the original plan, it
must infallibly have met the wall at about one half
of its height; and this it was necessary to avoid.
This state of things very forcibly claimed my atten-
tion; when one of the ants arriving at the place, and
visiting the works, appeared to be struck by the dif-
ficulty which presented itself; but this it as soon
obviated, by taking down the ceiling, and raising the
wall upon which it reposed. It then, in my presence,
constructed a new ceiling with the fragments of the
former one.

“« When the ants commence any undertaking, one
would suppose that they worked after some precon-
ceived idea, which, indeed, would seem verified by
the execution, Thus, should any ant discover upon
the nest two stalks of plants which lie crossways, a
disposition favourable to the construction of alodge,
or some little beams that may be useful in forming
its angles and sides, it examines the several parts
with attention; then distributes, with much sagacity
and address, parcels of earth in the spaces, and
along the stems, taking from every quarter materials
adapted to its object, sometimes not caring to destroy
the work that others had commenced; so much are
its motions regulated by the idea it has conceived,

MASON-ANTS. ; 269

and upon which it acts, with little attention to all
else around it. It goes and returns, until the plan
is sufficiently understood by its companions.

“Tn another part of the same ant-hill,” continues
M. Huber, “several fragments of straw seemed ex-
pressly placed to form the roof of a large house; a
workman took advantage of this disposition. These
fragments lying horizontally, at half an inch distance
from the ground, formed, in crossing each other, an
oblong parallelogram. The industrious insect com-
menced by placing earth in the several angles of this
frame-work, and all along the little beams of which
it was composed. ‘The same workman afterwards
placed several rows of the same materials against
each other, when the roof became very distinct. On
perceiving the possibility of profiting by another
plant to support a vertical wall, it began laying the
foundations of it; other ants having by this time
arrived, finished in common what this had com-
menced.,”’*

M. Huber made most of his observations upon the
processes followed by ants in glazed artificial hives

=

4) A.A ai
h 1 ]

* Huber on Ants, p. 43.

270 INSECT ARCHITECTURE.

or formicaries. The preceding figure represents a
view of one of his formicaries of mason-ants.

We have ourselves followed up his observations,
both on natural ant-hills and in artificial formicaries.
On digging cautiously into a natural ant-hill, esta-
blished upon the edge of a garden walk, we were
enabled to obtain a pretty complete view of the in-
terior structure. There were two stories, composed
of large chambers, irregularly oval, communicating
with each other by arched galleries, the walls of all
which were as smooth and well polished as if they
had been passed over by a plasterer’s trowel. The
floors of the chambers, we remarked, were by no
means either horizontal or level, but all more or less
sloped, and exhibiting in each chamber at least two
slight depressions of an irregular shape. We left
the under story of this nest untouched, with the
notion that the ants might repair the upper galleries,
of which we had made a vertical section ; but instead
of doing so they migrated during the day to a large
crack, formed by the dryness of the weather, about
a yard from their old nest.*

We put a number of yellow ants (Formica flava),
with their eggs and cocoons, into a small glass frame,
more than half full of moist sand taken from their
native hill, and placed in a sloping position, in order

* JR,

MASON-ANTS. 271

to see whether they would bring the nearly vertical,
and therefore insecure, portion toa level by masonry.
We were delighted to perceive that they immediately
resolved upon performing the task which had been
assigned them, though they did not proceed very
methodically in their manner of building ; for instead
of beginning at the bottom and building upwards,
many of them went on to add to the top of the outer
surface, which increased rather than diminished the
security of the whole. Withal, however, they seemed
to know how far to go, for no portion of the newly
built wall fell; and in two days they had not only
reared a pyramidal mound to prop the rest, but had
constructed several galleries ant chambers for lodging
the cocoons, which we had scattered at random
amongst the sand, The new portion of this building
is represented in the figure as supporting the upper
and insecure parts of the nest.

We are sorry to record that our ingenious little
masons were found upon the third day strewed about
the outside of the building, dead or dying, either from
over fatigue or perhaps from surfeit, as we had sup-
plied them with as much honey as they could devour.
A small colony of turf-ants have at this moment

July 28th, 1829) taken possession of the premises of
their own accord.*

*J.R.

272

Cuarrer XV.

Structures of the Wood-Ant or Pismire, and of Carpenter-Arts.

Tue largest of our ile ants is that called the
Hill-ant by Gould, the Fallow-ant by the English
translator of Huber, aril popularly the Pismire ; but
which we think may be more appropriately named
the Wood-ant (Formica rufa, Larr.), from its invari-
able habit of living in or near woods and forests. This
insect may be readily distinguished from other ants
by the dusky black colour of its head and hinder parts,
and the rusty brown of its middle. The structures
reared by this species are often of considerable mag-
nitude, and bear no small resemblance to a rook’s nest
thrown upon the ground bottom upwards. They oc-
cur in abundance in the woods near London, and in
many other parts of the country: in Oak of Honour
wood alone, we are acquainted with the localities of
at least two dozen,—some in the interior, and others
on the hedge-banks on the outskirts of the wood.*
The exterior of the nest is composed of almost
every transportable material which the colonists can
find in their vicinity: but the greater portion con-
sists of the stems of withered grass and short twigs of
trees, piled up in apparent confusion, but with suffi-
cient regularity to render the whole smooth, conical,
and sloping towards the base, for the ‘purpose, we
may infer, of carrying off rain-water. When within
reach of a corn-field, they often also pick up grains
of wheat, barley, or oats, and carry them to the nest

IR.

WOOD-ANTS. 273

as building materials, and not for food, as was be-
lieved by the ancients. There are wonders enough
observable in the economy of ants, without having
recourse to fancy—wonders which made Aristotle
extol the sagacity of bloodless animals, and Cicero
ascribe to them not only sensation, but mind, reason,
and memory.* lian, however, describes, as if he
had actually witnessed it, the ants ascending a staik
of growing corn, and throwing down “ the ears which
they bit off to their companions below,” (ry dnpy
7» xkarw). Aldrovand assures us that he had seen
their granaries ; and others pretend that they shrewdly
bite off the ends of the grain to prevent it from ger-
minating.+ These are fables which accurate obser:
vation has satisfactorily contradicted.

But these errors, as it frequently happens, have
contributed to a more perfect knowledge of the in-
sects than we might otherwise have obtained; for it
was the wish to prove or disprove the circumstance
of their storing up and feeding upon grain, which led
Gould to make his observations on English ants ; as
the notion of insects being produced from putrid
carcases had before led Redi to his ingenious experi-
ments on their generation.{ Yet, although it is more
than eighty years since Gould’s book was published,
we find the error still repeated in very respectable
publications.§

The coping which we above described as forming
the exterior of the wood-ants’ nest, is only a small
portion of the structure, which consists of a great
number of interior chambers and galleries, with fun-
nel-shaped avenues leading to them. ‘The coping,

* In formica non modo sensus, sed etiam mens, ratio, memoria.

+ Aldrovandus de Formicis, and Johnston, Thaumaturg. Nat.
p: 356.

{ See details of these in Insect Transformations, chap. i.

§ See Professor Paxton’s Illustr. of Scripture, i. 307.

274 INSECT ARCHITECTURE.

indeed, is one of the most essential parts, and we
cannot follow a more delightful guide than the
younger Huber, in detailing its formation.

«The labourers ” he says, “ of which the colony
is composed not only work continually on the out-
side of their nest, but, differing very essentially from
other species, who willingly remain in the interior,
sheltered from the sun, they prefer living in the open
air, and do not hesitate to carry on, even in our pre-
sence, the greater part of their operations.

“To have an idea how the straw or stubble-roof is
formed, let us take a view of the ant-hill at its origin,
when it is simply a cavity in the earth, Some of its
future inhabitants are seen wandering about in
search of materials fit for the exterior work, with
which, though rather irregularly, they cover up the
entrance ; whilst others are employed in mixing the
earth, thrown up in hollowing the interior, with frag-
ments of wood and leaves, which are every mo-
ment brought in by their fellow-assistants; and this
gives a certain consistence to the edifice, which in-
creases in size daily. Our little architects leave here
and there cavities, where they intend constructing
the galleries which are to lead to the exterior, and as
they remove in the morning the barriers placed at the
entrance of their nest the preceding evening, the pas-
sages are kept open during the whole time of its con-
struction, We soon observed the roof to become con-
vex; but we should be greatly deceived did we con-
sider it solid, This roof is destined to include many
apartments or stories. Having observed the mo-
tions of these little builders through a pane of glass
adjusted against one of their habitations, I am thence
enabled to speak with some degree of certainty upon
the manner in which they are constructed. I ascer-
tained, that it is by excavating, or mining the under
portion of their edifice, that they form their spacious

WOOD-ANTS. 275

halls, low indeed, and of heavy construction, yet suf-
ficiently convenient for the use to which they are
appropriated, that of receiving, at certain hours of the
day, the larvee and pupe.

“These halls have a free communication by gal-
leries made in the same manner. If the materials
of which the ant-hill is composed were only interlaced,
they would fall into a confused heap every time the
ants attempted to bring them into regular order,
This, however, is obviated by their tempering the
earth with rain-water, which, afterwards hardened in
the sun, so completely and effectually binds together
the several substances as to permit the removal of
certain fragments from the ant-hill without any in-
jury to the rest; it, moreover, strongly opposes the
introduction of the rain. I never found, even after
long and violent rains, the interior of the nest wetted
to more than a quarter of an inch from the surface,
provided it had not been previously out of repair,
or deserted by its inhabitants.

“The ants are extremely well sheltered in their
chambers, the largest of which is placed nearly in
the centre of the building; it is much loftier than
the rest, and traversed only by the beams that sup-
port the ceiling; it is in this spot that all the gal-
leries terminate, and this forms, for the most part,
their usual residence.

“As to the underground portion, it can only be
seen when the ant-hill is placed against a declivity ;
all the interior may be then readily brought in view,
by simply raising up the straw-roof. The subter-
ranean residence consists of a range of apartments,
excavated in the earth, taking an horizontal direc-
tion.”’*

M. P. Huber, in order toobserve the operations of

* Huber on Ants, p, 15,

276 INSECT ARCHITECTURE.

the wood-ants with more attention, transferred colo-
nies of them to his artificial formicaries, plunging
the feet of the stand into water to prevent their es-
cape till they were reconciled to their abode, and
had made some progress in repairing it. The fol-
lowing is a figure of the apparatus which he used for
this purpose.

There is this remarkable difference in the nest of
the wood-ants, that they do not construct a long co-
vert way asif for concealment, as the yellow and
the brown ants do. The wood-ants are not, like them,
afraid of being surprised by enemies, at least during —
the day, when the whole colony is either foraging in
the vicinity or employed on the exterior. But the
proceedings of the wood-ants at night are well wor-
thy of notice; and when M. Huber began to study

WOOD-ANTS. 277

their economy, he directed his entire attention to
their night proceedings. “I remarked,” says he,
«that their habitations changed in appearance hourly,
and that the diameter of those spacious avenues,
where so many ants could freely pass each other
during the day, was, as night approached, gradually
lessened. The aperture, at length, totally disap-
peared, the dome was closed on all sides, and the
ants retired to the bottom of their nest.

“In further noticing the apertures of these ant-
hills, I fully ascertained the nature of the labour of
its inhabitants, of which I could not before even
guess the purport; for the surface of the nest pre-
sented such a constant scene of agitation, and so
many insects were occupied in carrying materials in
every direction, that the movement offered no other
image than that of confusion.

T saw then clearly that they were engaged in
stopping up passages; and, for this purpose, they at
first brought forward little pieces of wood, which
they deposited near the entrance of those avenues
they wished to close; they placed them in the stubble;
they then went to seek other twigs and fragments
of wood, which they disposed above the first, but in
a different direction, and appeared to choose pieces
of less size in proportion as the work advanced.
They at length brought in a number of dried leaves,
and other materials of an enlarged form, with which
they covered the roof: an exact miniature of the art
of our builders when they form the covering of any
building! Nature, indeed, seems everywhere to
have anticipated the inventions of which we boast,
and this is doubtless one of the most simple.

“ Our little insects, now in safety in their nest,
retire gradually to the interior before the last pas-
sages are closed ; one or two only remain without, or
concealed behind the doors on guard, while the rest

R

278 INSECT ARCHITECTURE.

either take their repose, or engage in different occu-
pations in the most perfect security. I was impatient
to know what took place in the morning upon these
ant-hills, and therefore visited them at an early hour.
I found them in the same state in which I had left
them the preceding evening. A few ants were
wandering about on the surface of the nest, some
others issued from time to time from under the
margin of their little roofs formed at the entrance of
the galleries: others afterwards came forth who
began removing the wooden bars that blockaded the
entrance, in which they readily succeeded. This
labour occupied them several hours. The passages
were at length free, and the materials with which
they had been closed scattered here and there over
the ant-hill. Every day, morning and : evening,
during the fine weather, I was a witness to similar
proceedings. On days of rain the doors of all the
ant-hills remained closed. When the sky was cloudy
in the morning, or rain was indicated, the ants, who
seemed to be aware of it, opened but in part their
several avenues, and immediately closed them when
the rain commenced,’’*

The galleries and chambers which are roofed in
as thus described, are very similar to those of the
mason-ants, being partly excavated in the earth, and
partly built with the clay thence procured. It is in
these they pass the night, and also the colder months
of the winter, when they become torpid or nearly
so, and of course require not the winter granaries of
corn with which the ancients fabulously furnished
them,

* Huber on Ants, p. 11.

CARPENTER-ANTS. 279

CARPENTER-ANTS,

Tur ants that work in wood perform much more
extensive operations than any of the other carpenter
insects which we have mentioned. Their only tools,
like those of bees and wasps, are their jaws or man-
dibles ; but though these may not appear so curiously
constructed as the ovipositor file of the tree-hopper
(Cicade), or the rasp and saw of the saw-flies We
thredinide), they are no less efficient in the perform-
ance of what is required, Among the carpenter-ants
the emmet or jet-ant (F. fuliginosa) holds the first
rank, and is easily known by being rather less in
size than the wood-ant, and by its fine shining black
colour. It is less common in Britain than some of
the preceding, though its colonies may occasionally
be met with in the trunks of decaying oak or willow
trees in hedges.

“The labourers,” says Huber, “of this species
work always in the interior of trees, and are desirous
of being screened from observation: thus every hope
on our part is precluded of following them in their
several occupations. I tried every expedient I could
devise to surmount this difficulty ; I endeayoured to
accustom these ants to live and work under my in-
spection, but all my efforts were unsuccessful; they
even abandoned the most considerable portion of
their nest to seek some new asylum, and spurned the
honey and sugar which I offered them for nourish-
ment. I was now, by necessity, limited to the in-
spection only of their edifices; but by decomposing
some of the fragments with care, I hoped to acquire
some knowledge of their organization.

“On one side I found horizontal galleries, hidden
in great part by their walls, which follow the circular
direction of the layers of the wood; and on an-
other, parallel galleries, separated by extremely thin

R 2

280 INSECT ARCHITECTURE.

partitions, haying no communication except by a few
oval apertures. Such is the nature of these works,
remarkable for their delicacy and lightness.

“Tn other fragments I found avenues which opened
laterally, including portions of walls and transverse
partitions, erected here and there within the galleries,
so as to form separate chambers. When the work
is further advanced, round holes are always observed,
encased, as it were, between two pillars cut out in
the same wall. These holes in course of time become
square, and the pillars, originally arched at both
ends, are worked into regular columns by the chisel
of our sculptors. ‘This, then, is the second specimen
of their art. This portion of the edifice will probably
remain in this state.

“ But in another quarter are fragments differently
wrought, in which these same partitions, pierced
now in every part, and hewn skilfully, are trans-
formed into colonnades, which sustain the upper
stories, and leave a free communication throughout
the whole extent. It can readily be conceived how
parallel galleries, hollowed out upon the same plan,
and the sides taken down, leaving only from space
to space what is necessary to sustain their ceilings,
may form an entire story; but as each has been
pierced separately, the flooring cannot be very level :
this, however, the ants turn to their advantage, since
these furrows are better adapted to retain the larvee
that may be placed there.

“The stories constructed in the great roots offer
greater irregularity than those in the very body of the
tree, arising either from the hardness and interlacing
of the fibres, which render the labour more difficult,
and obliges the labourers to depart from their accus-
tomed manner, or from their not observing in the
extremities of their edifice the same arrangement as
in the centre; whatever it be, horizontal stories and

CARPENTER-ANTS. 281

Portion of a tree, with chambers and galleries chiseled out by Jet-Ants.

numerous partitions are still found. If the work be
less regular, it becomes more delicate; for the ants,
profiting by the hardness and solidity of the mate-
rials, give to their building an extreme degree of
lightness. I have seen fragments of from eight to
ten inches in length, and of equal height, formed of
wood as thin as paper, containing a number of apart-
ments, and presenting a most singular appearance.
At the entrance of these apartments, worked out
with so much care, are very considerable openings ;
but in place of chambers and extensive galleries, the
layers of the wood are hewn in areades, allowing the
ants a free passage in every direction. These may
be regarded as the gates or vestibules conducting to
the several lodges.’’*

It is a singular circumstance in the structures of
these ants, that all the wood which they carve is
tinged of a black colour, as if it were smoked ; and M.
Huber was not a little solicitous to discover whence
this arose. It certainly does not add to the beauty

* Huber, p. 56.
R3

282 INSECT ARCHITECTURE.

of their streets, which look as sombre as the most
smoke-dyed walls in the older lanes of the metro-
polis. M. Huber could not satisfy himself whether
it was caused by the exposure of the wood to the
atmosphere, by some emanation from the ants, or
by the thin layers of wood being acted upon or de-
composed by the formic acid.* But if any or all
of these causes operated in blackening the wood,
we should be ready to anticipate a similar effect
in the case of other species of ants which inhabit
trees; yet the black tint is only found in the excava-
tions of the jet-ant.

We are acquainted with several colonies of the jet-
ants,—one of which, in the roots and trunk of an
oak on the road from Lewisham to Sydenham, near
Brockley in Kent, is so extremely populous that the
numbers of its inhabitants appeared to us beyond
any reasonable estimate. None of the other colo-
nies of this species which we have seen appear to
contain many hundreds. On cutting into the root
of the before mentioned tree, we found the vertical
excavations of much larger dimensions, both in width
and depth, than those represented by Huber in the
preceding cut (page 281). What surprised us the
most, was to see the tree growing vigorously and
fresh, though its roots were chiselled in all directions
by legions of workers, while every leaf and every
inch of the bark was also crowded by parties of
foragers. On one of the low branches we found a
deserted nest of the white-throat (Sylvia cinerea,
Tremmincx), in the cavity of which they were piled
upon one another as close as the unhappy negroes in
the hold of a slave ship; but we could not discover
what had attracted them hither. Another dense group,
collected on one of the branches, led us to the dis-
covery of a very singular oak-gall, formed on the

* The acid of ants,

CARPENTER-ANTS. 283

bark in the shape of a pointed cone, and crowded
together. It is probable that the juice which they
extracted from these galls was much to their taste.*

Beside the jet-ant, several other species exercise
the art of carpentry,—nay, what is more wonderful
still, they have the ingenuity to knead up, with
spiders’ web for a cement, the chips which they
chisel out into a material with which they construct
entire chambers. The species which exercise this
singular art are the Ethiopian (Formica nigra) and
the yellow-ant (F. flava).

We once observed the dusky ants (F. fusca), at
Blackheath in Kent, busily employed in carrying out
chips from the interior of a decaying black poplar,
at the root of which a colony was established; but,
though it thence appears that this species can chisel
wood if they choose, yet they usually burrow in the
earth, and by preference, as we have remarked, at
the root of a tree, the leaves of which supply them
with food.

Among the foreign ants, we may mention a small
yellow ant of South America, described by Dampier,
which seems, from his account, to construct a nest
of green leaves. “Their sting,” he says, “ is like
a spark of fire; and they are so thick among the
boughs in some places, that one shall be covered with
them before he is aware. These creatures have nests
on great trees, placed on the body between the limbs :
some of their nests are as big as a hogshead. This
is their winter habitation; for in the wet season they
all repair to these their cities, where they preserve
their eggs. In the dry season, when they leave their
nests, they swarm all over the woodlands, for they
never trouble the savannahs. Great paths, three or

*LR + Huber.

284 INSECT ARCHITECTURE.

four inches broad, made by them, may be seen in
the woods. They go out light, but bring home
heavy loads on their backs, all of the same sub-
stance, and equal in size. I never observed any-
thing besides pieces of green leaves, so big that I
could scarcely see the insect for his burthen; yet
they would march stoutly, and so many were pressing
forward that it was a very pretty sight, for the path
looked perfectly green with them.”

Ants observed in New South Wales, by the gentle-
men in the expedition under Captain Cook, are still
more interesting. “Some,” we are told, “are as green
as a leaf, and live upon trees, where they build their
nests of various sizes, between that of a man’s head
and his fist. ‘These nests are of a very curious struc-
ture ; they are formed by bending down several of
the leaves, each of which is as broad as a man’s
hand, and glueing the points of them together, so as
to form a purse. The viscous matter used for this
purpose is an animal juice which nature has enabled
them to elaborate. Their method of first bending
down the leaves we had no opportunity to observe ;
but we saw thousands uniting all their strength to
hold them in this position, while other busy multi-
tudes were employed within, in applying this gluten
that was to prevent their returning back. To satisfy
ourselves that the leaves were bent and held down
by the efforts of these diminutive artificers, we dis-
turbed them in their work ; and as soon as they were
driven from their stations, the leaves on which they
were eraployed sprang up with a force much greater
than we could have thought them able to conquer by
any combination of their strength. But, though we
gratified our curiosity at their expense, the injury did
not gounrevenged ; for thousands immediately threw
themselves upon us, and gave us intolerable pain with
their stings, especially those which took possession

FOREIGN ANTS. 285

of our necks and hair, from whence they were not
easily driven. Their sting was scarcely less painful
than that of a bee; but, except it was repeated, the
pain did not last more than a minute.

“ Another sort are quite black, and their operation
and manner of life are not less extraordinary. Their
habitations are the inside of the branches of a tree,
which they contrive to excavate, by working out the
pith almost to the extremity of the slenderest twig,
the tree at the same time flourishing as if it had no
such inmate. When we first found the tree, we
gathered some of the branches; and were scarcely
less astonished than we should have been to find
that we had profaned a consecrated grove, where
every tree, upon being wounded, gave signs of life;
for we were instantly covered with legions of these
animals, swarming from every broken bough, and
inflicting their stings with incessant violence.

“A third kind we found nested in the root of a
plant, which grows on the bark of trees in the manner
of mistletoe, and which they had perforated for that
use. This root is commonly as big as a large turnip,
and sometimes much bigger. When we cut it, we
found it intersected by innumerable winding pas-
sages, all filled with these animals, by which, how-
ever, the vegetation of the plant did not appear to
have Pacer any injury. We neyer cut one of these
roots that was not inhabited, though some were not
bigger than a hazel-nut, ‘The animals themselves
are very small, not more than half as big as the
common red ant in England. They had stings, but
scarcely force enough to make them felt: they had,
however, a power of tormenting us in an equal, if
not in a greater degree; for the moment we handled
the root, they swarmed from innumerable holes, and
running about those parts of the body that were un-

286 INSECT ARCHITECTURE.

covered, produced a titillation more intolerable than
pain, except it is increased to great violence.”*

The species called sugar-ants in the West Indies
are particularly destructive to the sugar-cane, as well
as to lime, lemon, and orange-trees, by excavating
their nests at the roots, and so loosening the earth
that they are frequently up-rooted and blown down
by the winds. If this does not happen, the roots are
deprived of due nourishment, and the plants become
sickly and die.+

* Hawkeswortl’s Account of Cook’s First Voyage.
+ Phil. Trans. &xx. p. 346.

287

Cuartrr XVI.
Structures of White Ants, or Termites.

WueEn we look back upon the details which we have
given of the industry and ingenuity of numerous
tribes of insects, both solitary and social, we are
induced to think it almost impossible that they could
be surpassed. “The structures of wasps and bees,
and still more those of the wood-ant (Formica rufa),
when placed in comparison with the size of the
insects, equal our largest cities compared with the
stature of man. But when we look at the build-
ings erected by the white ants of tropical climates,
all that we have been surveying dwindles into in-
significance. ‘Their industry appears greatly to sur-
pass that of our ants and bees, and they are cer-
tainly more skilful in architectural contrivances. The
elevation, also, of their edifices is more than five
hundred times the height of the builders. Were
our houses built according to the same proportions,
they would be twelve or fifteen times higher than
the London Monument, and four or five times
higher than the pyramids of Egypt, with corre-
sponding dimensions in the basements of the edi-
fices, These statements are, perhaps, necessary to
impress the extraordinary labours of ants upon the
mind; for we are all more or less sensible to the
force of comparisons. The analogies between the
works of insects and of men are not perfect ; for in-
sects are all provided with instruments peculiarly
adapted to the end which they instinctively seek,
while man has to form a plan by progressive thought

288 INSECD ARCHITECTURE.

and upon the experience of others, and to complete
it with tools which he also invents.

The termites do not stand above a quarter of an inch
high, while their nests are frequently twelve feet ; and
Jobson mentions some which he had seen as high as
twenty feet ; “of compasse,”’ he adds, “ to contayne a
dozen men, with the heat of the sun baked into that
hardnesse, that we used to hide ourselves in the ragged
toppes of them when we took up stands to shoot at
deere or wild beasts,”* Bishop Heber saw a num-
ber of these high ant-hills in India, near the principal
entrance of the Sooty or Moorshedabad river. “‘ Many
of them,” he says, “ were five or six feet high, and
probably seven or eight feet in circumference at the
base, partially overgrown with grass and ivy, and
looking at a distance like the stumps of decayed trees.
I think it is Ctesias, among the Greek writers, who
gives an account alluded to by Lucian, in his ‘ Cock,’
of monstrous ants in India, as large as foxes. The
falsehood probably originated in the stupendous
fabrics which they rear here, and which certainly
might be supposed to be the work of a much larger
animal than their real architect.”’+ Herodotus has
a similar fable of the enormous size and brilliant ap-
pearance of the ants of India,

Nor is it only in constructing dwellings for them-
selyes that the termites of Africa and of other hot
climates employ their masonic skill. Though, like
our ants and wasps, they are almost omnivorous, yet
wood, particularly when felled and dry, seems their
favourite article of food; but they have an utter
aversion to feeding in the light, and always eat their
way with all expedition into the interior. It thence
would seem necessary for them either to leave the bark
of a tree, or the outer portion of the beam or door

* Jobson’s Gambia, in Purchas’s Pilgrim, ii. p. 1570.
} Heber’s Journal, vol. i, p. 248.

WHITE ANTS. 289.

of a house, undevoured, or to eat in open day.
They do neither ; but are at the trouble of construct-
ing galleries of clay, in which they can conceal
themselves, and feed in security. In all their forag-
ing excursions, indeed, they build covert ways, by
which they can go out and return to their encamp-
ment.*

Others of the species (for there are several), in-
stead of building galleries, exercise the art of miners,
and make their approaches under ground, penetrating
beneath the foundation of houses or areas, and rising
again either through the floors, or by entering the
bottom of the posts that support the building, when
they follow the course of the fibres, and make their
way to the top, boring holes and cavities in different
places, as they proceed. Multitudes enter the roof,
and intersect it with pipes or galleries, formed of
wet clay ; which serve for passages in all directions,
and enable them more readily to fix their habitations
in it. They prefer the softer woods, such as pine and
fir, which they hollow out with such nicety, that they
leave the surface whole, after having eaten away the
inside. A shelf or plank attacked in this manner
looks solid to the eye, when, if weighed, it will not
out-balance two sheets of pasteboard of the same di-
mensions. It sometimes happens that they carry
this operation so far on stakes in the open air, as to
render the bark too flexible for their purpose; when
they remedy the defect by plastering the whole stick
with a sort of mortar which they make with clay ; so
that, on being struck, the form vanishes, and the ar-
tificial covering falls in fragments on the ground,
In the woods, when a large tree falls from age or
accident, they enter it on the side next the ground,
and deyour it at leisure, till little more than the bark

* Smeathman, in Phil. Trans., vol. Ixxi.
s

290 INSECT ARCHITECTURE.

is left. But in this case they take no precaution of
strengthening the outward defence, but leave it in
such a state as to deceive an eye unaccustomed to
see trees thus gutted of their insides; and “ you
may as well,” says Mr. Smeathman, “step upon a
cloud.” Itis anextraordinary fact, that when these
creatures have formed pipes in the roof of a house,
instinct directs them to prevent its fall, which would
ensue from their having sapped the posts on which
it rests; but as they gnaw away the wood, they fill
up the interstices with clay, tempered to a surprising
degree of hardness; so that, when the house is
pulled down, these posts are transformed from wood
to stone. They make the walls of their galleries of
the same composition as their nests, varying the
materials according to their kind: one species
using red clay, another black clay, and a third a
woody substance, cemented with gums, as a security
from the attacks of their enemies, particularly the
common ant, which, being defended by a strong
horny shell, is more than a match for them; and
when it can get at them, rapaciously seizes them,
and drags them to its nest for food for its young
brood. If any accident breaks down part of their
walls, they repair the breach with all speed. Instinet
guides them to perform their office in the creation,
by mostly confining their attacks to trees that are
beginning to decay, or such timber as has been se-
vered from its root for use, and would decay in time.
Vigorous, healthy trees do not require to be de-
stroyed, and, accordingly, these consumers have no
taste for them.”

M. Adanson describes the termites of Senegal as
constructing covert ways along the surface of wood.
which they intend to attack; but though we have no

* Smeathman.

WHITE ANTS. 291

reason to distrust so excellent a naturalist, in de-
scribing what he saw, it is certain that they more
commonly eat their way into the interior of the wood,
and afterwards form the galleries, when they find
that they have destroyed the wood till it will no
longer afford them protection.

But it is time that we should come to their prin-
cipal building, which may, with some propriety, be
called a city; and, according to the method we have
followed in other instances, we shall trace their la-
bours from the commencement. We shall begin
with the operations of the species which may be ap-
propriately termed the Warrior (Zermes fatalis,
Linn.; 7. Bellicosus, Smuaru.).

Termes bellicosus in the winged state.

We must premise, that though they have been
termed white ants, they do not belong to the same
order of insects with our ants; yet they have a
slight resemblance to ants in their form, but more
in their economy. Smeathman, to whom we owe
our chief knowledge of the genus, describes them as
consisting of kings, queens, soldiers, and workers,
and is of opinion that the workers are larve, the
soldiers nymphe, and the kings and queens the per-
fect insects. In this opinion, he coincides with
Sparrmann* and others; but Latreille is inclined

* Quoted by De Geer, vol. vii.
s2

292 INSECT ARCHITECTURE.

to think from what he observed in a Europeatt
species (Termes lucifugus), found near Bordeaux,
that the soldiers form a distinct race, like the neuter
workers among bees and ants, while the working
termites are larys,* which are furnished with strong
mandibles for gnawing; when they become nymphs,
the rudiments of four wings appear, which are fully
developed in the perfect insects. In this state, they
migrate to form new colonies, but the greater number
of them perish in a few hours, or become the prey of
birds, and even the natives, who fry them as delicacies.
“JT have discoursed with several gentlemen,” says
Smeathman, “upon the taste of the white ants, and,
on comparing notes, we have always agreed that they
are most delicious and delicate eating. One gentle-
man compared them to sugared marrow, another to
sugared cream and a paste of sweet almonds.’

Mr. Smeathman’s very interesting paper affords us
the most authentic materials for the further descrip-
tion of these wonderful insects; and we therefore
continue partly to extract from, and partly to abridge,
his account.

The few pairs that are so fortunate as to survive
the various casualties that assail them are usually
found by workers (larve) which, at this season, are
running continually on the surface of the ground,
on the watch for them. As soon as they discover
the objects of their search, they begin to protect
them from their surrounding enemies, by enclosing
them in a small chamber of clay, where they
become the parents of a new community, and are
distinguished from the other inhabitants of the nest,
by the title of king and queen. Instinct directs
the attention of these labouring insects to the pre-
servation of their race, in the protection of this:

* Hist. Nat. Générale, vol. xiii. p. 66.
+ Smeathman in Phil. Trans. vol, lxxi. p. 169, note.

WHITE ANTS. 293

pair and their offspring. The chamber that forms
the rudiment of a new nest is contrived for their
safety, but the entrances to it are too small to admit
of their ever leaving it; consequently, the charge of
the eggs devolves upon the labourers, who construct
nurseries for their reception. These are small, irre-
gularly-shaped chambers, placed at first round the
apartment of the king and queen, and not exceeding
the size of a hazel-nut ; but in nests of long standing
they are of great comparative magnitude, and dis-
tributed at a greater distance. The receptacles for
hatching the young are all composed of wooden ma-
terials, apparently joined together with gum, and, by
way of defence, cased with clay. The chamber that
contains the king and queen is nearly on a level with
the surface of the ground; and as the other apart-
ments are formed about it, it is generally situated at
an equal distance from the sides of the nest, and di-
rectly beneath its conical point. Those apartments
which consist of nurseries and magazines of provi-
sions form an intricate labyrinth, being separated by
small empty chambers, and galleries, which sur-
round them, or afford a communication from one to
another. ‘This labyrinth extends on all sides to the
outward shells, and reaches up within it to two-
thirds or more of its height, leaving an open area
above, in the middle, under the dome, which reminds
the spectator of the nave of an old cathedral.
Around this are raised three or four large arches,
which are sometimes two or three feet high, next
the front of the area, but diminish as they recede
further back, and are lost amidst the innumerable
chambers and nurseries behind them.

Every one of these buildings consists of two dis-
tinct parts, the exteriorand the interior. The exterior
is one large shell, in the manner of a dome, large and
strong enough to enclose and shelter the interior from

294 INSECT ARCHITECTURE.

the vicissitudes of the weather, and the inhabitants
from the attacks of natural or accidental enemies, It
is always, therefore, much stronger than the interior
building, which is the habitable part, divided with a
wonderful kind of regularity and contrivance, into an
amazing number of apartments for the residence of
the king and queen, and the nursing of the numerous
progeny; or for magazines, which are always found
well filled with stores and provisions. The hills
make their first appearance above ground by a little
turret or two, in the shape of sugar-loaves, which are
run a foot high or more. Soon after, at some little
distance, while the former are increasing in height
and size, they raise others, and so go on increasing
their number, and widening them at the base, till
their works below are covered with these turrets, of
which they always raise the highest and largest in
the middle, and, by filling up the intervals between
each turret, collect them into one dome. They are
not very curious or exact in the workmanship, except
in making them very solid and strong; and wher,
by their joining them, the dome is completed, for
which purpose the turrets answer as. scaffolds, they
take away the middle ones entirely, except the tops,
which, joined together, make the crown of the cupola,
and apply the clay to the building of the works
within, or to erecting fresh turrets for the purpose of
raising the hillock still higher; so that some part of
the clay is probably used several times, like the
boards and posts of a mason’s scaffolds.

When these hills are little more than half their
height, it is a common practice of the wild bulls to
stand as sentinels on them, while the rest of the herd
are ruminating below. ‘They are sufficiently strong
for that, purpose ; and at their full height, answer
excellently well as places of look-out; and Mr.
Smeathman has been, with four more, on the top

WHITE ANTS. 295

‘of one of these hillucks, to watch for a vessel in
sight. The outward shell, or dome, is not only of
use to protect and support the interior buildings from
external violence and the heavy rains, but to collect
and preserve a regular degree of the warmth and
moisture necessary for hatching the eggs and che-
rishing the young. The royal chamber, occupied by
the king and queen, appears to be, in the opinion of
this little people, of the most consequence, being
always situated as near the centre of the interior
building as possible. It is always nearly in the shape
of half an egg, or an obtuse oval, within, and may be
supposed to represent along oven. In the infantstate
of the colony, it is but about aninch in length ; but
in time will be increased to six or eight mches, or
more, in the clear, being always in proportion to the
size of the queen, who, increasing in bulk as in age,
at length requires a chamber of such dimensions.

Queen distended with eggs.

Its floor is perfectly horizontal, and, in large
hillocks, sometimes more than an inch thick of solid
clay. The roof, also, which is one solid and well-
turned oval arch, is generally of about the same
solidity, but in some places it is not a quarter of an
inch thick, on the sides where it joins the floor, and
where the doors or entrances are made level with it,
at nearly equal distances from each other. These
entrances will not admit any animal larger than the
soldiers or labourers ; so that the king and the queen

296 INSECT ARCHITECTURE.

(who is, at full size, a thousand times the weight of
a king) can never possibly go out, but remain close
prisoners.

The royal chamber, if in a large hillock, is sur-
rounded by a countless number of others, of different
sizes, shapes, and dimensions; but all of them arched
in one way or another—sometimes elliptical or oval.

These either open into each other, or communicate by
passages as wide as, and are evidently made for, the
soldiers and attendants, of whom great numbers are
necessary, and always in waiting. These apartments
are joined by the magazines and nurseries. The
former are chambers of clay, and are always well filled
with provisions, which, to the naked eye, seem to
consist of the raspings of wood, and plants which the
termites destroy ; but are found by the microscope to

_be principally the gums or inspissated juices of plants.
These are thrown together in little masses, some of
which are finer than others, and resemble the sugar
about preserved fruits ; others are like tears of gum,
one quite transparent, another like amber, a third
brown, and a fourth quite opaque, as we see often in
parcels of ordinary gums. ‘These magazines are
intermixed with the nurseries, which are buildings
totally different from the rest of the apartments; for
these are composed entirely of wooden materials,
seemingly joined together with gums. Mr. Smeath-
man calls them the nurseries, because they are inya-
riably occupied by the eggs and young ones, which
appear at first in the shape of labourers, but white
as snow. ‘These buildings are exceedingly compact,
and divided into many very small irregular shaped
chambers, not one of which is to be found of half an
inch in width. They are placed all round, and as
near as possible to the royal apartments.

When the nest is in the infant state, the nurseries
are close to the royal chambers; but as, in process

.

ee a

WHITE ANTS. 297

of time, the queen enlarges, it is necessary to enlarge
the chamber for her accommodation; and as she
then lays a greater number of eggs, and requires a
greater number of attendants, so it is necessary to
enlarge and increase the number of the adjacent
apartments ; for which purpose the small nurseries
which are first built are taken to pieces, rebuilt a
little further of a size larger, and the number of
them increased at the same time. Thus they conti-
nually enlarge their apartments, pull down, repair,
or rebuild, according to their wants, with a degree of
sagacity, regularity, and foresight, not even imitated
by any other kind of animals or insects.

All these chambers and the passages leading to
and from them being arched, they help to support
each other ; and while the interior large arches prevent
them from falling into the centre, and keep the area
open, the exterior building supports them on the out-
side. There are, comparatively speaking, few open-
ings into the great area, and they, for the most part,
seem intended only to admit into the nurseries that
genial warmth which the dome collects. The interior
building, or assemblage of nurseries, chambers, &c.,
has a flattish top or roof, without any perforation,
which would keep the apartments below dry, in case
through accident the dome should receive any injury,
and let in water; and it is never exactly flat and
uniform, because the insects are always adding to it
by building more chambers and nurseries; so that
the division or columns between the future arched
apartment resemble the pinnacles on the fronts of
some old buildings, and demand particular notice, as
affording one proof that for the most part the in-
sects project their arches, and do not make them by
excayation. The area has also a flattish floor, which
lies over the royal chamber, but sometimes a good
height above it, having nurseries and magazines

s3

298 INSECT ARCHITECTURE.

between. It is likewise waterproof, and contrived to
let the water off if it should get in, and run over by
some short way into the subterraneous passages,
which run under the lowest apartments in the hill in
various directions, and are of an astonishing size,
being wider than the bore of a great cannon. One
that Mr. Smeathman measured was perfectly cylin-
drical, and thirteen inches in diameter. These sub-
terraneous passages, or galleries, are lined very thick
with the same kind of clay of which the hill is com~-
posed, and ascend the inside of the outward shell in
a spiral manner; and winding round the whole
building up to the top, intersect each other at dif-
ferent heights, opening either immediately in the
dome in various places, and into the interior build-
ing, the new turrets, &c., or communicating with
them by other galleries of different diameters, either
circular or oval.

From every part of these large galleries are va-
rious small covert ways, or galleries leading to dif-
ferent parts of the building. Under ground there
are a great many that lead downward by sloping
descents, three and four feet perpendicular among
the gravel, whence the workers cull the finer parts,
which, being kneaded up in their mouths to the con-
sistence of mortar, becomes that solid clay or stone
of which their hills and all their buildings, except
their nurseries, are composed. Other galleries again
ascend, and lead out horizontally on every side, and
are carried under ground near to the surface a vast
distance: for if all the nests are destroyed within a
hundred yards of a house, the inhabitants of those
which are left unmolested farther off will still carry
on their subterraneous galleries, and, invading it by
sap and mine, do great mischief to the goods and
merchandizes contained it.

It seems there is a degree of necessity for the gal-

’ WHITE AN'TS. 299

leries under the hills being thus large, since they are
the great thoroughfares for all the labourers and sol-
diers going forth or returning, whether fetching clay,
wood, water or provisions; and they are certainly
well calculated for the purposes to which they are
applied, by the spiral slope which is given them;
for if they were perpendicular, the labourers would
not be able to carry on their building with so much
facility, as they ascend a perpendicular with great
difficulty, and the soldiers can scarcely do it at all.
It is on this account that sometimes a road like a
ledge is made on the perpendicular side of any part
of the building within their hill, which is flat on the
upper surface, and half an inch wide, and ascends
gradually like a staircase, or like those winding roads
which are cut on the sides of hills and mountains,
that would otherwise be inaccessible; by which and
similar contrivances they travel with great facility to
every interior part.

This, too, is probably the cause of their building a
kind of bridge of one great arch, which answers the
purpose of a flight of stairs from the floor of the area
to some opening on the side of one of the columns
that support the great arches. This contrivance
must shorten the distance exceedingly to those la-
bourers who have the eggs to carry from the royal
chamber to some of the upper nurseries, which in
some hills would be four or five feet in the straight-
est line, and much more if carried through all the
winding passages leading through the inner cham-
bers and apartments. Mr. Smeathman found one
of these bridges, half an inch broad, a quarter of an
inch thick, and ten inches long, making the side of
an elliptic arch of proportionable size ; so that it is
wonderful it did not fall over, or break by its own
weight befofe they got it joined to the side of the
column above.

=

——)' —2s -. _ <2... a ee Pw

300 INSECT ARCHITECTURE,

It was strengthened by a small arch at the bottom,
and had a hollow or groove all the length of the
upper surface, either made purposely for the inha-

ion of the Hill-nest of the

Hill-nest of the Termites bellicost, entire.

WS

yy airs |

way and nest, on the branch of a tree, oj the Termites arborum. b, Sect:

Termites bellicosi, to show the interior.

a
a, A covered

WHITE ANTS. 301

hitants to travel over with more safety, or else, which
is not improbable, worn by frequent treading

Turret-Burtp1ne Waiter Ants.

Apparently more than one species, smaller than
the preceding, such as the Termes mordax and T.
atrox of Smeathman, construct nests of a very dif-
ferent form, the figures of which resemble a pillar,
with a large mushroom for a capital. These turrets
are composed of well-tempered black earth, and
stand nearly three feet high. The conical mush-
room-shaped roof is composed of the same material,
and the brims hang over the column, being three or
four inches wider than its perpendicular sides. Most
of them, says Smeathman, resemble in shape the
body of a round windmill, but some of the roofs
have little elevation in the middle. When one of
these turrets is completed, the insects do not after-
wards enlarge or alter it; but if it be found too small

Turret Nests of White Ants. One nest is represented cut
Through, wit, the upper part lying on the ground,

302 INSECT ARCHITECTURE,

for them, they lay the foundation of another at a few
inches’ distance. They sometimes, but not often,
begin the second before the first is finished, and a
third before they have completed the second. Five
or six of these singular turrets in a group may be
seen in the thick woods at the foot of a tree. They
-are so very strongly built, that, in case of violence,
they will sooner tear up’ the gravel and solid heart of
their foundation than break in the middle. When
any of them happen to be thus thrown down, the
insects do not abandon them: but, using their over-
turned column as a basis, they ryn up another per-
pendicularly from it, to the usual height, fastening
the under part at the same time to the ground, to
render it the more secure.

The interior of a turret is pretty equally divided
into innumerable cells, irregular in shape, but usually
more or less angular, generally quadrangular or
pentagonal, though the angles are not well defined.
Each shell has at least two entrances; but there are
no galleries, arches, nor wooden nurseries, as in the
nests of the warrior (7. bellicosus). The two species
which build turret-nests are very different in size,
and the dimensions of the nests differ in proportion.

Tar Waite Ants or TREES.

Latreille’s species of white ant (Termes lucifugus,
Rossr), formerly mentioned as found in the south of
Europe, appear to have more the habits of the jet-
ant, described page 279, than their congeners of the
tropics. ° They live in the interior of the trunks of
-trees, the wood of which they eat, and form their
habitations of the galleries which they thus excavate.
M. Latreille says they appear to be furnished with an
acid for the purpose of softening the wood, the odour
of which is exceedingly pungent. They prefer the

WHITE ANTS. 303

part of the wood nearest to the bark, which they are
careful not to injure, as it affords them protection.
All the walls of their galleries are moistened with
small globules of a gelatinous substance, similar to
gum-arabic. They are chiefly to be found in the
trunks of oak and pine-trees, and are very numerous.*

Another of the species (Termes arborum), described
by Smeathman, builds a nest on the exterior of trees,
altogether different from any of the preceding. These
are of a spherical or oval shape, occupying the arm
or branch of a tree sometimes from seventy to eighty
feet from the ground, and as large, in a few instances,
as a sugar-cask, ‘The composition used for a build-
ing material is apparently similar to that used by the
warriors for constructing their nurseries, being the
gnawings of wood in very small particles, kneaded
into a paste with some species of cement or glue,
procured, as Smeathman supposes, partly from gum-
miferous trees, and partly from themselves ; but it is
more probable, we think, that it is wholly secreted,
like the wax of bees, by the insects themselves.
With this cement, whatever may be its composition,
they construct their cells, in which there is nothing
very wonderful except their great numbers. They
are very firmly built, and so strongly attached to the
trees, that they will resist the most violent tornado.
It is impossible, indeed, to detach them, except by
cutting them in pieces, or sawing off the branch,
which is frequently done to procure the insects for
young turkeys. (See engraving, p. 300, for a figure
of this nest.)

This species very often, instead of selecting the
bough of a tree, builds in the roof or wall of a house,
and unless observed in time and expelled, occasions
considerable damage. It is easier, in fact, to shut

* Latreille, Hist. Nat. Générale, tom. xiii. p. 64.

304 INSECT ARCHITECTURE.

one’s door against a fox or a thief, than to exclude
such insidious enemies, whose aversion to light ren-
ders it difficult to trace them even when they are
numerous.

If we reflect on the prodigious numbers of those
insects, and their power and rapidity of destroying,
we cannot but admire the wisdom of Providence in
creating so indefatigable and useful an agent in
countries where the decay of vegetable substances is
rapid in proportion to the heat of the climate. We
have already remarked that they always prefer decay-
ing or dead timber; and it is indeed a very general
law among insects which feed on wood to prefer what
is unsound: the same principle holds with respect to
fungi, lichens, and other parasitical plants.

All the species of Termites are not social; but the
solitary ones do not, like their congeners, distinguish
themselves in architecture. In other respects, their
habits are more similar; for they destroy almost every
substance, animal and vegetable. The most common
of the solitary species must be familiar to all our
readers by the name of wood-louse (Termes pulsa-
torium, Linn.; Atropos lignarius, LEaca)—one of
the insects which produces the ticking, supersti-
tiously termed the death-watch. It is not so large as
the common louse, but whiter and more slender,
having a red mouth and yellow eyes. It lives in old
books, the paper on walls, collections of insects and
dried plants, and is extremely agile in its movements,
darting, by jerks, into dark corners for the purpose
of concealment. It does not like to run straight for-
ward, without resting every half-second, as if to listen
or look about for its pursuer, and at such resting-
times it is easily taken. The ticking noise is made
by the insect beating against the wood with its head,
and it is supposed by some to be peculiar to the
female, and to be comnected with the laying of her

WHITE ANTS. 305

eggs. M. Latreille, however, thinks that the wood-
louse is only the grub of the Psocus abdominalis, in
which case it could not lay eggs; but this opinion is
somewhat questionable. Another death-watch is a
small beetle (Anobium tesselatum).

( 306 )

Cuarrer XVII.
Structures of Silk spun by Caterpillars, including the Silk-Worm,

*€ Millions of spinning worms,
That in their green shops weave the smooth-hair'd silk.”
Mixton’s Comus.

Aut the caterpillars of butterflies, moths, and, in
general, of insects with four wings, are capable of
spinning silk, of various degrees of fineness and
strength, and differing in colour, but usually white,
yellow, brown, black, or grey. This is not only of
advantage in constructing nests for themselves, and
particularly for their pupa, as we have so frequently
exemplified in the preceding pages, but it enables
them, the instant they are excluded from the egg, to
protect themselves from innumerable accidents, as
well as from enemies. If a caterpillar, for instance,
be exposed to a gust of wind, and blown off from its
native tree, it lets itself gently down, and breaks its
fall, by immediately spinning a cable of silk, along
which, also, it can re-ascend to its former station
when the danger is over. In the same way it fre-
quently disappoints a bird that has marked it out for
prey, by dropping hurriedly down from a branch,
suspended to its never-failing delicate cord. The
leaf-rollers, formerly described, have the advantage
of other caterpillars in such cases, by being able to
move as quickly backwards as forwards; so that
when a bird puts in its bill at one end of the roll, the
insects makes a ready exit at the other, and drops
along its thread as low as it judges convenient. We

SPINNING CATERPILLARS. 307

have seen caterpillars drop in this way from one to
six feet or more; and by means of their cable, which
they are careful not to break, they climb back with
great expedition to their former place.*

The structure of their legs is well adapted for
climbing up their singular rope—the six fore-legs
being furnished with a curved claw; while the pro-
legs (as they have been termed) are no less fitted
for holding them firm to the branch when they have
re-gained it, being constructed on the principle of
forming a vacuum, like the leather-sucker with
which, boys lift and drag stones. The foot of the
common fly has a similar sucker, by which it is
enabled to walk on glass, and otherwise support it-
self against gravity. ‘The different forms of the leg
and pro-leg of a spinning caterpillar are represented
in the figure.

Leg and Pro-leg of w Caterpillar, greatly magnified.

In order to understand the nature of the appa-
ratus by which a caterpillar spins its silk, it is to be
recollected that its whole interior structure differs
from that of warm-blooded animals. It has, pro-
perly speaking, no heart, though a long tubular
dorsal vessel, which runs along the back, and pul-
sates from twenty to one hundred times per minute,
has been called so by Malpighi and others: but

* See Insect Transformations, p. 186.

308 INSECT ARCHITECTURE.

neither Lyonnet nor Cuvier could detect any vessel
issuing from it; and consequently the fluid which is
analogous to blood has no circulation. It differs also
from the higher orders of animals in having no
brain, the nerves running along the body being only
united by little knobs, called ganglions.* Another
circumstance is, that it has no lungs, and does not
breathe by the mouth, but by air-holes, or spiracles,
eighteen in number, situated along the sides, in the
middle of the rings, as may be seen in the following
figure from Lyonnet :

Caterpillar of the Goat-Moth (Cossus ligniperda).

These spiracles communicate on each side with
tubes that have been called the wind-pipes (trachee).+
The spinning apparatus is placed near the mouth,
and is connected with the’silk-bags, which are long,
slender, floating vessels containing a liquid gum.
The bags are closed at their lower extremity, become
wider towards the middle, and more slender towards
the head, where they unite to form the spinning-tube,
or spinneret. The bags being in most cases longer
than the body of the caterpillar, necessarily lie in a
convoluted state, like the intestines of quadrupeds.
The capacity, or rather the length of the silk-bags,
is in proportion to the quantity of silk required for
spinning ; the Cossus ligniperda, for example, from
living in the wood of trees, spins little, having a bag
only one-fourth the Jength of that of the silk-worm,
though the caterpillar is at least twice the dimensions
of the latter. The following figure, taken from the

* See Insect Transformations, concluding chapter.
+ Ibid. p. 155,

SPINNING CATERPILLARS.

silk tube, through which the viscid matter, of

?

Interior structure of the Cossus.—A, silk bags; B.
which the silk threads are formed, is forced by a peristaltic motion; C, stomach; D, D, intestines.

309

310 ‘INSECLY ARCHITECTURE.

admirable treatise of Lyonnet on the anatomy of the
Cossus, will render these several organs more easily
understood than any description.

The spinneret itself was supposed by Réaumur to
have two outlets for the silk; but Lyonnet, upon
minute dissection, found that the two tubes united
into one before their termination; and he also almost
assured himself that it was composed of alternate
slips of horny and membranaceous substance,—the
one for pressing the thread into asmall diameter, and
the other for enlarging it at the insect’s pleasure. It
is cut at the end somewhat like a writing-pen, though
with less of a slope, and is admirably fitted for being
applied to objects to which it may be required to
attach silk. The following are magnified figures of
the spinneret of the Cossus from Lyonnet.

Side view of the Silh-tube, Section of the Silh-tube, magnified
22,000 times.

“You may sometimes have seen,” says the Abbé
de la Pluche, “‘in the work-rooms of goldsmiths or
gold-wire drawers, certain iron plates, pierced with
holes of different calibres, through which they draw
gold and silver-wire, in order to render it finer. The
silk-worm has under her mouth such a kind of instru-
ment, perforated with a pair of holes [united into one
on the outside*], through which she draws two drops
of the gum that fills her two bags. These instruments

* Lyonnet.

SPINNING CATERPILLARS. 311

Labium, or lower lip of Cossus.—a, silk-tube.

are like a pair of distaffs for spinning the gum into a
silken thread. She fixes the first drop of gum that
issues where she pleases, and then draws back her
head, or lets herself fall, while the gum, continuing
to flow, is drawn out and lengthened into a double
stream. Upon being exposed to the air, it imme-
diately loses its fluidity, becomes dry, and acquires
consistence aud strength. She is never deceived in
adjusting the dimensions of the [united] apertures,
or in calculating the proper thickness of the thread,
but invariably makes the strength of it proportion-
able to the weight of her body.

“Tt would bea very curious thing to know how
the gum which composes the silk is separated and
drawn off from the other juices that nourish the
animal, It must be accomplished like the secretions
formed by glands in the human body. I am there-’
fore persuaded that the gum-bags of the silk-worm
are furnished with a set of minute glands, which,
being impregnated with gum, afford a free passage
to all the juices of the mulberry-leaf corresponding

312 INSECT ARCHITECTURE.

with this glutinous matter, while they exclude every
fluid of a different quality.”* When confined in an
open glass vessel, the goat-moth caterpillar will effect
its escape, by constructing a curious silken ladder,
as represented by Roesel.

Caterpillars, as they increase in size, cast their skins
as lobsters do their shells, and emerge into renewed
activity under an enlarged covering. Previous to this
change, when the skin begins to gird and pinch them,
they may be observed to become languid, and indiffe-
rent to their food, and at length they cease to eat, and
await the sloughing of their skin.f It is now that
the faculty of spinning silk seems to be of great ad-
vantage to them; for being rendered inactive and
helpless by the tightening of the old skin around their
expanding body, they might be swept away by the
first puff of wind, and made prey of by ground-beetles
or other carnivorous prowlers. To guard against such

_ accidents, as soon as they feel that they can swallow
no more food from being half choked by the old skin,
they take care to secure themselves from danger by
moorings of silk spun upon the leaf or the branch
where they may be reposing. The caterpillar of the
white satin-moth (Zeucoma salicis, SrerHEens) in this
way draws together with silk one or two leaves, similar
to the leaf-rollers (Zortricide), though it always
feeds openly without any covering. ‘The caterpillar
of the puss-moth again, which, in its third skin,
is large and heavy, spins a thick web on the upper
surface of a leaf, to which it adheres till the change
is effected,

The most important operation, however, of silk-
spinning is performed before the caterpillar is trans-
formed into a chrysalis, and is most remarkable in
the caterpillars of moths and other four-winged flies,

* Spectacle de la Nature, vol. i,
+ See Insect Transformations, chap, vii.

SPINNING CATERPILLARS. 313

with the exception of those of butterflies ; for though
these exhibit, perhaps, greater ingenuity, they seldom
spin more than a few threads to secure the chrysalis
from falling, whereas the others spin for it a com-
plete envelope or shroud. We have already seen, in
the preceding pages, several striking instances of this
operation, when, probably for the purpose of husband-
ing a scanty supply of silk, extraneous substances are
worked into the texture. In the case of other cater-
pillars, silk is the only material employed. Of this
the cocoon of the silk-worm is the most prominent
example, in consequence of its importance in our
manufactures and commerce, and on that account
will demand from us somewhat minute details, though
it would require volumes to incorporate all the in-
formation which has been published on the subject.

Srrx-Worm.

The silk-worm, like most other caterpillars,
changes its skin four times during its growth. The
intervals at which the four moultings follow each
other depend much on climate or temperature, as
well as on the quality and quantity of food. It is
thence found, that if they are exposed toa high
temperature, say from 81° to 100° Fahrenheit, the
moultings will be hastened; and only five days will
be consumed in moulting the third or fourth time,
whilst those worms that have not been hastened take
seven or eight days.*

The period of the moultings is also influenced by
the t(mperature in which the eggs have been kept
during the winter. When the heat of the apartment
has been regulated, the first moulting takes place on
the fourth or fifth day after hatching, the second
begins on the eighth day, the third takes up the
thirteenth and fourteenth days, and the last occurs

* Cours d’Agriculture, par M. Rozier. Paris, 1801.
T

314 INSECT ARCHITECTURE.

on the twenty-second and twenty-third days. The
fifth age, in such cases, lasts ten days, at the end of
which, or thirty-two days after hatching, the cater-
pillars attain their full growth, and ought to be three
inches in length; but if they have not been properly
fed, they will not be so long.

With the age of the caterpillar, its appetite in-
creases, and is at its maximum after the fourth moult-
ing, when it also attains its greatest size, The silk
gum is then elaborated in the reservoirs, while the
caterpillar ceases to eat, and soon diminishes again
in size and weight. This usually requires a period
of nine or ten days, commencing from the fourth
moulting, after which it begins to spin its shroud of
silk. In this operation it proceeds with the greatest
caution, looking carefully for a spot in which it may
be most secure from interruption. —

“We usually,” says the Abbé de la Pluche, “ give
it some little stalks of brocm, heath, or a piece of
paper rolled up, into which it retires, and begins to
move its head to different places, in order to fasten
its thread on every side. All this work, though it
looks to a bystander like confusion, is not without
design. The caterpillar neither arranges its threads
nor disposes one over another, but contents itself
with distending a sort of cotton or floss to keep off
the rain; for Nature having ordained silk-worms to
work under trees, they never change their method,
even when they are reared in our houses.

““When my curiosity led me to know how they
spun and placed their beautiful silk, I took one of
them, and frequently removed the floss with which it
first attempted to make itself a covering ; and as by
this means I weakened it exceedingly, when it at last
became tired of beginning anew, it fastened its threads
on the first thing it encountered, and began to spin
very regularly in my presence, bending its head up

SILK-WORM. 315

and down, and crossing to every side. It soon con-
fined its movements to a very contracted space, and,
by degrees, entirely surrounded itself with silk; and
the remainder of its operations became invisible,
though these may be understood from examining the
work after it is finished. In order to complete the
structure, it must draw out of the gum-bag a more
delicate silk, and then with a stronger gum bind all
the inner threads over one another.

“Here, then, are three coverings entirely differ-
ent, which afford a succession of shelter. The outer
loose silk, or floss, is for keeping off the rain; the
fine silk in the middle prevents the wind from caus-
ing injury ; and the glued silk, which composes the
tapestry of the chamber where the insect lodges, re-
pels both air and water, and prevents the intrusion
of cold.

“After building her cocoon, she divests herself 0
her fourth skin, and is transformed into a chrysalis,
and subsequently into a moth (Bombyx mort), when,
without saw or centre-bit, she makes her way through
the shell, the silk, and the floss; for the Being who
teaches her how to build herself a place of rest, where
the delicate limbs of the moth may be formed with
out interruption, instructs her likewise how to open
a passage for escape.

“The cocoon is like a pigeon’s egg, and more
pointed at one end than the other; and it is remark-
able that the caterpillar does not interweave its silk
to vards the pointed end, nor apply its glue there as
it does in every other part,* by bending itself all
around with great pliantness and agility: what is
more, she never fails, when her labour is finished, to
fix her head opposite to the pointed extremity. The
reason of her taking this position is that she has

* This is denied by recent observers
T2

316 INSECT! ARCHI1ECI URE.

purposely left this part less strongly cemented, and
less exactly closed. She is instinctively conscious
that this is to be the passage for the perfect insect
which she carries in her bowels, and has therefore
the additional precaution never to place this pointed
extremity against any substance that might obstruct
the moth at the period of its egress.

‘When the caterpillar has exhausted herself to
furnish the labour and materials of the three cover-
ings, she loses the form of a worm, her spoils drop
all around the chrysalis; first throwing off her
skin, with the head and jaws attached to it, and the
new skin hardening into a sort of leathery consist-
ence. Its nourishment is already in its stomach, and
consists of a yellowish mucus, but gradually the ru-
diments of the moth unfold themselves,—the wings,
the antenne, and the legs becoming solid. In about
a fortnight or three weeks, a slight swelling in the
chrysalis may be remarked, which at length produces
a rupture in the membrane that covers it, and by
repeated efforts the moth bursts through the leathery
envelope into the chamber of the cocoon.”

“The moth then extends her antenne, toget \r
with her head and feet, towards the point of the cone,
which, not being thickly closed up in that part, gra-
dually yields to her efforts; she enlarges the open-
ing, and at last comes forth, leaving at the bottom
of the cone the ruins of its former state—namely, the
head and entire skin of the caterpillar, which bear
some resemblance to a heap of foul linen.’’*

Réaumur was of opinion that the moth makes use
of its eyes asa file, in order to effect its passage
through the silk; while Malpighi, Peck, and others,
believe that it is assisted by an acid which it dis-
charges in order to dissolve the gum that holds the

* Spectacle de la Nature, vol. i.

SILK-WORM. 317

fibres of the silk together (see p. 195). Mr. Swayne
denies that the threads are broken at all, either by
filing or solution ; for he succeeded in unwinding a
whole cocoon from which the moth had escaped. ‘The
soiling of the cocoon by a fluid, however, we may
remark, is no proof of the acid; for all moths and
butterflies discharge a fluid when they assume wings,
whether they be inclosed in a cocoon or not; but it
gives no little plausibility to the opinion, that “the
end of the cocoon is observed to be wetted for an
hour, and sometimes several hours, before the moth
makes its way out.”* Other insects employ different
contrivances for escape, as we haye already seen,
and shall still further exemplify.

It is the middle portion of the cocoon, after re-
moving the floss or loose silk on the exterior, which
is used in our manufactures; and the first prepara-
tion is to throw the cocoons into warm water, and
to stir them about with twigs, to dissolve any slight
gummy adhesions which may have occurred when
the caterpillar was spinning. The threads of several
cones, according to the strength of the silk wanted,
are then taken and wound off upona reel. The
refuse, consisting of what we may call the tops and
bottoms of the cones, are not wound, but carded,
like wool or cotton, in order to form coarser fabrics.
We learn from the fact of the cocoons being generally
unwound without breaking the thread, that the
insect spins the whole without interruption. It is
popularly supposed, however, that if it be disturbed
during the operation by any sort of noise, it will
take alarm, and break its thread; but Latreille says
this is a vulgar error.}

* Count Dandolo’s Art of Rearing Silk-Worms, Eng. Trans}.
p- 215. :
+ On a tort de croire que le bruit nuise 4 ces insectes, Hist,
Nat. Générale, vol. xiii., p. 170.
13

318 INSECT ARCHITECTURE.

The length of the unbroken thread in a cocoon
varies from six hundred to a thousand feet; and as
it is all spun double by the insect, it will amount to
nearly two thousand feet of silk, the whole of which
does not weigh above three grains and a half: five
pounds of silk from ten theusand cocoons is consi- -
derably above the usual average. When we consider,
therefore, the enormous quantity of silk which is
used at present, the number of worms employed in
producing it will almost exceed our comprehension.
The manufacture of the silk, indeed, gives employ-
ment, and furnishes subsistence, to several millions
of human beings; and we may venture to say that
there is scarcely an individual in the civilized world
who has not some article made of silk in his pos-
session.

In ancient times, the manufacture of silk was
confined to the East Indies and China, where the
insects that produce it are indigenous, It was
thence brought to Kurope in small quantities, and in
early times sold at so extravagant a price that it was
deemed too expensive even for royalty. The Emperor
Aurelian assigned the expense as a reason for re-
fusing his empress a robe of silk; and our own
James I., before his accession to the crown of Eng-
land, had to borrow of the Earl of Mar a pair of
silk stockings to appear in before the English am-
bassador, a circumstance which probably led him to
promote the cultivation of silk in England.* The
Roman authors were altogether ignorant of its origin,
—some supposing it to be grown on trees as hair
grows on animals,—others that it was produced by a
shell-fish similar to the mussel, which is known to
throw out threads for the purpose of attaching itself
to rocks,—others that it was the entrails of a sort of

* Shaw's Gen, Zoology, vol, vi.

SILK-WORM. 319

spider, which was fed for four years with paste, and
then with the leaves of the green willow, till it burst
with fat,—and others that it was the produce of a
worm which built nests of clay and collected wax.
The insect was at length spread into Persia; and
eggs were afterwards, at the instance of the Emperor
Justinian, concealed in hollow canes by two monks,
and conveyed to the isle of Cos. This emperor, in
the sixth century, caused them to be introduced into
Constantinople, and made an object of public utility.
They were thence successively cultivated in Greece,
in Arabia, in Spain, in Italy, in France, and in all
places where any hope could be indulged of their
succeeding. In America the culture the silk-worm
was introduced into Virginia in the time of James I.,
who himself composed a book of instructions on the
subject, and caused mulberry-trees and silk-worms’
eges to be sent to the colony. In Georgia, also,
lands were granted on condition of planting one hun-
dred white mulberry-trees on every ten acres of
cleared land.*

The growth of the silk-worm has also been tried,
but with no great success, in this country. Evelyn
computed that one mulberry-tree would feed as many
silk-worms annually as would produce seven pounds
of silk. ‘* According to that estimate,” says Barham,t
‘the two thousand trees already planted in Chelsea
Park (which take up one-third of it) will make
14,000]bs. weight of silk; to be commonly worth but
twenty shillings a pound, those trees must make
£14,000 per annum, During the last century, some
French refugees in the south of Ireland made con-
siderable plantations of the mulberry, and had begu

* North American Review, Oct. 1828, p. 449.
+ Essay on the Silk-worm, p. 95. London, 1719.

320 INSECT ARCHITECTURE.

the cultivation of silk with every appearance of suc-
cess; but since their removal the trees have been
cut down.” In the vicinity of London, also, a con-
siderable plantation of mulberry-trees was pur-
chased by the British, Irish, and Colonial Silk
Company in 1825; but we have not learned whether
this Company have any active measures now in
operation,

The manufacture of silk was introduced into this
country in 1718, at Derby, by Mr. John Lombe, who
travelled into Italy to obtain the requisite informa-
tion; but so jealous were the Italians of this, that
according to some statements which have obtained
belief, he fell a victim to their revenge, having
been poisoned at the early age of twenty-nine. +

There are not only several varieties of the common
silk-worm (Bombyx mort), but other species of ca-
terpillars, which spin silk capable of being manufac-
tured, though not of so good qualities.as the common
silk. None of our European insects, however, seem
to be well fitted for the purpose, though it has been
propose by Fabricius and others to try the crimson
under-wing (Catocala sponsa, Scurank), &. M.
Latreille quotes from the ‘ Recreations of Natural
History,’ by Wilhelm, the statement that the cocoons
of the emperor-moth (Saturnia pavonia) had been
successfully tried in Germany, by M. Wentzel He-
geer de Berchtoldsdorf, under an imperial patent.

Emrrror-Morn.
The emperor-moth, indeed, is no less worthy of
our attention with respect to the ingenuity of its ar-
chitecture than the beauty of its colours, and has

* Preface to Dandolo on the Silk-Worm, Eng. transl. p. xiii.
+ Glover's Directory of the County of Derby, introd. p. xvi.

EMPEROR-MOTH. 321

consequently attracted the attention of every Ento-
mologist. The caterpillar * feeds on fruit-trees and
on the willow, and spins a cocoon, in form of a Flo-
rence flask, of strong silk, so thickly woven, that it
appears almost like damask or leather. It differs
from most other cocoons in not being closed at the
upper or smaller end, which terminates in a narrow
circular aperture, formed by the convergence of little
bundles of silk, gummed together, and almost as
elastic as whalebone. In consequence of all these
terminating in needle-shaped points, the entrance of
depredators is guarded against, upon the principle
which prevents the escape of a mouse from a wire
trap. ‘The insect, however, not contented with this
protection, constructs another in form of a canopy
or dome, within the external aperture, so as effec-
tually to shield the chrysalis from danger. We have
formerly remarked (page 192) that the caterpillar of
the Algeria asiliformis of Stephens, in a similar way
did not appear to be contented with a covering of
thin wood, without an additional bonnet of brown

Cocoons of the Emperor-moth, cul open to shew their structure,

* Figured in Insect Transformations, p. 186.

322 INSECT ARCHITECTURE.

wax. The cocoon of the emperor-moth, though
thus in some measure impenetrable from without, is
readily opened from within; and when the moth
issues from its pupa case, it easily makes its way
out without either the acid or eye-files ascribed to the
silk-worm. The elastic silk gives way upon being
pushed from within, and when the insect is fairly.
out, it shuts again of its own accord, like adoor with
spring hinges,—a circumstance which at first puzzled
Roesel not a little when he saw a fine large moth
in his box, and the cocoon apparently in the same
state as when he had put it there. Another na-
turalist conjectures that the converging threads are
intended to compress the body of the moth as it
emerges, in order to force the fluids into the nervures
of the wings; for when he took the chrysalis pre-
viously out of the cocoon, the wings of the moth
never expanded properly.* Had he been much
conversant with breeding insects, he would rather,
we think, have imputed this to some injury which
the chrysalis had received. We have witnessed the
shrivelling of the wings which he alludes to, in many
instances, and not unfrequently in butterflies which
spin no cocoon, ‘The shrivelling, indeed, frequently
arises from the want of a sufficient supply of food to
the caterpillar in its last stage, occasioning a defi-
ciency in the fluids.

The elasticity of the cocoon is not peculiar to the
emperor-moth. A much smaller insect, the green
cream-border-moth (Tortrix chlorana) before men-
tioned (page 170), for its ingenuity in bundling up
the expanding leaves of the willow, also spins an
elastic shroud for its chrysalis, of the singular shape
of a boat with the keel uppermost. Like the cater-
pillar of Pyralis strigulalis (page 198), whose build-

* Meinecken, quoted by Kirby and Spence, iii, 280.

MOTHS. 323

ing, though of different materials, is exactly of the
same form,—it first spins two approximating walls
of whitish silk, of the form required, and when
these are completed, it draws them forcibly together
with elastic threads, so placed as to retain them
closely shut. The passage of the moth out of this
cocoon might have struck Roesel as still more mar-
vellous than that of his emperor, in which there was
at least a small opening; while in the boat cocoon
there isnone. We have now before us two of these,
which we watched the caterpillars through. the pro-
cess of building, in the summer of 1828, and from
one only a moth issued,—the other, as often happens,
having died in the chrysalis. But what is most re-
markable, it is impossible by the naked eye to tell
which of these two has been opened by the moth, so
neatly has the joining been finished.*

Some species of moths spin a very slight silken
tissue for their cocoons, being apparently intended
more to retain them from falling, than to afford pro-
tection from other accidents. The gipsey-moth
(Hypogymna dispar), rare in most parts of Britain,
is one of these. It selects for its retreat a crack in
the bark of the tree upon which it feeds, and over
this spins only a few straggling threads. We found
last summer (1829), in the hole of an elm-tree in the
Pare at Brussels, a group of half a dozen of these,
that did not seem to have spun any covering at all,
but trusted toa curtain of moss (Hypna) which
margined the entrance. In aspecies nearly allied to
this, the yellow-tussock (Dasychira pudibunda, Stx-
PHENS), the cocoon, one of which we have now before
us, is of a pretty close texture, and interwoven with
the long hairs of the caterpillar itself (see figure 6,
page 20), which it plucks out piece-meal during the

*J.R. tJ. R.

~ 324 INSECT ARCHITECTURE.

process of building,—as is also done by the vapourer
(Orgyia antiqua, uBNER), and many others.*

These are additional instances of the remarks we
formerly made, that caterpillars which spin a slight
web are transformed into perfect insects in a much
shorter period than those which spin more substantial
ones. ‘Thus the cream-spot tiger (Arctia villica,
Srepuens) lies in chrysalis only three weeks, and
therefore does not require a strong web. Itis figured
below, along with another, which is still slighter,
though more ingeniously woven, being regularly
meshed like net-work.

Net-work cocoon.

A very prettily-netted cocoon is constructed by the
grub of a very small grey weevil (Hypera Rumicis),
which is not uncommon in July, on the seed spikes
of docks (Rumices). ‘This cocoon is globular, and
not larger than a garden pea, though it appears to

* See this figured in Insect Transformations, p.

SPINNING CATERPILLARS. 325

be very large in proportion to the pupa of the insect,
reminding us not a little of the carved ivory balls
from China. The meshes of the net-work are also
large, but the materials are strong and of a waxy
consistence. Upon remarking that no netting was
ever spun over the part of the plant to which the
cocoon was attached, we endeavoured to make them
spin cocoons perfectly globular, by detaching them
when nearly finished; but though we tried four or
five in this way, we could not make them add a sin-
gle mesh after removal, all of them making their
escape through the opening, and refusing to re-enter
in order to complete their structure.*

The silk, if it may be so termed, spun by many
species of larve, is of astill stronger texture than the
waxy silk of the little weevil just mentioned. We
recently met with a remarkable instance of this at
Lee, in the cocoons of one of the larger ichneumons,
(Ophion Vinule ? Sternens), enclosed in that of a
puss-moth (Cerura Vinula)—itself remarkable for
being composed of sand as well as wood, the fibres
of which had been scooped out of the underground
cross-bar of an old paling, to which it was attached.
But the most singular portion of this was the
junction of the outer wall with the edges of the
hollow thus scooped out, which was formed of fibres
of wood placed across the fibres of the bar nearly at
right angles, and strongly cemented together, as if
to form a secure foundation for the building.

In this nest were formed, surreptitiously introduced
into the original building, five empty cells of a black
colour, about an inch long, and a sixth of an inch in
diameter; nearly cylindrical in form, but somewhat
flattened ; vertical and parallel to one another, though
slightly curved on the inner side. The cells are com-
posed of strong and somewhat coarse fibres, more

*J.R.
u

i tte ee te ol

326 INSECT ARCHITECTURE.

like the carbonized rootlets of a tree than silk, and
resembling in texture a piece of coarse milled cloth
or felt, such as is used for the bases of platted hats,
It is worthy of remark, that all these cells opened

Nest of Puss-Moth, inclosing five cocoons of an Ichneumon,
Natural size.

towards one end, as if the caterpillars which con-
structed them had been aware that the wall of the
puss-moth, in which the flies would have to make a
breach, was very hard, and would require their
united efforts to effect an escape. The importance
of such a precaution will appear more strikingly,
when we compare it with the instance formerly men-
tioned (page 195), in which only one ichneumon
had been able to force its way out.”

It appears indispensable to some grubs to be con-
fined within a certain space, in order to construct
their cocoons. We saw this well exemplified in the
instance of a grub of one of the mason-bees (Osmia
bicornis), which we took from its nest, and put into
a box, with the pollen paste which the mother-bee
had provided for its subsistence. (See pages 40, 41.)

* JR.

SPINNING CATERPILLARS. 827

When it had completed its growth, it began to spin,
but in a very awkward manner—attaching threads,
as if at random, to the bits of pollen which re-
mained undevoured, and afterwards tumbling about
to another part of the box, as if dissatisfied with
what it had done. It sometimes persevered to spin
in one place till it had formed a little vaulted wall ;
but it abandoned at the least three or four of these
in order to begin others, till at length, as if com-
pelled by the extreme urgency of the stimulus of its
approaching change, it completed a shell of shining
brown. silk, woven into a close texture. Had the
grub remained within the narrow clay cell built for
it by the mother-bee, it would, in all probability, not
have thus exhausted itself in vain efforts at building,
which were likely to prevent it from ever arriving at
the perfect state—a cireumstance which often happens
in the artificial breeding of insects. This bee, how-
ever, made its appearance the following spring.

Beside silk, the cocoons of many insects are
composed of other animal secretions, intended to
strengthen or otherwise perfect their texture. We
have already seen that some caterpillars pluck off
their own hair to interweave amongst their silk :
there are others which produce a peculiar substance
for the same purpose. The lackey-caterpillar (Clisio-
campa neustria, Curtis) in this manner lines its
cocoon with pellets of a downy substance, resem-
bling little tufts of the flowers of sulphur. The
small egger, again (Eriogaster lanestris, GERMAR),
can scarcely be said to employ silk at all,—the
cocoon being of a uniform texture, looking, at
first sight, like dingy Paris-plaster, or the shell
of a pheasant’s egg, but upon being broken, and
inspected narrowly, a few threads of silk may be
seen interspersed through the whole. In size, it is

«JR.
u 2

328 INSECT ARCHITECTURE.

not larger than the egg of the gold-crested wren. It
has been considered by Brahm a puzzling cireum-
stance, that this cocoon is usually perforated with
one or two little holes, as if made by a pin from with-
out; and Kirby and Spence tell us that their use
has not been ascertained.* May they not be left as
air-holes forthe included chrysalis, as the close texture
of the cocoon might, without this provision, prove
fatal to the animal? Yet, on comparing one of these
with a similar cocoon of the large egger-moth (La-
siocampa Quercus), we find no air-holes in the latter,
as we might have been led to expect from the close-
ness of its texture. We found a cocoon of a saw-fly
(Trichiosoma), about the same size as that of the
egger, attached to a hawthorn twig, in a hedge at
New Cross, Deptford, but of a leathery texture, and,
externally, exactly the colour of the bark of the
tree. During the summer of 1830 we found a con-
siderable number of the same cocoons. These were
all without air-holes. The egger, we may remark,
unlike the dock-weevil, or the bee-grub just men-
tioned, can work her cocoon without any point of
attachment. We had acolony of these caterpillars in
the summer of 1825, brought from Epping Forest,
and saw several of them work their cocoons, and we
could not but admire the dexterity with which they
avoided filling up the little pin-holes. The supply of
their building material was evidently measured out to
them in the exact quantity required ; for when we
broke down a portion of their wall, by way of expe-
riment, they did not make it above half the thickness
of the previous portion, though they plainly preferred
haying a thin wall to leaving the breach unclosed.+
Several species of caterpillars that spin only silk
are social, like some of those we formerly mentioned,

* Brahm’s Ins. Nat. 289; be Kirby and Spence’s Intr, iii. 223.
JR.

SPINNING CATERPILLARS. 329

which unite to form a common tent of leaves (see
pages 172, 3). The most common instance of this is
in the caterpillars which feed on the nettle—the small
tortoise-shell (Vanessa urtice), and the peacock’s eye
(V. I6). Colonies of these may be seen, after Mid-
summer, on almost every clump of nettles, inhabiting
a thin web of an irregular oval shape, from which
they issue out to feed on the leaves, always returning
when their appetite is satisfied, to assist their com-
panions in extending their premises. Other ex-
amples, still more conspicuous from being seen on
fruit-trees and in hedges, occur in the caterpillars of
the small ermine-moth (¥ponomeuta padella), and
of the lackey (Clisiocampa neustria), which in some
years are but too abundant, though in others they
are seldom met with. In the summer of 1826,
every hedge and fruit-tree around London swarmed
with colonies of the ermine, though it has not since
been plentiful ;* and in the same way, during the
summer of 1829, the lackeys were to’ be seen every-
where. We mention this irregularity of appearance
that our readers may not disappoint themselves by
looking for what is not always to be found. It is
probable, that, in 1830, the lackeys will be few, for,
notwithstanding the myriads of caterpillars last sum-
mer, we saw only a single moth of this species, and
out of a number of chrysalides which a young friend
had in his nurse-boxes, not one moth was bred.

The caterpillars of other moths, which are in some
years very common—such as the brown-tail (Por-
thesia auriflua), and the golden-tail (P. Chry-
sorrh@a), are also social; and, as the eggs are
hatched late in the summer, the brood passes the
winter in a very closely-woyen nest of warm silk.
This is usually represented as composed of leaves
which have had their pulpy parts eaten as food

* See Insect Transformations, p, 206-7.

330 INSECT ARCHITECTURE.

by the colonists; but, from minute observation of
at least twenty of these nests in the winter of
1828-9, we are quite satisfied that leaves are only
an accidental and not a necessary part of the struc-
ture. When a leaf happens to be in the line of the
walls of the nest, it is included; but there is no ap-
parent design in pressing it into the service, nor is
a branch selected because it is leafy. On the con-
trary, by far the greater number of these nests do not
contain a single leaf, but are composed entirely of
grey silk. In external form, no two of these nests
are alike; as it depends entirely upon the form of the
branch. When, therefore, there is only one twig, it is
somewhat egg-shaped; but when there are several
twigs, it commonly joins each, assuming an angular
shape, as may be seen in the figure.

Winter nest of the Social Caterpillars of the Brown-tail Moth
(Porthesia auriflua), figured from specimen.

SPINNING CATERPILLARS. 331

This irregularity arises from the circumstance of
each individual acting on its own account, without
the direction or superintendence of the others. The
interior of the structure is, for the same reason,
more regular, being divided into compartments, each
of which forms a chamber for one or more indi-
viduals. Previous to the cold weather these cham-
bers have but slight partitions ; but before the frosts
set in the whole is made thick and warm.

Winter nests of Porthesia chrysorrhaa, one being cut open to show
the chambers. The dots represent the egesta of the caterpillars.

A no less remarkable winter nest, of a small spe-
cies of social caterpillar, is described by M. Bonnet,
which we omitted to introduce when treating of the
Glanville fritillary (page 172). The nest in question
is literally pendulous, being hung from the branch of
a fruit-tree by a strong silken thread. It consists of
one or two leaves neatly folded, and held together

332 INSECLE ARCHITECTURE.

with silk, in which the caterpillars live harmoniously
together.

Pendulous leaf-nests, from Bonnet.

In a recently published volume of ‘Travels in
Mexico,’ we find a very remarkable account of some
pendulous nests of caterpillars, which appear to be
almost as curious as the nests of the pasteboard-mak-
ing wasps, described at p. 88. The author of these
travels does not define the species of caterpillar
whose constructions attracted his observation. He
says, “‘ After having ascended for about an hour, we
came to the region of oaks and other majestically
tall trees, the names of which I could not learn.
Suspended from their stately branches were innu-
merable nests, enclosed, apparently, in white paper
bags, in the manner of bunches of grapes in Eng-
land, to preserve them from birds and flies. I had
the curiosity to examine one of them, which I found
to contain numberless caterpillars. The texture is
so strong that it is not easily torn; and the interior
contained a quantity of green leaves, to support the
numerous progeny within.*

* Hardy’s Travels in the Interior of Mexico, p. 32.

SPINNING CATERPILLARS. 333

In all the nests of social caterpillars, care is
taken to leave apertures for passing out and in.
It is remarkable, also, that however far they may
ramble from their nest, they never fail to find
their way back when a shower of rain or night-
fall renders shelter necessary. It requires no great
shrewdness to discover how they effect this: for
by looking closely at their track it will be found
that it is carpeted with silk—no individual moving
an inch without constructing such a pathway, both
for the use of his companions and to facilitate his
own return. All these social caterpillars, therefore,
moye more or less in processional order, each follow-
ing the road which the first chance traveller has
marked out with his strip of silk carpeting.

There are some species, however, which are more
remarkable than others in the regularity of their pro-
cessional marchings, particularly two which are found
in the south of Europe, but are not indigenous in
Britain. The one named by Réaumur the proces-
sionary (Cnethocampa processionea, Steruxns) feeds
upon the oak; a brood dividing, when newly hatched,
into one or more parties of several hundred indivi-
duals, which afterwards unite in constructing a com-
mon nest nearly two feet long, and from four to six
inches in diameter. As it is not divided, like that
of the brown-tails, into chambers, but consists of one
large hall, it is not necessary that there should be
more openings than one ; and accordingly, when an
individual goes out and carpets a path, the whole
colony instinctively follow in the same track, though
from the immense population they are often com-
_pelled to march in parallel files from two to six deep.
The procession is always headed by a single cater-
pillar ; sometimes the leader isimmediately followed
by one or two in single file, and sometimes by two
abreast, as represented in the cut, A similar pro-

u 3

334 INSECT ARCHITECTURE.

cedure is followed by a species of social caterpillars,
which feed on the pine in Savoy and Languedoc ;
and though their nests are not half the size of the
preceding, they are more worthy of notice, from the
strong and excellent quality of their silk, which
Réaumur was of opinion might be advantageously
manufactured. - Their nests consists of more cham-
bers than one, but are furnished with a main entrance,
through which the colonists conduct their foraging
processions.

aenen
Yana amnen
CQomieinre mY
phe

Nest and order of marching of the Processionary Caterpillars
of the oak (Cnethocampa processionea).

335

Cuarter XVIII.

Structure of Spiders.

Mopern naturalists do not rank spiders among in-
sects, because they have no antenne, and no division
between the head and the shoulders; they breathe
by leaf-shaped gills, situated under the belly, instead
of spiracles in the sides; have a heart connected
with these; have eight legs instead of six; and
eight fixed eyes. But as spiders are popularly con-
sidered insects, it will sufficiently suit our purpose to
introduce them here as such.

The apparatus by which spiders construct their
ingenious fabrics is much more complicated than
that which we have described as common to the
various species of caterpillars. Caterpillars have
only two reservoirs for the materials of their silk;
but spiders, according to the dissections of M. Trevi-
ranus, have four principal vessels, two larger and
two smaller, with a number of minute ones at their
base, Several small tubes branch towards the reser-
voirs, for carrying to them, no doubt, a supply of
the secreted material. Swammerdam describes them
as twisted into many coils of an agate colour.* We
do not find them coiled, but nearly straight, and of a
deep yellow colour. From these, when broken, threads
can be drawn out like those spun by the spider,
though we cannot draw them so fine by many degrees.

From these little flasks or bags of gum, situated
near the anus, and not at the mouth as in cater-
pillars, a tube originates, and terminates in the exter

+ Hill's Swammerdam, part i. p. 23.

336 INSECT ARCHITECTURE.

nal spinnerets, which may be seen by the naked eye
in the larger spiders, in the form of five little teats
surrounded by a circle, as represented in the figure
below.

Garden Spider (Epeira diadema) suspended by a thread pro-
ceeding from its spinneret.

We have seen that the silken thread of a cater-
pillar is composed of two united within the tube of
the spinneret, but the spider’s thread would appear,
from the first view of its five spinnerets to be quin-
tuple, and in some species which have six teats,
so many times more. It is not safe, however, in our
interpretations of nature to proceed upon conjecture,
however plausible, nor to take anything for granted
which we have not actually seen; since our inferences
in such cases are almost certain to be erroneous.

SPIDERS. 337

If Aristotle, for example, had ever looked narrowly
at a spider when spinning, he could not have fancied,
as he does, that the materials which it uses are nothing
but wool stripped from its body. On looking, then,
with a strong magnifying glass, at the teat-shaped
spinnerets of a spider, we perceive them studded with
regular rows of minute bristle-like points, about a
thousand to each teat, making in all from five to six
thousand. These are minute tubes which we may
appropriately term spinnerules, as each is connected
with the internal reservoirs, and emits a thread of
inconceivable fineness. In the figure below, this
wonderful apparatus is represented as it appears in
the microscope.

Spinnerets of a Spider magnified to show the Spimnerules.

We do not recollect that naturalists have ventured
to assign any cause for this very remarkable multi-
plicity of the spinnerules of spiders, so different from
the simple spinneret of caterpillars. To us it ap-
pears to be an admirable provision for their mode of
life. Caterpillars neither require such strong ma-
terials, nor that their thread should dry as quickly.

338 INSECT ARCHITECTURE.

Itis well known in our manufactures, particularly in
rope-spinning, that in cords of equal thickness those
which are composed of many smaller ones united
are greatly stronger than those which are spun at
once. In the instance of the spider’s thread, this
principle must hold still more strikingly, inasmuch
as itis composed of fluid materials that require to be
dried rapidly, and this drying must be greatly
facilitated by exposing so many to the air separately
before their union, which is effected at the distance
of about a tenth of an inch from the spinnerets. In
the following figure each of the threads represented
is reckoned to contain one hundred minute threads,
the whole forming only one of the spider’s common
threads.

A

Asingle thread of a Spider, greatly magnified, so that, for the small
9!

space represented, the lines are shown us parallel,

Leeuwenhoeck, in one of his extraordinary miecro-

scopical observations on a young spider not bigger
than a grain of sand, upon enumerating the thread-

SPIDERS. 339

lets in one of its threads, calculated that it would
require four millions of them tobe as thick as a hair
of his beard.

Another important advantage derived by the spider
from the multiplicity of its threadlets is, that the
thread affords a much more secure attachment to a
wall, a branch of a tree, or any other object, than if
it were simple; for, upon pressing the spinneret
against the object, as spiders always do when they
fix a thread, the spinnerules are extended over an
area of some diameter, from every hair’s breadth of
which a strand, as rope-makers term it, is extended
to compound the main cord. The following figure
exhibits this ingenious contrivance.

Attached end of a Spider's thread, magnified.

Those who may be curious to examine this con-
triyance will see it best when the line is attached
to any black object, for the threads, being whitish, are,
in other cases, not so easily perceived.

SHooTING or THE LinEs.

It has long been considered a curious though a
difficult investigation, to determine in what manner
spiders, seeing that they are destitute of wings, trans-

340 INSECT ARCHITECTURE.

port themselves from tree to tree, across brooks, and
frequently through the air itself, without any appa-
rent starting point. On looking into the authors who
have treated upon this subject, it is surprising how
little there is to be met with that is new, even in the
most recent. Their conclusions, or rather their conjec-
tural opinions, are, however, worthy of notice ; for by
unlearning error, we the more firmly establish truth.

1, One of the earliest notions upon this subject
is that of Blancanus, the commentator on Aristotle,
which is partly adopted by Redi, by Henricus Regius
of Utrecht, by Swammerdam,* by Lehmann, and
by Kirby and Spence.t The “spider’s thread,”
says Swammerdam, “is generally made up of two or
more parts, and after descending by such a thread,
it ascends by one only, and is thus enabled to waft
itself from one height or tree to another, even across
running waters; the thread it leaves loose behind, it
being driven about by the wind, and so fixed to some
other body.” “TI placed,” says Kirby, “the large
garden-spider (Epeira diadema) upona stick about
a foot long set upright in a vessel containing wa«
ter... ... It let itself drop, not by a single thread,
but by two, each distant from the other about the
twelfth of an inch, guided, as usual, by one of its
hind feet, and one apparently smaller than the other,
When it had suffered itself to descend nearly to the
surface of the water, it stomped short, and by some
means, which I could not distinctly see, broke off,
close to the spinners, the smallest thread which,
still adhering by the other end to the top of the
stick, floated in the air, and was so light as to be
carried about by the slightest breath. On ap-
proaching a pencil to the loose end of this line, it
did not adhere from mere contact. I, therefore,

* Swammerdam, part i, p. 24, + Intr. vol. i, p, 415.

SPIDERS. 341

twisted it once or twice round the pencil, and then
drew it tight. The spider, which had previously
climbed to the top of the stick, immediately pulled
at it with one of its feet, and finding it sufficiently
tense, crept along it, strengthening it as it pro-
ceeded by another thread, and thus reached the pen-
eile:

We have repeatedly witnessed this occurrence, both
in the fields, and when spiders were placed for ex-
periment, as Kirby has described; but we very much
doubt that the thread broken is ever intended as a
bridge cable, or that it would have been so used in
that instance, had it not been artificially fixed and ac-
cidentally found again by the spider. According to
our observations, a spider never abandons, for an in-
stant, the thread which she despatches in quest of an
attachment, but uniformly keeps trying it with her
feet, in orderto ascertain itssuccess. We are, there-
fore, persuaded, that when a thread is broken in the
manner above described, it is because it has been
spun too weak, and spiders may often be seen break-
ing such threads in the process of netting their webs.*

The plan, besides, as explained by these distin-
guished writers, would more frequently prove abor-
tive than successful, from the cut thread not being
sufficiently long. They admit, indeed, that spiders’
lines are often found “a yard or two long, fastened to
twigs of grass not afoot inheight...... Here, there-
fore, some other process must have been used,’ +

2. Our celebrated English naturalist, Dr. Lister,
whose treatise upon our native spiders has been the
basis of every subsequent work on the subject, main-
tains that “some spiders shoot out their threads in
the same manner that porcupines do their quills;
that, whereas the quills of the latter are entirely se-

* TR, + Kirby and Spence, vol. i. Intr. p.-416,

342 INSECT ARCHITECTURE.

parated from their bodies, when thus shot out, the
threads of the former remain fixed to their anus, as
the sun’s rays to its body.”* A French periodical
writer goes a little farther, and says, that spiders have
the power of shooting out threads, and directing them
at pleasure towards a determined point, : judging of
the distance and position of the object by some sense
of which we are ignorant.t Kirby also says, that
he once observed a small garden-spider (Aranea reti-
culata) “standing midway on a long perpendicular
fixed thread, and an appearance caught ” his “eye,
of what seemed to be the emission of threads.” “ 1}?
therefore, he adds, ‘moved my arm in the direction
in which they apparently proceeded, and, as I had
suspected, a floating thread attached itself to my coat,
along which the spider crept. As this was connected
with the spinners of the spider, it could not have
been formed” by breaking a “ secondary thread.”
Again, in speaking of the gossamer-spider, he says,
“it first extends its thigh, shank, and foot, into a
right line, and then, elevating its abdomen till it be-
comes vertical, shoots its thread into the air, and flies
off from its station.”’§

Another distinguished naturalist, Mr. White of
Selborne, in speaking of the gossamer-spider, says,
“Every day in fine weather in autumn do I see
these spiders shooting out their webs, and mounting
aloft: they will go off from the finger, if you will
take them into your hand, Last summer, one
alighted on my book as I was reading in the par-
lour; and running to the top of the page, and
shooting out a web, took its departure from thence.
But what I most wondered at was, that it went off
with considerable velocity in a place where no air

* Lister, Hist, Animalia Anglim, 4to. p. 7.

+ Phil. Mag, ii, p. 275.
{ Vol. i. Intr, p, 417, § Ibid. ii. p. 339.

SPIDERS. 343

was stirring, and I am sure I did not assist it with
my breath.’’*

Having so often witnessed the thread set afloat in
the air by spiders, we can readily conceive the way
in which those eminent naturalists were led to sup-
pose it to be ejected by some animal force acting like
a syringe; but as the statement can be completely
disproved by experiment, we shall only at present
ask, in the words of Swammerdam—“ how it can be
possible that a thread so fine and slender should be
shot out with force enough to divide and pass through
the air ?—is it not rather probable that the air would
stop its progress, and so entangle it, and fit it to per-
plex the spider's operations?” + The opinion, indeed,
is equally improbable with another, suggested by Dr.
Lister, that the spider can retract her thread within
the abdomen, after it has been emitted.{ De Geer§
very justly joins Swammerdam in rejecting both of
these fancies, which, in our own earlier observations
upon spiders, certainly struck us as plausible and
true. There can beno doubt, indeed, that the animal
has a voluntary power of permitting the material to
escape, or stopping it at pleasure, but this power is
not projectile,

3. “ There are many people,” says the Abbé de la
Pluche, “ who believe that the spider flies when they
see her pass from branch to branch, and even from
one high tree to another; but she transports herself
in this manner: she places herself upon the end of
a branch, or some projecting body, and there fastens
her thread ; after which, with her two hind feet, she
squeezes her dugs (spinnerets), and presses out one or
more threads of two or three ells in length, which she
leaves to float in the air till it be fixed to some par-

* Nat. Hist. of Selborne, vol. i. p. 327.
+ Book of Nature, part i. p. 25.
} Hist. Anim. Anglia, 4to. § Memoires, vol. vii. p. 189.

344 INSECT ARCHITECTURE.

ticular place.’* Without pretending to have ob-
served this, Swammerdam says, “I can easily com-
prehend how spiders, without giving themselves any
motion, may, by only compressing their anus, spin
out a thread, which being driven by the wind, may
serve to waft them from one place to another,”
Others, proceeding upon a similar notion, give a
rather different account of the matter. “The spider,”
says Bingley, “ fixes one end of a thread to the place
where she stands, and then with her hind paws draws
out several other threads from the nipples, which,
being lengthened out and driven by the wind to some
neighbouring tree or other object, are by their natu-
ral clamminess fixed to it.”’{

Observation gives some plausibility to the latter
opinion, as thespider always actively uses her legs,
though not to draw out the thread, but to ascertain
whether it has caught upon any object. The notion
of her pressing the spinneret with her feet must be
amere fancy ; at least it is not countenanced by any-
thing which we have observed.

4. An opinion much more recondite is mentioned,
if it was not started, by M. D’Isjonval, that the float-
ing of the spider’s thread is electrical. “ Frogs, cats,
and other animals,” he says, “are affected by natural
electricity, and feel the change of weather; but no
other animal more than myself and my spiders.”
During wet and windy weather he accordingly found
that they spun very short lines, “but when a spider
spins a long thread, there is a certainty of fine wea-
ther for at least ten or twelve days afterwards.Ӥ A
periodical writer, who signs himself Carolan,|| fancies
that in darting out her thread the spider emits a

* Spectacle de Ja Nature, vol. i. + Book of Nature, part i. p. 25.
t Animal Biography, vol. iii. p. 475, 3rd edition.
§ Brez, Flore des Insectophiles. Notes, Supp. p. 134.
Thompson's Ann, of Philosophy, vol, iii. p, 806.

SPIDERS. 345

stream of air, or some subtle electric fluid, by which
she guides it as if by magic.

A living writer (Mr. John Murray), whose learn-
ing and skill in conducting experiments give no lit-
tle weight to his opinions, has carried these views
considerably farther, ‘‘ The aéronautic spider,” he
says, “can propel its thread both horizontally and
vertically, and at all relative angles, in motionless
air, and in an atmosphere agitated by winds; nay
more, the aérial traveller can even dart its thread, to
use a nautical phrase, in the ‘ wind’s eye.’ My opi-
nion and observations are based on many hundred ex-
periments...... The entire phenomena are elec-
trical. When a thread is propelled in a vertical
plane, it remains perpendicular to the horizontal
plane, always upright, and when others are projected
at angles more or less inclined, their direction is in-
variably preserved; the threads never intermingle,
and when a pencil of threads is propelled, it ever
presents the appearance of a divergent brush. These
are electrical phenomena, and cannot be explained
but on electrical principles.”

“In clear fine weather the air is invariably posi-
tive ; andit is precisely in such weather that the aéro-
nautic spider makes its ascent most easily and ra-
pidly, whether it be insummer or in winter.”’ “ When
the air is weakly positive, the ascent of the spider
will be difficult, and its altitude extremely limited,
and the threads propelled will be but little elevated
above the horizontal plane. When negative electri-
city prevails, as in cloudy weather, or on the approach
of rain, and the index of De Saussure’s hygrometer
rapidly advancing towards humidity, the spider is un-
able to ascend,’’*

Mr. Murray had previously told us, that “when

* Loudon’s Mag. of Nat. Hist., vol. i. p. 322,

346 INSECT ARCHITECTURE.

astick of excited sealing-wax is brought near the
thread of suspension, it is evidently repelled; con-
sequently, the electricity of the thread is of a nega-
tive character,” while ‘‘an excited glass tube brought
near seemed to attract the thread, and with it the
aéronautic spider.”* His friend Mr. Bowman fur-
ther describes the aérial spider as “shooting out
four or five, often six or eight, extremely fine webs
seyeral yards long, which waved in the breeze, di-
verging from each other like a pencil of rays.” One
of them “had two distinet and widely diverging fasi-
culi of webs,” and “a line uniting them would have
been at right angles to the direction of the breeze.”+

Such is the chief evidence in support of the elec-
trical theory ; but though we have tried these ex-
periments, we have not succeeded in verifying any
one of them. The following statements of Mr. Black-
wall come nearer our own observations.

5. “ Having procured asmall branched twig,” says
Mr. Blackwall, “I fixed it upright in an earthen ves-
sel containing water, its base being immersed in the
liquid, and upon it I placed several of the spiders
which produce gossamer. Whenever the insects
thus circumstanced were exposed to a current of air,
either naturally or artificially produced, they directly
turned the thorax towards the quarter whence it
came, even when it was so slight as scarcely to be
perceptible, and, elevating the abdomen, they emitted
from their spinners a small portion of glutinous
matter, which was instantly carried out in a line,
consisting of four finer ones, with a velocity equal,
or nearly so, to that with which the air moyed, as
was apparent from observations made on the motion
of detached lines similarly exposed. The spiders,
in the next place, carefully ascertained whether their

* Experim. Researches in Nat. Hist. p. 136. ‘
P Mag. Nat. Hist., vol. i. p. 324.

SPIDERS. 347

lines had become firmly attached to any object or
not, by pulling at them with the first pair of legs ;
and if the result was satisfactory, after tightening
them sufficiently, they made them pass to the twig;
then discharging from their spinners, which they ap-
plied to the spot where they stood, a little more of
their liquid gum, and committing themselves to these
bridges of their own constructing, they passed over
them in safety, drawing asecond line after them as
a security in case the first gave way, and so effected
their escape.

“Such was invariably the result when spiders
were placed where the air was liable to be sensibly
agitated; I resolved, therefore, to put a bell-glass
over them; and in this situation they remained
seventeen days, evidently unable to produce a single
line by which they could quit the branch they occu-
pied, without encountering the water at its base;
though, on the removal of the glass, they regained
their liberty with as much celerity asin the instances
already recorded.

“« This experiment, which from want of due pre-
caution has misled so many distinguished naturalists,
I have tried with several geometric spiders, and
always with the same success,””*

Mr. Blackwall, from subsequent experiments, says
he is “confident in affirming, that in motionless air
spiders have not the power of darting their threads
even through the space of half an inch.”+ The fol-
lowing details are given in confirmation of this
opinion. Mr. Blackwall observed, the lst Oct., 1826,
a little before noon, with the sun shining brightly,
no wind stirring, and the thermometer in the shade
ranging from 55°5 to 64°, a profusion of shining
lines crossing each other at every angle, forming a

* Linon. Trans., vol. xv. p. 456.
+ Mag. Nat. Hist., vol. ii. p. 397.

348 INSECT ARCHITECTURE.

confused net-work, covering the fields and hedges,
and thickly coating his feet and ankles, as he walked
across apasture. He was more struck with the phe-
nomenon, because on the previous day a strong gale
of wind had blown from the south, and as gossamer
is only seen in calm weather, it must have been all
produced within a very short time.

“ What more particularly arrested my attention,”
says Mr. Blackwall, “was the ascent of an amazing
quantity of webs, of an irregular, complicated struc-
ture, resembling ravelled silk of the finest quality, and
clearest white ; they were of various shapes and di-
mensions, some of the largest measuring upwards of
a yard in length, and several inches in breadth in the
widest part; while others were almost as broad as
long, presenting an area of a few square inches only.

“These webs, it was quickly perceived, were not
formed in the air, as is generally believed, but at the
earth’s surface. The lines of which they were com-
posed, being brought into contact by the mechanical
action of gentle airs, adhered together, till, by con-
tinual additions, they were accumulated into flakes or
masses of considerable magnitude, on which the
ascending current, occasioned by the rarefaction of
the air contiguous to the heated ground, acted with
so much force as to separate them from the objects
to which they were attached, raising them in the
atmosphere to a perpendicular height of at least
several hundred feet. I collected a number of these
webs, about mid-day, as they rose; and again in the
afternoon, when the upward current had ceased, and
they were falling; but scarcely one in twenty con-
tained a spider; though, on minute inspection, I
found small winged insects, chiefly aphides, entangled
in most of them.

“From contemplating this unusual display of
gossamer, my thoughts were naturally directed to

SPIDERS. 349

the animals which produced it, and the countless
myriads in which they swarmed almost created as
much surprise as the singular occupation that en-
grossed them. Apparently actuated by the same
impulse, all were intent upon traversing the regions
of air; accordingly, after gaining the summits of
various objects, as blades of grass, stubble, rails,
gates, &c., by the slow and laborious process of
climbing, they raised themselves still higher by
straightening their limbs; and elevating the abdo-
men, by bringing it from the usual horizontal posi-
tion, into one almost perpendicular, they emitted
from their spinning apparatus a small quantity of the
glutinous secretion with which they construct their
webs. This viscous substance being drawn out by
the ascending current of rarefied air into fine lines
several feet in length, was carried upward, until the
spiders, feeling themselves acted upon with sufficient
force in that direction, quitted their hold of the objects
on which they stood, and commenced their journey by
mounting aloft. ;

““ Whenever the lines became inadequate to the
purpose for which they were intended, by adhering
to any fixed body, they were immediately detached
from the spinners and so converted into terrestrial
gossamer, by means of the last pair of legs, and the
proceedings just described were repeated; which
plainly proves that these operations result from a
strong desire felt by the insects to effect an ascent.”*
Mr. Blackwall has recently read a paper (still unpub-
lished) in the Linnean Society, confirmatory of his
opinions.

6. Without going into the particulars of what
agrees or disagrees in the above experiments with our
own observations, we shall give a brief account of
what we have actually seen in our researches.t So

* Linn Trans., vol. xv. p. 453. wR,
x

350 INSECT ARCHITECTURE.

far as we have determined, then, all the various
species of spiders, how different soever the form of
their webs may be, proceed in the circumstance of
shooting their lines precisely alike; but those which
we have found the most manageable in experimenting
are the small gossamer-spider (Aranea oblextriz,
Becustrin), known by its shining blackish-brown
body and reddish-brown semi-transparent legs; but
particularly the long-bodied spider (Tetragnatha
extensa, Larr.), which varies in colour from green to
brownish or grey—but has always a black line along
the belly, with a silvery white or yellowish one on
each side. The latter is chiefly recommended by
being a very industrious and persevering spinner,
while its movements are easily seen, from the long
cylindrical form of its body and the length of its legs.
We placed the above two species with five or six
others, including the garden, the domestic, and the
labyrinthic spiders, in empty wine glasses, set in tea-
saucers filled with water to prevent their escape.
When they discovered, by repeated descents from the
brims of the glasses, that they were thus surrounded
by a wet ditch, they all set themselves to the task of
throwing their silken bridges across. For this
purpose they first endeavoured to ascertain in what
direction the wind blew, or rather (as the experiment
was made in our study) which way any current of
air set,—by elevating their arms as we have seen
sailors do in a dead calm, But, as it may prove
more interesting to keep to one individual, we shall
first watch the proceedings of the gossamer-spider.
Finding no current of air on any quarter of the brim
of the glass, it seemed to give up all hopes of con-
structing its bridge of escape, and placed itself in the
attitude of repose; but no sooner did we produce a
stream of air, by blowing gently towards its position,
than, fixing a thread to the glass, and laying hold

SPIDERS. 351

of it with one of its feet, by way of security, it placed
its body in a vertical position, with its spinnerets ex-
tended outwards ; and immediately we had the pleasure
of seeing a thread streaming out from them several
feet in length, on which the little aéronaut sprung up
into the air. We were convinced, from what we thus
observed, that it was the double or bend of the thread
which was blown into the air; and we assigned as a
reason for her previously attaching and drawing out
a thread from the glass, the wish to give the wind
a point d’appui—something upon which it might
have a purchase, as a mechanic would say of a lever.
The bend of the thread, then, on this view of the
matter, would be carried out by the wind,—would
form the point of impulsion,—and, of course, the
escape bridge would be an ordinary line doubled.

Such was our conclusion, which was strongly
corroborated by what we subsequently found said by
M. Latreille—than whom no higher authority could
be given. ‘ When the animal,” says he, “desires to
cross a brook, she fixes to a tree or some other object
one of the ends of her first threads, in order that the
wind or a current of air may carry the other end
beyond the obstacle ;”* and as one end is always
attached to the spinnerets, he must mean that the
double of the thread flies off. In his previous publi-
cations, however, Latreille had contented himself
with copying the statement of Dr. Lister.

In order to ascertain the fact, and put an end to all
doubts, we watched, with great care and minuteness,
the proceedings of the long-bodied spider above men-
tioned, by producing a stream of air in the same
manner, as it perambulated the brim of the glass.
It immediately, as the other had done, attached a

* —“ Tun des bouts de ces premiers fils, afin que le vent
ou un courant d’air pousse lautre extremité de l'un deux au de
1a de l’obstacle.”"—Dict. Classique d’Hist. Nat., vol. i. p. 510.

x 2

352 INSECT ARCHITECTURE.

thread and raised its body perpendicularly, like a
tumbler standing on his hands with his head down-
wards ; but we looked in vain for this thread bending,
as we had at first supposed, and going off double.
Instead of this it remained tight, while another
thread, or what appeared to be so, streamed off from
the spinners, similar to smoke issuing through a pin
hole, sometimes in a line, and sometimes at a con-
siderable angle with the first, according to the current
of the air,—the first thread, extended from the glass
to the spinnerets, remaining all the while tight-drawn
ina right line. It further appeared to us, that the first
thread proceeded from the pair of spinnerets nearest the
head, while the floating thread came from the outer
pair,—though it is possible in such minute objects we
may have been deceived. That the first was continu-
ous with the second, without any perceptible joining,
we ascertained in numerous instances, by catching the
floating line and pulling it tight, in which case the
spider glides along without attaching another line
to the glass; but if she have to coil up the floating
line to tighten it, as usually happens, she gathers
it into a packet and glues the two ends tight together.
Her body, while the floating line streamed out, re-
mained quite motionless, but we distinctly saw the
spinnerets not only projected, as is always done when
a spider spins, but moved in the same way as an
infant moves its lips when sucking. We cannot
doubt, therefore, that this motion is intended to emit
Gf eject or project be deemed too strong words) the
liquid material of the thread; at the same time, we
are quite certain that it cannot throw out a single
inch of thread without the aid of a current of air.
A long-bodied spider will thus throw out in succes-
sion as many threads as we please, by simply blowing
towards it; but not one where there is no current, as
under a bell-glass, where it may be kept till it die,

»*

SPIDERS. 353

without being able to construct a bridge over water of
an inch long. We never observed more than one
floating thread produced at the same time; though
other observers mention several.

The probable commencement, we think, of the
floating line, is by the emission of little globules of
the glutinous material to the points of the spinnerules
—perhaps it may be dropped from them, if not
ejected, and the globules being carried off by the
current of air, drawn out into a thread. But we give
this as only a conjecture, for we could not bring a
glass of sufficient power to bear upon the spinnerules
at the commencement of the floating line.

In subsequent experiments we found that it was
not indispensable for the spider to rest upon a solid
body when producing a line, as she can do so while
she is suspended in the air by another line. When
the current of air also is strong, she will sometimes
commit herself to it by swinging from the end of the
line. We have even remarked this when there was
scarcely a breath of air.*

We tried another experiment. We pressed pretty
firmly upon the base of the spinnerets, so as not to
injure the spider, blowing obliquely over them; but
no floating line appeared. We then touched them
with a pencil and drew out several lines an inch or
two in length, upon which we blew in order to extend
them, but in this also we were unsuccessful, as they
did not lengthen more than a quarter of an inch.
We next traced out the reservoirs of a garden-spider
(Epeira diadema), and immediately taking a drop of
the matter from one of them on the point of a fine
needle, we directed upon it a strong current of air,
and succeeded in blowing out a thick yellow line, as
we might have done with gum-water, of about an inch
and a half long.

* See Insect Transformations, end of chap. xvi.

> |

354 INSECT ARCHITECTURE.

When we observed our long-bodied spider eager
to throw a line by raising up its body, we brought
within three inches of its spinnerets an excited stick
of sealing-wax, of which it took no notice, nor did
any thread extend to it, not even when brought almost
to touch the spinnerets. We had the same want of
success with an excited glass rod: and indeed we had
not anticipated any other result, as we have never
observed that these either attract or repel the floating
threads, as Mr. Murray has seen them do; nor have
we ever seen the end of a floating thread separated
into its component threadlets and diverging like a
brush, as he and Mr. Bowman describe. It may be
proper to mention that Mr. Murray, in conformity
with his theory, explains the shooting of lines in a
current of air by the electric state produced by motion
in consequence of the mutual friction of the gaseous
particles. But this view of the matter does not seem
to affect our statements.

Nests, Wess, AnD Nets or SpipErs.

The neatest, though the smallest, spider’s nest which
we have seen, was constructed in the chink of a gar-
den post, which we had cut out the previous summer
in getting at the cells of a carpenter-bee. The archi-
tect was one of the larger hunting-spiders, erroneously
said by some naturalists to be incapable of spinning.
The nest in question was about two inches high,
composed of a very close satin-like texture. There
were two parallel chambers placed perpendicularly,
in which position also the inhabitant reposed there
during the day, going, as we presume, only abroad
to prey during the night. But the most remarkable
circumstance was, that the openings (two above and
two below) were so elastic that they shut almost as
closely as the boat-cocoon of the Tortria chlorana

.

SPIDERS. 355

(see page 322). We observed this spider for several
months, but at last it disappeared, and we took the
nest out, under the notion that it might contain eggs ;
bnt we found none, and therefore conclude that it
was only used as a day-retreat.* The account which
Evelyn has given of these hunting-spiders is so
interesting, that we must transcribe it.

“Of all sorts of insects,’’ says he, “ there is none
has afforded me more divertisement than the vena-
tores (hunters), which are a sort of /wpi (wolves) that
have their dens in rugged walls and crevices of our
houses ; a small brown and delicately-spotted kind
of spiders, whose hinder legs are longer than the
rest. Such I did frequently observe at Rome, which,
espying a fly at three or four yards’ distance, upon
the balcony where I stood, would not make directly
to her, but crawl under the rail, till being arrived to
the antipodes, it would steal up, seldom missing its
aim; but if it chanced to want anything of being
perfectly opposite, would, at first peep, immediately
slide down again,—till taking better notice, it would
come the next time exactly upon the fly’s back: but
if this happened not to be within a competent leap,
then would this insect move so softly, as the very
shadow of the gnomon seemed not to be more im-
perceptible, unless the fly moved; and then would
the spider move also in the same proportion, keeping
that just time with her motion, as if the same soul
had animated both these little bodies; and whether
it were forwards, backwards, or to either side, with-
out at all turning her body, like a well managed horse:
but if the capricious fly took wing and pitched upon
another place behind our huntress, then would the
spider whirl its body so nimbly about, as nothing
could be imagined more swift: by which means she
always kept the head towards her prey, though, to
appearance, as immoveable as if it had heen a nail

wR

_ ae

356 INSECT ARCHITECTURE.

driven into the wood, till, by that indiscernible pro-
gress, being arrived within the sphere of her reach,
she made a fatal leap, swift as lightning, upon the fly,
catching him in the poll, where she never quitted hold
till her belly was full, and then carried the remainder
home.”

One feels a little sceptical, however, when he adds,
““T have beheld them instructing their young ones how
to hunt, which they would sometimes discipline for not
well observing; but when any of the old ones did (as
sometimes) miss a leap, they would run out of the field
and hide themselves in their crannies, as ashamed, and
haply not to be seen abroad for four or five hours after ;
for so long have I watched the nature of this strange
insect, the contemplation of whose so wonderful
sagacity and address hasamazed me; nor do I find in
any chase whatsoever more cunning and stratagem
observed. I have found some of these spiders in my
garden, when the weather, towards spring, is very hot,
but they are nothing so eager in hunting as in Italy.”*

We have only to add to this lively narrative, that
the hunting-spider, when he leaps, takes good care
to provide against accidental falls by always swing-
ing himself from a good strong cable of silk, as
Swammerdam correctly states,} and which any body
may verify, as one of the small hunters (Sa/ticus sce-
nicus), known by having its back striped with black
and white like a zebra, is very common in Britain.

Mr. Weston, the editor of Bloomfield’s Remains,
falls into a very singular mistake about hunting-spiders,
imagining them to be web-weaying ones which have
exhausted their materials, and which are therefore
compelled to hunt. In proof of this he gives an in-
stance which fell under his own observation !{

* Evelyn’s Travels in Italy.

+ Book of Nature, part i. p, 24.
{| Bloomfield’s Remains, vol. ii, p. 64, nofe.

i

SPIDERS. 357

As a contrast to the little elastic satin nest of the
hunter, we may mention the largest with which we
are acquainted,—that of the labyrinthic spider (Age-
lena labyrinthica, WaLcKENarER), Our readers must
often have seen this nest spread out like a broad
sheet in hedges, furze, and other low bushes, and
sometimes on the ground. The middle of this sheet,
which is of a close texture, is swung like a sailor’s
hammock, by silken ropes extended all around to the
higher brauches; but the whole curves upwards and
backwards, sloping down to a long funnel-shaped
gallery which is nearly horizontal at the entrance,
but soon winds obliquely till it becomes quite per-
pendicular. This curved gallery is about a quarter
of an inch in diameter, is much more closely woven
than the sheet part of the web, and sometimes de-
scends into a hole in the ground, though oftener
into a group of crowded twigs, or a tuft of grass.
Here the spider dwells secure, frequently resting
with her legs extended from the entrance of the gal-
lery, ready to spring out upon whatever insect may
fall into her sheet-net. She herself can only be caught
by getting behind her and forcing her out into the
web; but though we have often endeavoured to make
her construct a nest under our eye, we have been as
unsuccessful as in similar experiments with the com-
mon house-spider (Aranea domestica).”*

The house-spider’s proceedings were long ago de-
scribed by Homberg, and the account has been copied,
as usual, by almost every subsequent writer. Gold-
smith has, indeed, given some strange misstatements
from his own observations, and Bingley has added
the original remark, that after fixing its first thread,
creeping along the wall, and joining it as it proceeds,
it “darts itself’ to the opposete side, where the other
end is tobe fastened + Homberg’s spider took the
“Noa aR. + Animal Biography, iii. 470-1.

=

358 INSECT ARCHITECTURE.

more circuitous route of travelling to the opposite
wall, carrying in one of the claws the end of the
thread previously fixed, lest it should stick in the
wrong place. Thiswe believe to be the correct state-
ment, for as the web is always horizontal, it would
seldom answer to commit a floating thread to the
wind, as is done by other species. Homberg’s spider,
after stretching as many lines, by way of warp, as it
deemed sufficient between the two walls of the corner
which it had chosen, proceeded to cross this in the
way our weavers do in adding the woof, with this
difference, that the spider’s threads were only laid on,
and not interlaced.* 'The domestic spiders, however,
in these modern days, must have forgot this mode of
weaving, for none of their webs will be found to be
thus regularly constructed.

The geometric or net-working spiders (Tendeuses,
Larr.) are as well known in most districts as any of
the preceding; almost every bush and tree in the
gardens and hedge-rows having one or more of their
nets stretched out in a vertical position between ad-
jacent branches. The common garden-spider ( Epeira
diadema), and the long-bodied spider (Tetragnatha
extensa), are the best known of this order,

The chief care of a spider of this sort is, to form
a cable of sufficient strength to bear the net she means
to hang upon it; and, after throwing out a floating
line as above described, when it catches properly she
doubles and redoubles it with additional threads.
On trying its strength she is not contented with the
test of pulling it with her legs, but drops herself down
several feet from various points of it, as we have often
seen, swinging aud bobbing with the whole weight of
her body. She proceeds in a similar manner with the
rest of the frame-work of her wheel-shaped net; and
it may be remarked that some of the ends of these, j

* Mem. de l’Acad. des Sciences pour 1707, p. 389.

y,
oe

-

SPIDERS. 359

Geometric Net of Kpeira diadema.
lines are not simple, but in form of a Y, giving her the
additional security of two attachments instead of one.
In constructing the body of the net, the most re-
markable circumstance is her using her limbs as a -
measure, to regulate the distances of her radii or
wheel-spokes, and the circular meshes interweaved
into them. These are consequently always propor-
tional to the size of the spider. She often takes up
her station in the centre, but not always, though
it is so said by inaccurate writers; for she as fre-
quently lurks in a little chamber constructed under
a leaf or other shelter at the corner of her web,
ready to dart down upon whatever prey may be en-

360 INSECT ARCHITECTURE. ©

tangled in her net. The centre of the net is said
also to be composed of more viscid materials than its
suspensory lines,—a circumstance alleged to be proved
by the former appearing under the microscope
studded with globules of gum.* We have not been
able to verify this distinction, having seen the suspen-
sory lines as often studded in this manner as those in
the centre.

Mason-SpipeErs.

A no less wonderful structure is composed by a
sort of spiders, natives of the tropics and the south
of Europe, which have been justly called mason-
spiders by M. Latreille. One of these (Mygale
nidulans, Waucxn.), found in the West Indies, “ digs
a hole in the earth obliquely downwards, above three
inches in length, and one in diameter. This cavity
she lines with a tough thick web, which, when taken
out, resembles a leathern purse; but what is most
curious, this house has a door with hinges, like the
operculum of some sea-shells, and herself and family,
who tenant this nest, open and shut the door when-
ever they pass and repass. This history was told
me,” says Darwin, “and the nest, with its door,
shown me by the late Dr. Butt, of Bath, who was
some years physician in Jamaica.” {

The nest of a mason-spider, similar to this, has
been obligingly put into our hands by Mr. Riddle,
of Blackheath. It came from the West Indies,
and is probably that of Liatreille’s clay-kneader
(Mygale cratiens), and one of the smallest of the
genus. We have since seen a pair of these spiders,
in possession of Mr. William Mello, of Blackheath.
The nest is composed of very hard argillaceous clay,
deeply tinged with brown oxide of iron. It is ia

* Kirby and Spence, Intr. i, 419. +. RR
{ Darwin’s Zoonomia, i. 253, 8vo, ed.

SPIDERS. 361

form of a tube, about one inch in diameter, between
six and seven inches long, and slightly bent towards
the lower extremity—appearing to have been mined
into the clay rather than built. The interior of the
tube is lined with a uniform tapestry of silken web,
of an orange-white colour, with a texture interme-
diate between India paper and very fine glove leather.
But the most wonderful part of this nest is its en-
trance, which we look upon as the perfection of insect
architecture. A circular door, about the size of a
crown-piece, slightly concaye on the outside and
convex within, is formed of more than a dozen layers
of the same web which lines the interior, closely laid
upon one another, and shaped so that the inner
layers are the broadest, the outer being gradually less
in diameter, except towards the hinge, which is about
an inch long; and in consequence of all the layers
being united there, and prolonged into the tube, it
becomes the thickest and strongest part of the struc-
ture. The elasticity of the materials, also, gives to
this hinge the remarkable peculiarity of acting like a
spring, and shutting the door of the nest spontane-
ously. It is, besides, made to fit so accurately to the
aperture, which is composed of similar concentric
layers of web, that it is almost impossible to distin-
guish the joining by the most careful inspection. ‘To
gratify curiosity, the door has been opened and shut
hundreds of times, without in the least destroying
the power of the spring. When the door is shut, it
resembles some of the lichens (Lecidea), or the
leathery fungi, such as Polyporus versicolor, (Mt-
CHELI,) or, nearer still, the upper valve of a young
oyster shell. The door of the nest, the only part seen
above ground, being of a blackish-brown colour, it
must be very difficult to discover.*

Another mason-spider(Mygale cementaria, Latr.),

* JR.
Y

362 INSECT ARCHITECTURE.

found in the south of France, usually selects for her nest
a place bare of grass, sloping in such a manner as to
carry off the water, and of a firm soil, without rocks
or small stones. She digs a gallery a foot or two
in depth, and of a diameter (equal throughout) suf-
ficient to admit of her easily passing. She lines this
with a tapestry of silk glued to the walls. The door,
which is circular, is constructed of many layers of
earth kneaded, and bound together with silk. Ex-
ternally, it is flat and rough, corresponding to the
earth around the entrance, for the purpose, no doubt,
of concealment: on the inside it is convex, and ta-
pestried thickly with a web of fine silk. The threads

Nest of the Mason-Spider.
A. The nest shut. B. The nest open. C. The spider, mygale camentarla.
D. The eyes magnified. E, F. Parts of the foot and claw magnified.

SPIDERS. 363

of this door-tapestry are prolonged, and strongly at-
tached to the upper side of the entrance, forming an
excellent hinge, which when pushed open by the
spider, shuts again by its own weight, without the
aid of spring hinges. When the spider is at home,
and her door forcibly opened by an intruder, she
pulls it strongly inwards, and even when half-opened
often snatches it out of the hand; but when she is
foiled in this, she retreats to the bottom of her den,
as her last resource.*

Rossi ascertained that the female of an allied species
(Mygale sauvagesii, Larr.), found in Corsica, lived
in one of these nests with a numerous posterity. He
destroyed one of these doors to observe whether a
new one would be made, which it was: but it was
fixed immoyeably, without a hinge; the spider, no
doubt, fortifying herself in this manner till she thought
she might re-open it without danger.t+

“The Rey. Revett Shepherd has often noticed,
in the fen ditches of Norfolk, a very large spider
(the species not yet determined) which actually
forms a raft for the purpose of obtaining its pre
with more facility. Keeping its station upon a ball
of weeds about three inches in diameter, probably
held together by slight silken cords, it is wafted
along the surface of the water upon this floating
island, which it quits the moment it sees a drowning
insect. The booty thus seized it devours at leisure
upon its raft, under which it retires when alarmed by
any danger.”{ In the spring of 1830, we found a
spider on some reeds in the Croydon Canal, which
agreed in appearance with Mr. Shepherd’s.

Among our native spiders there are several besides

* Mem. Soc. d’Hist. Nat. de Paris, An. vii.
+ Ibid. p. 125, and Latreille, Hist. Nat. Génér, viii. p. 163.
Kirby and Spence, Intr. i. 425.

¥2

364 INSECT ARCHITECTURE.

this one, which, not contented with a web like the rest
of their congeners, take advantage of other materials
to construct cells where, “hushed in grim repose,”
they “expect their insect prey.” The most simple of
those spider-cells is constructed by a longish-bodied
spider ( Aranea holosericea, Lann.), which is a little
larger than the common hunting-spider. It rolls up a
leaf of the lilac or poplar, precisely in the same manner
as is done by the leaf-rolling caterpillars, upon whose
cells it sometimes seizes to save itself trouble, having
first expelled, or perhaps devoured, the rightful owner.
The spider, however, is not satisfied with the tapestry
of the caterpillar, and always weaves a fresh set of
her own, much more close and substantial. ‘
Another spider, common in woods and copses
(Epeira quadrata ?) weaves together a great number
of leaves to form a dwelling for herself, and in front of it
she spreads her toils for entrapping the unwary insects
which stray thither. These, as soon as caught, are drag-
ged into her den, and stored up for a time of scarcity.
Here also her eggs are deposited and hatched in safety.
When the cold weather approaches, and the leaves of
her edifice wither, she abandons it for the more secure
shelter of a hollow tree, where she soon dies; but the
continuation of the species depends upon eggs, de-
posited in the nest before winter, and remaining to be
hatched with the warmth of the ensuing summer.
The spider’s den of united leaves, however, which has
just been described, is not always useless when with-
ered and deserted; for the.dormouse usually selects
_it as a ready-made roof for its nest of dried grass.
That those old spiders’ dens are not accidentally chosen
by the mouse, appears from the fact, that out of about
a dozen mouse-nests of this sort found during winter
in a copse between Lewisham and Bromley, Kent, every
second or third one was furnished with such a roof.*
#0.

ae eT

SPIDERS. 365

Divine Warter-SpipeEr.

That spiders may be able to breathe under water,
we can well understand from their breathing like
amphibious reptiles by means of gills ; but there is an
aquatic spider (Argyroneta aquatica, WALCKENAER)
which is not contented, as a frog would be, with the
air furnished by the water, but actually carries down
a supply of air from the atmosphere to her subaqueous
nest. This spider does not like stagnant-water, but
prefers slow running streams, canals, and ditches,
where she may often be seen, in the vicinity of London
and elsewhere, living in her diving-bell, which shines
through the water, like a little globe of silver: her sin-
gular economy was first, we believe, described by
Clerck,* L. M. de Lignac,t and De Geer.

“The shining appearance,” says Clerck, “ pro-
ceeds either from an inflated globule surrounding the
abdomen, or from the space between the body and the
water. The spider, when wishing to inhale the air,
rises to the surface, with its body still submersed, and
only the part containing the spinneret rising just to
the surface, when it briskly opens and moves its four
teats. A thick coat of hair keeps the water from ap-
proaching or wetting the abdomen. It comes up for
air about four times an hour or oftener, though
I have good reason to suppose it can continue with-
out it for several days together.

“‘T found in the middle of May one male and ten
females, which I put into a glass filled with water,
where they lived together very quietly for eight days.
I put some duck-weed (Zemna) into the glass to
afford them shelter, and the females began to stretch
diagonal threads in a confused manner from it to the
sides of the glass about half-way down. Each of the

* Aranei Suecici, Stockholm, 1757.
+ Mem. des Araign, Aquat. 12mo. Paris, 1799.

366 INSECT ARCHITECTURE.

females afterwards fixed a close bag to the edge of
the glass, from which the water was expelled by the
air from the spinneret, and thus a cell was formed
capable of containing the whole animal. Here they
remained quietly, with their abdomens in their cells,
and their bodies still plunged in the water; and in a
short time brimstone-coloured bags of eggs appeared
in each cell, filling it about a fourth part. On the 7th
of July several young ones swam out from one of the
bags :—all this time the old ones had nothing to eat,
and yet they never attacked one another, as other
spiders would have been apt to do.?*

“These spiders,” says De Geer, ‘ spin in the water
a cell of strong, closely woven, white silk in the form
of half the shell of a pigeon’s egg, or like a diving-bell.
This is sometimes left partly above water, but at others
is entirely submersed, and is always attached to the
objects near it by a great number of irregular threads.
It is closed all round, but has a large opening below,
which, however, I found closed on the 15th of Decem-
ber, and the spider living quietly within, with her head
downwards. I made a rent in this cell and expelled
the air, upon which the spider came out; yet though
she appeared to have been laid up for three months
in her winter quarters, she greedily seized upon an
insect and sucked it. I also found that the male as
well as the female constructs a similar subaqueous
cell, and during summer no less than in winter.”+
We have recently kept one of these spiders for
several months in a glass of water, where it built a
cell half under water, in which it laid its eggs.

CLEANLINESS or SPIDERS.

When we look at the viscid material with which
spiders construct their lines and webs, and at the

* Clerck, Aranei Suecici, cap. viii.
+ De Geer, Mem. des Insectes, vii. 312.

SPIDERS. 367

rough hairy covering (with a few exceptions) of
their bodies, we might conclude that they would
be always stuck over with fragments of the minute
fibres which they produce. This, indeed, must often
happen, did they not take careful precautions to avoid
it: for we have observed that they seldom, if ever, leave
a thread to float at random, except when they wish to
form a bridge. When a spider drops along a line,
for instance, in order to ascertain the strength of her
web, or the nature of the place below her, she inva-
riably, when she re-ascends, coils it up into a little ball,
and throws it away. Her claws are admirably
adapted for this purpose, as well as for walking along
ae lines, as may be readily seen by a magnifying
glass.

Triple-clawed foot of a Spider, magnified.

There are three claws, one of which acts as a
thumb, the others being toothed like a comb, for
gliding along the lines. This structure, however,
unfits it to walk, as flies can do, upon any upright
polished surface like glass; although the contrary
is erroneously asserted by the Abbé de la Pluche.
Before she can do so, she is obliged to construct a
ladder of ropes, as Mr. Blackwall remarks,} by ele-
vating her spinneret as high as she can, and laying
down a step upon which she stands to form a second;

* Spectacle de la Nature, i. 58. } Linn, Trans. vol. xv.

368 INSECT ARCHITECTURE.

and so on, as any one may try by placing a spider at
the bottom of a very clean wine-glass.

The hairs of the legs, however, are always catching
bits of web and particles of dust; but these are not
suffered to remain long. Most people may have re
marked that the house-fly is ever and anon brushing
its feet upon one another to rub off the dust, though
we have not seen it remarked in authors that spiders
are equally assiduous in keeping themselves clean.
They have, besides, a very efficient instrument in their
mandibles or jaws, which, like their claws, are
furnished with teeth; and a spider which appears toa
careless observer as resting idly, in nine cases out of
ten will be found slowly combing her legs with her
mandibles, beginning as high as possible on the thigh,
and passing down to the claws. The flue which she
thus combs off is regularly tossed away.*

With respect to the house-spider (A. domestica),
we are told in books, that “she from time to time
clears away the dust from her web, and sweeps the
whole by giving it a shake with her paw, so nicely
proportioning the force of her blow, that she never
breaks anything.”+ That spiders may be seen
shaking their webs in this manner, we readily admit ;
though it is not, we imagine, to clear them of dust,
but to ascertain whether they are sufficiently sound
and strong.

We recently witnessed a more laborious process of
cleaning a web than merely shaking it. On coming
down the Maine by the steem-boat from Frankfort,
in August 1829, we observe the geometric-net of a
conic-spider (Epeira conica, Wack.) on the frame-
work of the deck, and as it was covered with flakes
of soot from the smoke of the engine, we were sur-
prised to see a spider at work on it ; for, in order to

* See Insect Transformations, page 358, fora more minute account.
Spectacle de la Nature, i. p 61.

SPIDERS. 869

be useful, this sort of net must be clean. Upon ob-
serving it a little closely, however, we perceived that
she was not constructing a net, but dressing up an
old one; though not, we must think, to save trouble,
so much as an expenditure of material. Some of the
lines she dexterously stripped of the flakes of soot
adhering to them; but in the greater number, finding
that she could not get them sufficiently clean, she
broke them quite off, bundled them up and tossed
them over. We counted five of these packets of
rubbish which she thus threw away, though there
must have been many more, as it was some time
before we discovered the manceuvre, the packets
being so small as not to be readily perceived, except
when placed between the eye and the light. When
she had cleared off all the sooted lines, she began to
replace them in the usual way ; but the arrival of the
boat at Mentz put an end to our observations.”
Bloomfield, the poet, having observed the disappear-
ance of these bits of ravelled web, imagined that the
spider swallowed them; and even says that he
observed a garden-spider moisten the pellets before
swallowing them !t Dr. Lister, as we have already
seen, thought the spider retracted the threads within
the abdomen.
* 7. R, + Remains, ii. 62-5.

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370

Cuarrer XIX.

Structures of Gall-flies and Aphides.

Many of the processes which we have detailed
bear some resemblance to our own operations of
building with materials cemented together; but we
shall now turn our attention to a class of insect-
architects, who cannot, so far as we know, be matched
in prospective skill, by any of the higher orders of
animals. We refer to the numerous family which have
received the name of gall-flies, —a family which, as yet,
is very imperfectly understood, their economy being no
less difficult to trace than their species is to arrange
im the established systems of classification; though
the latter has been recently much improved by Mr.
Westwood.

Small berry-shaped gulls of the oah-leaf, produced by Cynips Quercus fulit ?

_——— Ce

GALL-FLIES. 374

One of the most simple and very common in-
stances of the nests constructed by gall-insects may
be found in abundance during the summer, on the
leayes of the rose-tree, the oak, the poplar, the wil-
low (Salix viminalis), and many other trees, in the
globular form of a berry, about the size of a currant,
and usually of a green colour, tinged with red, like
a ripe Alban or Baltimore apple.

When this pseudo-apple in miniature is cut into,
it is found to be fresh, firm, juicy, and hollow in the
centre, where there is either an egg or a grub safely
lodged, and protected form all ordinary accidents.
Within this hollow ball the egg is hatched, and the
grub feeds securely on its substance, till it prepares
for its winter sleep, before changing into a gall-fly
(Cynips) in the ensuing summer. There is a mys-
tery as to the manner in which this gall-fly contrives
to produce the hollow miniature-apples, each en-
closing one of her eggs; and the doubts attendant
upon the subject cannot, so far as our present know-
ledge extends, be solved, except by plausible conjec-
ture. Our earlier naturalists were of opinion that it
was the grub which produced the galls, by eating,
when newly hatched, through the cuticle of the leaf,
and remaining till the juices flowing from the wound
enveloped it, and acquired consistence by exposure to
the air. This opinion, however plausible it ap-
peared to be, was at once disproved by finding un-
hatched eggs on opening the galls.

There can be no doubt, indeed, that the mother
gall-fly makes a hole in the plant for the purpose ot
depositing her eggs. She is furnished with an ad-
mirable ovipositor for that express purpose, and
Swammerdam actually saw a gall-fly thus depositing
her eggs, and we have recently witnessed the same in
several instances. In some of these insects the ovi-
vositor is conspicuously long, even when the insect is

372 INSECT ARCHITECTURE.

at rest; but in others, not above a line or two of it
is visible, till the belly of the insect be gently pressed.
When this is done to the fly that produces the cur-
rant-gall of the oak, the ovipositor may be scen issuing
from a sheath in form of a small curved needle, of a
chesnut-brown colour, and of a horny substance, and
three times as long as it at first appeared.

Ovipositor of gall-fly, greatly magnified.

What is most remarkable in this ovipositor is, that
it is much longer than the whole body of the insect,
in whose belly it is lodged in a sheath, and, from its
horny nature, it cannot be either shortened or length-
ened. It is on this account that it is bent into the
same curve as the body of the insect. The mechanism
by which this is effected is similar to that of the
tongue of the woodpeckers (Picid@), which, though
rather short, can be darted out far beyond the beak,
by means of a forked bone at the root of the tongue,
which is thin and rolled up like the spring of a watch.
The base of the ovipositor of the gall-fly is, in a simi-
lar way, placed near the anus, runs along the curva-
ture of the back, makes a turn at the breast, and
then, following the curve of the belly, appears again
near where it originates. We copy from Réaumur
his accurate sketch of this remarkable structure.

a”
*

GALL-F LIES. 373

Gall-fly, and mechanism of ovipostor, greatly magnified.

With this instrument the mother gall-fly pierces
the part of a plant which she selects, and, according
to our older naturalists, ‘‘ ejects into the cavity a drop
of her corroding liquor, and immediately lays an egg
or more there; the circulation of the sap being thus
interrupted, and thrown, by the poison, into a fer-
mentation that burns the contiguous parts and
changes the natural colour. The sap, turned from
its proper channel, extravasates and flows round the
eggs, while its surface is dried by the external air, and
hardens into a vaulted form.”* Kirby and Spence
tell us, that the parent-fly introduces her egg “into
a puncture made by her curious spiral sting, and in a
few hours it becomes surrounded with a fleshy cham-
ber.” + M. Virey says, the gall tubercle is produced
by irritation, in the same way as an inflamed tumour

* Spectacle de la Nature, i, 119,
+ Introd.,, ii, 449.

374 INSECT ARCHITECTURE.

in an animal body, by the swelling of the cellular
tissue, and the flow of liquid matter, which changes
the organization, and alters the natural external
form.* This seems to be the received doctrine at
present in France.t+

Sprengel, speaking of the rose-willow, says, the
insect in spring deposits its eggs in the leaf-buds.
“The new stimulus attracts the sap,—the type of the
part becomes changed, and from the prevailing
acidity of the animal juice, it happens, that in the rose
and stock-shaped leaves which are pushed out, a red
instead of a green colour is evolved.” {

Without pretending positively to state facts which
are, perhaps, beyond human penetration, we may
view the process in a rather different light.§ Follow-
ing the analogy of what is known to occur in the case
of the saw-flies (see page 156), after the gall-fly has
made a puncture and pushed her egg into the hole,
we may suppose that she covers it over with some
adhesive gluten or gum, or the egg itself, as is usual
among moths, &c., may be coated over with such a
gluten. In either of these two cases, the gluten will
prevent the sap that flows through the puncture from
being scattered over the leaf and wasted; and the
sap, being thus confined to the space occupied by the
eggs, will expand and force outwards the pellicle of
gluten that confines it, till becoming thickened by
evaporation and exposure to the air, it at length shuts
up the puncture, stops the further escape of the sap,
and the process is completed. This explanation will
completely account for the globular form of the
galls alluded to; that is, supposing the egg of the

* Hist. des Maurs et de 1'Instinct, vol. ii.
+ Entomologie, par R.A. K. p. 242. Paris, 1826.
} Elements of the Philosophy of Plants, Eng. Trans. p, 286.
6 JR.

GALL-FLIES. 375

gall-fly to be globular, and covered or coated with a
pellicle of gluten of uniform thickness, and conse-
quently opposing uniform resistance, or rather uni-
form expansibility, to the sap pressing from within.
It will also account for the remarkable uniformity in
the size of the gall-apples ; for the punctures and the
eggs being uniform in size, and the gluten, by sup-
position, uniform in quantity, no more than the
same quantity of sap can escape in such circum-
stances.

But though this explanation appears to be plau-
sible, it is confessedly conjectural; for though
Swammerdam detected a gall-fly in the act of de-
positing her eggs, he did not attend to this circum-
stance ; and in the instances which we have observed,
some unlucky accident always prevented us from
following up our observations. The indefatigable
Réaumur, on one occasion, thought he would make
sure of tracing the steps of the process in the case of
the gall-fly, which produces the substance called
bedeguar on the wild-rose tree, and to which we shall
presently advert. His plan was to enclose in a box,
in which a brood of flies had just been produced from
a bedeguar, a living branch from a wild rose-tree ;
but, to his great disappointment, no eggs were laid,
and no bedeguar formed. Upon further investiga
tion, he discovered that the brood of flies produced
from the bedeguar were not the genuine bedeguar
insects at all, but one of the parasite ichneumons
(Callimone Bedeguaris, Sreruens), which had
surreptitiously deposited their eggs there, in order
to supply their young with the bedeguar grubs, all of
which they appeared to have devoured. It may
prove interesting to look into the remarkable structure
of the bedeguar itself, which is very different from
the globular galls above described.

376 INSECT ARCHITECTURE.

Bedeguar gall of the rose, produced by Cynips Rose.

The gall-fly of the willow (Cynips viminalis) de-
posits, as we have just seen, only a single egg on
one spot ; but the bedeguar-insect lays a large cluster
of eggs on the extremity of a growing branch of the
wild rose-tree, making, probably, a proportionate
number of punctures to procure materials for the
future habitation of her young progeny. As in the
former case, also, each of these eggs becomes (as we
may suppose) surrounded with the sap of the rose,
enclosed in a pellicle of gluten. The gluten, how-
ever, of the bedeguar-insect, is not, it would appear,
sufficiently tenacious to confine the flowing sap
within the dimensions of any of the little clustered
globes containing the eggs, for it oozes out from
numerous cracks or pores in the pellicle; which

GALL-FLIES. 377

cracks or pores, however, are not large enough to
admit a human hair. But this, so far from being a
defect in the: glutinous pellicle of the bedeguar-fly,
is, as we shall presently see, of great utility. The
sap which issues from each of those pores, instead of
being evaporated and lost, shoots out into a reddish-
coloured, fibrous bristle.

One of the bristles of the Bedeguar of the rose magnified,

It is about half an inch long, and, from the natural
tendency of the sap of the rose-tree to form prickles,
these are all over studded with weak pricklets. The
bedeguar, accordingly, when fully formed, has some
resemblance, at a little distance, to a tuft of reddish-
brown hair or moss, stuck upon the branch. Some-
times this tuft is as large as a small apple, and of a
rounded but irregular shape; at other times it is
smaller, and, in one instance mentioned by Réaumur,
only a single egg had been laid on a rose leaf, and,
consequently, only one tuft was produced. Each
member of the congeries is furnished with its own
tuft of bristles, arising from the little hollow globe in
which the egg or the grub is lodged. .

The prospective wisdom of this curious structure
is admirable. The bedeguar-grubs live in their cells
through the winter, and as their domicile is usually
on one of the highest branches, it must be exposed
to every severity of the weather. But the close, non-
conducting, warm, mossy collection of bristles with
which it is surrounded forms for the soft, tender
grubs a snug protection against the winter’s cold, till.

378 INSECT ARCHITECTURE.

through the influence of the warmth of the succeed-
ing summer, they undergo their final change into the
winged state ;* preparatory to which they eat their
way with their sharp mandibles through the walls of
their little cells, which are now so hard as to be cut
with difficulty by a knife.

Another structure, similar in principle, though dif-
ferent in appearance, is very common upon oak-trees,
the termination of a branch being selected as best
suited for the purpose. This structure is rather
larger than a filbert, and is composed of concentric
leaves diverging from the base, and expanding up-
wards, somewhat like an artichoke. Whether this

Artichoke Gall of the Oak-bud, with Gall-fly ( Cynips quercus
gemme), natural size, and its ovipositor (a) magnified,

* See Insect Transformations, chaps. iv. and vii
JR.

GALL-FLIES. 379

leafy structure is caused by a superinduced disease,
as the French think, or by the form of the pores in
the pellicle of gluten surrounding the eggs, or rather
by the tendency of the exuding sap of the oak to
form leaves, has not been ascertained ; but that it is
intended, as in the case of the bedeguar, to afford
an efficient protection against the weather to the in-
cluded eggs or grubs, there can be no doubt.

From the very nature of the process of forming
willow-galls, bedeguar, and the artichoke of the
oak, whatever theory be adopted, it will be obvious
that their growth must be rapid; for the thicken-
ing of the exuded sap, which is quickly effected by
evaporation, will soon obstruct and finally close the
orifice of the puncture made by the parent insect.
It is accordingly asserted by Réaumur and other ob-
servers, that all the species of galls soon reach their
full growth.

A very minute reddish-coloured grub feeds upon
dyer’s-broom (Genista), producing a sort of gall, fre-
quently globular, but always studded with bristles,
arising from the amorphous leaves. The stem of
the shrub passes through this ball, which is com-
posed of a great number of leaves, shorter and
broader than natural, and each rolled into the form
of a horn, the point of which ends in a bristle. In
the interior we find a thick fleshy substance, serving
to sustain the leaves, and also for the nourishment
of the grubs, some of which are within and some
between the leaves. They are in prodigious num-
bers,—hundreds being assembled in the same gall,
and so minute as scarcely to be perceived without the
aid of a magnifying glass. The bud of the plant
attacked by those grubs, instead of forming a shoot,
pushes out nothing put leaves, and these are all
rolled and turned round the stem. Some shrubs

380 INSECT ARCHITECTURE.

have several of these galls, which are of various sizes
from that of a filbert to that of a walnut.

Leafy Gall of Dyer's-Broom, produced by Cynips geniste ?
A, gall, natural size; B, a leafet magnified.

A similar but still more beautiful production is
found upon one of the commonest of our indigenous
willows (Salia purpurea), which takes the name of
rose-willow, more probably from the circumstance
than from the red colour of its twigs. The older
botanists, not being aware of the cause of such ex-
crescences, considered the plants so effected as dis-
tinct species; and old Gerard, accordingly, figures
and describes the rose-willow as ‘not onlie making
a gallant shew, but also yeelding a most cooling aire
in the heat of summer, being set up in houses for
decking the same.” The production in question,
however, is nothing more than the effect produced
by a species of gall-fly (Cynips sulicis) depositing its
eggs in the terminal shoot of a twig, and, like the

GALL-FLIES. 381

bedeguar and the oak artichoke, causing leaves to
spring out, of a shape totally different from the other
leaves of the tree, and arranged very much like the
petals of a rose. Decandolle says it is found chiefly
on the Salta helix, S. alba, and S. riparia.*

A production very like that of the rose-willow
may be commonly met with on the young shoots of
the hawthorn, the growth of the shoot affected being
stopped, and a crowded bunch of leaves formed at
the termination. These leaves, beside being smaller
than natural, are studded with short bristly prickles,
from the sap (we may suppose) of the hawthorn
being prevented from rising into a fresh shoot, and
thrown out of its usual course in the formation of
the arms. These bristles appear indiscriminately
on both sides of the leaves, some of which are bent
inwards, while others diverge in their natural manner.

This is not caused by the egg or grub of a true
gall-fly, but by the small white tapering grub of
some dipterous insect, of which we have not ascer-
tained the species, but which is probably a ceci-
domyia. Each terminal shoot is inhabited by a
number of these—not lodged in cells, however, but
burrowing indiscriminately among the half-withered
brown leaves which occupy the centre of the pro-
duction.

A more remarkable species of gall than any of
the above, we discovered in June, 1829, on the
twig of an oak in the grounds of Mr. Perkins, at
Lee, in Kent. When we first saw it, we imagined
that the twig was beset with some species of the
lanigerous aphides, similar to what is vulgarly called
the American or white blight (aphis lanata); but
on closer examination we discarded this notion, The
twig was indeed thickly beset with a white downy,

* Flore Frang. Disc. Préliminaire.
+ JR,

382 INSECT ARCHITECTURE.

Semi-Gall of the Hawthorn, produced by Cecidomyia ? drawn from a
Specimen.

or rather woolly substance around the stem at the
origin of the leaves, which did not appear to be
affected in their growth, being well formed, healthy,
and luxuriant. We could not doubt that the woolly
substance was caused by some insect; but though
we cut out a portion of it, we could uot detect any
egg or grub, and we therefore threw the branch
into a drawer, intending to keep it as a specimen,
whose history we might complete at some subse-
quent period.

A few weeks afterwards, on opening this drawer,
we were surprised to see a brood of several dozens
of a species of gall-fly (Cynips), similar in form and
size to that whose eggs cause the bedeguar of the
rose, and differing only in being of a lighter colour,
tending to a yellowish brown. We have since met
with a figure and description of this gall in Swam-
merdam. We may remark that the above is not the
first instance which has occurred in our researches,
of gall insects outliving the withering of the branch
or leaf from which they obtain their nourishment.

GALL-FLIES. 383

Woolly Gall of the Oak, less than the natural size, caused by a
cynips, and drawn from a specimen.

The woolly substance on the branch of the oak
which we have described was similarly constituted
with the bedeguar of the rose, with this difference,
that instead of the individual cells being diffused
irregularly through the mass, they were all arranged
at the off-goings of the leaf-stalks, each cell being
surrounded with a covering of the vegetable wool,
which the stimulus of the parent egg, or its gluten,
had caused to grow, and from each cell a perfect
fly had issued. We also remarked that there were
several small groups of individual cells, each of which
groups was contained in a species of calyx or cup
of leaf-scales, as occurs also in the well-known gall
called the oak-apple.

384 INSECT ARCHITECTURE.

We were anxious to watch the proceedings of these
flies in the deposition of their eggs, and the subse-
quent developments of the gall-growths; and endea~
voured for that purpose to procure a small oak plant
in a garden-pot; but we did not succeed in this: and
though they alighted on rose and sweet-briar trees,
which we placed in their way, we never observed that
they deposited any eggs upon them. Ina week or
two the whole brood died, or disappeared.”

There are some galls, formed on low-growing
plants, which are covered with down, hair, or wool,
though by no means 80 copiously as the one which
we have just described. Among the plants so affected
are the germander speedwell, wild-thyme, ground-
ivy, and others to which we shall afterwards advert.

The well-known oak-apple is a very pretty example
of the galls formed by insects ; and this, when com-
pared with other galls which form on the oak, shows
the remarkable difference produced on the same plant
by the punctures of insects of different species. The

Vak-apple galls, one being cut open to show the vessels running to
granules.

* JR.

GALL-FLIES. 385

oak-apple is commonly as large as a walnut or small
apple, rounded, but not quite spherical, the surface
being irregularly depressed in various places. ‘The
skin is smooth, and tinged with red and yellow, like a
ripe apple; and at the base there is, in the earlier
part of the summer, a calyx or cup of five or six small
brown scaly leaves ; but these fall off as the season
advances. If an oak-apple be cut transversely, there
is brought into view a number of oval granules, each
containing a grub; and embedded in a fruit-looking
fleshy substance, having fibres running through it. As
these fibres, however, run in the direction of the stem,
they are best exhibited by a vertical section of the gall ;
and this also shows the remarkable peculiarity of each
fibre terminating in one of the granules, like a foot-
stalk, or rather like a vessel for carrying nourishment,
Réaumur, indeed, is of opinion that these fibres are
the diverted nervures of the leaves, which would have
sprung from the bud in which the gall-fly had inserted
her eggs, and actually do carry sap-vessels throughout
the substance of the gall.

Réaumur says the perfect insects (Cynips quercus)
issued from his galls in June and the beginning of
July, and were of a reddish-amber colour. We have
procured insects, agreeing with Réaumur’s descrip-
tion, from galls formed on the bark or wood of the

Root-Galls of the Oak, produced by Cynips quercus inforus ?
drawn from a specimen.

oak, at the line of junction between the root and the
seem. These galls are precisely similar in structure
Zz

386 INSECT ARCHITECTURE

to the oak-apple, and are probably formed at a season
when the fly perceives, instinctively, that the buds of
the young branches are unfit for the purpose of nidifi-
cation.

There is another oak-gall, differing little in size
and appearance from the oak-apple, but which is
very different in structure, as, instead of giving pro-
tection and nourishment to a number of grubs, it is
only inhabited by one. This sort of gall, besides, is
hard and woody on the outside, resembling a little
wooden ball of a yellowish colour, but internally of
a soft, spongy texture. The latter substance, how-
ever, incloses a small hard gall, which is the im-
mediate residence of the included insect. Galls of
this description are often found in clusters of from
two to seven, near the extremity of a branch, not in-
corporated, however, but distinctly separate.

We have obtained a fly very similar to this from a
very common gall, which is formed on the branches

Woody-Gall on a Willow branch, drawn from a specimen,

of the willow. Like the one-celled galls just de-
scribed, this is of a hard, ligneous structure, and forms
an irregular protuberance, sometimes at the ex-

GALL-FLIES. 387

tremity, and sometimes on the body, of a branch.
But instead of one, this has a considerable number of
cells, irregularly distributed through its substance.
The structure is somewhat spongy, but fibrous; and
externally the bark is smoother than that of the branch
upon which it grows.*

The currant-galls (as the French call them) of the
oak are exactly similar, when formed on the leaves,
to those which we have first described as produced
on the leaves of the willow and other trees. But the
name of currant-gall seems still more appropriate to
an excrescence which grows on the catkins of the oak,
giving them very much the appearance of a strag-
gling bunch of currants or bird-cherries. The galls
resemble currants which have fallen from the tree
before being ripe. These galls do not scem to differ
from those formed on the leaves of the oak; and are
probably the production of the same insect, which

Currant-Gall of the catkins of the Oak, produced by Cynips
quercus pedunculi ?
ale Fa) |
z2

388 INSECT ARCHITECTURE.

selects the catkin in preference, by the same instinct
that the oak-apple gall-fly, as we have seen, some-
times deposits its eggs in the bark of the oak near the
root.

The gall of the oak, which forms an important
dye-stuff, and is used in making writing-ink, is also
produced by a Cynips, and has been described in the
Library of Entertaining Knowledge (Vegetabie
Substances, p. 16). The employment of the Cynips
psenes for ripening figs is described in the same
volume, p. 244.

Gatyt oF a Hawrnorn WEEVIL.

In May, 1829, we found on a hawthorn at Lee, in
Kent, the leaves at the extremity of a branch neatly
folded up in a bundle, but not quite so closely as is
usual in the case of leaf-rolling caterpillars. On
opening them, there was no caterpillar to be seen,
the centre being occupied with a roundish, brown-
coloured, woody substance, similar to some excres-
cences made by gall-insects (Cynips). Had we been
aware of its real nature, we should have put it imme-
diately under a glass or in a box, till the contained
insect had developed itself; but instead of this, we
opened the ball, where we found a small yellowish
grub coiled up, and feeding on the exuding juices of
the tree. As we could not replace the grub in its
cell, part of the walls of which we had unfortunately
broken, we put it in a small pasteboard box witha
fresh shoot of hawthorn, expecting that it might con-
struct a fresh cell. This, however, it was probably
incompetent to perform: it did not at least make the
attempt, and neither did it seem to feed on the fresh
branch, keeping in preference to the ruins of its
former cell. To our great surprise, although it was
thus exposed to the air, and deprived of a considerable
portion of its nourishment, both from the part of the

-

HAWTHORN-WEEVIL. 389

cell having been broken off, and from the juices of
the branch having been dried up, the insect. went
through its regular changes, and appeared in the
form of a small greyish-brown beetle of the weevil

Gall of the Hawthorn-Weevil, drawn from specimen.

a, opened to show the grub.
family. The most remarkable circumstance in the
case in question was the apparent inability of the
grub to construct a fresh cell after the first was in-
jured,—proving, we think, beyond a doubt, that it
is the puncture made by the parent insect when the
egg is deposited, that causes the exudation and sub-
sequent concretion of the juices forming the gall.
These galls were very abundant during the summer of
1830.*

A few other instances of beetles producing galls
are recorded by naturalists. Kirby and Spence have
ascertained, for example, that the bumps formed on
the roots of kedlock or charlock (Sinapis arvensis)
are inhabited by the larvee of a weevil (Curculio
contractus, Marsaam ; and Rhynchenus assimilis,
Far.) ; and it may be reasonably supposed that
either the same or similar insects cause the clubbing

*J.R.
z3

390 INSECT ARCHITECTURE.

of the roots of cabbages, and the knob-like galls on
turnips, called in some places the anbury. We have
found them also infesting the roots of the holyhock
(Alcea rosea). They are evidently beetles of an allied
genus which form the woody galls sometimes met
with on the leaves of the guelder-rose ( Viburnum),
the lime-tree (Tilia Europea), and the beech (Fagus
sylvatica).

There are also some two-winged flies which pro-
duce woody galls on various plants, such as the
thistle-fly (Tephritis cardui, Larr.) The grubs of
this pretty fly produce on the leaf-stalks of thistles
an oblong woody knob. On the common white
briony (Bryonica dioica) of our hedges may be found
a very pretty fly of this genus, of a yellowish brown
colour, with pellucid wings, waved much like those
of the thistle-fly with yellowish brown. ‘This fly lays
its eggs near a joint of the stem, and the grubs live
upon its substance. The joint swells out into an
oval form furrowed in several places, and the fly is
subsequently disclosed. In its perfect state it feeds
on the blossom of the briony.* Flies of another
minute family, the gall-gnats (Cecidomyia, Larr.),
pass the first stage of their existence in the small
globular cottony galls which abound on germander
speedwell (Veronica chamedrys), wild-thyme (T'hy-
mus serpyllum), and ground-ivy (Glechoma hede-
racea). ‘The latter is by uo means uncommon, and
may be readily recognised.

Certain species of plant-lice ( Aphides), whose
complete history would require a volume, produce
excrescences upon plants which may with some pro-
priety be termed galls, or semi-galls. Some of these
are without any aperture, whilst others are in form
of an inflated vesicle, with a narrow opening on the
under side of a leaf, and expanding (for the most

* OLR.

GALL-BEETLES. 393

part irregularly) into a rounded knob on its upper
surface. The mountain-ash (Pyrus aucuparia) has
its leaves and young shoots frequently affected ir
this way, and sometimes exhibits galls larger than a
walnut, or even than a man’s fist; at other times
they do not grow larger than a filbert. Upon open-
ing one of these, they are found to be filled with the
aphides sorbi. If taken at an early stage of their
growth, they are found open on the under side of the
leaf, and inhabited only by a single female aphis,
pregnant with a numerous family of young. In a
short time, the aperture becomes closed, in conse-
quence of the insect making repeated punctures
round its edge, from which sap is exuded, and
forms an additional portion of the walls of the cell.

A Plant-Louse (Aphis), magnified.

In this early stage of its growth, however, the gall
does, not, like the galls of the cynips, increase very
much indimensions. It is after the increase of the
inhabitants by the young brood that it grows with
considerable rapidity: for each additional insect, in
order to procure food, has to puncture the wall of the
chamber and suck the juices, and from the punctures
thus made the sap exudes, and enlarges the walls.
As those galls are closed all round in the more ad-
vanced state, it does not appear how the insects can
ever effect an exit from their imprisonment.

392 INSECT ARCHITECTURE.

A much more common production, allied to the
one just described, may be found on the poplar, in
June and July. Most of our readers may have ob-
served, about Midsummer, a small snow-white tuft
of downy-looking substance floating about on the
wind, as if animated. Those tufts of snow-white
down are never seen in numbers at the same time,
but generally single, though some dozens of them
may be observed in the course of one day. This sin-
gular object is a four-winged fly (Hriosoma popult,
Leacn), whose body is thickly covered with long
down—a covering which seems to impede its flight,
and make it appear more like an inanimate substance
floating about on the wind, than impelled by the
volition of a living animal. This pretty fly feeds
upon the fresh juices of the black poplar, preferring
that of the leaves and leaf-stalks, which it punctures
for this purpose with its beak. It fixes itself with
this design to a suitable place upon the principal
nervure of the leaf, or upon the leaf-stalk, and re-
mains in the same spot till the sap, exuding through
the punctures, and thickening by contact with the
air, surrounds it with a thick fleshy wall of living
vegetable substance, intermediate in texture between
the wood and the leaf, being softer than the former
and harder than the latter. In this snug little cham-
ber, secure from the intrusion of lady-birds and the
grubs of aphidivorous flies (Syrphi), she brings
forth her numerous brood of young ones, who imme-
diately assist in enlarging the extent of their dwelling,
by puncturing the walls. In one respect, however,
the galls thus formed differ from those of the moun-
tain-ash just described,—those of the poplar having
always an opening left into some part of the cell, and
usually in that portion of it which is elongated into
an obtuse beak. From this opening the young, when
arrived at the winged state, make their exit, to form

GALL-APHIDES. 393

new colonies; and, during their migrations, attract
the attention of the most incurious by the singularity
of their appearance.”

Galls produced on the leaves and leaf-stalks of the Poplar by
Eriosoma populi, with the various firms of the insects, winged,
not winged, and covered with wool, both of the natural size and
magnijied.

On the black poplar there may be found, later in
the season than the preceding, a gall of a very dif-
ferent form, though, like the other, it is for the most
part on the leaf-stalk. The latter sort of galls are
of aspiral form; and though they are closed, they
open upon slight pressure, and appear to be formed
of two lamina, twisted so as to unite. It is at this

* JR.

394 INSECT ARCHITECTURE.

opening that an aperture is formed spontaneously for
the exit of the insects, when arrived ata perfect state.
In galls of this kind we find aphides, but of a dif-
ferent species from the lanigerous ones, which form
the horn-shaped galls above described.

Lear-Rouiurne Apnipes.

It may not be improper to introduce here a brief
sketch of some other effects, of a somewhat similar
kind, produced on leaves by other species of the
same family (Aphide). In all the instances of this
kind which we have examined, the form which the
leaf takes serves as a protection to the insects, both
from the weather and from depredators. That there
is design in it appears from the circumstance of the
aphides crowding into the embowering vault which
they have formed; and we are not quite certain
whether they do not puncture certain parts of the
leaf for the very purpose of making it arch over
them; at least, in many cases, such as that of the
hop-fly (Aphis humuli), though the insects are in
countless numbers, no arching of the leayes follows.
The rose-plant louse, again (Aphis rose), sometimes
arches the leaves, but more frequently gets under the
protecting folds of the half expanded leaf-buds.*

One of the most common instances of what we
mean occurs on the leaves of the currant-bush,
which may often be observed raised up into irregular
bulgings, of a reddish-brown colour. On examining
the under side of such a leaf, there will be seen a
crowd of small insects, some with and some without
wings, which are the Aphides ribis in their different
stages, feeding securely and socially on the juices of
the leaf.

The most remarkable instance of this, however,

*SR

APHIDES. 395

Leaj’ of the Currant-bush, bulged out by the Aphis ribis.

which we have seen, occurs on the leaves of the elm,
and is caused by the Aphis ulmi. The edge of an
elm-leaf inhabited by those aphides is rolled up in
an elegant convoluted form, very much like a spiral
shell ; and in the embowered chamber thus formed,
the insects are secure from rain, wind, and, partially,
from the depredations of carnivorous insects. One
of their greatest enemies, the lady-bird (Coccinella),
seldom ventures, as we have remarked, into concealed
corners, except in cold weather, and contrives to
find food enough among the aphides which feed
openly and unprotected, such as the zebra aphides of
the alder (Aphides sambuci). The grubs, however,
of the lady-bird, and also those of the aphidivorous
flies (Syrphi), may be found prying into the most
secret recesses of a leaf to prey upon the inhabitants,

396 INSECT ARCHITECTURE.

whose slow movements disqualify them from effect-
ing an escape.*

The effects of the puncture of aphides on growing
plants is strikingly illustrated in the shoots of the
lime-tree and several other plants, which become
bent and contorted on the side attacked by the insects,
in the same way that a shoot might warp by the loss
of its juices on the side exposed to a brisk fire. The
curvings thus effected become very advantageous to
the insects, for the leaves sprouting from the twig,
which naturally grow at a distance from each other,
are brought close together in a bunch, forming a
kind of nosegay, that conceals all the contour of
the sprig, as well as the insects which are em-
bowered under it, protecting them against the rain
and the sun, and, at the same time, hiding them
from observation. It is only requisite, however,

Shoot of the Lime-tree contorted by the punctures of the Aphis Tile.

where they have formed bowers of this descrip-

tion, to raise the leaves, in order to see the little

colony of the aphides,—or the remains of those
PTakte

PSEUDO-GALLS. 397.

habitations which they have abandoned, We haye
sometimes observed sprigs of the lime-tree, of a
thumb’s thickness, portions of which resembled spiral
screws ; but we could not certainly have assigned the
true cause for this twisting, had we not been ac-
quainted with the manner in which aphides contort
the young shoots of this tree.* The shoots of the
gooseberry and the willow are sometimes contorted in
the same way, but not so strikingly as the shoots of
the lime.

Psrupo-Ga.zs.

It may not be out of place to mention here certain
anomalous excrescences upon trees and other plants,
which, though they much resemble galls, are not so
distinctly traceable to the operations of any insect. In
our researches after galls, we have not unfrequently
met with excrescences, which so very much resemble
them, that before dissection we should not hesitate to

Pseudo-galls of the Bramble, drawn from a specimen.

* Réaumur, vol. iii.
ZA

_-- ——_— _—— ‘4 = i -—-. . =

398 INSECE ARCHITECTURE.

consider them as such, and predict that they formed
the nidus of some species of insects. In more
instances than one we have felt so strongly assured of
this, that we have kept several specimens for some
months, in nurse-boxes, expecting that in due time the
perfect insects would be disclosed.

One of these pseudo-galls occurs on the common
bramble (Rubus fruticosus), and bears some resem-
blance to the bedeguar of the rose when old and
changed by weather. It clusters round the branches
in the form of irregular granules, about the size of a
pea, very much crowded, the whole excrescence being
rather larger than a walnut. We expected to find
this excrescence full of grubs, and were much sur-
prised to discover, upon dissection, that it was only a
diseased growth of the plant, caused (it might be)
by the puncture of an insect, but not for the purpose
of a nidus or habitation.*

Another sort of excrescence is not uncommon on
the terminal shoots of the hawthorn. This is in
general irregularly oblong, and the bark which covers
it is of an iron colour, similar to the scoriz of a black-
smith’s forge. When dissected, we find no traces of
insects, but a hard, ligneous, and rather porous tex-
ture. It is not improbable that this excrescence may
originate in the natural growth of a shoot being
checked by the punctures of aphides, or of those grubs
which we have described (page 389).

Many of those excrescences, however, are probably
altogether unconnected with insects, and are simply
hypertrophic diseases, produced by too much nourish-
ment, like the wens produced on animals. Instances
of this may be seen at the roots of the holyhock

Alihea rosea) of three or four years’ standing ; on
the stems of the elm and other trees, immediately

* IR.

PSEUDO-GALLS. 399

Pseudo-galls of the Hawthorn, drawn from specimens.

above the root; and on the upper branches of the
birch, where a crowded cluster of twigs sometimes
grows, bearing no distant resemblance to a rook’s
nest in miniature, and provincially called witch-knots.

One of the prettiest of those pseudo-galls with
which we are acquainted is produced on the Scotch
fir (Pinus sylvestris), by the aphis pini, which is one
of the largest species of our indigenous aphides. The
production we allude to may be found, during the

Poetudo-gall produced by Aphis Pini on the Scotch fir, drawn from
@ specimen.
2a2

400 INSECT ARCHITECTURE.

summer months, on the terminal shoots of this tree,
in the form of a small cone, much like the fruit of the
tree in miniature, but with this difference, that the
fruit terminates in a point, whereas the pseudo-gall
is nearly globular. Its colour also, instead of being
green, is reddish ; but it exhibits the tiled scales of the
fruit-cone.

We haye mentioned this the more willingly that it
seems to confirm the theory which we have hazarded
respecting the formation of the bedeguar of the rose
and other true galls—by which we ascribed to the sap,
diverted from its natural course by insects, a tendency
to form leaves, &c., like those of the plant from which
it is made to exude.

401

Cuarrer XX.
Animal Galls,* produced by Breeze-Flies and Snail-Beetles.

Tue structures which we have hitherto noticed have
all been formed of inanimate materials, or at the
most of growing vegetables ; but those to which we
shall now avert are actually composed of the flesh
of living animals, and seem to be somewhat akin to
the galls already described, as formed upon the
shoots and leaves of plants. ‘These were first inves-
tigated by the accurate Vallisnieri, and subsequently
by Réaumur, De Geer, and Linneus; but the best
account which has hitherto been given of them is by
our countryman Mr. Bracey Clark, who differs essen-
tially from his predecessors as to the mode in which
the eggs are deposited. As, in consequence of the
extreme difficulty, if not the impossibility, of personal
observation, it is no easy matter to decide between
the conflicting opinions, we shall give such of the
statements as appear most plausible.

The mother breeze-fly (Oestrus bovis, CLARK ;—
Hypoderma bovis, Latr.), which produces the tu-
mours in cattle called wurbles, or wormuls (quast,
worm-holes), is a two-winged insect, smaller, but
similar in appearance and colour to the carder-bee
(p. 64), with two black bands, one crossing the
shoulders and the other the abdomen, the rest being

* In order to prevent ambiguity, it is necessary to remark that
the excrescences thus called must not be confounded with the
true galls, which are occasionally found in the gall bladder.

402 INSECT ARCHITECTURE.

covered with yellow hair. This fly appears to haye
been first discovered by Vallisnieri, who has given a
curious and interesting history of his observations
upon itseconomy. “ After having read this account,”
says Réaumur, “with sincere pleasure, I became ex-
ceedingly desirous of seeing with my own eyes what
the Italian naturalist had reported in so erudite and
pleasing a manner. I did not then imagine that it
would ever be my lot to speak upon a subject which
had been treated with so much care and elegance ;
but since I have enjoyed more favourable opportuni-
ties than M. Vallisnieri, it was not difficult for me to
investigate some of the circumstances better, and to
consider them under a different point of view. It is
not indeed very wonderful to discover something
new in an object, though it has been already carefully
inspected with very good eyes, when we sit down to
examine it more narrowly, and in a more favourable
position ; while it sometimes happens, also, that most
indifferent observers have detected what had been
previously unnoticed by the most skilful interpreters
of nature.”*

From the observations made by Réaumur, he
concluded that the mother-fly, above described, de-
posits her eggs in the flesh of the larger animals, for
which purpose she is furnished with an ovipositor of
singular mechanism. We have seen that the ovi- -
positors of the gall-flies (Cynips) are rolled up within
the body of the insect somewhat like the spring of a
watch, so that they can be thrust out to more than
double their apparent length. To effect the same
purpose, the ovipositor of the ox-fly lengthens, by
a series of sliding tubes, precisely like au opera-
glass. There are four of these tubes, as may be
seen by pressing the belly of the fly till they come

* Réaumur, Mem. iy. 505.

.

ANIMAL GALLS. 403

into view. Like other ovipositors of this sort, they
are composed of a horny substance ; but the terminal
piece is very different indeed from the same part in
the gall-flies, the tree-hoppers (Cicad@), and the
ichneumons, being composed of five points, three of
which are longer than the other two, and at first
sight not unlike a fleur-de-lys, though, upon nar-
rower inspection, they may be discovered to termi-
nate in curved points, somewhat like the claw of a
cat. The two shorter pieces are also pointed, but
not curved; and by the union of the five, a tube is
composed for the passage of the eggs.

Ovipositor of the breeze-fly, greatly magnified, with a claw
and part of the tube distinct.
It would be necessary, Réaumur confesses, to see
the fly employ this instrument to understand in what
manner it acts, though he is disposed to consider it

404 INSECT ARCHITECTURE.

fit for boring through the hides of cattle. “ When-
ever T have succeeded,” he adds, “in seeing these
insects at work, they have usually shewn that they
proceeded quite differently from what I had imagined ;
but unfortunately I have never been able to see one
of them pierce the hide of a cow under my eyes.”’*

Mr. Bracey Clark, taking another view of the
matter, is decidedly of opinion that the fly does not
pierce the skin of cattle with its ovipositor at all, but
merely glues its eggs to the hairs, while the grubs,
when hatched, eat their way under the skin. If this
be the fact, as is not improbable, the three curved
pieces of the ovipositor, instead of acting, as Réaumur’s
imagined, like a centre:bit, will only serve to prevent
the eggs from falling till they are firmly glued to the
hair, the opening formed by the two shorter points
permitting this to be effected. This account of the
matter is rendered more plausible, from Réaumur’s
statement that the deposition of the egg is not at-
tended by much pain, unless, as he adds, some very
sensible nervous fibres have been wounded. According
to this view, we must not estimate the pain produced
by the thickness of the instrument ; for the sting
of a wasp or a bee, although very considerably
smaller than the ovipositor of the ox-fly, causes a
very pungent pain. It is in the latter case, the
poison infused by the sting, rather than the wound,
which oceasions the pain; and Vallisnieri is of
opinion that the ox-fly emits some acrid matter along
with her eggs; but there is no proof of this beyond
conjecture,

It ought to be remarked, however, that cattle have
very thick hides, which are so far from being acutely
sensitive of pain, that in countries where they are put
to draw ploughs and waggons, they find a whip

* Mem. iy. 538,

ANIMAL GALLS. 405

ineffectual to drive them, and have to use a goad, in
form of an iron needle, at the end of a stick. Were
the pain inflicted by the fly very acute, it would find
it next to impossible to lay thirty or forty eggs without
being killed by the strokes of the ox’s tail; for though
Vallisnieri supposes that the fly is shrewd enough
to choose such places as the tail cannot reach, Réau-
mur saw a cow repeatedly flap its tail upon a part
full of the gall-bumps; and in another instance he
saw a heifer beat away a party of common flies from
a part where there were seven or eight gall-bumps,
He concludes, therefore, with much plausibility, that
these two beasts would have treated the ox-flies in the
same way, if they had given them pain when de-
positing their eggs.

The extraordinary effects produced upon cattle, on
the appearance of one of these flies, would certainly
lead us to conclude that the pain inflicted is excru-
ciating, Most of our readers may recollect to have
seen, in the summer months, a whole herd of cattle
start off across a field at full gallop, as if they were
racing,—their movements indescribably awkward—
their tails being poked out behind them as straight
and stiff as a post, and their necks stretched to their
utmost length. All this consternation has been |
known, from the earliest times, to be produced by the
fly we are describing. “Yirgil gives a correct and
nively picture of it in his Georgics,* of which the fol-
owing is a translation, a little varied from Trapp :—

Round Mount Alburnus, green with shady oaks,
And in the groves of Silarus, there flies

* Est lucos Silari circa illicibusque, virentem
Plurimus Alburnum volitans, cui nomen asilo
Romanum est, CEstrum Graii vertere vocantes,
Asper, acerba.sonans; quo tota exterrita sylvis
Diffugiunt armenta; furit mugitibus ather
Concussus, sylveeque et sicci ripi Tanagri.

Georg. lib. iii. 1. 146,
243

406 INSECY ARCHITECTURE,

An insect pest (named Q¥strus by the Greeks,
By us Asilus): fierce with jarring hum

It darts towards the herd, driving them terrified
From glade to glade, while the far sky resounds,
And woods and rivers’ banks echo their lowings.

Had we not other instances to adduce, of similar
terror caused among sheep, deer, and horses, by in-
sects of the same genus, which are ascertained not
to penetrate the skin, we should not have hesitated to
conclude that Vallisnieri and Réaumur are right, and
Mr. Bracey Clark wrong. In the strictly similar in-
stance of reindeer fly (Cstrus tarandi, Linn.), we
have the high authority of Linngeus for the fact, that
it lays its eggs upon the skin. .

“T remarked,” he says, “‘ with astonishment, how
greatly the reindeer are incommoded in hot weather,
insomuch that they cannot stand still a minute, no
not a moment, without changing their posture, start-
ing, puffing and blowing continually, and all on
account of a little fly. Even though amongst a herd
of perhaps five hundred reindeer there were not
above ten of those flies, every one of the herd trem-
bled and kept pushing its neighbour about. The
fly, meanwhile, was trying every means to get at
them; but it no sooner touched any part of their
bodies, than they made an immediate effort to shake
it off. I caught one of these insects as it was flying
along with its tail protruded, which had at its extremity
a small linear orifice perfectly white. The tail itself
consisted of four or five tubular joints, slipping into
each other like a pocket spying-glass, which this fly,
like others, has a power of contracting at pleasure.’”*

In another work. he is still more explicit. ‘ This
well-known fly,” he says, “hovers the whole day
over the back of the reindeer, with its tail protruded

* Linnaeus Lachesis Lapponica, July 19th.

ANIMAL GALLS. 407

and a little bent, upon the point of which it holds a
small white egg, scarcely so large as a mustard-seed,
and when it has placed itself in a perpendicular posi-
tion, it drops its egg, which rolls down amongst the
hair to the skin, where it is hatched by the natural
heat and perspiration of the reindeer, and the grub
eats its way slowly, under the skin, causing a bump
as large as an acorn.”* The male and female of
the reindeer breeze-fly are figured in the Library of
Entertaining Knowledge, Menageries, vol. i., p. 405.

There is one circumstance which, though it appears
to us to be of some importance in the question, has
been either overlooked or misrepresented in books.
“While the female fly,” say Kirby and Spence, ‘is
performing the operation of oviposition, the animal
attempts to lash her off as it does other flies, with
its tail;”+ though this is not only at variance with
their own words in the page but one preceding,
where they most accurately describe “the herd with
their tails in the air, or turned upon their backs, or
stiffly stretched out in the direction of the spine,”}
but with the two facts mentioned above from
Réaumur, as well as with common observation. If
the ox then do not attempt to lash off the breeze-fly,
but runs with its tail stiffly extended, it affords a
strong presumption that the fly terrifies him by
her buzzing (asper, acerba sonans), rather than
pains him by piercing his hide; her buzz, like the
rattle of the rattle-snake, being instinctively under-
stood, and intended, it may be, to prevent an over-
population, by rendering it difficult to deposit the
eggs.

The horse breeze-fly (Gasterophilus equi, Leacn),
which produces the maggots well known by the name
of botts in horses, is ascertained beyond a doubt to

* Linnaeus, Flora Lapponica, p. 378, ed. Lond. 1792.
+ Kirby and Spence, Introd. i, 151, { Ibid. p, 14%

408 INSECT ARCHITECTURE,

deposit her eggs upon the hair, and, as insects of the
same genus almost invariably proceed upon similar
principles, however much they may vary in minute
particGlars, it may be inferred with justice, that the
breeze-flies which produce galls do the same. The
description given by Mr. Bracey Clark, of the pro-
ceedings of the horse breeze-fly, is exceedingly in-
teresting.

“When the female has been impregnated, and her
eggs sufficiently matured, she seeks among the
horses a subject for her purpose, and approaching
him on the wing, she carries her body nearly upright
in the air, and her tail, which is lengthened for the
purpose,* curved inwards and upwards: in this way
she approaches the part where she designs to de-
posit the egg; and suspending herself for a few
seconds before it, suddenly darts upon it and leaves
the egg adhering to the hair; she hardly appears to
settle, but merely touches the hair with the egg held
out on the projected point of the abdomen.* ‘The
egg is made to adhere by means of a glutinous
liquor secreted with it. She then leaves the horse
at a small distance, and prepares a second egg, and
poising herself before the part, deposits it in the same
way, The liquor dries, and the egg becomes firmly
glued to the hair; this is repeated by these flies till
tour or five hundred eggs are sometimes placed on
one horse.”

Mr. Clark farther tells us that the fly is careful to
select a part of the skin which the horse can easily
reach with his tongue, such as the inside of the
knee, or the side and back part of the shoulder. It

* These circumstances afford, we think, a complete answer to
the query of Kirby and Spence,—* There can be Tittle doubt (or
else what is the use of such an apparatus ?) that it bores a hole
in (he skin,””—Introd., i, 162, 2nd edit,

ANIMAL-GALLS. 409

was at first conjectured, that the horse licks off the
eggs thus deposited, and that they are by this means
conveyed into its stomach; but Mr. Clark says, “I
do not find this to be the case, or at least only by
accident; for when they have remained on the hair
four or five days, they become ripe, after which time
the slightest application of warmth and moisture is
sufficient to bring forth, in an instant, the latent larva.
At this time, if the tongue of the horse touches the
egg, its operculum is thrown open, and a small
active worm is produced, which readily adheres to
the moist surface of the tongue, and is thence con-
veyed with the food to the stomach.” He adds,
that “a horse which has no ova deposited on him
may yet have botts, by performing the friendly office
of licking another horse that has.”* The irrita-
tions produced by common flies (Anthomyie me-
teorice, Mricen) are alleged as the incitement to
licking.

The circumstance, however, of most importance to
our purpose, is the agitation and terror produced
both by this fly, and by another horse-breeze-fly
(Gasterophilus hemorrhordalis, Lracn), which de-
posits its eggs upon the lips of the horse, as the
sheep-breeze-fly (Gistrus ovis) does on that of the
sheep. The first of these 1s described by Mr. Clark
as “very distressing to the animal, from the excessive
titillation it occasions ; for he immediately after rubs
his mouth against the ground, his fore-feet, or some-
times against a tree, with great emotion ; till, finding
this mode of defence insufficient, he quits the spot in
arage, and endeavours to avoid it by galloping away
to a distant part of the field, and if the fly still con-
tinues to follow and teaze him, his last resource is in
the water, where the insect is never observed te pur-

* Linn. Trans. ii, 305.

410 INSECT ARCHITECTURE.

sue him. These flies appear sometimes to hide them-
selves in the grass, and as the horse stoops to graze
they dart upon the mouth or lips, and are always
observed to poise themselves during a few seconds
in the air, while the egg is preparing on the extended
povnt of the abdomen.” *

The moment the second fly just mentioned touches
the nose of a sheep, the animal shakes its head, and
strikes the ground violently with its fore-feet, and at
the same time, holding its nose to the earth, it runs
away, looking about on every side to see if the flies
pursue. A sheep will also smell the grass as it goes,
lest a fly should be lying in wait, and if one be de-
tected, it runs off in terror. As it will not, like a horse
or an ox, take refuge in the water, it has recourse to a
rut or dry dusty road, holding its nose close to the
ground, thus rendering it difficult for the fly to get at
the nostril.

When the egg of the ox-breeze-fly (Hypoderma

a, the belly of the grub, b, its back. ¢, the tail of the grub,
greatly magnified. d, the bump, or gall, having its external
aperture filled with the tail of the grub,

* Linn. Trans. iii. 305,

ANIMAL-GALLS. 411

bovis, Latn.) is hatched, it immediately (if Mr.
Bracey Clark be correct) burrows into the skin;
while, according to Réaumur, it is hatched there.
At all events, the grub is found in a bump on the
animal’s back, resembling a gall on a tree,—“‘ a
place,’ says Réaumur, “where food is found in
abundance, where it is protected from the weather,
where it enjoys at all times an equal degree of
warmth, and where it finally attains maturity.”’ *
When in an advanced stage, the bumps appear much
like the swellings produced upon the forehead by a
smart blow. These, with the grubs, are represented
in the foregoing figure, and also at page 412.

Every bump, according to Réaumur, has in its
inside a cavity, which is a lodging proportionate to
the size of the insect. The bump and cavity also
increase in proportion to the growth of the grub. It
is not until about the middle of May that these bumps
can be seen full grown. Owing to particular cir-
cumstances, they do not all attain an equal size. The
largest of them are sixteen or seventeen lines in dia-
meter at their base, and about an inch high; but they

Fly, maggot, and grub of the Ox-breeze-fly, with @ microscopic
view of the maggot.

* Mem. iv. 540.

412 INSECT ARCHITECTURE.

are scarcely perceptible before the beginning or dur-
ing the course of the winter.

It is commonly upon young cattle, such, namely,
as are two or three years old, that the greatest num-
ber of bumps is found ; it being rare to observe them
upon very old animals. The fly seems to be well
aware that such skins will not oppose too much re-
sistance, and seems to know, also, that tender flesh
is the most proper for supplying good nourishment
to its progeny. ‘‘ And why,” asks Reaumur, “should
not the instinct which conduets it to confine its eggs
to the flesh of certain species only, lead it to prefer
the flesh of animals of the same species which is most
preferable?” The number of bumps which are found
upon a beast is equal to the number of eggs which
have been deposited in its flesh; or, to speak more
correctly, to the number of eggs which have suc-
ceeded, for apparently all are not fertile; but this
number is very different upon different cattle. Upon

Bumps or wurbles produced on cattle by the Ox-breeze-fly.

ANIMAL-GALLS. ; 413

one cow only three or four bumps may be observed,
while upon another there will appear from thirty to
forty. They are not always placed on the same parts,
nor arranged in the same manney: commonly, they
are near the spine, but sometimes upon or near the -
thighs and shoulders. Sometimes they are at remote
distances from each other; at other times they are
so near that their circumferences meet. In certain
places, three or four tumours may be seen touching
each other; and more than a dozen sometimes occur
arranged as closely together as possible.

It is very essential to the grub that the hole of the
tumour should remain constantly open; for by this
aperture a communication with the air necessary for
respiration is preserved; and the grub is thence
placed in the most favourable position for receiving
air. Its spiracles for respiration, like those of many
other grubs, are situated immediately upon the pos-
terior extremity of the body. Now being almost
always placed in such a situation as to have this part
above, or upon a level with the external aperture, it
is enabled to respire freely.*

We have not so many examples of galls of this
kind as we haye of vegetable-galls; and when we
described the surprising varieties of the latter, we did
not perceive that it was essential to the insects inha-
biting them to preserve a communication with the
external air: in the galls of trees, openings expressly
designed or kept free for the admission of air are
never observed. Must the grub, then, which inhabits
the latter have less need of respiring air than the
grub of the breeze-flies in a flesh-gall? Without
doubt, not; but the apertures by which the air is
admitted to the inhabitants of the woody gall, al-
though they may escape our notice, im consequence
of their minuteness, are not, in fact, less real. We

* Réaumur, iv. 549,

414 INSECT ARCHITECTURE,

know that, however careful we may be in inserting a
cork into a glass, the mercury with which it is filled
is not sheltered from the action of the air, which
weighs upon the cork; we know that the air passes
through, and acts upon the mercury in the tube.
The air can also, in the same way, penetrate through
the obstruction of a gall of wood, though it have no
perceptible opening or crack ; but the air cannot pass
in this manner so readily through the skins and mem-
branes of animals.

In order to see the interior of the cavity of an
animal-gall, Réaumur opened several, either with
a razor or a pair of scissors; the operation, however,
cannot fail to be painful to the cow, and consequently
it renders it impatient under the process. The grub
being confined in a tolerably large fistulous ulcer, a
part of the cavity must necessarily be filled with pus
or matter. The bump is a sort of cautery, which
has been opened by the insect, as issues are made by
caustic : the grub occupies this issue, and preyents it
from closing. If the pus or matter which is in the ca-
vity, and that which is daily added to it, had no means
of escaping, each tumour would become a consider-
able abscess, in which the grub would perish: but the
hole of the bump, which admits the entrance of the
air, permits the pus or matter to escape; that pus
frequently matts the hairs together which are above
the small holes, and this drying round the holes
acquires a consistency, and forms in the interior of
the opening a kind of ring. This matter appears to
be the only aliment allowed for the grub, for there is
no appearance that it lives, like the grubs of flesh~
flies, upon putrescent meat. Mandibles, indeed, simi-
lar to those with which other grubs break their food,
are altogether wanting. A beast which has thirty,
forty, or more of these bumps upon its back, would
be in a condition of great pain and suffering, terrible

ANIMAL-GALLS. 415

indeed in the extreme, if its flesh were torn and de-
voured by as many large grubs; but there is every
appearance that they do not at all afflict, or only afflict
it with little pain. For this reason cattle most covered
‘with bumps are not considered by the farmer as in-
jured by the presence of the fly, which generally se-
lects those in the best condition.

A fly, evidently of the same family with the pre-
ceding, is described in Bruce’s Travels, under the
name of zimb, as burrowing during its grub state in
the hides of the elephant, the rhinoceros, the camel,
and cattle. “It resembles,” he says, “the gad-fly in
England, its motion being more sudden and rapid,
than that of a bee. There is something peculiar in
the sound or buzzing of this insect; it is a jarring
noise together with a humming, which as soon as it
is heard all the cattle forsake their food and run
wildly about the plain, till they die, worn out with
fatigue, fright, and hunger. I have found,” he adds,
“some of these tubercles upon almost every elephant
and rhinoceros that I have seen, and attribute them
to this cause. When the camel is attacked by this
fly, his body, head, and legs break out into large
bosses, which swell, break, and putrefy, to the certain
destruction of the creature.”* That camels die under
such symptoms, we do not doubt; but we should
not, without more minutely-accurate observation,
trace all this to the breeze-fly.

MM. Humboldt and Bonpland discovered, in
South America, a species, probably of the same
genus, which attacks man himself. The perfect in-
sect is about the size of our common house-fly,
(Musca domestica), and the bump formed by the
grub, which is usually on the belly, is similar to that
caused by the ox-breeze-fly. It requires six months
to come to maturity, and if it is irritated it eats

* Bruce’s Travels, i. 5, and y. 191.

416 INSECT ARCHITECTURE.

deeper into the flesh, sometimes causing fata] inflam-
mations.
Grup Parasite in THE SNAIL.

During the summer of 1829, we discovered in the
hole of a garden-post, at Blackheath, one of the
larger grey snail shells (Helix aspersa, Muuurr,)
with three white soft-bodied grubs, burrowing in the
body of the snail. They evidently, from their appear-
ance, belonged to some species of beetle, and we
carefully preserved them in order to watch their
economy. It appeared to us that they had attacked
the snail in its strong hold, while it was laid up tor-
pid for the winter; for more than half of the body
was already devoured. They constructed for them-
selves little cells attached to the inside of the shell,
and composed of a sort of fibrous matter, having no
distant resemblance to shag tobacco, both in form
and smell, and which could be nothing else than the
remains of the snail's body. Soon after we took
them, appearing to have devoured all that remained
of the poor snail, we furnished them with another,
which they devoured in the same manner. They
formed a cocoon of the same fibrous materials during
the autumn, and in the end of October appeared in
their perfect form, turning out to be the Drilus fla-
vescens, the grub of which was first discovered in
France in 1824, The time of their appearance, it
may be remarked, coincides with the period when
snails become torpid.*

In the following autumn we found a shell of the
same species with a small pupa-shaped egg deposited
on the lid. From this a caterpillar was hatched, which
subsequently devoured the snail, spun a cocoon within
the shell, and was transformed into a small moth (of
which we have not ascertained the species) in the
spring of 1830.

wer Bl

417

Tur subject of Insect Architecture, to which this
volume is devoted, forms only one division, though a
most interesting and important one, of that branch of
natural history which relates to insects. It presents
some of the most striking views of their economy ;
and, as we have endeavoured to render the examples
of extraordinary instinct with which it abounds
obvious and familiar to every reader, it precedes
somewhat naturally a more minute account of the
physiological part of the science of Entomology, and
of the benefits and injuries to man produced by insects
in the respective stages of their existence. The
present volume is complete in itself; but the subject
of Insects is continued in a second volume, entitled
“Insect TRANSFORMATIONS.”

418

ILLUSTRATIONS.

Page

1 Eggs of insects, magnified . . . . . . « 19
2 Larva, grubs, caterpillars, or maggots . » . . « 20
8 Pupe, or chrysalides . J = . . . . .* 21
4 Insects in the imago or perfect state . . . . . « 22
5 Mason-wasp . i : . ® ‘ . . ° + 26
6 Jaws of mason-wasp, magnified ° . . . " ate.
7 Cuckoo-fly 5 . . . e . . . . eo) 29;
8 Mason-wasp’s nest and cocoons . . . . . » ib.
9 Mason-wasp . . . . ° . , . . . ib.
10 Nests, &c. of mason-wasps . . . . . « 31
11 Mason-bee ay Ss Fy . . é . ° . 84
12 Exterior wall of mason-bee's nest , . - . ‘ . ib.
13 Cells of mason-bee’s nest , . ’ . . . . » 85
14 Varieties in cells of mason-bee’s nest, three figures , a . 4i
15 Mason-bee and nest . ¥ ,, % e * ° A oie 48
16 Cellof mining-bee . ° ° . . « . . « ib.
17 Nests of carpenter-bees, four figures , . . . . - 49
18 Carpenter-bee . . F . . . e . » ib.
19 Teeth of carpenter-bee, magnified . ° . . + ib.
20 Nests of carpenter-wasps, two figures . . . . » 53
21 Carpenter-wasp p . . . eyed Wit « tb,
22 Cocoon of acarpenter-wasp ~ . : gab Pei Ot » ib,
23 Rose-leaf-cutter bees, and nest lined with rose-leaves oh ere
24 Carder-bees heckling moss for their nests , . eifimteg » 66
25 Exterior of the carder-bee's nest ; a . ‘ wf Fe bth
26 Breeding cells of the carder-bee z . = : 5 - 68
27 Interior of carder-bee's nest, two figures, . . e «69
28 Section of social-wasp's nest , . . . A . . 16
29 Suspension rod of social-wasp’s nest . . . . . Catone itf
30 Portion of external crust of Social-wasp’s nest , . . « ib,
31 Hornet's nest in its first stage , . . . . . » 80
32 Singular wasp's nest F . . . . . . « 82
33 Wasp's cells attached toabranch . tates . - 88
34 Nest of the card-maker-wasp . > . . . « + 88
85 Part of a honeycomb, and bees at work . . ° » 89
86 Worker-bee, magnified , ° a . . . . « 108
37 Abdomen of wax-working bee . < sig . . ‘ + 104
88 Structure of the legs of the bee for carrying Propolis, &e. . - 110
39 Curtain of wax-workers secreting wax . . ‘ “ « lia
40 Wax-worker laying the foundation of the first cell, . » 17
41 Curtain of wax-workers . : ‘ . . . . - 1g
42 Arrangement of cells of hive-bees . é . r) 1 188
43 Foundation-wall enlarged and the cells commenced , » 125
44 Ovipositors, with files, of the tree-hopper, magnified , i .» 150
45 Excavations for eggs of tree-hopper, with lid raised , . « Wi
46 Ovipositor of saw-ily protruded from its sheath, magnified . ; 158
47 Ovipositor saw of saw-fly, magnified . . ‘ . . - 154
48 Portion of saw-fly’s comb-toothed rasp, and saw, . Fs . 156
49 Nest of eggs of saw-fly , 4 F * . . . . 158
50 Lilac-tree moth ‘i . * . . 5 . . + 160
51 Nest ofa lilac leaf-roller , . . * . . ‘ + 161

ILLUSTRATIONS,

52 Another nest of lilac leaf roller . .
53 Small green-oak-moth . . . .
54 Nests of onk-leaf-rolling caterpillars . .
55 Nest of the nettle-leaf-rolling caterpillars .
56 Leaf-rolling caterpillars of the sorrel ° .

57 Nests of the hesperia malya, with caterpillar, chrysalis, &c,

58 Nest of willow-leaf-roller .
59 Ziczac caterpillar and nest z .
60 Cypress-spurge caterpillars , . .
61 Cocoon of ditto ona branch . ° .
62 Small caterpillar and moss cell of the same
63 Leaf nest of the caddis-worm . . °
64 Reed nest of ditto . < . .

65 Aquatic nest of ditto , « A ‘
66 Shell nest of ditto, five figures 7 .
67 Stone nest of ditto 3

68 Sand nest of ditto balanced with a stone

69 Nest of ditto balanced with straws .

70 Caterpillar of goat-moth in a willow tree
71 Winter nest of the goat-caterpillar . ri
72 Nest of goat-moth, raised to show the pupa
73 Eggs of the puss-moth . . .

74 Rudiments of the cell of the puss-moth .
75 Cell built by the larva of the puss-moth .
76 Ichneumon , ° . . . .
77 Magnified cells of Pyralis strigulalis A
78 Nests of earth-mason caterpillars, two figures

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

79 Earth-mason caterpillars’ nests, caterpillar and ntoth

80 Earth-mason caterpillars’ nests, moth, &c., seven figures

81 Nests of the grubs of ephemera, two figures,
82 Grub of ephemera . . . . . .

+83 Nest of ephemera in holes of cossus =, x
84 Grub of the ant-lion magnified

85 Trap of the ant-lion in different stages, two figures -

86 Ant-lions’ pitfalls in an experimenting box

87 Cases, &c., of the clothes-moth, and perfect moths 3

88 Caterpillar’s tent nee the leaf of an elm s
89 Tents of the caterpillar in different stages A
90 Tents and caterpillars, natural size,an magnified
91 Branch of the willow with seed spikes , .
92 Muff-tents made of the above cotton . .
93 Muff-making caterpillar . . . . .
94 Leaf of the monthly rose mined by caterpillars
95 Leaf of the dewberry-bramble mined a
96 Leaf ofthe primrosé mined . . : .
97 Capricorn beetle rounding off the bark ofa tree
98 Mole-cricket, with outline of one of its bands ,
99 Nest of the mole-cricket . s 5 .
100 Acrida verrucivora depositing hereggs .
101 Artificial hive for observing the mason-ants
102 Vertical section for mason-ant's nest

103 Contrivance of mason-ants to strengthen the building of their nest271

104 Artificial hive for the wood-ant °

105 Portion of a tree, with chambers, &c., chiseled out by jet-ants

106 Warrior-ant in the winged state , .
107 White-ant queen distended with eggs. .
108 Covered way and nest of the termites arborum

2 ee wea eK we We ee

.

270

276
281
291
295
300

420 ILLUSTRATIONS.

109 Section of the hill nest of the termites bellicosi

110 Hill nest of the termites bellicosi .
111 Turret nests of white-ants

112 Leg and pro-leg of a cater illar, greatly magnified

118 Caterpillar of the goat-moth . :
114 Interior structure of the cossus .
115 Side view of the silk tube A »
116 Section of silk tube, magnified .
117 Labium or lower lip of cossus «

118 Cocoons of the emperor-moth . .
119 Cocoon of arctia villica .« ’ .
i20 Net-work cocoon .

121 Nest of puss-moth, inclosing five cocoons

122 Winter nest of the social caterpillars of the brown

123 Winter nests of Porthesia chrysorrh@a
124 Pendulous leafnests .

125 Nest and order of marching of the processionary caterpillars

tail moth

126 Garden-spider pi al by a thread from its spinneret .

127 Spinneret of a spi

130 Geometric net of the garden-spider -

131 Nests of the mason-spider . ;

132 The spider, mygale cementaria «
183 The eyes, magnified . ° *

134 Parts of the foot and claw, magnified
135 Triple-clawed foot of agpiiler, magnified
136 Small berry-shaped galls of the oak-leaf
137 Ovipositor of gall-fly, greatly megnified

139 Bedeguar-gall of the rose, produced by

142 Leafy gall of dyer’s broom =.

143 Semi-gall of the hawthom . . . .
144 Woolly gall of the oak. ¥ . . . :
145 Oak-apple galls, one cut open to show the vessels .
146 Root galls ofthe oak. . F . .

147 Woody gall on a willow branch « . .

148 Currant gall of the catkins ofthe oak . < ‘
149 Gall of the hawthorn weevil . . . .
150 A plant louse, magnified. . : . . .
151 produced on the leaves of the poplar, with the

forms of the insect, ten figures.

152 Leaf of the currant-bush, bulged out by th

magnified

.

138 Gall-fly, and mechanism of ovipositor, ey magnified
'ynips rose

140 One of the bristles of the bedeguar of the rose,

141 Artichoke gall of the oak-bud, with gall-tly

e Aphis ribes

153 Shoot of the lime-tree contorted by the Aphis tiliw .

154 Psendo-gall of the bramble. ‘
155 Pseudo-galls of the hawthorn . «
156 Pseudo-gall on the Scotch fir « °
157 Ovipositor of the breeze-fly - .
158 Grub of the breeze-fly, four figures .
159 Fly, maggot, and grub of the ox-breeze-fl

y

260 Bumps or wurbles produced on cattle.

er magnified to show the spinxierules -.
128 Single thread of a spider, greatly magnified
129 Attached end of a spider's thread, magnified

ae One

Page

= ene et Mam er are) Ss: Wen &

300

ib.
801
307
308
309
310

ib.
Sil
821
324

ib.
326
330
331
332
334
336
337
338
339
359
362

ib.

ib.

ib.
367
370
372
3713
876
377
878
380
382
383
884
385
886
387
389
391

393
395
396
397
399

ib.
403
410
4i1
412