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ie UNIVERSITY OF COLUMNS
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TERE NON ING WORK.

A NATURAL HISTORY

ORBWEAVING SPIDERS OF THE UNITED STATES

WITH SPECIAL REGARD TO THEIR INDUSTRY AND HABITS.

BY
7 oat (Br NVNVG ee ae Bh eos
HENEY C. McCOOK. D.D.
VICE-PRESIDENT OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA;
VICE-PRESIDENT OF THE AMERICAN ENTOMOLOGICAL SOCIETY ;
AUTHOR OF “THE AGRICULTURAL ANTS OF TEXAS,”

“THE HONEY AND OCCIDENT ANTS,”
ETC., ETC.

PUBLISHED BY THE AUTHOR,
ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA.

A. D. 1889.

AUTHOR'S EDITION,

This Edition is limited to Two HunprepD AnD Firry copies, of
which this set is

SUBSCRIPTIO ere

AvuTHOR’S SIGNATURE,--

THE PRESS OF
ALLEN, LANE & SCOTT,

PHILADELPHIA,

THESE STUDIES IN NATURAL HISTORY
ARE DEDICATED TO
THE VENERATED MEMORY

OF MY FATHER,
JOHN McCOOK, M. D.,

A LOVER OF NATURE, A FRIEND OF SCIENCE,
A GOOD PHYSICIAN, A SERVANT OF
HIS FELLOW MEN
WHOSE FAITH IN THE UNSEEN

NEVER FALTERED.

lo Ve tie ad

f

oy

oe

fy

a

PREFACE.

THe studies whose results are here given have been prosecuted
throughout the last sixteen years. I have largely limited my investiga-
tions to the habits and industry of spiders, as the matters which seemed
most important at this stage of scientific knowledge.

None but the field naturalist can fully know and appreciate the diffi-
culties of my task. To these ordinary obstacles have been added special

hindrances of my own. The cabinet or laboratory student, with
A Field jig pinned and alcoholic specimens, is largely independent of
Natural- fake ; ay ;
ist’s Diffi- outward conditions; but he who studies nature as a living thing
culties, iS the servant of seasons, hours, moods. He must live amidst

the life which he would see, and seize the opportunities as they
come, or lose his venture for that season or year, or perhaps wholly. The
duties of my calling in a large city have held me rigorously away from
the open country except during two months of the year. Summer vaca-
tions, and such leisure hours as a most busy life would allow, have been
given to the pleasant task of following my little friends of the aranead
world into their retreats, and watching at the doors of their fragile domi-
ciles for such secrets of their career as they might happen to uncover.
Occasional excursions at other times were unavoidably brief, and often
broken off at the point of promised discoveries. I have, in part, indeed,
overcome this obstacle by transporting and colonizing specimens, and by
directing the observations of others. But, at the best, artificial conditions
fall short of Nature’s fullness, and no faithfulness of assistants can quite
equal personal investigations.

Then, again, the natural disposition of the spider is a great hindrance
to the prosecution of field studies. It is a solitary and secretive animal,

and the most ingenious device for winning its confidence is as

ee ,. apt to drive it into hiding as to persuade it to revelations. In
ider’s ee
Solitary this respect there is a great difference between these solitary

Nature, Creatures and those sociable and demonstrative insects, the ants,
whose life history I have heretofore been permitted to give to
the scientific world. The success which was readily obtained by spending
a few weeks or months encamped among formicaries of emmets, contin-
ually eluded me when trying like methods with araneads,
(9)

6 PREFACE.

To be sure, in some respects the Orbweavers and Lineweavers are more
approachable than other tribes of spiders; for, as they are sedentary crea-
tures, and are found continuously upon their webs, one often has the oppor-
tunity to observe them with comparative freedom and comfort. But this
is only true of the commoner species, and of that part of their life which
concerns the structure of snares and trapping of food. In other, and even
more interesting fields, these sedentary spiders, like all the wandering groups,
persistently conceal their manners.

When it is considered that most of the facts presented in my books
consecutively, as a connected history, have been collected under such diffi-
culties, and at widely separated periods and places, it is not strange that
some gaps in the life record may be found. But, if in some parts the
connecting links are lacking, and the story is incomplete, it is no more
than ordinarily befalls other naturalists when investigating the habits
of other animals. While, therefore, no one can regret more than I the
blanks which here and there occur in the pages of that wonderful his-
tory of industrial life and art which I have attempted to unfold, I ven-
ture to urge the above reasons for indulgence towards any failures which
may appear.

The general plan of my work, as it will be given to the public, may
briefly be stated as follows: The first volume is chiefly taken up with de-

scriptions of those parts of aranead spinningwork which are gen-
General erally known as the web or snare, and the nest or den. The
Fon oF ye former concerns the nurture of the spider, as the snare is its

manufactured tool for capturing insects. The latter concerns the
protection of the animal from changes of weather and assaults of enemies.
In my studies of the snares of Orbweavers, I have tried to obtain the full-
est possible details of the spinning methods of every species; to mark the
striking differences which exist among the various groups; and to associate
these, as far as my knowledge would permit, with the general habits of
See the various families. Furthermore, I have brought to bear upon
Volume 1, Hese, in a comparative way, the spinningwork and habits of

other tribes, so that the reader may be able to trace resemblances
and differences, and to perceive what relations, if any, exist between the
general life habits of all spiders.

The consideration of these topics has necessarily suggested the degree
of intelligence and the variety and adaptation of methods shown by spi-
ders in their ordinary and special behavior. Thus have come into view
the profound and interesting problems relating to animal mentalism.

Finally, I have endeavored, in the closing chapters, to present a bird’s
eye view of the entire field of industrial life treated of in the volume,
with special bearing upon a common origin, whether from the one stand-
point of a single originating Mind, or from the other standpoint of a
genetic evolution from common ancestral actions and tendencies.

PREFACE. 7

In the second volume I shall take up and treat in the same way the
habits and industry associated with mating and maternal instincts, the
life of the young, the distribution of species, and other general
Plan of habits indicated in the appended table of contents. The third
Volumes ; : ; .
IL andi, Volume of the series will be a systematic presentation of the
Orbweavers of the United States, and this I hope to make toler-
ably complete. The descriptions will be accompanied by a number of
plates drawn in the best style of lithographic art, and painted by hand in
the colors of nature.

The above plan is the result of an entire change in my original pur-
pose, which was to write a natural history of all American spiders, following
consecutively and separately the several tribes, beginning with the Orb-
weavers. A vast amount of material has been gathered with
this purpose in view, but I have found that the work thus
marked out is so great that I doubt my ability to accomplish it
all. For, even should my life be sufficiently lengthened to overtake the
entire field mapped out, the expense of the undertaking appears to be an
impassable barrier. I have, therefore, concluded to introduce, in the com-
parative way referred to, such notes of tribes, other than Orbweayers, as
seemed most desirable and important for solution of the various problems
which have arisen as my studies progressed. Thus, while the Orbweavers
are treated fully, the natural history of all other tribes of our spider fauna
comes well into view. Although I confess some regret at the abandonment
of the original plan, I am confident that most naturalists will agree with
me that the present treatment adds to the value of the volumes now pub-
lished, and is, perhaps, after all the best that could have been adopted.

There is another point at which this work departs from my original
plan. As my observations have especially traversed the spinning habits of

spiders, it seemed important to make a careful study of the spin-
Study of ning organs, not only of Orbweavers, but of all other spider
Spinning | ., :
Gigans. tribes. It was thought that such a comparative study would not

only give valuable hints in the systematic determination of the
animals, but would have an especial bearing upon the variations in spin-
ning habit. It was inferred that there must be some connection between
special function and the organs thereof. In this line work was begun and
prosecuted far enough to see how promising and interesting is the field.
But a severe attack of sickness, whose consequences were felt for several
years, compelled an entire cessation of work with the dissecting knife and
microscope. I was, therefore, reluctantly compelled to omit from the open-
ing chapters much material which I had hoped to present, and to limit
my illustrations to the few which are really necessary to give the reader a
correct idea of the structure of the spinning organs and the manner in
which the spinning material of spiders is formed. Even these illustrations
I have borrowed in part from others. I venture to express the hope that

8 PREFACE.

some one who can thoroughly prosecute this line of studies will be led to
take it up and give the results to the scientific world.

I have made a point of illustrating all descriptions with drawings
whenever the proper material was in hand. During my studies of ara-
nead spinningwork, I have made thousands of original sketches
Full Illus: + sy note books, from which I have selected those that seemed
trations. So. ; 2 :

best suited to make clear the points treated of. Judging by my
own experience, even an outline drawing is better to communicate certain
facts than pages of verbal explanation. Acting upon this belief, I have
preferred to risk excessive illustration rather than fall upon obscure descrip-
tion. Indeed, I cherish the hope that the contents of some of the follow-
ing chapters might be fairly understood by a simple examination of the
cuts with their explanatory legends.

I have not been unmindful of the artistic sense of my readers, which,
I trust, has been measurably satisfied; but I take it for granted that
those who honor me by looking at my work will understand that the
chief object of the engravings is to make plain what I have to say. In
other words, the figures are for illustration and not for embellishment.
Many of the cuts have been redrawn by competent artists, but a large
number remain as figured by myself on block or paper. Among those
who have assisted in making the drawings are the well known artists
and arachnologists, Mr. J. H. Emerton, of Boston, and Dr. George Marx, of
Washington ; also, Messrs. Edwin Sheppard and Frank Stout, of the Acad-
emy of Natural Sciences of Philadelphia; and the Misses Bonsall, of this
city.

It may not be out of place to allude to the fact that, in order to give
my investigations to the public in any form that would satisfy me, I have

been compelled to undertake the entire burden and expense of
Why the publication. Few things could be more inconvenient and dis-
Author is; ae : 3
Publisher t#Steful than the business details thus imposed; but I have ac-
cepted them as a part of the sacrifice required of one who, as a
prophet of the mysteries of Nature, feels called to declare, at whatever cost,
the truths known to him.

Those who have undergone a like experience need not be told that the
amount of loss to fall upon an author will be largely determined by the
interest which friends and associates take in procuring for his book a
place on the shelves of scientific societies and leading libraries.

| have received many favors and much generous help in procuring in-
formation and specimens from various naturalists and friends, for which
Thanks. [ express my thanks. I have tried to give full credit to all in

the appropriate place in text or foot note, but will make de-
served personal acknowledgments in a succeeding volume.

Ee Ca Mee:

Tie Manse,
Put YOV 38
LADELPHIA, Noyember Ist, 1889.

TAS Ee OE CONTENTS OF VOLUME I.

PART I.—STRUCTURE AND SPINNING ORGANS.

CHAPTER I.
GENERAL CLASSIFICATION AND STRUCTURE.

PAGES
The Origin of the Name Spider—Principal Groups, Sedentary and Wandering—Tribal

Divisions—Blackwall’s Classification—Thorell and Bertkau—Highest Forms—Superi-
ority of Lycosids—Orbweavers and Lineweavers—Anatomy of a Spider—Caput—
Eyes—Mandibles —Sternum—Labium—Maxille and Palps—Legs and Claws—The
Abdomen—Pulmonary Sac —The Epigynum and Male Organs—Hints to Collector—
A Spidery—How to Observe Spinningwork and Habits—Preserving Specimens. . 15-33

CHAPTER II.
THE SPINNING ORGANS.

External Spinning Organs—The Spinnerets or Spinning Fingers—The Posterior Spin-
nerets—Middle Spinnerets—Anterior Spinnerets—Bucholz and Landois’ Studies—
Studies of Meckel—Spinning Spools—Internal Spinning Organs—Silk Glands—Liquid
Silk—Pyriform Glands and Ducts—Cylindrical Glands—Treeform Glands—Spinning
Spools of the Pyriform Glands—Spigot Spools—Spools of Middle and Anterior Spin-
nerets—Generic Differences in Spinning Spools—The Muscular System for Expelling
Peck? yy Gel aad Gl Oe le OU et gee ee Se re ere «rae |

PART II.—GENERAL CHARACTERISTICS, CONSTRUCTION,
AND ARMATURE OF WEBS.

CHAPTER III.
GENERAL CHARACTERISTICS OF ORBWEAVERS SNARES.

Popular Errors—An Orbweb Defined—Great Groups of Orbwebs—Parts of the Orb—
Forms of the Hub—The Free Zone—Notched Zone ........... 2... 52-5

CHAPTER IV.
CONSTRUCTION OF AN ORBWEB.

Laying Out the Frame—Dragline—The Prime Foundation—Foundations by Air Currents—
Bridge Lines—Webs Between Trees—Webs on Water Plants—Cobweb Bridges—Trial
Air Lines—Swinging Inspection Baskets—Jonathan Edwards as an Arachnologist—
Double Foundation Lines—Placing in Radii—Alternate Apposition of Radii—Form-
Lubec. NOUCDOGMAOT oes mr tc a Ae 2) 2) 8 nw) <ul is see eee a ee es 2 60=78
(9)

10 TABLE OF CONTENTS.

CHAPTER V.

ARMATURE OF ORBWEBS: VISCID SPIRALS.
PAGES
Spiral Scaffolding—Corner Loops—Spinning Viscid Spirals—Cutting Away the Scaffold—
Size of Beads—Elasticity of Spiral Line—Formation of Beads—Beads Dissolved by
Rains—Tortion of Spirals by Rain—Number and Adhesiveness of Beads—Medicinal
Properticd4 == fs =, <+ she me eee ot Lees oo * ome, cee! na ya ot ge ec

PART III—CHARACTERISTIC FORMS AND VARIATIONS
OF SNARES.

CHAPTER VI.
ARGIOPE AND HER RIBBONED ORB.

Full Orbs—Argiope cophinaria, the Basket Argiope—Distribution and Habitat—The Zig-
zag Ribbon—The Central Shield—How the Shield is Spun—Spinning the Zigzag
Ribbon—A Spider Diary—Swathing Insects—The Notched Zone—Fenders or Pro-
tective Wings—Web of the Male Argiope—Size and Details of Orbs—Argiope
argyraspis, the Banded Argiope—An African Argiope—The Silvered Argiope, A.
STE TILC Oe Sees Sart oa eaaish sh GBI toe wi Se os occ Spy oy Cemlioeh Soe a oa ees aia em Tan

CHAPTER VII.
EPEIRA AND THE ROUND VERTICAL WEB MAKERS.

Familiar Orbwebs—Epeira Strix, the Furrow Spider—Spider Stowaways—The Head
Downward Position—How the Feet Command the Snare—‘ Under Her Thumb ”’—
Natural Sites of Snares—Epeira domiciliorum, or the Domicile Spider—The Insular
Spider, Epeira insularis—The Shamrock Spider, Epeira trifoliam—Tents in Hedge-
rows—Epeira vertebrata—A California Colonist—Epeira trivittata—Gasteracantha—
Tufted Webs—Orbs with Open Hubs—Acrosoma—The Mitred Spider—Epeira cau-
data, the Tailed Spider—Meta—A Cave Dweller. ......... ..... 110-129

CHAPTER VIII.
COMPOSITE SNARES AND SECTORAL ORBS.

The Labyrinth Spider—How the Maze is Made—Uses of the Labyrinth—The Orb—The
Trapline and Hub—Fayorite Sites—Epeira triaranea—Open Sector and Free Radius —
Orientation of Trapline—Spirals Spun in Loops—The Spinningwork of Three Tribes
in One Web —Epeira thaddeus—Zilla and Her Snare—A Scotch Colony—Wilder’s
Nephila—WNephila’s Snares. 69% 62s) ES as es ae ee S019

CHAPTER IX.
HORIZONTAL SNARES AND DOMED ORBS.

The Orchard Spider—Variations in the Orb Plane—Protective Apron—The Hunchback
Spider, Epeira gibberosa—Hunchback’s Hammock—Tetragnatha extensa—Cosmo-
politan Distribution—The Stilt Spider, Tetragnatha grallator—Snares Over the
Water—Tetragnatha as a Sailor—Influence of Distribution and Environment—
Climate as Influencing Distribution—Domed Orbs—The Basilica Spider—Basilica
Spider’s Domed Orb—Basilica and Linyphia—Triple Domed Snare of Linyphia—
PPIMMINEWOLKeAMALORTOR spite h) s+ cs aa” avd ave toca lg ee ees OE D7

TABLE OF CONTENTS. TE

PART IV.—UNBEADED ORBS AND SPRING SNARES.

CHAPTER X.

THE FEATHERFOOT SPIDER, ULOBORUS PLUMIPES.

PAGES
Distribution—Character of the Snare—Ribboned Decorations—Circular Decorations—

Snares in Hollow Trees and Stumps—Webs Among the Laurel—No Viscid Beads—
The Flocculent Spirals—Calamistrum and Cribellum—Position of the Snare—A
cEritS OL WONVCtarmty fears eae tes bp vee 6 whe 6, bub hs ote a eo LFZ-179

CHAPTER XI.
THE TRIANGLE SPIDER AND ORB SECTOR.

Hyptiotes cavatus—Her Favorite Site —Geographical Distribution—Construction of the
Web—Making the Frame—Mode of Spinning the Spirals—The Radii—The Floccu-
lent Spiral Thread—Using the Spring Net—The Coil of Slack Line—Springing the
Snare—Securing the Prey—Feeding Habits—Muscular Rigidity ...... .. 180-194

CHAPTER XII.
THE RAY SPIDER AND HER SNARE: ACTINIC ORB.

Name and Systematic Position—The Peculiar Snare—Bowing the Snare-—How the
Snare is Operated—Springing the Snare—Locking the Rays—Wear and Tear of the
Web—Affinities with Hyptiotes—The Spirals are Viscid—Insects Entangled upon
the Snare—Genesis of the Trapline —Both Trail and Telegraph—Multiplex Trap-
lines—Natural Habitat of the Ray Spider—Distribution . Sie ota, cei Seth ae “a. a ees ODA

PART V.—MECHANICAL SKILL, INTELLIGENCE, AND
EQUIPMENT.

CHAPTER XIII.
ENGINEERING SKILL OF SPIDERS.

Geometric Arrangements Imperfect—A Wind swept Snare —Anthropomorphism—Counter-
poising Webs—Zilla Leaf Counterpoise—Professor Parona’s Case—Meta’s Counter-
poise—Special Adaptations—Swinging Sawdust Nest—How Labyrinthea Braces her
Roof—Pitching a Leaf Tent—Alternate Apposition—The Trestlework of Therid-
ium—Skill of the Speckled Tubeweaver, Agalena nceyia—Dysdera’s Tubular Nest—
PPR SNSpPengion MTIORE, 6 Desiw «tel v (e « slots 2 ay as Bee nS aise le Sees

CHAPTER XIV.
MECHANICAL STRENGTH OF WEBS AND PHYSICAL POWERS OF SPIDERS.

Size of Orbwebs—Modified by Site—Modified by Weather—Structural Requirements—
Strength of Snares—Webs that Entrap Birds—Argiope as a Bird Catcher —Endurance
of an Orbweb—Physical Power of Spiders—A Spider Captures a Fish—A Snake En-
snared by a Spider—Medicinal Spider’s Snare—Theridium Captures a Mouse—Mr.
Hopper’s Testimony—Hon. Proctor Knott’s Testimony—The Conclusion—The Inci-
dent Proved—she Aranead Heroine. +.) 5% 6 Vee eta ee es + 220-246

12 TABLE OF CONTENTS.

PART VI—PROVISION FOR NURTURE AND DEFENSE.

CHAPTER XV.

PROCURING FOOD AND FEEDING.
; PAGES
Food taking Tools—Handling the Snare—Accuracy of Perception—Treatment of Insects—

Swathing the Prey—The Banquet Room—Deporting Swathed Insects—Trussing Cap-
tives—Acrosoma Trapping Flies—Order and Subordination of Instincts—Flies Ban-
queting with a Spider—Location Controls Food—Prolonged Abstinence—Comparative
Feeding Habits—How the Tarantula Feeds—Need of Water—Drinking Habits—
Does the Spider Eat Its Web?—Wear and Tear of Snares—Mending the Web—En-
tangling Insects—The Spider as a Philanthropist—Man as an Ingrate . .. . . 247-267

CHAPTER XVI.
EFFECTS AND USES OF POISON.

The Fangs and Poison Bag—Blackwall’s Experiments—Effect of Epeira’s Bite—The
Inoculation Test—General Harmlessness of Spiders—The Other Side—The Venomous
Spider of New Zealand—Latrodectus mactans—The Popular “ Black Spider ”—In-
definite Testimony—Phidippus morsitans—Effect of Spider Venom on Insects—
Poison as a Reserve Weapon—-Popular Notions—Medical Imaginings—Queer Reme-
Gice—Uinelessumears*-. at eres Cue hr cte Ay eye ck ee a te. We tng Sn on O28)

PART VII.—NESTING HABITS, PROTECTIVE ARCHITECTURE,
AND DEVELOPMENT.

CHAPTER XVII.
NESTING HABITS AND PROTECTIVE ARCHITECTURE OF ORBWEAVERS.

Varieties of Spinningwork—The Nests of Epeira insularis—Leaf rolled Habitations—
Woven Tents—Shelter Tents—Spider Seamstresses— Variations in Individual Habit—
Special Adaptations—The Shamrock Spider’s Nest—Epeira domiciliorum and _tria-
ranea—The Angulata Group—How the Spider Makes a Nest—Sewing Leaves To-
gether—Spider Upholstery —Nest of the Young—The Nest of Epeira thaddeus—The
Domed Tent of Triaranea—Labyrinthea’s Nest—The Leafy Canopy of Labyrinthea—
Origin of the Nest making Habit—Intelligent Selection—Design Showed in Sewing—
Nesting Industry Protective—Various Forms of Tents Summarized... . . . . 284-3

te

CHAPTER XVIII.
NEST MAKING: ITS ORIGIN AND USE: DEVELOPMENT IN VARIOUS TRIBES.

Comparative Studies—Nests of Tubeweavers—Saltigrades—Lineweavers—Theridium ripar-
ium, the Prince of Spider Architects—Mode of Building—Use of Artificial Material
Nesting Snares of Linyphia—A Tent Among the Morning Glories—Territelarian
Tubes—Atypus and Cyrtauchenius—Nesting Habit of Citigrades—Of Laterigrades—
One Common and Typical Form of Nest—The Modes of Making Nests—Method of
Atypus—Of the Mygalidee—Of the Water Spider—Of Speckled Agalena—Unity of
Method in All Tribes—Nest Parasitism-—Squatter Sovereignty—Comparison with
Other Orders—Tube making Larvee—Nests of the Caddis Fly Larva—Leaf thatched
Nest of the Bag Worm—Nest of a Theridioid Spider—The Leaf rolier Tortricid
Moth—Shamrock Spider’s Nest in the Ferns—The Shell of Difflugia—Catholic Re-
semblance in External Architecture—Creation’s Harmony. en tl no LO-OOD

TABLE OF CONTENTS. 138

CHAPTER XIX.

GENESIS OF SNARES.
. . . . . ‘ . . . PAGES
Spinningwork Relations—A Hypothetical Standpoint—Genesis of a Trapline—A Simple

Trail—Trail Telegraph—Foot Lines Commanding Snare—Acrosoma at Her Hub—
Utilizing Web Fragments—Stellate Spider Trapping with a Fragment—Multiplex
Traplines—Hyptiotes’ Trapline—Ray Spider’s Trapline—The Original Thread—Drag-
line—Trestlework of Theridium—Theridium’s Parental Snare—Beautiful Snares of
Linyphia—Snare Among the Morning Glories—From Sheet to Dome—From Dome
to Tube—Linyphia costata’s Snare—Influence of Maternity—Cocooning Nest of Dolo-
medes—Codperative Housekeeping—Origin of Orbwebs—Dictyna’s Orb like Snare—
Orbweavers’ Curled Spirals—The Ray Spider’s Link—Viscid Lines of Dictyna and
Amaurobius—Are Theridium’s Threads Viscid?—Another Starting Point—From
Tubeweaver to Lineweaver—Agalena and Theridium—FEpeira and Theridium—See-
toral and Horizontal Orbs—Unity of Industrial Habit... ....... . . . 336-356

CHAPTER I.
i:
III.

LV.

V.

V1.
Valle
VITl.
IX.
x.
pxale

xeile
XIII.

XIV.

CONTE NLS: OF VOM UVEH i:

Wooing and Mating of Orbweavers.

Courtship and Pairing of the Tribes: Love Dances of Saltigrades.

Maternal Industry: Cocoons of Orbweavers.

Cocooning Habits of Spiders: Comparative Industries.
Motherhood.

Cocoon Life and Babyhood.

Maternal Instincts :

Aeronautic or Ballooning Habit: Distribution of Species.
Senses of Spiders, and their Relations to Habit.

Color and Color Sense: their Relations to Structure and Habit.
Toilet, Moulting, and General Habits.

The Orbweayers’ Enemies.

Mimicry.

Death and its Disguises.

Fossil Spiders: Habits and Habitat of Ancestral Araneads.

Cea PTE A
GENERAL CLASSIFICATION AND STRUCTURE.

Er

THe order Araneze has given the name of the true spiders, which it
embraces, to the class of invertebrates to which it belongs, Arachnida. This
name, again, is due to that special function by which the spider
is and has ever been popularly known. According to the Greek
myth, Arachne was transformed into a spider by Pallas Minerva
because she had boasted her superiority over that goddess in the use of the
distaff. Hence the Greek name for spider (dedyyy), arachne. The Eng-
lish name is doubtless derived from the same function which led the un-
happy Arachne upon her doom.! Spider is a corruption of ‘“spinder,” the
spinning one. ‘The word survives in a different form in the term “ spinster,”
by which the virgin mistress of the distaff was
commonly known in the days of our grand-
sires. There is therefore a popular and phil-
ological as well as natural fitness in the gen-
eral classification of the order Araneze which
we adopt after Thorell,? who in turn has
substantially followed the arrangement of La-
treille.*

This classification is based upon the web
making characteristics of the various groups

and is as follows: The order may be

Origin of
the Name

General divided into two principal groups,
Classifi- the Sedentary spiders and the Wan-
cation. Sere he ;

dering spiders.* The former group
includes those whose habit it is to remain, for
the most part, upon or within their webs and take their prey by means of
snares. ‘The second group includes those which stalk or pursue their prey

Fig. 1. An Orbweaver, Epeira gemma.

' See Ovid’s Metamorphoses, Chap. vi. The story is told in the first 150 lines.

? On European Spiders, by T. Thorell. Nova Acta Reg. Soc. Scientarium Upsaliensis.
Upsala, 1869.

§ Latreille: In Cuvier’s “Le Regne Animal,” edition 1817, Paris. Sedentaires (Sedentary),
page 79; Vagabondes (Wandering), page 95; Territéles, page 79; Tubitéles, page 81; Inequi-
téles (Retitelariz), page 84; Orbitéles, page 86; Laterigrades, page 91; Citigrades, page 95;
Saltigrades, page 98.

(15)

16 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

afield, upon the ground, water, or trees, and as a rule have no fixed domi-
cile, except at the brooding time and during winter. These principal groups

are subdivided into seven secondary groups, sections or suborders.?
Seden- ‘The four tribes comprising the Sedentary spiders are named strictly
vary from the chief characteristics of their spinningwork, viz.: the Orbi-
Group. . : : : : :

telarie, from their orb shaped web; the Retitelarize, from their
net like web or snare of crossed lines; the Tubitelariz, from the tubular
web which they spin, and from the opening of which, in some species, a
close textured snare spreads out in
all directions; the Territelariz, from
the silken cylinder with which the
typical species line their burrows
in the ground.

The Wandering spiders include
three tribes, which are conspicuous
by their ordinary independence of
snares for the capture of prey, and
have been named from certain pe-
culiarities of motion. The
Laterigradee have legs so
inserted as to permit a
motion sidewise, as well as forward
or backward. For this reason La-
treille called them also Crab spiders.
The Citigrade include those species
that keep chiefly to the land and
water, upon which they run with
great rapidity. The Saltigrade, or
vaulting spiders, are named from
their hopping movement in ordi-
nary progress. The individuals of
these three tribes are almost equal-
oi; ly entitled to be called citigrades,
A i i for they all move swiftly, but the
if" i Citigrades technically so termed are

(hy
ff
ye

i

W ander-
ing Group

Fic. 2. Territelarie: Eurypelma Steindachnerii Ausserer. habitually running spiders, keeping
(Dr. Marx, del.) Natural size. : ¥ ‘ :
closely upon the ground, while the
Laterigrades and Saltigrades are arboreal, habitually dwelling upon plants
and vertical surfaces. The three are also quite distinct in their structure,
and the systematic position of any one, as far as above indicated, can com-
monly be told by a glance at the form.

ab . see ts ” : : Jae ; ge teo
Thorell uses the term “suborders” in his European Spiders for these principal groups,
but adopts the term “sections” in his “Descriptions of the Aranez of Colorado” (Bulletin

U.S. Geological Survey, Vol. IIL, No. 2, page 477, note), and still later the name tribe (tribus).

GENERAL CLASSIFICATION AND STRUCTURE. iwi

The following tabular exhibit is given of this classification
ing, if that word seems to any one more suitable :—

, or group-

CiAss ARACHNIDA.
ORDER ARANEA.
I. First Division.—Sedentary Spiders.
Tribe 1. Orbitelariz,! Orbweavers. Tribe 3. Tubitelariz, Tubeweavers.
“ 2. Retitelariz,? Lineweavers. “4. Territelarize, Tunnelweavers.
II. Second Division.—Wandering Spiders.
Tribe 5. Citigradee,? Citigrades. Tribe 6. Laterigradee, Laterigrades.
Tribe 7. Saltigradee, Saltigrades.

This arrangement is the best, perhaps, that can be adopted, and seems
more natural and satisfactory than that which commanded the approval of
such a distinguished arachnologist as
Black- = Blackwall, and which is based upon

ea: the number of the eyes. Blackwall
cation, founded three tribes, within which all

the species known to him are includ-

ed. They are: (1) Octonoculina, eyes, eight; (2)
Senoculina, eyes, six; (5) Binoculina, eyes, two.
In the first tribe, Octonoculina, which is the
most extensive of the three, he included all the
genera haying eight eyes, without regard to
other characteristics or to the considerable dif-
ferences in organization and economy. ‘The
Fic.3. Laterigrade Spider, Misume. Second tribe, Senoculina, as known to Black-
na rosea Keyserling. wall included but ten or eleven genera, and
embraced all tribes having six eyes, with the same disregard to other char-
‘acteristics. The third tribe, Binoculina, contained the single genus Nops,
instituted by Mr. W. 8. McLeay for the reception of two remarkable species

? Araneze Orbitelarize: Perty, Delect. Anim. Art. Bras., page 193.

2 From retus,a net. The word “net” very well expresses the knotted and meshed char-
acter of most spinningwork of this group. But since it is used popularly as a general term
for the webs of all spiders, I have preferred “Lineweavers” to “Netweavers” as a dis-
tinctive popular name of this tribe.

’ Prof. Thorell assigns the Laterigrades to the fifth tribe, the Citigrades to the sixth. I
have ventured to so far change this arrangement as to reverse the positions of the Lateri-
grades and Citigrades. The Citigrades appear to me to approach the Tunnelweavers and
Tubeweavers, both in structure and economy, more nearly than the Laterigrades. So also
the step from the Citigrades to the Laterigrades through the genus Dolomedes appears more
natural than the reverse, as Thorell has it; and the step to the Saltigrades from the Lateri-
grades is quite as, if not more, natural than from the Citigrades. From the standpoint of
economy alone the passage is certainly easier.

* Blackwall, “Spiders of Great Britain and Ireland,’ Preface, page 6.

18 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

has so admirably expressed as above, will at least’ be preferred by those
who set as much store upon the habits and functions of the creatures as
upon their forms. The latter indeed will not be undervalued by a wise
and careful student; but the systematists and anatomists will doubtless
bear with those who would fain keep natural history from swinging too
far away from the paths which earlier naturalists trod, and which so
thoroughly traversed the life history of created things.

A general classification based upon the spider’s behavior, especially in
relation to its chief function, has the advantage that it compels attention

to the creature’s habit without at all neglecting its structure. It
The Clas- j. not claimed that this classification is without objections. There
eciney are, indeed, some incongruities, more or less serious, which will

appear hereafter. But until these interesting animals shall have
received from naturalists that attention which their character and impor-
tance in nature justify, and which will enable some future arachnologist to
show us a better way, we shall, perhaps, be best repaid by accepting this
general grouping of the great families of the spider fauna. At least it is
that which best serves my own purposes in the special lines marked out
for this treatise.

Students who are interested in a more thorough consideration of this
point will find the objections to the above system well stated, and a classi-
fication proposed based more upon anatomical structure, by Dr. Philip
Sertkau, of Bonn.' _A very satisfactory answer to these objections has
been published by Prof. Tamarlan Thorell, M. D.,2 who adheres substan-
tially to his former system but, confessing his indebtedness to Prof. Bert-
kau for certain modifications, proposes a rearrangement which, he thinks,
answers to our present knowledge of this order, as follows :—

Orpo ARANES.
Suporpo |. TETRAPNEUMONES.
Tribus I. Territelarie.
Susorpo I]. DipnEuMONEs.
Tribus Il. Tubitelariz.
Eeribellatee. Cribellatee.
Tribus III. Retitelariee.
Tribus IV. Orbitelarie.
Cribellatee. Ecribellate.
Tribus V. Laterigradee. Tribus VI. Citigrade. Tribus VII. Saltigrade.

The scheme embraces European families for the most part, but includes

a few exotic ones.

‘See especially his “Versuch einer natirlichen Anordnung der Spinnen,” in Archiv fiir
Naturgeschichte, xliv., i., page 351, sq., 1878; and his treatise “Ueber das Cribellum und Cala-
mistrum. Ein Beitrag zur Histiologie, Biologie, und Systematik der Spinnen,” ibid., xlviii,, i.
page 316, et seq., 1882.

“Annals and Magazine Nat. Tist., Apl, 1886. “On Dr. Bertkau’s Classification of the
Order Aranee or Spiders,’ by Prof. T. Thorell.

GENERAL CLASSIFICATION AND STRUCTURE. 19

Ff.

The propriety of beginning the series of spiders with the Orbweavers has
been generally recognized by authors. Perhaps some have had no better
reason than that which popularly associates this group with the
name spider; but others have thought that the highest forms
in the order Aranez are really included within the Orbitelariz.
The suggestion of Thorell can hardly be allowed that the more artistic
construction of web shows higher development of instincts
in Epeiroids than in other families of the order. Surely the
nests of some Lineweavers, as Theridium riparium and Liny-
phia marginata; of such Citigrades as our Turret spider,
Lycosa arenicola Scudder; and such 'Tunnelweayers as our
California trap door spider, Cteniza californica Cambridge,
show a grade of instinct quite as high as that of the Orb- goa ne
weavers, and which, moreover, as it seems to me, exhibits a mum scenicum
wider range of voluntary action and variation than the more
mechanical spinning of a geometric web. With greater justice Thorell,
when speaking to the point of structure alone, disallows the
claims of the Orbweavers to the highest position in their order.
If we consider (he says) as we reasonably ought to do, more
the harmonious development of the body’s various parts, the superior de-
velopment of the organs of sense, and such like, we see that the Epeiroide,
with their weak cephalothorax and heavy abdomen,
their slow and clumsy motions, and their compara-
tively small eyes, are surpassed by more than one of
the other families usually looked upon as lower. ‘The
Lycosoide are distinguished by their well proportioned
forms, their powerfully developed cephalothorax, by
the quickness and force of their movements, and
highly developed organs of sight.

The Attoide also, as may be easily remarked by
a casual observer in the little striped, jumping spider
(Epiblemum scenicum) familiar around all
our rural and suburban homes, have a strik-
ing expression of intelligence. This may be
an optical effect solely due to the peculiar eyes and
neryous jerking action of the animal, but certainly
mie. >.” Tubeweaving Spider, one is strongly reminded thereby of the “ expression”

aphosa variegata Hentz.

(Marx, del.) Much magni Of the Hymenoptera, as ants and wasps, the most
BEC: highly developed of the order of insects.

As regards the other reasons adduced to support the preéminence of
the Epeiroids above all other spiders, such as the number and beauty of
the species, the small number of transition forms, ete., they hold equally
true of the Attoids. These form a unit quite as close, compact, and rich

Highest
Forms.

Thorell’s
Views.

The
Attoide.

20 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

in species as the Epeiroids; in brilliancy and yariety of colors they sur-
pass both these and other families of spiders, and may even be compared
with the showy families of Coleoptera.!
Great as is the weight which this justly distinguished arachnologist car-
ries toward the Attoids, I am inclined, in consideration of both instincts
and structure, to place the Lycosids at the head of the order.
Superior- The organization of this family is, to say the least, but little
pe ag inferior, if at all, to that of the Attoids; and in their spinning
habits I have no hesitation in pronouncing them to be superior.
Indeed, the Saltigrades are by no means remarkable for their spinning-
work, in this respect scarcely equaling the
/ | , Tubeweavers, perhaps the lowest of the
i spiders. The Citigrades, however, exhibit
most interesting industries; and especially
in the personal care of their young, from
the egg cocoon to the period when the
spiderlings can shift for themselves, the
Lycosids seem to me to show a higher
order of instinct than the Attoids, certainly
one as high. The whole subject, however,
is one which in-
cludes difficulties
too numerous and
serious to allow a

full discussion in Fic.7. Lineweaving Spider, Therid-
these pages. ium tepidariorum. (Marx, del.)
The Orbweavers have their nearest rela-
tions in the Lineweavers, whose snares of
netted lines are familiar in the
Orbweav-angles of our houses, forming

ers and :
Line largely the domestic “ cobwebs.”
ce As In most eases the two tribes can

be distinguished by a practiced
eye by the general form. But they can

Fic. 6. Citigrade Spider, Lycosa scutulata most sasily be separated thus: The Kpei-
Hentz. (Marx, del.) X 2. i

roids have a low forehead, not transversely
impressed ; from the margin of the clypeus to the middle front pair of
eyes the distance is less, or at any rate not greater than the distance be-
tween the middle front and middle rear eyes. In the Retitelarize, on the
contrary, the distance from the margin of the clypeus to the middle front
eyes is greater than that from the middle front to the middle rear eyes.?

* Kuropean Spiders, page 40. :

* There are exceptions in the case of some Epeiroid males with strongly projecting fore-
head, and in the genus Tapinopa, among the Retitelarize.

GENERAL CLASSIFICATION AND STRUCTURE. 21

Thus Fig. 8 represents the eyes of an Epeira, and Fig. 9 the eyes of the
Retitelarian genus Theridium. Dr. Bertkau distinguishes these two tribes

by the presence

in the Epeitroids of what he calls a basal spot (Basalfleck )

upon the mandibles.

IT.

For the convenience of readers not acquainted with the anatomy of
spiders, a general description of the animal is here given. It is not in

Fic. 8. Face of Epeira.

set immediately

accord with the purpose of this work to enter into the
details of structure; for these the studies of anatomists
and histologists must be consulted. But some knowledge
of the principal organs, especially in their relations to
the spinning industry, is necessary to the understanding
of much of what follows.

The principal parts are the cephalothorax and abdo-
men. The cephalothorax consists of the cephalic part
(cp, Fig. 11) and the thoracic part, tp; the two parts
are united directly, and not by a neck, the caput being
upon the thorax, whence the name cephalothorax. The

point of juncture is marked by a suture, more or less distinct, extending
along the lower margin of the caput backward, on each side, and con-
verging in a depression more or less profound at the summit of the

thoracic part.

The cephalothorax is externally a hard, chitinous case

composed of two principal plates, resembling more nearly than any other
part of the body the tough shell of true insects.

The front and upper portion of the cephalic part is the caput, which
in Orbweavers is sometimes depressed, more frequently elevated. On the

The
Caput.

number six and even two. The arrangement of the
eyes upon the caput forms good generic and specific characters.
The eyes in the Orbweayers are disposed across the caput in
two rows of four each, known as front and rear rows (lig. 8) ;

The
Hyes.

middle eyes, those in front being mid front or middle

fore part of the caput are situated eyes, which in
this group are eight, but in other groups sometimes

they are again divided into three groups, of which

the middle group contains four eyes, known as _ the Fis. 9% Face of

Lineweaver,
Theridium te-

front (M.F.) and those behind, the mid rear or middle rear Pidarioram.
eyes (M.R.). The remaining four eyes, known as the side eyes (or lateral

eyes), are placed

in two’s on either side of and equidistant from the middle

group. They are known as the side front (S.F.) and side rear (S.R.); they
are generally quite near to each other, frequently touch, but occasionally
are well separated; for the most part they are smaller than the middle
eyes. They, as well as the middle group, are often placed upon tubercles
more or less prominent.

22 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

The part of the caput included between the two rows of eyes is called
the eye space. The space between the front row of eyes and the lower
margin of the face where it joins upon the mandibles is the clypeus
(Cp). That between the upper row of eyes and
the vertex (v) of the caput is the forehead. The
entire space thus occupied, from the vertex to the
margin of the clypeus, is the face or facial space.

The mandibles (mb) are two jaw lke organs
attached to the head beneath the margin of the
clypeus, within which they articulate lat-
erally. They are placed perpendicularly,
or inclined more or less backward or
toward the sternum. In shape they are conical or
subovate. Each mandible is composed of two parts,
the base or falx (fx) and the fang (fg). The fang
is a curved movable tooth, smooth, hard, and
pointed. It is hollow, pierced on the inner side
Fic. 10. Ventral view of Argiope near the point with a small hole, which opens into
argyraspis. ps, palps; mb, :

inandible di digitalljoint’or 2a) SUS Mteaurrow. | Phe

Ralpe 5 ee) Tadial joules au ollow vorthe: rane. sg
humeral; cu, cubital; ax, ax-

Mandi-
bles.

illary; mx, maxille; Ib, labi- OCCUpied by a membra- cu

um; sm, sternum; cx, coxa of > as j .

Bae Geen ic ae Oe duct which leads ie

epyginum ; sp, spinnerets rep- U pwar d to a gland ie --

resented closed; ac, anal clos- lodged within the falx Pea

ure. ae

This gland is supposed ~*
=i
to secrete a poisonous liquid. SS
The falx is covered with hair, especially 4-4

near the base, and at the apex is formed
into a toothed groove or sheath
into which the fang is folded down pt
when at rest.

The sternum (sm) is a cordate plate which
forms the under part of the shell of the

Ce} yhalothorax, It has four inden- Fic. 11. Dorsal view of Epeira insularis.
tations on each side, which mark 4») abdomen; b, base; ap, apex of ab-
. : i domen; pt, pits which mark the attach-
the insertion of legs. On the for- ment of abdominal muscles; ep, ceph-
ward part at the middle is placed the labium i¢ Part of cephalothorax; tp, thoracic
" ; ; part; mb, mandibles. 1, 2, 3, and 4,
or lower lip (Ib), a subtriangular or seml-ovate the legs represented in their order,
ip , Tp: first, second, third, and fourth. Tch
organ of the m« see Kio EIEN ’ ’
. a ruth. (Se e | 1g. 10.) trochanter of the leg; cx, coxa; fm,
Opposed to the labium and above it igs femur; dg, digital, ra, radial, cu, cu-
bital, hu, humeral joint of palps.

Falx.

Sternum.
Labium.

the upper lip, a slight hair tipped projection,
. which is the terminatio * the palate ither i ‘
Maxillc. ition of the palate. On either side of the

labium is placed one of the maxillee or lower jaws. They vary
in form, the variation giving good generic characters, They have a

GENERAL CLASSIFICATION AND STRUCTURE. 23

rotary motion upon the fore part of the sternum, moving toward and
against each other, thus crushing the interposed prey.

The palps (ps) or palpi are two organs inserted into the free end of
the maxille, of which they are an organic part.t Each palp has five
joints of various lengths named in order from the maxilla, (1)
axillary, ax, (2) humeral, hu, (3) cubital, cu, (4) radial, ra, and
(5) digital, dg. The axillary joint is the shortest of the five and corre-
sponds to the second joint of the leg or trochanter, the maxilla being the

Palps.

equivalent of the coxa.? The :
humeral joint is much _ longer \
than the axillary; the cubital \ .

again is short, being a sort of
knee joint. The radial is one
and a half or twice as long as
the above, and the digital is
usually the longest joint of all.?
The palps vary greatly in
the two sexes. In the female
each digital, dg, ter-

Sexual minates like the foot
Forms of . :
and is usually armed :
Palps. ) i
with a well developed 4)
curved claw (palpal claw) pec-
tinated or serrated. These or- \

gans are prehensile, are used va-

riously as hands or feet to hold

and turn the prey, to dig, to

sustain the body when suspend-

ed upon webs, to grasp the CO- rie.12, Male of Agalena nevia: the speckled Tubeweaver.
coon, etc., and even to aid in ee)

locomotion. In the male the digital joint contains the genital organ; it is
enlarged, often very greatly, into a bulb whose structure is complicated and
subject to great specific variations. (Fig. 12.) It is always more or less
covered on top by a plate, which may be distinguished from other parts
by a more or less dense pubescence scattered upon the superior surface and

1 On account of the curved process upon the top of each maxilla whose convexity is
toward its fellow, the palp may be said to issue from the side instead of the end of the
maxilla.

2 Westring, “ Aranez Svecize,’ Termini Technici, page 11.

37 have adopted the terminology of Walckenaer, which is followed also by Blackwall
and Cambridge. That of Westring is (in the same order as above): (1) basal, (2) femoral,
(3) patellar, (4) tibial, (5) tarsal. The analogy between this terminology and that of the
legs, perhaps has some advantage to the memory, but the Walckenaer names appear to me
to be preferable, as being quite distinctive, and thus preventing confusion with names given
to the joints of the legs.

24 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

sometimes under the apex. This genital plate or lamina corresponds to
the apical part of the female digital, but the digital claw is entirely
wanting, or rudimentary and hidden by pubescence. The genital organ is
placed under the base of the lamina. It is furnished with processes vary-
ing in form, size, and number, and with a hook or tube (or tubes) which
fit into corresponding cavities in the female organ, and transfer the semi-
nal fluid thereto. This peculiar formation does not appear until the last
moult, when the spider is mature. Previous to that the male digital is
The term genital bulb is also applied to the genital
Sometimes the bulb is quite one with the lam-
ina in which it is muffled, in which case the bulb is
called the clava.!

During the interval between the third and fourth
moulting a considerable change takes place. In the
male the extremities of the palpi swell like clubs and
develop into different indentations, teeth, threads, or
leaves, which later on serve as transmitters of
the semen. At first the clubs are filled with
semitransparent fluid, while the forming inner
organs are yellowish or brownish; at first the skin is
quite soft, but soon hardens and forms a shell, which
turns darker by the action of the air. Inasmuch as

simply a hairy bulb.

organ.
-el =

Moulting
Changes.

Fig.

13.

Leg of Epeira

magnified.
the joint which unites
the leg with the ster-

Cx, coxa,

num; tch, trochanter,
small joint by which

the femur articulates

these organs are almost devoid of soft parts it follows
naturally that as the shell cannot come off, no further
moulting can take place.

At the time the palpi become fully developed a

great change takes place also in the female genitals ;
the immediate surroundings become roughened and
somewhat hardened, presenting little humps which serve
partly as rests for the male palpi and partly as recep-
tacles for the semen, and is what is designated as “vulva.”2 When fully
matured the sexes, hitherto separated, come together, and the copulation
takes place in a different manner by different varieties.3

upon the coxa; fm, fe-
mur; ptl, patella; tb,
tibia; mt, metatarsus;
t, tarsus; cl, claws.

The legs of the spider are eight, symmetrically disposed, four on each
side of the sternum to which they are articulated. Their relative lengths
give one of the best characters for systematic arrangement. They
are numbered from the face backward as first (1), second (2),
third (3), and fourth (4) pairs. (Fig. 11.) The relative lengths
are Indicated by a formula composed of the above numerals arranged in
the order of greatest lengths from highest to lowest, thus: 1 2 4 3 is the

formula which expresses the prevailing order among Orbweavyers and de-

The
Legs.

' Westring, Araneze Svecize, page 12.
* Menge, “ Die Preussische Spinnen.”

‘See Chapter on “Wooine and Matine Habits,’ Vol. LI,

GENERAL CLASSIFICATION AND STRUCTURE. 25

~

clares that the first leg is the longest, then the second leg, then the fourth
leg, and lastly the third leg. When two pairs of legs are of equal length
the numerals expressing them are united by the sign of equality; thus,
12483 indicates that the second and fourth legs are of equal length.!
For the most part the third leg is much the shortest of the four, and the
first pair decidedly the longest. This rule, however, varies in certain
genera, as Acrosoma, in which the fourth pair is as long as, or longer
than the first, a variation which seems to be adapted to the peculiar form
of the spider. The males have legs longer and slighter than the females,
and in some species have a special armature in the shape of a comb of
stout spines upon the tibia of the second pair, which probably serves as a
clasping organ in the act of pairing.

The legs have seven joints, which are arranged in the following order,
counting from the point of union with the sternum: First, the coxa (cx,
Fig. 13), the short joint which unites the leg to the body.
It is partly concealed beneath the cephalothorax, and
sometimes carries short, pointed processes. Second, the
trochanter (tch), a minute joint which really serves for
the articulation of the leg upon the body, the coxa being
fixed. Third, the femur (fm), usually the longest and
stoutest joint of all. Fourth, the patella (ptl), which
nearly corresponds in length with the coxa, and serves as ,, svn

3 i : 1G. 14. Foot of Epeira
a sort of knee joint. Fifth, the tibia (tb), whose length — insularis. s.cl, superior
is usually a little less than that of the femur. Sixth, ER pul ce
the metatarsus (mtr), the penultimate joint, which ap- _ icl,inferiorclaws; au.cl
proaches the length of the femur, is commonly longer “ZUStYcawsuponthe
than the tibia, but much shghter. Seventh, the tarsus
(tr), the ultimate joint, which is usually shorter than the metatarsus. The
last five of these joints are armed with a great number of spines, bristles,
‘and hairs, which are placed more freely along the inner surfaces of the
legs, and thus are disposed for the greatest advantage of the animal in
manipulating its prey, embracing its mate, or fighting its enemies. They
are also used in spinning the snare.

Orbweavers have three strong, genuine claws upon their tarsi, of which
the two superior are pectinated, and (with rare exceptions) the inferior is
armed with two close and blunt comb teeth (cb.th). The supe-
rior claws are of equal size, placed side by side. The inferior
claw is smaller than the others and is below them, bent down
near the base. The extremity of the tarsus is always provided with two
or more auxiliary claws (au.cl).2 One of these, a strong spine, has the

Tarsal
Claws.

'T have taken this formula as more convenient for expression in type. In most authors
the equal members are joined by a bracket above, thus: 1 2 4 3.

* Thorell, European Spiders, page 47.

26 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

power of motion toward the claws beneath which it is situated, thus act-
ing as a sort of thumb, which is used especially in grasping the spinning-
work.!

In the armature of the legs must be reckoned also the calamistrum
which. characterizes the family Uloborinee among the Orbitelariea, in com-
mon with certain Ciniflonide. This is a double row of curved spines,
placed upon the inside of the metatarsus of the hind pair of legs, in form
not unlike the old fashioned “flyers” of a spinning wheel. (Fig. 15.)
They are used for the flocculation of the threads as they pass from the
spinning tubes, thus forming the peculiar cross lines which characterize the
spinningwork of the above families, and serve the purpose of viscid beads.
The second principal part of the spider is the abdomen. Among
Orbweavers it assumes widely varying forms, being globular,
ovate, subtriangular, cylindrical; sometimes flat, some-
times convex above; on the ventral surface nearly
‘flat or slightly convex. Thus, the face of a section
cut transversely through the middle would, for the most part,
be properly or approximately described as semicircular, except
in the case of gravid females. The integument is soft, some-

The
Abdomen

Fig. 15. Cala-

mistrum of
Ciniflo. (Af-
ter Black-
wall.) a,
upper row
of spines;
b, lower
row; c, the

times leathery; usually hairy, but not densely so, sometimes
naked and glossy. The organ is generally smooth, but in some
species is marked with conical tubercles upon the base, and in
some genera is bordered with sharp, hard, spinous processes,
and in some is ridged or striated along the rear. The base
generally overhangs the cephalothorax as much as one-third or

spur.

even one-half the length of that organ with which it is united
by the pedicle, a short cartilaginous tube through which pass the organs
of nutrition and circulation.

In the female the size of the abdomen is large, as compared with the
cephalothorax, a proportion which is greatly increased during the period
of gestation. In the male spider the relative size of the abdo-

Pigment- . .
ee men is even less than, or is equal to the cephalothorax. The
Hairs markings upon the tergum are various, and are more or less

uniform with every species, though subject to some decided
specific variations. They are caused, when present, by a pigment under

' This arrangement gives a strong color of justification to the use of the word “hands”
in the familiar quotation from Holy Scripture, Proverbs, xxx., 28: “The spider taketh hold

with her hands, and is in king’s palaces.’ In various palaces in Europe, and in many pub-

lic buildings of America, I have never failed to observe spider’s webs, usually some species of
Lineweayer, whose occupants hung by their “hands” within their silken domiciles. I hesitate
to think, notwithstanding the philological objection that the Hebrew M7) (Semamith)
means “lizard,” that Solomon had any other animal in view than the spider. The natural
history of the text so exactly harmonizes with the habits of spiders, especially Lineweavers
and Orbweavers, that I have difficulty in believing that so careful an observer of nature as

the Royal Proyerbialist could have used the above language concerning any other animal.

GENERAL CLASSIFICATION AND STRUCTURE. 2

~J

the translucent epiderm, rather than by pubescence. These colors are often
very bright, shades of yellow and red preyailing, and bright metallic white
or silver being frequent.

The tough integument which covers the abdomen consists of three
layers; the external one is a thin, transparent, horny membrane,. nearly
colorless, but more or less densely covered with colored hairs. Beneath
this lies the soft layer of pigmentary matter upon which the peculiar color
of the body largely depends. ‘The third or inner layer consists of an
expanded network of muscular fibres, which are irregularly interlaced, and
which must enable the spider forcibly to compress the abdomen. The
muscles forming this layer are very faintly, if at all, marked with trans-
verse strize. (Meade.)

On the ventral side or venter near the base (anterior part) are situated
two gills, breathing holes, or pulmonary sacs (bg). They are scales or plates
symmetrically apposed on either side, form-
ing the covering of cavities com-
municating with the tracheze or
air tubes. Externally they present
the appearance of simple transverse slits in
the venter. Each cavity contains about fifty
extremely thin, triangular, white leaflets, fast-
ened together at the edge of the breathing
hole. Each is double, being in fact a flat 5. 16 Diagram of location of spinning
pouch with an opening on the lower side organs and their relations to other organs
communicating with the outer air. The spi- Of ;ne abdomen: SPR» Spies ee

pyriform glands; tr.g, treeform glands;
racular plates are usually conspicuous objects cy-8, cylindrical glands; ep, epigynum;

upon the venter, differmg in color therefrom, ore Saaken eae ee
sometimes slightly pubescent, but more com- at ex, cephalothorax. (After Under-
monly smooth, and of harder substance than ,
‘the surrounding surface. (Cambridge.) In the male spider a minute orifice
which leads to the seminal organs is located between the spiracular plates.
In the same situation in the female is an aperture usually rather
conspicuous, which is surmounted or surrounded with a corneous
process of greater or less development. This aperture is the vulva.
The process is known as the epigynum, and probably has the function of
an ovipositor. The form and structure of the epigynum are characteristics
highly valued by systematic arachnologists in the determination of species.
But the organ is not present in immature spiders, and until the female
reaches maturity no aperture is visible. The organs of reproduction in the
female consist of two long ovoid plates, longitudinally placed within the
ventral surface of the abdomen. These unite and form a short broad
oviduct, whose external opening between the spiracular orifice is the epigy-
num (ep), Fig. 16.

The ovaries, which shortly before the deposition of eggs occupy a large

Pulmona-
ry Sacs.

Epigy-
num.

25 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

portion of the abdominal cavity, are seated in the central and posterior
part. The intestinal tube runs through it in nearly a straight direction
from the base to the apex, and the sacs and tubes which elaborate the
material for forming the webs are placed in the lower, lateral, and anterior
parts. In the male, the organs for the secretion of seminal fluid consist
of two long, narrow, convoluted tubes, occupying the same relative posi-
tion as the ovaries in the female. They also open outwardly into the
minute orifice noted above.

The manner in which the act of pairing between the sexes occurs is a
matter of doubt, and probably differs among different species. Mr, Cam-
bridge! reports a case in which a perfect apparent coition was
effected between sexual apertures of the male and female spider,
the palpi not being used at all; and I have observed what
seemed to be a similar act in the pairing of the sexes of Agalena ncevia.
On the other hand, it is evident that the spermatic fluid is conveyed to
the female parts of gener-
ation by the male palpi.
I have seen and_ recorded
this action in the case of
Linyphia marginata. Menge
and Ausserer have observed
that the male spider before
the act of union emits from
the sexual aperture a drop
_of sperma on a web made
for the purpose, which drop
he then takes up in the
genital bulb of the palpi and then communicates it to the female.

With regard to the function exercised by the remarkable organs con-
nected with the digital joint of the palpi of male spiders, there exists some

difference of opinion. Taking anatomy as his guide, Treviranus

Male
Organs.

ca Fic. 17. Collecting a spider in a box.

Digital oes — : : :
a ee arrived at the conclusion that the parts in question are used for
Palpi. the purpose of excitation merely, preparatory to the actual union

of the sexes by means of appropriate organs situated near the
anterior part of the inferior regions of the’ abdomen. This view of the
subject, which is very generally adopted, is opposed to that derived from
physiological facts by Dr. Lister and the earlier systematic writers on
arachnology, who regarded the palpal organs as strictly sexual; and _ re-
cent researches, conducted with the utmost caution, have clearly established
the accuracy of the opinion advanced by that distinguished Englishman.?

' For valuable anatomical notes see his “Arachnida,” Eneyclopeedia Britannica.
* Blackwall: “Reports 14th Meeting British Association Ady. of Sci.” pages 67-69. Also
“Spiders of Great Brit. and Ireland,’ Introduction, page 95,

GENERAL CLASSIFICATION AND STRUCTURE. 29

EV:

Perhaps a few of my readers may become sufficiently interested in the
subjects considered in this volume to wish to make personal observations
on the habits of spiders, and collections of species. A few hints for the
benefit of such persons may be given. For collectors a small satchel or
hand-bag with a strap by which it can be slung across the shoulder is a
most convenient arrangement. This should be furnished with a number
of small paper or wooden boxes, such as are used for putting up pills and
like drugs. Wide mouthed vials and bottles may also be used.

In capturing a spider, the lid should be removed from the box and
the two parts placed one upon one side and another upon the other side

of the orb, or above and below, as circumstances may require.
fae . When they are gradually approached they may be suddenly
a closed, and the spider will be captured inside the box. Care

should be taken to get the spider well inside before the cover is
closed, as there is danger of crushing the specimens. Any note or record
may briefly be made upon the top or bottom of the box, or it may be
numbered and the memoran-
dum kept in the note book.
The imprisoned spider will
keep without injury until the
collector has reached his
home, when he can make a
further personal examination
by opening the box carefully
and dropping the spider into
a glass vessel with steep sides. Long test tubes of several sizes are very
convenient for decanting collections from the boxes and, after examination,
‘into .aleohol.

If one wishes to observe the habits under artificial conditions, a series
of wooden boxes may be made with sliding glass covers, as represented in
-the accompanying cut. These may be ventilated by fine wire
cloth or gauze. Such boxes may be made of sizes to suit the
habit of the species. For cocooning purposes, eight by ten
inches will be large enough ordinarily, and also quite large enough to
observe the spinning habits of the smaller species. Large glass jars of
any sort make good homes for trying the manners of many species.
When the creature’s habit requires, earth and sticks should be inserted.
(See Fig. 18.)

What is still better, if circumstances will permit, the collecting boxes
may be opened upon vines and shrubbery in the garden or grounds. It
is not a difficult thing to establish a spidery in this way. The observer
may open the boxes promiscuously and allow the spiders to settle their

pj jl carp OTT TT

IN

Fic. 18. Example of a trying-box.

Trying
Boxes.

30 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

own habits in their own way; or if he wish, he may deposit all those of
one species upon certain parts of the ground, in which case they will be
very sure to permanently colonize. In this manner the most
interesting species of an entire neighborhood or district may, in
the course of a couple of years, be so thoroughly domesticated
upon a small space that observation of habits will be greatly facilitated.

There are many other points of practical value which might be men-
tioned, but, as a matter of fact, the collector’s experience will soon show
him what is the best thing to do. A few failures in capturing prizes
will teach caution, and successes will in like manner show the best way
of procedure. Caution is always necessary. While looking for spiders one
needs to move with his eyes thrown well in advance, and to be careful
to disturb as little as possible the bushes and surrounding shrubbery,
upon which the greatest prizes may be domiciled and may be lost by
careless or too rapid approach.

In searching for spiders, one should take such a position toward the
sun as to enable the light to fall upon the webs in the direction towards

which he is moving. Frequently the head should be turned to
See ae. one side and lowered towards the ground in order to catch the

sheen of the spinningwork hanging in secluded places, or even
in quite open places. A soft black hat or something that will be a good
substitute therefor, is a necessary part of the spider collector’s outfit.
Placed behind a web, it brings out all its white lines clearly, and one can
thus study the structure with greater ease.

As a rule the evening is the best time to observe the netmaking
habits, and, indeed, many other habits of the spider fauna. Some species
begin to spin early in the evening, as early as four or five o’clock.
Others are rarely found abroad until a later hour. These actions,
however, are always more or less conditioned by the weather.
During the night spiders are nearly always out upon their webs, and by
means of a lantern one can make good collections and observations after
nightfall. A dewy morning is perhaps the best time of all for finding
webs. Provided with a stout pair of shoes or rubber boots, one may
tramp through the dew laden fields of a summer morning, and_ find
myriads of webs, great and small, of all species, hanging from every part
of bushes, trees, grasses, weeds, and even spread in great multitudes upon
the fresh soil of an upturned field. At such times the Orbweavers will
not always be found upon their webs, at least certain species of them can-

not conveniently be out, but the character of the webs can thus
ra be readily perceived, and the habitat of the spider known. Little
eos. bits of paper should be carried in the satchel, and they may be
fastened upon twigs in the neighborhood of the webs which thus

are well located. A little slit in the centre of the patch of paper, thrust
over a forked twig, will stay for many days, and will at once mark the

Natural
Spidery.

Best
Times.

GENERAL CLASSIFICATION AND STRUCTURE. on

desired position. A note to identify the species may be scratched upon
this paper guidon. A cotton string will answer the same purpose in a
small field of observation. Another method is to puncture a leaf with a
pencil point, making a letter, figure, or symbol. The holes leave a dry
border which easily identifies a particular spot for many days.

Larger boxes should be placed in the satchel to be used for collecting
cocoons and nests. The nests are often difficult to preserve, but some of
them are so beautiful that they are well worth the effort. I
usually take special boxes for this purpose, or when not so pro-
vided, carry the nests free in my hand, or wrapped in little paper
bags. Cotton should always be kept in the satchel, and when the nests are
taken they should be carefully filled in with the cotton wool until the
natural proportions are fully marked out. Of course, the leaves will
rapidly dry up and wither and the nests will lose their form unless this
precaution be taken.

In collecting spider nests, it will nearly always be necessary to cut away
carefully a part of the adjoining foliage, in order to prevent the collapse
of the whole when the supporting lines are cut. It is better
to fill a nest with cotton before it is cut away from its site,
or immediately thereafter. Tissue paper or eyen crushed
leaves will answer where cotton is wanting.

An ordinary pocket rule, a strong knife with a good, big
blade for taking out ground spiders, should also go into the
hand bag. Pencils, several of them, for one is apt to lose a =
pencil in the excitement of collecting unless it be tied to the Fie. 19. A paper
neck or button; a hand lens for the satchel, and two or ig hares
three others to carry in the pockets, are almost necessary. A
good objective may be carried in a vest pocket, and will give one an
opportunity for rough microscopic observations while he is afield. Proyide
‘also a pair of shears for clipping off twigs and branches; and a few elastic
bands for fastening the boxes whose covers are a little loose.

For one who wishes to collect spiders withaut particularly observing
the habits, a glass bottle or good sized glass tube filled with alcohol, is

the chief requisite. If one is collecting Orbweayvers or Line-

Taking
Nests.

Cabinet Weavers, by placing the open bottle beneath the spider and
Spee ently touching the creature, it will frequently drop into the
mens. £ AY £ 3 ah 9 | J }

alcohol, or the bottle can be placed rapidly beneath the spider,
and with the sudden impulse to drop which is characteristic of it, it will
fall directly into the alcohol. A cyanide bottle, such as is used by collectors
of Lepidoptera may be used instead of alcohol.

After the spiders have been collected in the bottle, they may be assorted
and placed in separate tubes. No special method of mounting spiders can
be satisfactorily recommended. I have found nothing better for my own
purposes than glass bottles, well corked, with a bit of paper inside to

bo

AMERICAN SPIDERS AND THEIR SPINNINGWORK.

“

indicate the species, and these placed in small paper trays (see Fig. 19),
bound in by two India rubber bands slipped over the box. These trays

are placed upon end inside of my cabinet boxes, and the name
Preserv- of the species marked distinctly on the top. Any other notes
Bo Sees as to date, locality, ete., can be jotted upon the back or on the
cae inside of the tray. The trays may be readily stored in boxes
with stiff pasteboard or wooden partitions, according to the width of the
tray, and the whole kept in a small cabinet. (Fig. 20.) A quite small
cabinet will suffice to contain all the species of any neighborhood.

A stout umbrella is a very important implement in collecting. The
open umbrella should be placed (handle upwards) underneath the bushes,
and these beaten in the ordinary way. When the umbrella is lifted aside,
there will be found numbers of insects of various kinds, along with bits
of leaves, twigs, ete., and more or
fewer spiders of various sorts. These
can readily be taken in boxes or in
the collecting bottle. I have often
found advantage in holding the um-
brella off a little distance and invert-
ing it slowly. The rubbish will drop
on the ground and the spiders will
also fall, but hold on to the little
dropline which they instinctively
throw out when falling. The bottle
can then be rapidly placed beneath
these swinging individuals, who are
thus secured. The ordinary ento-
mologist’s bag may also be used for sweeping the grasses and hedge rows.
Many species will be found by sifting the fallen leaves and other rubbish
of the woods and fields, within which they hide. Others will be found
underneath the bark of old trees and fallen logs.

A cupping glass and a card usually answer for collecting large ground
spiders. I have taken the great tarantula of Texas in this way, watching
my opportunity to slip the glass over the animal. The card is
then gradually introduced between the glass and the ground,
and the spider can thus be lifted up in the hand. <A small vial
of chloroform or ether for such purposes may be carried in the satchel.
A pellet of cotton, moistened in either of these drugs, if slipped under-
neath the card within the cupping glass, will soon overcome the animal,
which may then be dropped without inconvenience into the alcohol.

| have never had any hesitation in handling our indigenous spiders in
order to collect them, though, of course, I should not care to lay hands
on a tarantula, and am careful with our largest species of Lycosids. But
there are few spiders, perhaps there are none, in our Northern and Mid-

3 Tetragnatha -

——————

S| a ear

Fic. 20. A collector’s cabinet.

Ground
Spiders.

9o

GENERAL CLASSIFICATION AND STRUCTURE. do

dle States, that may not be seized with comparative impunity and dis-
posed of according to the wishes of the collector. I have (I suppose I may
say thousands of times) picked out of their snares or from the ground all
sorts and sizes of spiders; even the largest orbweavers, as Argiope cophi-
naria and Epeira trifolium, I have collected and carried in my hands. Yet
only on one occasion do I remember to have been bitten. In point of fact
my respect for the good nature of my aranead pets has been greatly increased
by my experience of their forbearance and general harmlessness under ex-
treme provocation. I state the facts in my own case, but do not take the
responsibility of advising any one to follow my example.

Of course the above hints are bare outlines of what my own experience
has suggested as satisfactory. Others, doubtless, have better ways, and all
may find modes better for themselves. No man’s methods will quite fit
another; and, after all, experience is the best teacher for all. I have only
tried to give the tyro arachnologist a helpful start.

Cie Aes Riby
THE SPINNING ORGANS.

1h

Tue external spinning organs or spinning fingers, are located under the
posterior or apical extremity of the abdomen in most species. In some,
however, they are placed a little more underneath, and in such
External genera as Acrosoma and Gasteracantha they are located at or near
Bes the middle point of the ventral part of the abdomen, forming
"the apex of the inverted pyramid or cone, which it then assumes.
In the orbweaving species the external spinning organs consist ordinarily
of six spinnerets, which aré
divided into pairs arranged
symmetrically on either side
of the median line of the
venter, occupying a small cir-
cular space immediately for-
vard of the anal opening. The
hindermost pair (nearest the “., sommietey coparated
apex), will be known) in this a2 ecb mee

Fic. 21. View of the spinnerets of A back and flattened. ac,
Argiope cophinaria, represented work as the posterior or outer semilunar anal closure.

closed, but the parts not quite in : ane ieee, posterior; M, middle ;
contact. A, anterior, P, posterior, spimer ets ; the foremost pal’, A, anterior spinning warts.

M, middle spinnerets. SF, spin- as the anterior or inner spin- 1+ lancet shaped chitinous

ning field; ac, anal closure. ; leaf, between the two ante-
ar nerets; and the pair located be-_ rior spinnerets.

tween these two, as the middle spinnerets.! (See Figs. 21 and 22.) With

Orbweavers the spinnerets are short, and the anterior and posterior pairs

‘The nomenclature of these organs has become very much confused, and I have hesi-
tated as to what terms I should adopt, but finally have concluded to call the six “spinning
mammule” of Blackwall by the term which has now passed into common English use,
namely, spinnerets; and the minute tubes upon the tips of the spinnerets, out of which the
silk directly proceeds, by the name which they commonly receive among German writers,
namely, spinning spools. These latter organs, Blackwall has called spinnerets, but his name
has been transferred by naturalists and by the lexicographers to the larger organs which he
called spinning mammule, and which the Germans generally name “spinning warts.” The
names of the several groups of spinnerets, as determined by their relative position, are also
much confused. I have concluded to drop the titles prevalent among German. histologists
and others, namely, inferior, intermediate, and superior, and speak of them as the anterior
or inner, the middle, and the posterior or outer spinnerets. I also occasionally speak of
these organs as the spinning fingers, a name whose propriety has often been impressed upon
me by their use.

(34)

oO
OU

THE SPINNING ORGANS.

about equal in length. In form these organs are somewhat conical and
cylindrical, widened at the base and gently sloped or flattened at the tips.
The three pairs differ somewhat in appearance and size, the mid-
dle pair being shorter and less in size and more closely approx-
imated. ‘The posterior and anterior spinnerets have two joints
(Bucholz and Landois); the middle ones are unjointed cones.!. They are
movable, particularly the posterior and anterior pairs, articulating with the
integument of the body, and can
be closed in upon each other until
the tips touch at the spinning fields,
as when one closes the thumb upon
the four fingers of his hand. ‘The
spinning fields, Fig. 21, SF, are
those portions of the tips and sides
of the spinnerets on which are
placed the sessile tubes out of
which the silk passes.

In repose the spinnerets are gen-
erally closed (Fig. 21), forming a
sort of rosette of five divisions; but
when the spider is engaged in ac-
tive operations, the posterior and
anterior spinnerets are thrown well

back, and the two middle

The Spin-
nerets.

1. Poste- ones open up, and thus,
mor PE) quote the lansuape of
nerets. a Pe ee

Dugés, “this singular flow-
er unfolds.” The posterior spinner-
ets (Figs. 21 and 23, P)? are well
‘separated from each other, and le
directly forward of the semilunar Fic. 23. Posterior spinneret of Ep. diademata, greatly
anal covering (Fig. 21, ac). They — feta; nb, branched bristles; ab, simple bristles; sp,
are movable horizontally toward _ spigot spool; 1.ss, long spinning spools; s.ss, short

$ spools. (After Bucholz and Landois.)

each other, so that their long oval

spinning fields approximate and, indeed, may be said to lie upon the cor-
responding middle spinnerets. They may be described as thumb shaped
organs; are of a long, cylindrical form, and towards the free end are con-
ically rounded. The terminal joint is divided from the base by a suture,
Fig. 23, su, which extends along the inner and hinder edge, much farther
than on the opposite edge, so that the spinning field extends on that face
much farther towards the base.

‘ Meckel and Oeflinger both attribute three joints to the posterior and anterior, and two
to the middle spinnerets.

* To prevent confusion and the multiplication of references to figures the same letter
ing is preserved for like organs and parts thereof in all the anatomical figures.

36 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

The spinning field, SF, is an elliptical slope, which is situated on the

inner side of the spinneret, and extends across the summit to the opposite

_ face of the tip. The basal part of the spinneret is cylindrical

Spinning and eradually grows smaller toward the spinning field. At the
Field. j a: : .

lower or inferior edge is a row of long, strong branched bristles,

bb. On the inner surface, and at the border of the prolonged spinning

field, is a group of much shorter, stiff, simple bristles, sb.

On each posterior spinning field is placed a number of spools, which
may be estimated roundly at one hundred and twenty. Besides these, there
are five larger spools, sp, which after Bucholz and Landois we may dis-
tinguish as spigots. Through these spigots issue a corresponding number
of cylindrical and treeform glands presently to
be described. That part of the spinning field
which runs downward toward the base is com-
posed of numerous rows of long, closely placed
spools, Lss.; while that part of the field on the
summit is covered with short spools, s.ss. (See
Fig. 23.) Of the spinning spigots (Fig. 23),
four stand close together in one group towards
the middle of the spinning field, and one of
them is situated in the lower part of the field
(near Lss.), and appears to be covered by the
long spinning spools. Of the four grouped
spigots, three give exit to treeform glands; and
the one farthest towards the base is connected
soe Middle spinneret, largely mag- with a cylindrical gland. The isolated spool

ed. sp.c, spigot discharging cylin-

drical gland; ss, and s.ss, spinning Sp, (near Lss.) also discharges a treeform gland.
oP iresfotn aad eee "The middle spinnerets are or aithres raced

pyramidal form. (Fig. 22, M, and Fig. 24.)
The bases are directed towards the front, while their points, lying closely
together, are turned immediately backward. They are unjointed.1’ The
spinning field is triangular, and occupies almost the entire slope
of the spinneret from base to point. It contains quite a number
of long spinning spools, which may be approximately estimated
at one hundred. and fifty. On each middle spinneret there are
also three spinning spigots, of which two are close together at the tip,
sp.c, and give issue to cylindrical glands. A little further back, another
spigot gives exit to a treeform gland, sp.t. Along the inner base

2. Middle
Spinner-
ets.

3. Ante- ; . : :
aoe tin are rows of bristles. The anterior spinnerets are of stouter pro-
nerets, Portions and more conical shape than the posterior, from which

and the middle spinnerets they are divided by quite an inter-
vening space. (See ig. 22, A, A.) Their inner bases are almost in contact
and are divided only by a tongue like chitinous leaf, 1th Fes Ee

1 ‘ > . ® . e base
See Bucholz and Landois. Meckel describes them as with two joints.

THE SPINNING ORGANS. 37

The spinnerets articulate
obliquely from the outer side
and the front, inward and
backward, so that their tips
approximate the correspond-
ing spinning fields of the mid-
dle spinnerets. The base is
covered on both of its side
faces with many rows of bris-
tles (Fig. 25, b); it is divided
from the terminal field by a
suture, su, and a brown chit-
inous zone, z. The terminal
joint is cap-shape, and is only
partially occupied as a spin-
ning field.

On the top of the spinning
field are from sixty to seventy
very short spinning - spools,
s.ss, and a spinning spigot,
connected with a cylindrical
gland, Fig. 25, sp.c. The base
of these spigots is surrounded
by a pair of chitinized stripes,
which originate in the chit-
inous zone, z Close to this
place is inserted a very strong

W\W\\y

\\ +
Wt ;
A |
' NN
HAN

j
NI

f
hy

Rai HESS

Fic. 25. Anterior spinneret, magnified largely. z, brown chit-
inous zone that bounds the spinning field; sw, sinew of the
bending muscles of the anterior spinning wart; du.c, duct
from cylindrical spinning glands; sp.c, spigot discharging cy-
lindrical gland; sp.t, spigot of treeform gland; s.ss, spinning
spools of pyriform glands. (Bucholz and Landois.)

and long sinew, sw, which unites with the chitinous border of the spin-
ning field at the furrow (su) between the base and the terminal joint.

‘This sinew passes beyond the

|

root of the spinneret into the strong, motor

muscle, ms, which controls the movement of
the spinneret towards its fellows. Within the

a e)

Fig. 26. View of the spinning spools of
Argiope cophinaria, as they appear in
clusters. a, short spools; c, long spools;
b, a small cluster; tj, terminal joint;
bj, basal joint.

bases of the spinnerets are bundles of muscles
which contribute both to the general moye-
ment of the spinneret and to the movement
of the individual spools on the tip. On the
chitinous edge of the spinning field is a single
row of strong bristles, br.

On examining the spinnerets with a lens
of ordinary power, the tips or spinning: fields
are found to be covered with a great number
of fine movable spinning tubes, already men-
tioned, known as spinning spools (Fig. 26),
which are regularly disposed over the surface.

AMERICAN SPIDERS AND THEIR SPINNINGWORK.

w9
@ a)

As many as one hundred and fifty or two hundred may be counted upon
the tip of a single spinneret of an Epeiroid spider, as for example, Ar-
giope cophinaria. ‘These spinning spools are two jointed, at least they are
divided into two parts, of which the base is the thicker,

_. and sometimes the longer. ‘They are hollow
ae ae tubes, through which the delicate ducts connected

poe with the silk glands convey the liquid silk to the
surface. These spinning spools are of several sizes and
shapes (Fig. 26), and differ somewhat according to their
ee ee or Position upon the several spinnerets. Thus those upon the
a spinning spool anterior spinnerets have the basal part (bj) of a conical
ae eS ‘PY shape and rather shorter than the point or terminal joint,
ademata. (After tj, (Fig. 26 b, c,.compare with Fig. 27.)

ag Distributed here and there among these spools of ordi-
nary size are a few which are larger and stouter. (Fig. 28.) In Argiope
cophinaria there are three of these on each of the middle spinnerets, four
upon each of the posterior, and one upon each of the anterior ones. A
detailed description of these instruments will be given further on.

These groups of spinning spools are surrounded by ranks of hairs and
bristles (b, bb, br), both simple and branched, which are movable and
appear to have some important part in spinning. Possibly they
serve to direct the course of the threads as they issue from the
spools, or it may be that they form a protection to the more
delicately organized spinning spools themselves.

Hairs and
Bristles.

WE

The spinning spools are connected with a system of glands and ducts
constituting the internal spinning organs, the reservoir within which is
formed, and from which is secreted the material for all spinningwork,
When the integument of the lower and front

part of the abdomen is removed, to-

Interr i

ernal gether with the thin layer of fat and
Spinning ©
Organs, the muscles that move the spinner-

ets, a large bunch of minute vesicles
visible to the naked eye in a large spider such
as Argiope cophinaria is brought into view.
Examined by the microscope they are found
to be small, transparent, oval sacs. These are
the silk glands. They are about one two-hun-
dredth of an inch in diameter, in Epeira di-
ademata (Meade); or 0.22 millimetre (Bucholz
Fia. 29. View from beneath of the loca-

and Landois). In Argiope cophinaria they are tion of spinning glands in Epeira di-

of various lengths, averaging about (0.3 mm.) 24emata. (After Meade.) spn, spin-
: nee nerets; py.g, pyriform, cy. g, cylindri-
three-te1 iths of a milli netre. cal, tr.g, treeform, glands.

THE SPINNING ORGANS. 39

They are placed in a mass just above the spinnerets, and within their
bases and the abdomen, and along the venter forward and laterally. See
Fig. 30. The pyriform glands, which are smaller and very much the most
numerous, are arranged in five roundish clusters, about two millimetres in
diameter in A. cophinaria, each corresponding to one of the exterior spin-
nerets, one cluster being devoted to the two middle spinnerets, al-

Silk though even in this case the clusters can be separated into two.
Glands: the number of glands precisely corresponds with tl k f
aed glands } y sponds with the number o

spinning spools and spigots. Bucholz and Landois give about
seven hundred for Epeira diademata and they are as numerous in Argiope
cophinaria. Mr. Blackwall expresses the opinion that the total number of
spinning spools does not greatly exceed a thousand, even in adult females
of Epeira quadrata, whose weight is about. twenty grains, and in many other
species it is smaller. As the spools correspond in number with the glands,
this gives an indication of the number of silk glands within our best known

: eee os “spn

ep rg cY8 py-e

Fic. 30. Partly diagramatic view of the location of the spinning organs in Argiope
cophinaria. spn, spinnerets; py.g, pyriform glands; cy.g, cylindrical glands; tr.g,
treeform glands; ep, epigynum; gl, gills: E, eggs; al.c, alimentary canal; a, anus.
Th figure is a composite one.

Orbweayers. Each gland terminates in a long, delicate duct, and one duct
enters one of the spools; a distinct duct belongs to every spool, without any
connection, as a rule, with other ducts or glands.

Under the microscope the liquid silk can be seen very distinctly within
the glands, and presents the appearance of minute, yellowish, translucent glob-
ules of thickish oily or viscous substance. Some of the glands of Argiope
cophinaria appear to contain material which is rather smoother and of a
lighter color than that above described. The contents of some
glands in this species have a reddish brown color, which indicates
that they supply the brown silken padding that envelops the
eggs of this species and lie just within the outer cocoon case. Where the
glands have been broken, or the contents spilled on the mounting cover, the
liquid silk generally shows stringy or fibrous, but sometimes maintains the
globular appearance retained within the gland. It is very probable that

Liquid
Silk.

40 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

these differently formed glands prepare different secretions. However, the
only difference which Meckel obtained by applying a few reagents was that

the cylindrical
than others.

Fic. 31. Pyriform glands, caudate; A. cophinaria.

pecial spinnerets. Each spinneret

elands became more coagulated through aleohol and acids
We may now enter upon a detailed description of these silk

glands, for which I am particularly in-
debted to the admirable stud-

Ponte ies of Drs. Bucholz and Lan-
eee wi dois, and of Meckel.? In

some measure, also, I have
drawn upon the English microscopists,
Messrs. Underhill and Meade. I have
tried, however, to confirm all statements
accepted by me by independent studies
of our own fauna.

The secretions of Epeira diademata
on which spider most of the valuable
studies here referred to have been made,
are in not more than a thousand glands,
which are connected with an equal num-
ber of independent ducts. There are
three different sorts of these glands,
which are distributed to their own es-
possesses a large and somewhat variable

number of small pyriform glands, and besides this one or more larger

glands. Concerning these I have
adopted substantially the conclu-

sions of Bucholz and Landois, which
are confirmatory, for the most part,
of the principal statements of Meck-
el, and which are almost wholly in

; accord with my own stud-
Pyriform

ies as far as they have
Glands. ; ; Pate

been prosecuted. The py-
riform glands py.g, vastly exceed
the other forms in number, as there
are present in every spinneret one
hundred or

more. However, they

may not exceed the less numerous

Fic. 32.

Pyriform glands of Argiope.

but considerably larger gland forms in quantity of secretions. They are ar-

ranged, as has already been said, in round clusters of about two millimetres

Anatomische Untersuchungen iiber den Bau der Araneiden: von Dr. Reinhold Bucholz

und Dr. Leonard Landois.

page 240 sq. (Leipzig.)

* Heinrich Meckel: Mikrographie einiger Drisen Apparate der niederen Thiere.
f. Anat. Phys. (Berlin), 1846, page 1 sq., Pl. IIL.

Archiy Anatomie, Phisiologie und Missch. Med. Jahreang, 1868,

Archiy

THE SPINNING ORGANS. 41

in diameter (about one-twelfth of an inch), lying close to the bases of the
spinnerets. (Fig 30, py.g.) In form the individual glands are long, oval,
pear shaped vessels, 0.22 mm. long, or, expressed approximately in linear
measure, say one hundred and fifteen of average length would make an
inch. In Argiope I find the average length about one eighty-fifth of an
inch. At the inferior end they diminish grad-
ually, passing into a duct which narrows towards
the point of discharge, and which, together with
a compact bundle of similar ducts, enters the
interior of the spinneret, each one to discharge
through its appropriate separate spinning tube.
The wall of the gland contains a single cell stra-
tum of a diameter of from 0.020 mm. to 0.024
mm. These cells contain a quantity of small
drops, which consist of a strong refractory sub-
stance that agrees in appearance with the spin-
ning material within the ducts. This glandular
wall incloses a large middle cavity, which is entirely filled with a viscous
liquid spinning substance. The duct which projects from this
gland possesses at the beginning a diameter of 0.024 mm.; nar-
rows very soon after exit from the gland to the diameter of
0.01 to 0.012 mm. That is to say, the termination of the duct is about
one twenty-five-hundredth of
an inch in diameter. At this
width it runs unaltered to its
place of exit from the spin-
ning tube.

These pyriform glands, as
preserved in Argiope cophina-
ria, while agreeing in
general form vary a
good deal in details,
as shown by comparing the
figures, 31, 32, and 33. Some
of them are vermiform in
shape, Fig. 53, v; some are

Fic. 33. Pyriform silk glands.

Pyriform
Ducts.

Argiope’s
Glands.

Fie. 34. View of the cylindrical glands, cy.g, and treeform sf ee
glands, tr.g, of Epeira diademata. py.g, cluster of pyriform strictly pyritorm, Pp; some are
glands. d, bundle of ducts leading therefrom. spn, a spin- a | No 29 a- :

: ; , ‘cordate, Fig. 382, ¢; and some
neret into which the glands lead. (After Meckel.) i te ’ = 2 ; a
haye long caudal parts, Fig.

31, pe, which in general appearance resemble the cylindrical glands, but
are on a much smaller scale. The vermiform glands contain a yellowish
white substance. The other glands contain a somewhat similar material,
but of a deeper yellowish color, and broken into distinct globules; while
others contain a brownish liquid which has already been alluded to. This

42 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

difference in size and form is perhaps largely due to the presence in
greater or less quantities of the liquid silk contained within the glands.
The caudate extensions of the pyriform part manifestly permit the secre-
tion and storage of larger quantities of spinning material.

The Cylindrical glands, cy.g, have been considered by Meckel under two
distinct forms, according as they have in one case an ampullate extension

towards the duct, or in the other case are simply cylindrical
Cylin- ‘tubes. These forms he denominates Cylindrical and Ampullate.
drical They appear, however, to be the same glands, exhibited under
oe different conditions; and even according to Meckel they have the
same structure and discharge from the same character of spinning spigots.
They appear to be, as Bucholz and Landois regard them, but one gland.
The difference in their form is probably due to the same cause by which
the somewhat similar difference in the form of pyriform glands has been
explained, namely, the presence of more or less of the secreted spinning
substance. The number of cylindrical glands is eight, four of which are
located on each side of the body.!

These glands represent very long cylindrical tubes, which extend from
the root of the spinnerets to the fore part of the body, near the breathing
organs. Thence, bending with waying convolutions, they return to their
origin. If they were stretched out entire, their length would almost equal
the length of the animal itself, of which, perhaps, they occupy only a third
part. This extraordinarily long gland terminates with a double fold be-
neath the lower end of the gland and the spinneret, which if stretched out
straight would exceed the length of the whole gland section. On the walls
of the gland is a simple stratum of gland cells, whose diameter is 0.020
to 0.024 mm. They are precisely like the cells of the pyriform glands,
and like them are filled with a great number of minute shining globules
of spinning substance.

In the direction of the duct, the tubular part of the gland enlarges
greatly into an elliptical, ampullate extension, am, Fig. 35, from which the

duct proceeds. The construction of this ampullate swelling is
The Am- the same as that of the cylindrical section, and in fact the swell-
pulle and. SS ne? ; a
Duct. ing may be caused simply by the accumulation of spinning

material in the lower part of the gland, which thus rounds out
that part into an ampulle, am.

The duct of the cylindrical gland, c.du, has at its origin a width of
0.065 to 0.070 mm. (one three-hundred-and-fiftieth of an inch) and runs,
_,. quickly narrowing at first, to the root of the spinneret; thence
Cylindri- . : : :
aaiticct. i returns again, folded like a bent knee, k, and once more doub-

ling (do.) and proceeding downward discharges through its appro-
priate spinning spigot, a brown obtuse cone on which stands a clear trans-

' Meckel and Oeffinger both report six glands of this kind on either side.

THE SPINNING ORGANS.

43

Ray
3

ig
77H} ry

Fic. 35. Three forms of spinning glands opening into the posterior spinneret, spn. The middle one
enlarged in different proportion from the others. py.g,a group of pyriform glands. b.du, a bundle
of ducts opening into the spinneret through the spinning field, SF. tr.g, treeform gland; tr.d,
excretory duct with brownish glandular walls or boundaries, bs; cy.g, cylindrical gland; tu, its
tubular part; am, ampullate expansion of the same; b.du, beginning of duct from the ampulla ;

c.du, cylindrical duct; do and k, the noose shaped twist of the duct continued in an external
envelope, n.w, derived from the ampulla.

44 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

parent tube from which proceeds a thick thread. In its course it runs
between the delicate external net like walls (n.w), which originated as a
continuation of the ampulla, and terminate close at the base of the spin-
neret, The walls are without ordinary cell formations. There is no dif-
ference in construction between the cylindrical and ampullate part of this
gland. Of the Treeform, or as Meckel denominates them Aggregate glands,
tr.g, there are five on either side, of which four discharge at the anterior
spinneret, and one at the middle. The secreting part of these
elands consists of a large, white canal, widening into many sacs,
which form together a roundish cluster, ¢, ¢, « The duct, tr.d,
runs quite close to the middle of the cluster, like the umbilical cord from
the placenta in mammals. In the beginning it is straight and smooth, but
farther on is accompanied on its superficial part by a number of small blind
sacs (bs), with thin necks.
Towards the end, the duct
becomes smooth again, and
enters the spool destined for
it, which is somewhat larger
than that of the cylindrical
glands. Soon after its exit
from the gland the duct has
a diameter of 0.160 mm.,
but greatly narrows toward
the spimneret to 0.04 mim.
The duct appears, through-
out its entire length, spiral-

Treeform
Glands.

Fic. 36. Glands of Epeira diademata. (After Meckel.) cy.g, : : C
Meckel’s cylindrical glands; am.g, ampullate glands; bl.g, bulbous ly twisted, without forming

glands; py.g, cluster of pyriform glands leading into the spin- such folds as are seen in the
neret, spn.

eylindrical glands.

Meckel further describes what he calls the Tuberose or Bulbous glands
(glandule tuberosee), of which he says there is one on either side. (Fig. 36,
blg.) According to this author they are small, and consist of a few branching
tubes with knotted enlargements at short intervals, which pass finally into a
duct that unites with the duct of the large cylindrical gland (Ventricose gland
of Meckel), which leads into the middle spinneret. Bucholz and Landois,
however, declare that they have never been able to detect this gland, and
doubt its existence. I haye seen somewhat similar glands in Argiope cophi-
naria, but have simply regarded them as one of the various forms of the
pyriform glands.

A yaluable study of the internal spinning organs of spiders was made by
Mr. R. H. Meade, and reported to the British Association as early as 1844.1

‘ On some Points in the Anatomy of the Araneida or True Spiders, especially on the Internal
Structure of their Spinning Organs, by R. H. Meade, F. R. C.8.; British Association Reports,
1858, page 157, sq.

THE SPINNING ORGANS. 45

The immediate purpose of these anatomical studies was to throw light upon
the question, then much discussed, whether spiders actually possess the power
of shooting out threads to a greater or less distance into the air.
Can the The question is considered elsewhere, although it is now hardly
a ae worthy of a very serious discussion. As is often the case, both
Threads? Parties were right though they appeared to be at oppo-
site poles of the subject. In other words, spiders do not
possess the power of darting threads into the air to any consid-
erable distance, and are dependent upon the atmosphere to elevate
those lines upon which they ascend, and those which they ex-
trude for web foundations. But in the act of swathing insects,
and on other occasions also, it is possible for the aranead to
expel liquid silk with great rapidity and violence,
and at least for a short distance. This I have
often observed. Mr. Meade abundantly demon-
strated that the muscular apparatus furnished to
the internal spinning organs was sufficiently for-
midable to produce such a result. Independent
of this question, Mr. Meade’s somewhat extended
studies, during which he compared the external
spinning organs of Orbweavers with those of other
tribes, have a real histological value, and I have
made use of some of his results, particularly for
comparison with the more perfect work of others.
According to Mr. Meade, the nature and con-
struction of the silk glands are essentially the same
eS a haere in all species of British and foreign spiders dis-
g, and the long tri. Sected by him, though they differ greatly in form
articulate spinner- and number. As might be expected, they are
, et, sp, of Agalena
labyrinthea. (After most highly developed in the web spinning species,
wie while in those that hunt for their prey, as the
Lycosids, they are few and small in comparison, with the excep- ti Fae
tion of those species which are aeronautic in their young state.’ g; duct, a;
They appear to be similar in the males and females. In Agalena pe bee
labyrinthica the silk glands are of a large tubular or clavate domestica.
shape (see Fig. 37), as is also the case in Tegenaria domestica. nin.) » 125.

(See Fig. 38.)

III.

This detailed description of the spinning glands may be appropriately
followed by a somewhat more detailed description of the organs through
which they discharge for the purpose of forming the silken lines of

1 T have supposed that all Lycosids practice ballooning; but the subject is open for inquiry,

and it would be interesting if histology should point the way to a wider knowledge of natural
habit.

46 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

rate : = Jaa Tee
which the spider’s spinningwork is composed. The ordinary spimning

spool is a hollow, eylindrical,

chitinous formation, and consists of two

joints: first, a shorter or longer basal cylinder, bj, whose walls are strongly
brown colored: and second, a much smaller and transparent ter-
Spinning y inal joint, tj, which terminates in a very fine point, provided

Spools.

with a minute opening. The spools in which the pyriform

glands terminate, s.ss and lss, Fig. 24, stand in large number on. all the
spinning fields. They are not alike in form of the several spinnerets,
and those of the anterior spinneret especially, are quite differently con-

Fia. 39. Fig. 41. Fie. 40.

Fic. 89. Spinning spool of the usual form
from the posterior spinneret, and connected
with pyriform glands. Multiplied greatly,
2000 times. Fic. 40. Spinning spool from
the anterior spinneret. x 2000. Fie. 41.
Spinning cone or spigot into which a cylin-
drical gland empties. The whole taken
from the apex of the middie spinneret.
> 2000 times. bj, basal piece; c, circumfer-
ence or ring of the chitinous wall of the
basal piece, constituting a ring formed
chitinous thickening on its apex; em, the
exterior membrane of the chitinous wall
of the duct, du, with vertical striation; im,
inner membrane of the duct passing into
the canal of the basal piece.

structed from those of the posterior pairs.
On those spools of the posterior spimnerets
which receive pyriform glands, the basal
joint (Fig. 39, bj) forms everywhere a reg-
ular cylindrical tube of even
thickness, which seems to be
. obliquely cut at the exterior end
where the terminal joint is united to it.
This interrupted space is, as Fig. 39 (1s)
shows, a very little flat in the middle, and
towards the edge slightly curved. The base
of the tube is joined to the surface of the
spinneret by a ring formed enlargement,
and, as elsewhere, bristles and hairs with
chitinous rings are seated upon the skin.

Into the base of each spool enters a
single duct of a pyriform gland, and this
duct can be followed as a straight tube
to the end space of the base of the spool,
where it ceases to exist as a canal, and is
merged into the cavity of the terminal
joint.

The terminal joint (tj) is in the larger
tubes, about half the length of the basal
joint, bj, and sits precisely in, the centre
of the summit of the basal joint. The

Pyriform
Spools.

terminal joint is hollow, gradually diminishes, and terminates in a very
fine, round opening at the tip. The thickness of a single thread, coming
from this spinning spool, would be about 0.001 mm., or one twenty-five-
thousandth part of an inch. This form of spinning spool undergoes
changes at different places of the spinning field, caused by the basal cylin-
der varying in length. The central parts of the spinning field especially
are covered with yery short spools, The terminal joint, however, remains
unchanged in length, notwithstanding the varying lengths of the basal
joint. (Fig. 39.)

THE SPINNING ORGANS. 47

Somewhat different from the above are the spinning spools which are
found on the anterior spinnerets. On these (Fig. 40) the bases consist of
a short, more conical segment, which diminishes considerably from the
broader base toward the free end. This conical basal joint, bj, is provided
with a strongly concave end space. The terminal joint is almost double
the length of the base, and is not straight as in the spools of the pos-
terior spinnerets, but is a little curved. It stands in the centre of the
concave end space of the basal cylinder.

Dispersed among these smaller spools of the pyriform glands are
shorter and thicker spools, sp, through which discharge the cylindrical
and treeform glands, Fig. 35. Those belonging to the cylin-
drical glands differ from those of the treeform glands in the
character of the end space, which is in the former longer and
considerably thicker. In general, however, the construction of all these
formations is similar. Figure 41 shows the discharging spigot of a cylin-
drical gland, situated at the tip of the middle spinneret. This spigot like
spinning tube consists of a basal piece, bj, formed by brown
chitinous walls and a cylindrical end piece, tj, which tapers
more sharply towards the point.

We are now better prepared to consider these beautiful
instruments in their relation to their several silk glands.

Close by the lower end of the spinning field of the pos-
terior spinneret stands a large spool (Fig. 33, sp) into which
leads a cylindrical gland. Farther above are the spools of
two treeform glands, and. close by are the two spools of two
cylindrical glands. Besides these, innumerable spools of the “ ®, Epeita dia:
pyriform glands cover the spinning field, and they are here
all very long, especially those placed at the inferior position of the spin-
ning field.

On the spinning field of the middle spinneret stand many long spools
which are connected with the pyriform glands. The number, however, is
here less than on the other spinnerets. Just below these smaller
spools, stands toward the upper side of the field (Fig. 24) a very
large spool which is the mouth of a cylindrical gland. The
point of the entire spinneret is formed by a rounded projection at the ex-
treme end of the oval space, constituting the spinning field. On this none
of the smaller spools stand, but only two larger ones, of which the one is
the mouth of a cylindrical gland (ventricose of Meckel); the other gives
exit to a tuberose gland. Besides these, there is also a short, solid horn of
unknown use. The spinning field of the anterior or inner spinneret is
covered with short small spools, whose number exceeds that of
the other spinnerets. The chitinous epiderm which bounds the
spinning field forms a zone not entirely closed, and in the open
space is a horny cone (Fig. 25, sp.c) on whose point stands a spool of a

Spigot
Spools.

Middle
Spools.

Anterior
Spools.

48 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

cylindrical gland, the only larger gland which dis-
charges here. On the inside of this horny cone
is attached a long yellowish cord or point, upon
which strong muscles are inserted in order to
move the cone against the spinneret.

Mr. Underhill figures the spigots or large spin-
ning tubes which issue upon the posterior and
anterior spinnerets.! The former are situated upon
the interior margins and are connected with two
very large glands which are doubtless the cylin-
drical glands as heretofore described. These spig-
ots are shown at Fig. 48 together with a portion
of the ducts leading to their appropriate glands
(not represented) which le below the pyriform
glands. Fig. 44 shows one of these anterior spig-
ots, asp, compared with two spools ss. of the same

spinneret. Mr. Blackwall announced the
fact for the first time, so far as I know,
See Se that the spools vary greatly in number
derhill.) ss, spinning spools; in different species, and also differ considerably in

sp, spigot; py.g, pyriform glands

with their ducts, py.d. The
glandular epithelium is repre-
sented. cy.d, ducts belonging
to the spigots; sp, probably of
cylindrical glands, cy.g.

size not only in individuals of the same species,
but often even on the same spinnerets. The larger
species of the Epeiroids have the spinnerets most
amply provided with spools, and Blackwall ex-

presses the opinion that the total number does not greatly exceed a thou-
sand, even in adult females of Epeira quadrata, whose weight is about
twenty grains, and in many other /
species it is smaller.

As illustrating the difference in
various genera it may be stated that

Tegenaria domestica and
Numbers -y_ : pene :
Tegenaria civilis, for ex-

pany ample, have less than four —

hundred spinning spools each. In wey

Textrix agilis and Lycosa_ saccata

the number is below three hundred, \

In Segestria senoculata it scarcely \ &

exceeds one hundred, and in Many py, 44, a.sp, spigot on anterior spinneret of Epeira dia-

of the smaller spiders Ties eestr ll demata leading to cylindrical gland; ss, spools of pyri-
; form glands, same spinneret. (After Underhill.) X 165.
further reduced,

The difference in the number and size of the spools connected with the
several parts of the spimnerets in the same species, and with similar pairs
in different species, is also yery apparent. In spiders constituting the

‘Science Gossip, 1874, page 181.

THE SPINNING ORGANS. 49

genera LEpeira, Tetragnatha, Linyphia, Theridium, Agalena, and many
others, they are generally large, more numerous and minute on the an-
terior spinnerets than on the posterior and middle ones. The last are the
most sparingly supplied with them, and in the case of Segestria senoculata
each has only three large spools at its extremity. _

On each of the posterior spinnerets Mr. Underhill found three spigots
differing in character from those of the anterior spinnerets. Fig. 46, sp.
Their form and size as compared with the spools of the anterior pyriform
glands (ss.p) is shown in the figure. These spigots are evidently the ones
connected with treeform glands; which
glands Underhill estimates at five mil-
limetres (three-twentieths to four-twen-
tieths of an inch) in length, while the
common pyriform glands are about one
millimetre (one one-hundredth of an
inch). The ducts which connect those
glands and spigots are shown at tr.g,
Fig. 45, where their covering of curious
globular cells is indicated. These cells
according to Underhill are so slightly
attached as to be easily rubbed off dur-
ing manipulation. He had not seen
anything analogous to this gland on
any other genus than Epeira except the
exotic Orbweaver Nephila; and for this
reason conjectured that through these
spigots and from this gland the viscid
beading of the Orbweaver’s spirals may
be drawn.

Mr. Underhill has stated that in a
large Tegenaria domestica, one one-hun- Fic. 45. One posterior, P, and two middle, M,
dredth of an inch is the average length sme piesa ryote nme tala tna, duce
of the silk duct. On the posterior pair of the treeform glands; py.g, pyriform glands

: ns . with their ducts, du; m.ss, the middle spinning
of spinnerets are about sixty tubes; on — grcois in clusters.
the middle pair, although the spinnerets
are smaller, about eighty. The spools on these two pairs are alike, but
they differ in shape from those of the anterior pair and are much larger.
There are nearly two hundred and twenty spools on the anterior pair, thus
making altogether three hundred and sixty on the six spinnerets.

Spools Blackwall also made the discovery that the number of spools
pers ee varies with the age of the female. In specimens of Drassus
Age. c » ) J age J \S cb . S} cho ‘

ater, which had attained nearly a third of their growth, they
amounted to five or six. In others, which were two-thirds grown, to
six or seven. In adults which had acquired their full complement, they

50 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

were uniformly eight, two of which were situated on the inferior surface
of the spinneret at a greater distance from the extremity than the rest,
and were minute and almost contiguous.

It is a fact deserving notice that the spinning spools are not always
developed simultaneously on these spimerets, six, seven, and eight being
sometimes observed on one, while five, six, or seven are to be seen on the
other. “This remark is applicable not to the anterior spinnerets alone, but
to the intermediate ones also, which, in mature individuals, are further
modified by having the extremities of the terminal joints directed forwards
at right angles to their bases. The same condition was observed in a
species of Drassus and in Segestria senoculata. It is not improbable, there-
fore, that other species, and per-
haps all spiders, follow the same
law of development.

This whole system of lquid
silk supply is regulated by the
compression of surround-
ing muscles, which act
upon the several glands
in the manner of the hand when
squeezing upon the rubber bulb of
a spraying tube. The contents are
forced out of the glands in this
liquid condition, through the long,
delicate ducts, into the hollow spin-
Fic. 46. Epeira diademata. sp (p), spigot of treeform ning tubes, whence they issue in

gland on posterior spinneret; ss (p), spools of pyriform .. eM is .
Sain pacer, (Iu eCH TI) SCC minute jets through the exterior
| openings or mouths of the spools.
As the points of the spools or tips of the spinnerets are approximated, a
number of these jets flow together, and hardening instantly upon contact
with the air, form the thread or line familiarly known as the spider’s web.

The excretory ducts, as well as the silk glands themselves, are encircled by
a fibrous or muscular coat, which loosely surrounds them, and seems to be <
continuation of the outer coat or sac itself. The spinnerets are connected
with, or surmount the integument of the abdomen, by means of diverging
bands of muscular fibres, which enable them to move in different directions.
These muscles are placed immediately beneath the skin, and their expanded
extremities are inserted into it so that they are separated with it, unless
dissected very carefully. }

Muscular
System.

All the spinnerets are thus provided with many muscles which cause
the approachment of all the spools of one spinneret against one another,
as also the convergence of all the six spinnerets towards a central point,
in order to produce in this way a single thread. For this purpose the

' Meade.

THE SPINNING ORGANS. 51

exterior spools of the spinning field are always bent a little towards the
centre.! The spider, of course, possesses the power of regulating the flow
of silk as to quantity, and can graduate it from the most delicate gossamer
thread to the thickest blanket which is used for the rapid enswathment
of insects. She can also play upon the special glands as occasion requires,
and extrude the viscid substance which forms along the spiral lines of an
orbweb, or the variously colored silk used in cocooning.

The field of comparative anatomy, and especially of histology, affords
innumerable examples of the wonderful beauty of structure and adapta-
tion of organs to the various uses of living creatures. But there are few
objects better calculated to awaken admiration, even to the point of en-
thusiasm, than the machinery by which the Orbweaver is enabled to
prosecute her spinningwork.

1 Meckel.

Cea Dine ie
GENERAL CHARACTERISTICS OF ORBWEAVERS’ SNARES.
Tue so-called “geometric web” which one sees in art work and book
illustrations has no place in nature. Were that taken as the standard one
would decide that there is lttle need of comparison, and no room for
classification, since in the books no more differences exist among Orb-
weavers’ snares than might be found in the four wheels of a wagon.

Fic. 47. A vertical snare, full orbed. Snare of Argiope cophinaria.

Unfortunately our artists, and indeed the same is largely true of natural-
ists as concerns cobwebs, are too much intent upon general effects to attend
to such small details as variations in the web architecture of a spider.
As common a figure as is the wheel shaped snare of the Orbweaver, I re-
member but one which gaye proof of haying been drawn from a natural

(52

<)

GENERAL CHARACTERISTICS OF ORBWEAVERS SNARES. Oe

we

web by one who knew its characteristics.!. In point of fact, we shall see
that there are very striking differences in form and structure among the
snares spun by the Orbitelariz. In the following chapters these differences
will be pointed out and illustrated, and an attempt made to group and
arrange the various snares in some natural order. I define an
Orbweb - ie ; od
Defined, O'Pweb as a snare constructed of right lines radiating from a

common centre, and crossed spirally, for the most part, by num-
erous circular lines, or lines forming ares of circles.

The round web of the Orbweaver probably deserves the distinction of
having given the popular name cobweb to the whole spinningwork of
spiders. One easily sees how the
Anglo Saxon word cop, a head, could
have been appropriately applied to
objects which, by their rotundity and
size, suggest the contour of the hu-
man face.2 The orb is the figure
which quite unconsciously rises when
one speaks of the spider’s web, an in-
dication that it is perhaps the most
striking, although it is by no means & k
the most common form of araneal Bae enonzental searey Salt orbed.
spinningwork. Nevertheless, all orbwebs are not round, as will be seen
hereafter, hence the qualified terms of the definition given aboye.

Orbwebs fall naturally into two great groups, Vertical Snares and
Horizontal Snares. In Vertical Snares the orb is habitually perpendicular
to the plane of the horizon, or nearly so. In Horizontal Snares
the orb is habitually parallel with the plane of the horizon, or
nearly or approximately so. The normal positions of these
snares are as described, and they often appear thus in nature; but loca-

Great
Groups.

‘tion compels more or less variation. The exigencies of construction fre-
quently force such an arrangement of foundation lines as inclines the orb
to the plane of the horizon more or less sharply. Thus it may occur
that a true vertical and a true horizontal web may be stretched upon
nearly the same plane. The careful observer, however, will rarely fail to
note and allow for the peculiarities of the site which cause these deflec-
tions, and easily give each web its proper classification.

Vertical orbwebs may be arranged under four subdivisions: first, Full
Orb; second, Sectoral Orb; third, Ray or Actinic Orb; fourth, Orb Sector.

1 For example, I have collected, without much effort, quite a number of samples of
wall paper, into whose patterns the orbweb is introduced, showing how favorite a figure
this is in decorative art. Orbwebs also abound in embroidery and hammered ware.

2 The German has kopf, the Welsh cob, and the Greek «u37, kube. The word cob, how-
ever, has been applied to the spider herself, as a round or head-shaped object, just as we
give the name “cobble stone” to boulders.

54 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

1. In Full Orb snares the spiral concen-
trices cross all the radii, appearing to form
complete circles. (See Fig. 47.) They are
divided into Simple and Compound snares.

a. A Simple orbweb is simply an orb of
radiating straight lines crossed by spiral or
looped lines. The snare of the Furrow spi-
der (Epeira strix) is a typical example.

b. A Compound orbweb adds to the sim-
ple orb a system of netted or retitelarian lines
crossed and joined at different angles, and
placed above and on either side of the upper

Fic. 49. Subdivisions of an orbweb. part of the orb, or placed below the orb. The
snare of the Labyrinth Spider (Epeira labyrinthea) is an example. Sim-
ple orbicular snares may be approximately arranged into three groups
according as they have the Hub Meshed, Sheeted, or Open.

[ am not aware that any arrangement, description, or nomenclature of
the various parts of the orbweb has ever been attempted apart from the

following, which will therefore be found convenient and perhaps
Parts of ae asd z ae
eons sufficiently comprehensive.! The orb may be naturally divided

into the Central Space, CS, the Spiral Space, SS, and the Foun-
dation Space, FS. (See Fig. 49.)

The Central Space is included between the centre of the orb and the
origin of the Spiral Space. It has three
distinct parts, the Hub, the Notched zone,
and the Free zone. The Hub is a small
circular part immediately surrounding the

centre, which is either wholly open, or
covered in whole or in part by spinning-
work.

1. The Meshed Hub is wholly or partly
covered by a series of irregularly shaped
meshes, through which one can often trace
the continuation of the radii as zigzag lines.
In fact, it may be considered as a small
rudimentary and irregular orbweb (Fig.
50). Usually it nearly corresponds in size
to the length (including the legs) of the
spider that has woven it.

The spider when waiting for her prey
upon her snare is frequently and at night
generally stretched upon or near this hub,

Fie. 50. Meshed nub and central space.

' First published in “Our Continent,” Philadelphia, No, 33, page 862, 1882, and “ Pro-
ceedings of the Academy of Natural Sciences,” Philadelphia, 1882,

Noted

page 201

GENERAL CHARACTERISTICS OF ORBWEAVERS SNARES. or

~

and a close observation of her feet will show that the claws grasp, and
even draw out somewhat the lines which represent the radii -continued.
Every motion of the net is thus communicated more readily
through the taut lines to the sensitive feet. The brushes or
tufts of delicate hairs with which these organs are provided,
and which are in contact with the lines, must greatly increase the sensi-
tiveness of the creature to every movement.

This natural telegraphy is, perhaps, also aided by a short line extend-
ing from the spinnerets to the upper part of the hub. This line is apt
to divide into two, or radiate into several branches near the hub. In this
position, of course, the apex of the spider’s abdomen is slightly elevated
(Fig. 51). However, the chief design of this habit is probably to hold the
aranead to her snare when she rushes after her
prey, or to give her a point of attachment for
dropping out of the web, or running from it in
case of assault, with similar advantage when she
may wish to return.

2. The Sheeted Hub is wholly covered by a
closely woven sheet of white silk, against which
the under part of the spider is placed
as she hangs thereon. The type of
this form of hub is that made by the
Basket Argiope, A. cophinaria, (Walck.), the largest
and one of the most beautiful of our indige-
nous Orbweavers. It is shown at Fig. 52, where
a thick, irregular shield like piece two inches long
and one and a half wide, covers the entire hub.
Above, it extends in a broad ribbon of the same ,.. . ceded aan
consistency to the spiral space, a distance of hub, Argiope argyraspis.
‘one and seven-eighths inches; and below, it terminates in a narrow, zigzag
ribbon two inches in length. (Fig. 52.)

3. The Open Hub is entirely free from any spinningwork, being a
small opening in the centre of the orb, that is, the point toward which
the radii tend. It is characteristic of snares spun by the genus
Acrosoma, and prevails largely in horizontal orbs. But it is
frequently found in the webs of spiders whose general habit is
to spin a meshed hub. Such variation in habit of course prevents us
from taking these peculiarities of the hub as characteristics of absolute
determinative value. Nevertheless, they are valuable, and will
be found generally distinctive. The Notched Zone (NZ, Fig.
49) is a short series of spiral lines, ordinarily from four to ten
in number, immediately surrounding the hub. These spirals do not
cross the radii directly, but diagonally, thus causing a notch or angle
on each side when they are drawn taut. In other words, the spiral lne

Meshed
Hub.

Sheeted
Hub.

Open
Hub.

Notched
Zone.

56 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

overlays the radius longitudinally for a minute space at the point of
crossing. The precise effect of this arrangement may be produced thus:
Stretch a cord tightly; then take a second cord, loop it by one twist
around the first, and draw its two loose ends
in opposite directions. The appearance of these

notches is shown at Fig. 53.
The Free Zone (FZ, Fig. 49, see also Fig.
50), the third division of the Central space, is
that portion of the orb which, for the

Bree most part, lies between the notched

Zone. : é
zone and the spirals, and consists

simply of the radii without any crossing lines.
Its outer boundary appears always to be marked
by the last or innermost of the foundation
spirals. Blackwall! objects to the statement
of Kirby and Spence concerning a free zone
as characteristic of geometric webs, that this
is true of but one species. But the greater
part of our vertical orbs have the free zone.
It seems strange that Blackwall? should speak
of the nets which are destitute of the free zone
as having the centre entirely closed up (meshed

Fic. 52. Sheeted hub of Argiope.

hub), for certainly in America the orbs spun by the genus Epeira, which
are by far the most frequent, have both the closed centre and the free
zone, almost invariably. (See Fig. 50.) I must doubt the accuracy at
this point of the distinguished observer, and the
doubt is confirmed by my limited observation of
— the spinningwork of British spiders.?
Use of the ny),
Central.
Space. its several parts must be a matter of

economy of the Central Space in

conjecture, but there are some good
grounds for the following opinions :—

1. It must be noted, first, that no part of the
Central space has viscid beads. This permits the Fie. 53. Notched spirals (greatly en-
freer motion of the spider around the centre cian
without lability of entanglement upon her own snare. She is, indeed,
able to run over the beaded spiral space with apparent impunity, yet her

'“On the Construction of the Nets of Geometric Spiders,’ Zoological Journal, Vol. V.,
1832-4, page 184.

* As above, page 185.

) Mr. Cecil Warburton writes me from Southport, England, that the snares of Meta
segmentata are distinguishable at a glance from those of most common English Epeiroids,
as Zilla atrica, Mpeira diademata, Hp. quadrata, ete., by the presence of a notched zone
and the absence of a meshed centre. Kvyidently, his observation of the common species
showed a closed centre.

GENERAL CHARACTERISTICS OF ORBWEAVERS SNARES. Diy

movements there, always when capturing an insect, and often in bringing
the captive to the Hub, do at times result in the marring and breakage
of the snare. The fact that the prey are taken to the centre to be fed
upon and sometimes to complete the swathing is a reason why that por-
tion of the web should not be covered with viscid beads, which are obvyi-
ously a hinderance to feeding upon and
swathing the victim. In fact the viscid
parts have to be cut out in order to per-
mit the revolving of the captured prey
when it is being swathed.

2. Moreover, the struggles of insects en-
snared upon the beaded spirals, and subse-
quent actions of the spider to capture its
prey, invariably break up more or less of
the web. In the case of large insects the
damage done is quite serious. Were the
Central space also beaded it is evident

that the very seat and throne of the

Fic. 54. The ribbon brace of Acrosoma.

aranead at the hub of the snare would
be greatly liable to invasion, to her sore discomfort and disadvantage,
especially in cutting off her avenues of approach to the main portions
of the snare. This would be no less true in cases where her retreat
is a leafy or silken castle outside the lmits of the orb but connected with
the hub by a trapline. The breaking of the radii at the point of their
attachment to the hub of course must cause all
the connected parts towards the circumference
to relax, entangle, and drop away. Repair in
such cases is difficult or impossible. The far-
ther from the centre is the point at which the
insect is entangled, the less injury ensues, the
longer does the web remain serviceable, and
the more easily is it mended. Thus, the ab-
sence of beads from the entire Central space
gives added security to the snare.

3. In like manner the economy of the Free

zone may be considered as protective. The ab-
Hi. 65. Semicircular zigzag cords in gence of spiral lines enables many insects to
the hub of Argiope. : y §

pass quite through the net, with little or no

impediment. When there is a momentary arrest or entanglement, the

subsequent escape or capture is accompanied by very slight, if any, de-
struction,

4. Here, too, it may be observed that the necessity for viscid beads near

the centre is not as manifest as upon the outlying parts. The momentary

pause caused by an insect striking upon the naked radii of the Free zone

58 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

near the hub where the spider waits, is commonly quite long enough to
allow the active creature to reach and secure her victim, when capture is
desirable. When for any reason capture is not desirable or prudence sug-
vests caution, the nearness of the spider to an insect thus arrested on the
naked radii brings it within her vision, which at the best seems to be
limited, On the contrary, insects who strike upon the outer margin are
not only detained by the viscid beads, but made comparatively harmless.

5. The Free Zone gives the further advantage of allowing the spider
sasy access to the under part of the
share, a convenience which is some-
times important. It is perhaps worth
noting here that vertical snares which
have an open hub appear quite com-
monly to have no free zone, that
part of the web being occupied by

the notched zone prolonged to the
inner boundary of the spirals. Thus in either case, although by an inter-
esting variation in spinning habit, the way is left open for the spider to
pass from one side of her orb to the other. I have watched with great
interest the agility of a large Argiope in swinging herself from one side
of her shield to the other when threatened by danger. I could always by
demonstrations with finger or pencil cause her to change sides. This was
done invariably by crawling through the free zone. The space seemed over
small to give passage to such a large creature, but the elasticity of the
threads readily permitted the transfer,
which was made with remarkable deft-
ness and dexterity.
The chief purpose of the Notched
Zone seems to be to strengthen the

web, and particularly to brace
Notched

and hold in position the radii
Zone.

before the spirals are wrought
in. My observations indicate that the

notched spirals are invariably woven

Fic. 57. Flossy circular braces of Uloborus.

in before the beaded spirals. The outer
or diverging ends of the radii being supported by the Foundation lines,
the inner or converging ends by the notched space, the spider begins to
lay in her foundation spirals from the inner margin of the spiral space,
working toward the circumference. Thus her operations are conducted
somewhat after the architectural modes of a human builder erecting a
large scaffolding.

1 | make this statement with some qualifications and cannot positively say that it is true

of all snares with open hubs. That it is with many I know. The point is one for further in-
vestigation.

GENERAL CHARACTERISTICS OF ORBWEAVERS SNARES. 59

Certain species (indeed, the habit has its representatives among several
genera) further strengthen the notched space by a close, plain band of
white silk, which ordinarily extends between two radii, along the perpen-
dicular diameter upward from the hub to the spiral space. (Fig. 54.)
Sometimes also the ribbon reaches both upward and downward from the
hub, and takes the form of a scalloped band or thick winding cord. This
peculiarity prevails in all our indigenous examples of the genus Acrosoma,
and is also quite characteristic of the exotic species of the same genus.
Our beautiful and familiar representatives of the genus Argiope (A. cophi-
naria and A. argyraspis Walck.)! have the same habit. (See Figs. 55.)

Some species, as frequently Argiope argyraspis, add to this perpendicular
ribbon, on either side thereof, one or more semicircular zigzag cords, which
further tend to strengthen the central part of the orb. Some species of
Uloborus have a similar habit, but also at times throw the cord entirely
around the notched space, making a series of circles. (Figs. 56 and 57.) The
perpendicular cords are sometimes extended above and below the notched
space, and terminate in serpentine folds, bulb shaped tufts, or tapering
points. They give a striking and beautiful appearance to the web, the
graceful lines, and thick, white, flossy texture showing in pretty contrast
against the radii and spirals. Examples of these peculiarities will be found
among the descriptions of characteristic webs. (See Chap. VI.)

These bands and cords, besides probably serving as braces, are used by
the spider as supports when she hangs at the open hub. Acrosoma rugosa
will generally be found hanging by her hind pair of legs to the lower end
of the ribbon.

1 Epeira fasciata Hentz, and Argiope transversa Emerton.

Girigacle Iiiieeleye
CONSTRUCTION OF AN ORBWEB.
iB

A prescription of the remaining part of the orb will be better reached
by a detailed account of the manner in which an orbweb is constructed.
There are some variations in methods among different species,

caeee as might be expected from the varieties of webs, but the process
u

is substantially the same in all species observed. The first step
Frame

of Snare, iS to secure a suitable framework upon which to hang the orb,

which is known as the Foundation or Frame, and the soreiull
parts composing it, as Foundation Lines. The spider has two methods of
accomplhshing this.

First, the frame lines are laid down “by hand.” The spider crawls
along the objects over and upon which she purposes to spin her snare,

drawing after her a
A Frame jine which at various
Laid :
Down, Points she fastens to

the surface in this
wise: the spinnerets, which are
grouped in a little rosette at the
end of the abdomen, have a large ~
number of minute hollow tubes or spinning spools upon their tips, out
of which issues a liquid silk of which all spinningwork is formed. The
spinnerets and their hundreds of spools are movable at the will of the
spider. When they are held closely together, the numerous threads emitted
by them blend into one. When they are held apart, on the contrary,
various separate threads are formed. <As the spider runs along she stops
here and there, expands her spinning organs, and at the same time
thrusts them downward and touches the surface. The clustered threads
thus issued stick to the surface and at once harden.

Then the spider closes together the spinnerets, as one would close the
points of his fingers against his thumb, lifts them, moves on, and the con-
tinuous threads dragged behind her again converge into one
thread as shown in Fig. 58. An ordinary pocket lens, if applied
to one of the httle white dots which mark the point of adhesion,
will easily resolve it into various parts and show the above construction.
At Fig. 59 are magnified drawings of two of these spots.

(60)

Fic. 58. Epeira moving with dragline and anchorage.

Drag-
lines.

CONSTRUCTION OF AN ORBWEB. 61

Dr. Hulse, as early as A. D. 1670, noticed the habits of spiders to make
various anchorages of their drag line as they moved along. He thus wrote
to Mr. Ray: “ They will often fasten their threads in several places to the
things they creep up: the manner is by beating their bums or tails against
them as they creep along. This lne will express the way :—

ty - FO - -?O OOO OOo ht

By this frequent beating in of their thread among the asperities of the
place where they creep, they either secure it against the wind, that it is
not so easily blown away; or else whilst they hang by it, if one stitch

break, another holds fast, so that they do not fall to the ground.” ?
In this way the Orbweaver proceeds, with more or less variation, until
she has described the irregular polygon which forms the foundation of her
snare.?_ Each of these boundary lines, according to Blackwall’s

Prime — observation, is composed of five, six, or even more united
Founda- Be ve ? es : ; ;
fon threads.2 It is always sharply distinguished by its thickness and

strength, and often by its color, from the other lines of the snare.
The upper foundation line is quite commonly much the strongest. The
framework thus formed is braced by various cords passing diagonally from
line to line across the corners, and some- »

times also by numerous threads attached to | tee
surrounding objects. The entire foundation ——_€= =
thus hangs taut, and presents a framework I NS
having the requisite degree of strength and lll :

elasticity upon and within which to suspend
the true snare. as
This work is not always done rapidly and =
as though by an engineering instinct that Fic. 59. Dragline and anchorage
readily perceives the quickest and most ad- ees
vantageous sites and courses. Often there is much preparatory pioneering ;
the laying out or dragging out of tentative lines which appear to be to no
purpose ; a groping or “feeling” the way, so to speak, toward the best loca-
tion, and at last the seeming accidental determination of the frame lines.
Of course, even under such behavior there must be a general instinctive
movement in the direction of the polygonal or triangular outlines which
are the prevailing forms one sees. It has been said that the

ee spider seems careless about the shape of the area which the
gen : ‘ : : : we 1
. ) : 48 ‘lose » fact that these two forms do
Aclaetion: foundation lines inclose. But the fact that

prevail well nigh universally, places the architect’s action outside
the pale of mere chance. Moreover, examples are frequently found of

1 Correspondence of Ray, page 58.

2See an article by the author in “Our Continent,’ Philadelphia, September 27th, 1882.

3 Blackwall, Zoological Journal, Vol. V., 1832-4, page 182. “On the Construction of the
Nets of Geometric Spiders.”

4 Introduction to Entomology, Kirby & Spence, Vol. L, Set XIII, page 411.

62 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Orbweavers who move at once from the beginning of a foundation to its
completion as though directed by a sure knowledge; one cannot say by a
sure experience, for in point of fact this behavior is not the result of ex-
perience, inasmuch as it is observed in the youngest animals, and on the
other hand adults are quite apt to show the confused and indeterminate
action above referred to.
The second mode of securing an orb foundation is by means of air
currents. It has been questioned by naturalists whether the Orbweaver
ever pursues any other method than that of carrying around the
Founda- foundation lines. As recently as A. D. 1881, so good an arach-
Cea nologist as Mr. Cambridge expressed the belief that this is the
Currents, Usual mode of proceeding, and that air currents are never
utilized for the construction of orb foundations.! This opinion,
however, he shortly afterward abandoned, yielding to the facts presented
by other arachnologists.?
I have elsewhere treated
the question at some
length,? and now present
the evidence that the
prime foundation — lines
of orbwebs are often laid
by means of air currents.
In a great number of
cases I have observed
the Orbweavers
passing from
point to point
by means of lines emitted
from their spinnerets and
entangled upon adjacent
foliage or other objects.
Any one who will note with ordinary carefulness the movements of orb-
makers among shrubbery towards the close of a fair evening, may see such
examples. These mimic “suspension bridges” are of various lengths, owing
to the direction of the wind and the position of the spider relative to the
standing objects around it. Lines of two, three, and four feet are frequent ;
lines from seven to eight feet occur often; I have measured one twenty-six
feet long, and in several cases have seen lines strung entirely across country
roads thirty or forty feet wide.4 Many of these lines I have seen carried by

Bridge
Lines.

Fic. 60. Orbwebs on water plants in a pond.

Spidk rs of Dorset, Rey. O. Pickard-Cambridge, Vol. [., Introduction, page 21.
=X (joy cit., Vol. Il.
* Proceedings Academy Natural Sciences of Philadelphia, 1881, page 450, seq.— How
Orbweaving Spiders make the Framework or Foundation of Webs,”
Lister, the father of English araneology, observed such lines stretched between trees and
over streams. Tractatus Araneis, page 8.

CONSTRUCTION OF AN ORBWEB. 63

the wind directly from spiders’ spinnerets, have observed the entanglement,
have seen the animal draw the threads taut and then cross upon them.
That all the lines are similarly formed and used I have no doubt.

Mr. Terby, in a paper contributed in 1867 to the Royal Academy of
Belgium, makes a number of intelligent and accurate observations upon the
habit of spiders to throw out their floating threads in order to
secure passage from point to point. He demonstrated by numer-
ous experiments that these threads could not be projected by the power of
the spider without the aid
of the wind. I regret that
I only happened to fall | -.
upon this paper after the | #@ > we
completion of my manu- Fr ie:
script, so that I can insert y] if
here but a brief allusion to
it.! Blackwall also had ob-

M. Terby.

a Se

ae served as much _ | (hi Wyls es eu A Ih
a ; ee a tee x ey) hy —
al and gives a brief Wali ! | Yi
and accurate de- f

scription. ‘The manner, he
says, in which the lines of
spiders are carried out from
the spinners by a current of
air appears to be this: as
a preparatory measure, the
spinnerets are brought into
close contact and viscid
matter is emitted from the
spinning spools. They are
‘then separated by a lateral

motion, which extends the ga
viscid matter into fine fil- Sk eae ae =
&

or

] 4 « ¢ ie TANS"

aments, connecting the
spools. On these filaments Fic. 61. A cola oe spiders domiciled over water.
the current of air impinges,
drawing them out from the spinnerets to a length which is regulated
by the will of the animal, and on the spinnerets being again brought to-
gether the filaments coalesce and form one compound line.?

It is a more difficult matter to determine whether the lines used for the
foundations of orbwebs are formed in the same way. I have seen an orb-
weaver, after traversing a considerable space by a series of successive bridge

‘M. F. Terby, sur les procédés qu’emploient les araignées pour relier des points eloignés par
un fil. Bull. Académie Royale de Belgique, 1867, page 274, sq.
* Researches in Zoology, page 269.

64 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

lines, settle upon a site between the forked twigs of a bush and carry her
foundation lines around in the manner described. But, on the other hand,
I am prepared to say that the air laid bridge lines are also used for the
foundations or frames of orbs. The following are my reasons for this
opinion :—

1. First, the hours in the evening at which the greatest activity of web-
weaving begins are those in which also begin the formation of the bridge
lines. The latter action quite invariably precedes the former.

9. Again, a study of the foundation lines of very many webs has given
me almost conclusive evidence that they must have been laid by the aid of

air currents, For example, the webs of some species, as Acrosoma
Webs mitrata, A. spinea, and A. rugosa, are frequently found strung be-

eee tween young trees separated by two or three yards of space. That
ose. these builders might have dropped to the ground, crept over the

wood, grass, or dry leaves carrying the thread in the free, out-
stretched claw is, perhaps, not impossible, but does not seem to me at all
probable, although short spaces over smooth surfaces might be passed in
this way. I once found an orb hung upon lines which stretched from the
balustrade of a bridge that spans a deep glen in Fairmount Park, to the
foliage of a tree that springs out of the glen at least twenty-five feet below
the bridge. Unless the foundations of this orb were formed by line bridging
the interspace of a yard or more, it must be inferred that the spider had
dropped from the balustrade to the glen, crossed the interval to the trunk
of the tree, ascended it, and, having made a detour of nearly sixty feet to
the point directly opposite that from which she started, all the while car-
rying her line with her and keeping it free from entanglement, have drawn
the line taut and so completed her foundation. Such a supposition could not
well be entertained, and it is clear that a breeze carried the line across from
the spider’s spinnerets. '

I have noticed stronger examples of circumstantial evidence. Very many
webs of Tetragnatha extensa and T. grallator have been seen spread upon
bushes overhanging pools and streams of water; others were stretched be-
tween separated water plants or from such plants to the shore. (See Fig. 60.)
Either the foundation lines were borne by air currents, or the spiders must
have crossed upon the water, carrying their lines. The latter supposition is
not wholly untenable, but will hardly be raised by any one who has
studied the spinning economy of the creature.

One other example may be cited. At Atlantic City, by the boat-
landing where pleasure boats used for sailing upon the Inlet are stored,
a there is (or was) an immense colony of Epeiroids, chiefly Epeira

rbs over .,_; . ; a aki ate

Water. Strix, Ki. sclopetaria, and EE. benjamina (domiciliorum Hentz).
During the summer months of 1880-81 great numbers of these

spiders had their lines strung between the opposite exterior walls of the

boat houses, which were built upon piles driven into the water. These

CONSTRUCTION OF AN ORBWEB. 65

lines were about nine feet long, and were stretched over the water at
heights varying from one to ten feet. Most of them passed from wall to
wall; many were fastened at one end upon piles and sticks driven here and
there between the houses. (See Fig. 61.) It was a curious association, not
to say analogy, which started in the observer’s mind, as he saw the pic-
turesque methods of the ancient ‘‘ Lake dwellers” thus used by modern men,
and appropriated, with befitting modification, by the orbweaving araneads.
Certainly their silken domiciles were well secured above the inlet on their
silken frames, and were happily placed for obtaining ample food supplies

ey
7,

QE

Fic. 62. Spider suspension bridge over a stream.

of green-head flies and other insects hovering over the water. But when
we ask ourselves, how were these snares built? we are constrained to call
in the aeronautic habit and the air. It passes belief that these Epeiras
carried their lines back and forth upon the rough waters of an inlet of
the Atlantic Ocean. One must conclude that the foundations were formed
by air currents.

One must draw the same conclusion concerning those orbs found sus-
pended over streams. I haye seen these cobweb bridges at various times;
and they are not unfamiliar objects to wanderers in summer fields, woods,

66 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

and mountains. (See Fig. 62.) This habit is not limited to American
spiders. Vinson! says that in Madagascar Epeira (Nephila) tuberculosa
throws from one bank to the other of streams of considerable size
her lines of prodigous length, in which are arrested numbers
of Libellule and large Agrions. He had observed this phenom-
enon upon running streams of forest interiors. One might call them, in
truth, aerial bridges. In the island of Réunion it is to the wrinkled trunks
of the huge Pandanus that the gigantic Orbweavers attach their long silken
lines, and stretch them from one tree to another at a distance of many
metres.

3. I have greatly desired, but heretofore without complete success, that
to the above cases of circumstantial evidence might be added actual ob-
servations of the use for foundations of lines stretched by air currents.
Three summer evenings were once entirely devoted to endeavors to obtain
this result. On one evening I was interrupted and called off at a very
critical period of my observation; on the two other evenings the wind was
unfavorable; but some valuable results were obtained. The webs of three
adult individuals of Epeira strix, one male and two females, were selected,
the den or nest of each spider located, and the web entirely destroyed.

The latter precaution was made necessary by the fact that Orb-

Cobweb
Bridges.

Old Foun- weavers use the same foundation lines during many succes-
dations : : : Bs

sive days for the erection of their new webs. The great value
Preserved

which may attach to these old foundations appeared strikingly in
subsequent studies, and also the difficulty if not impossibility of procuring
suitable foundations for the webs of large spiders without the aid of the
wind, In fact, a good foundation frame is a “good property,” and it is ac-
cordingly treasured and used as long as it remains. I have noted many
cases of snares continuing on the same site as long as the foundation lines
endure. Their destruction is generally followed by a shifting of position.
Two of the above webs (one of the females) were so situated that the
prevailing air currents carried the lines in such wise that they could not
possibly find entanglement. In consequence neither of these
spiders succeeded, during two entire evenings up to half-past ten
o'clock, in making a web. They frequently attempted it in vain. One
spider that was more closely watched, was in motion during the whole
period, passing up and down, from limb to limb, apparently desirous of
fixing her web in its former site, but completely confused and foiled. The
site was one, moreover, which would have allowed her to carry around a
thread with comparative ease, being a dead sapling that forked near the
ground,

Failures.

This spider domiciled during the day on the ground, but had her orb
at the top of the forks, a height of six feet. Thus the space to be

' Arancides des les Isles La Réunion, &e., page XIX.

CONSTRUCTION OF AN ORBWEB. . 67

traversed in passing from the top of one of the forks to a similar point on
the opposite one, presented comparatively few difficulties. But no attempt was
made to carry the line around, and as the wind had evidently not changed
during the night, no web appeared on the tree in the morning. During
the next evening the same restless movement along the bare limbs of the
sapling was repeated, and was terminated at a late hour by a rare accident.
A large moth, attracted by the lantern, became entangled upon a single
short thread strung between two small twigs, whereupon Strix pounced
upon it, swathed and fell to feeding on it. Next morning a tiny orbweb
had been built around the shell of the moth at the point of capture.
During both evenings this spider at frequent intervals poised herself
at the extremity of twigs, and emitted threads from her spinnerets which

Fic. 638. Seeking attachment for foundation lines.

entangled upon some of the short twigs, but never upon the opposite fork,

d _ as the wind was steadily contrary. No other entanglement was
Trial Air

i secured, as there was no elevated object in the direction of the
Lines. :

wind for a great distance. However, I could at any time obtain
an entanglement upon my hand by arresting the thread. By imitating
the motion of a swaying leaf or limb, the spider was caused to perceive the
attachment, and immediately ventured upon the line. (See Fig. 63.) Once
the thread fastened upon my face, and the animal was allowed to cross the
line, a distance of four or five feet, until within a few inches of the face,
when she took in the situation, instantly cut the line and swung downward
and backward over the long are, and, after a few oscillations, climbed up
the line to the point of departure. Her willingness to use air currents for
making transit lines was thus quite as manifest as her then inability to
get a foundation thereby. The second spider exhibited a like behavior.
4. The third individual, a male, did not attempt to spin an orb in the
former site; the wind was unfavorable, but there would not have been
much difficulty in carrying the cord around. He came out of his rolled
leaf den at 7.20 P. M., and for more than an hour labored to secure a web
foundation. He was located upon a dead end of a bough with many

68 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

branching twigs. As with the former individual, so with this; many efforts
were made to obtain foundations by sending out threads from the spinner-
ets, and to this end he tried most of the numerous points of the twigs coy-
ering the territory which he seemed to have chosen as his general range.

One of these, a little pendant, which hung in the centre of the group,
was taken as the basis of a most interesting operation. ‘The spider dropped

_ from the pendant by a line three or four inches long, grasped the
lai line by one of the second pair of feet, and rapidly formed a tri-
angular basket of threads by connecting the point of seizure with
lines reaching to the feet of the remaining second leg and the third and
fourth pairs. (See Fig. 64.) In this basket he hung head upward, the
body held at an angle of about 45°, the two fore feet meanwhile stretched
out, and groping in the air, as though feeling for the presence of obstruc-
tions, of enemies, or of floating threads. At the same time he elevated his
spinners and emitted a line which was drawn out
at great length by the air, but secured no en-
tanglement. The body of the spider had a gen-
tle lateral oscillation that appeared to the observer
to result from a voluntary twisting of the central
rope by the animal, but may have been caused
by the air; the effect was to give the output line
a wider swing, and much increase the chance of
entanglement.

However, there was no entanglement, and the
spider dropped several inches further down and
repeated the process as described above. This was
repeated again and again, and when I allowed the
line to attach to my person the spider at once
proceeded to satisfy himself of the fact, and then to venture a crossing.
In all these actions there were evidences of an habitual mode of securing
transit by bridge lines. Since the first observation of this most interest-
ing habit I have frequently seen the construction of these “baskets” or
“hammocks” by adults of various species, and for a similar purpose by
baby spiderlings reared indoors and colonized.

I had supposed, for seyeral years, that the observation and record of
this use of a swinging basket was original with myself, until one day read-

ing Master Jonathan Edwards’ description of flying spiders. I

Fic. 64. The swinging basket used
in issuing trial cables.

'

ae was surprised there to note that this remarkable character, when
Antici. Put a child, had probably anticipated me by one hundred and
pated. sixty years. I quote his language, and reproduce his rude fig-

ures, which while perhaps leaving the matter in doubt to the
ordinary reader, will doubtless satisfy an arachnologist that the nimble-
witted lad really saw this interesting habit: “I have been so happy as very
frequently to see their manner of working; that when a spider would go

CONSTRUCTION OF AN ORBWEB. 69

from one tree to another, or would fly in the air, he first lets himself down
from the twig he stands on by a web as in Fig. 1, and then, laying hold
of it with his fore feet, and bearing himself by that, puts out a web as in
Fig. 2, which is drawn out of his tail with infinite ease in the gentle
moving air, to what length the spider pleases, and
if the farther end happens to catch by a shrub
or the branch of a tree, the spider immediately
feels it, and fixes the hither end of it to the web
by which he lets himself down, and goes over by
that web which he put out of his tail as in Fig.
3, and this my eyes have innumerable times made

me sure of.”! (See Fig. 65.) The habit indeed =

prevails and is utilized for many func-
Useof tions; sometimes to secure a convenient & b
Swinging attitude for cleansing the limbs and ab- 3
Basket. ; ae g

domen; sometimes as a position of guard Me 3

or rest when the spider through fright has cast
itself from its snare or nest, and has paused mid-
way of the ground; sometimes as a favorable point
of departure on a ballooning excursion. But most frequently the swinging
basket serves, as here, when exploiting surroundings for an available orb
site, and to work in the prime foundation line. While suspended thus she
keeps one, or yet more frequently both fore legs extended slightly curved
in the attitude of “on guard,” and either held rigidly or occasionally waved
to and fro feeling for the indi-
cations of the presence of the
friendly trial line, or of un-

friendly objects.
This use of the fore legs is
habitual in all movements of
spiders from point to

Fic. 65. Jonathan Edwards’ illus-
tration.

es point. While engaged
egsas. : :
Antenne, 12 dragging a founda-

tion line around vines
and twigs, over leaves or other
surfaces, she will often pause and
wave the extended fore legs as

though prospecting her way not

Fic. 66. Antennal use of the fore legs.

only, but testing the safety of
her: surroundings. The action frequently reminded me of the character-
istic use of the antenne by ants and other insects; and, indeed, I have
little doubt the fore legs of spiders do have in part the function of an-
tenne. (See Fig. 66.)

1 Am. Jour. Sci. and Arts, Vol. XXI., 1832, pages 112, 113.

70 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

During the intervals of the attempts above described, and, indeed, pre-
ceding them, our Furrow spider passed back and forth along the branch-
ing twigs, leaving behind him trailed threads or lines connect-
Tentative ing the ends, many of which seemed to be purely tentative. At
Move- — jast_ a central point was taken, a short thread dropped therefrom
ra ees and attached to one of these tentative lines. The confused net-
work of cireumjacent lines was gathered together in a little flossy ball at
the point of union, which was now made the centre of the orb, the first
dropline and two divisions of the cross line constituting the three original
radii. From these the spider proceeded to lay in the radii and complete
an orb. The time occupied in constructing the web proper was half an
hour, while the work of prospecting for and obtaining a foundation con-
sumed more than an hour. Even then the orb was very irregular, and
showed decided traces of the want of the usual well and orderly laid
foundations. An examination of a number of web sites which I had
marked upon the same grounds, showed that in every case where the sur-
roundings had allowed an easy and good entanglement by the wind, the
spiders had made webs at an early hour, and with straight and regular
foundations.

I feel justified in saying that the above observations which might be
indefinitely multiplied, are sufficient warrant for the belief that air currents

have a large part in placing the original framework or foundation
Not Per- Jines of orbwebs, and that spiders habitually make use of them
ema for that purpose. I doubt, however, whether there is anything
trolled, like a deliberate purpose in any case to connect the point of

occupancy with any special opposite point. The spider seems to
act in the matter very much at hap hazard, but with a general knowledge
that such behavior would somewhere secure available attachments. Many
of her bridge lines are evidently tentative and chiefly at the mercy of the
breeze, although some observations indicated a limited control of the thread
by manipulation.

This use of air currents is depended very much upon the site chosen,
the condition of the wind, the abundance of prey, etc. Webs built in large
open spaces are perhaps always laid out by bridge lines, at least as to the
first and principal line or lines. In more contracted sites the frame lines
are generally carried around, and often a foundation is the result of both
methods.' The above observations have been fully confirmed by the
behavior of spiders colonized upon the vines and shrubbery in my manse
yard. The securing of one principal line is the important desideratum.
This obtained, the remainder is generally easy. In carrying around a frame
line the largest spider will move with great deftness over the leaves and

‘ Blackwall, Constr. Nets Geom. Spiders, page 186, and Kirby and Spence, Introduction, i.,
page 413, knew that spiders could form foundation lines by means of air currents.

CONSTRUCTION OF AN ORBWEB. 71

tendrils, frequently securing an anchorage by attaching her dragline, and
all the while holding aloof from contact with the foliage the new founda-
tion line which is spun after her as she moves.
Kirby and Spence describe this curious variation of the habit. A spider
isolated upon a stick set within a vessel of water dropped from the top of
the stick to which the usual dragline attachment had been made,
A Varia- and emitted two threads as it descended. Having reached a point
tion of :
the Habit, 22" the surface of the water, it stopped, and by some unobserved
means, severed one of the threads close to the spinnerets. The
free end of the released filament floated up and outward from the top of
the stick, and was caused to entangle upon a pencil held in the observer’s
hand. The spider, which had meanwhile mounted the summit of the stick,
perceived the line to be taut, and having tested it by pulling, crept over it to
the pencil, dragging another line behind her as she moved. This isan iso-
lated example, and may, of course, have been a simple coincidence, as it is
not certain that the spider designed to secure a bridge line by the above
behavior. Yet it is worthy of notice as suggesting a line of observation
that may yield good results.

Len

We may now construct the diagramatic figure, Fig. 67, to show the proc-
ess by which an orb frame is laid when the prime foundation is obtained
by an air current. We suppose that an Orbweaver in the act of web-
making has stopped upon the leaf at the left of the cut. Turning her
abdomen toward the course of the wind, she issues a line (a, a) that floats
outward until it entangles at x. This fact is at once perceived, and the
spider (ss) ventures over it as at bb, dragging behind her a thread which
unites with and strengthens the original line, which had been drawn taut,
as e, c, ¢, x. This may be repeated several times, until, at last, the prime
foundation line is formed.

This strengthening by means of overspinning is not necessarily, perhaps
not generally, done in immediate succession of threads, but from time to time.
At various stages of working in the radii of other parts, the crea-
ture seems to perceive the need of strengthening the supporting
lines, and proceeds to stretch a new strand or two. Then she re-
sumes work upon the orb, to return as occasion requires, and adds strands
to her cable. When the upper line is completed, especially if it be one which
has been used for several days, it presents the appearance of a white or
yellowish white thread as thick as a bit of sewing silk. It may readily be
reeled upon a stick or spool, and its numerous filaments can be seen and
even separated. It has a glossy appearance, and may often be found sey-
eral feet in length.

First
Line.

1 Introduction to Entomology, Volume 1, set XIII., page 415.

~I
bo

AMERICAN SPIDERS AND THEIR SPINNINGWORK.

From some point in this first line, as d, the spider makes an attachment
and drops down, paying out her thread as she goes, until she reaches the
eround or touches the first object directly underneath her. If the air is
quite still and the spider large, the line will be nearly perpendicular, as d dd.
It will vary more or less from the perpendicular according to the spider’s
weight and the wind’s force.

This vertical line, d dd, is lashed to the grass, foliage, or other object,
and then is reascended to a point, 0, where an attachment is made and a
new line begun. This is held out in one of the hind feet quite free from the

(A i} ;
an es rae
i GO
Sas ,
I ‘
ye

~

alt

(i 7
G Nj nH! iP
Wass, Ys

SIV =

a i Re
//
af i it MH

|
i

a

~s= ae
SS
. ‘ Rin:

+\ | = ae, ~
PAS
) a Sup

wee
i

Z

eed
Se

dy it
ns

Ws W®

4)

<<

=

/

Fic. 67. Laying foundation lines by air currents. (First lines.)

dropline, d dd, as the ascent is continued. The new free line (the dotted
line odce) is thus carried up dd and along ex to the point e, where it is
fastened, after having been drawn taut. This last act pulls out the lne dd
until o reaches the point oo, and the deported (dotted) line, o d e thus be-
comes the line, e oo. There is then completed the triangle, ed oo, within
which the spider at once proceeds to spin her orb. When a four sided
frame is spun instead of the three sided one here illustrated, precisely the
same method is pursued, the line eb oo being simply carried farther around
and down the bush until it forms the lower boundary of a trapezoid, and
is parallel to ecx.

CONSTRUCTION OF AN ORBWEB. Gs

Ww

It must be understood that I have only taken a case that may be con-
sidered fairly typical of the general plan of construction. It will explain
the ordinary principles and a common mode of proceeding; but in point

of fact the details continually vary, according to the local pecul-
The Plan

; larities of the orb site, the conditions of the wind, and I suppose
Variable. ? ; PI}

to some extent the individuality of the spider. Some incident will
‘ause a variation; the advent of an insect, the presence of an enemy, the
neighborhood of another web, a falling leaf, a fright or excitement of any
sort may divert the spider’s attention, and cause a variation in her plan.
In short, her “plan” is to some extent elastic, and variable by the stress of
accidents and circumstances; but as a general fact the exterior frame of the
orb will be found to be a more or less regular quadrilateral or a triangle.

Fic. 68. Double foundation lines.

The foundation lines most commonly observed take the form of a
trapezoid, whose sides are directly anchored to surrounding objects. Webs
frequently occur, however, in which the orb with its trapezoidal

Double ers :
me as frame is hung within an outer foundation of strong cords usu-
ane ally, but not always, triangular in arrangement, as illustrated in

Fig. 67. This form prevails in cases where the snare is hung
within large open spaces, or stretched between two trees or bushes in
woods. Some species appear to hang their snares quite habitually in this
way, as with all the indigenous species of the genus Acrosoma whose
industry is known to me.

An example of this style of foundation is shown at F

‘ig, 68, which is a
snare of Acrosoma rugosa. Here we have two strong cords, ab, cd,
united at J in a point, and joined at the base by ec, which was probably
the line used in securing the union of the two long cords at J. The
lower line, ed, is caught up by a short perpendicular line, id, and stayed
upon a cross line (i), which again is supported by an upper straight cord
attached to the leaves of the grapevine in which the orb hangs.

74 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

The trapezoidal foundation lines, x—x, are woven within the basilar
part of the triangle thus formed. We have here the usual Foundation
Space, FS, and indeed might aptly apply that term to the entire Founda-
tion system. But it will be convenient, in webs of this form, to name
the inner side of the trapezoid, IL, the Inner Foundation Lines, and the
large exterior cords, ab, cd, the Outer Foun-
dation Lines, and the intermediate space,
OFS, the Outer Foundation Space.

The inner foundation lines are of course
necessary to the construction of the orb
under such circumstances, but
they are plainly so adjusted as
not only to allow the nicest bal-
ance of the beautiful snare, but also to
afford the greatest power of resistance by

ie! cua Gpiming (theuitaal edie distributing the disturbing forces of wind

and struggling entangled insects along the
elastic inner foundation lines. Webs of this character have less rigidity
and would seem to be better designed to endure, than those which are
directly attached to limbs and foliage.

A foundation having been secured, the spider proceeds to place in
the radii. ‘To this end a position is taken at or near the centre of
the orb, usually by dropping down from a top line, dragging
after her a thread which becomes the initial radius, Fig. 69, a.
At the central terminus of this radius a little ball of floss (H)
is formed by emitting a thick ray of silk or by gathering together into a
wad the many tentative lines with which the space within the frame is
frequently matted. This ball evidently serves as an
anchorage for the radii and perhaps also as a guidon
for the animal herself. Sometimes as the work pro-

Use of In-
ner Lines.

Placing in
the Radii.

ceeds and the strain of the new laid radii is felt
upon the centre, the bit of floss is pulled out into
an irregular frayed mass with interlacing filaments,
as at Fig. 70, which shows a hub of a snare of
Epeira vertebrata arrested when nine radii had been

spun. The spider hung at the centre, and the posi-- “5%, 19) m= oe

tions of the feet in their order (first, second, ete.) are indicated by the
numerals,

The spider may now proceed in two ways: first to drop downward
from HH along ¢, to the foundation line, and attach thereto the thread,
which is done by touching the spinnerets to the point of attachment, the
natural yiscidity of the exuded silk causing it to adhere. This gives the
second radius. Thence the spider returns along ¢ to the centre H, and
ascends a, to form the third radius Hk or Hi. If, however, the tentative

CONSTRUCTION OF AN ORBWEB. 75

lines which net the enclosed space haye such an entan-
glement with the guidon ball as to brace it sufficiently
from beneath, the spider instead of dropping down may
first climb up the radius a, carrying a free thread in
one of her hind feet which is held out quite well from
the radius for this purpose as shown at Fig. 71. When
a desired point of attachment, as K, has been reached, Fic. 71. Putting in a
the deported line x is drawn taut, fastened, and the radius ae
e is now formed, which in this case will be the second radius. Next the
spider returns to the guidon H by e, or more likely by a, and thence
drops to the line, mn (Fig. 69), forming a third radius, ec. The radii are
all inserted in the above manner, and not consecutively, but alternately on
the opposite sides of the included space, by single lines or successive coup-
lets. The behavior of different individuals. of the same species or of the
individuals of different species may show variations more or less decided,
but the above action is fairly typical.
Blackwall says! that the radii are formed by the spider “ without
observing any regularity in the order of her progression.” On the con-
trary there seems to be at least so much order in this act that a
Alternate sort of alternation as to the orientation of the lines is observed,

Apposi- . Ae : <
ale which I have called the alternate apposition of the radii. A
Bae purpose to maintain a balance in the radial framework during

its construction is thus suggested, although, certainly, an absolute
regularity of alternate progression cannot be asserted.

The order in which the radii are spun into the frame of the orb was
quite fully shown in the work of an Epeira sclopetaria observed at Alex-
andria Bay, New York. When the observation began the foundation lines
were already laid, and also the original radii
marked A, B, C, D, Fig.'72. These cords were
united at the centre by a tuft of silk, and
braced by a few concentric lines, which form-
ed the basis of the hub. I counted seventeen
radi1 before the spider ceased. Their alter-
nate apposition can easily be seen by tracing
them in the order of the numerals in Fig. 72,
which are arranged in the order of construc-
tion. That is, radius 1 was formed by car-
rying the line along D to 1 and tightening it.
Thence the spider went to the centre, ran
along B, which had previously been inserted,

thence down to 2, where the radius 2 was

Fic. 72. Alternate apposition of radii. formed, Krom Z again she went to the centre,

1 Op. Cit., page 182.

76 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

passed down 1 and along D to 3, where attachment was made, and radius
3 was formed. Once more the centre was sought, and passing along the
line A the point 4 was reached and another radius there fastened. Thus
on from 4 to 5, from 5 to 6, and so around the entire circle. The mechan-
ical advantage of this order is apparent. Several times the central termini
of the radii were strengthened by lapping threads across them.

This tendency to alternate apposition I have frequently observed in
various species, and its character will be better shown by giving several
other schemes of the order of progression in spinning radi. The
schemes do not present a complete sequence of the radii from
the very beginning, but number from the point at which I hap-
pened to catch the spider at work. They are to be read as in Fig. 72, the
order of numerals showing the relative position of the radial lines in the
order of their spinning. The-series will show, I think, that while no abso-
lute mathematical regularity marks the succession, some method of alterna-
tion evidently dominates the spider’s movements. She knows the necessity

Order of
Radii.

re
Fic. 73. The order of spinning Fic. 74. Order of inserting Fia. 75. Ohare radii. Fic.76. Order of
in twelve radii. Epeira ver- nine radii. five radii.
tebrata.
which exists for balancing such a peculiar and delicate structure, and
adopts her mode of spinning to the exigencies of her spinningwork.

Blackwall states that after the completion of the radii the spider pro-
ceeds to the centre, turns around and pulls each radius with her feet to
ascertain its strength, breaking such as are defective, and replacing them
by others. I have never seen anything of the kind; the spider in settling
herself and gathering the radial lines into her eight claws naturally jerks
them somewhat. But no such purpose was ever suggested to my mind as
that declared by Blackwall. He also says that the radii are composed of
double lines, a statement which my observations contradict. I have seen
very many radii spun, but have never observed any one overlaid or doubled
Gf that be the meaning) as is often the case with foundation lines. On
the contrary they were always composed of one thread drawn out in the
usual way from the spinning spools.

tennie in his remarks upon the construction of an orbweb expresses
the opinion that the most remarkable circumstance in the process is that

‘Nets of the Geometric Spiders, page 182.

UNIVERSITY

OF COLQRAD

MUSEUM
BOULDER, COLORADG

~I

~]

CONSTRUCTION OF AN ORBWEB.

the spider uses her limbs as a measure to regulate the distances of her
radii or “wheel spokes,” and the circular meshes interweaved into them.}
The above method of alternate apposition shows that the dis-
Legs no tances between radii, at least, are not determined by any such men-
Unit of . . ; Be.
Measure, SUttion, which of course would only apply on the supposition that
the lines were spun consecutively. Moreover, having frequently
measured the distances between the radii at their circumference or attach-
ment to the foundation lines, I have found that there is often great irreg-
ularity therein; the interspaces sometimes vary in the proportion of three
to one on the same orb. The fact that the number of radii is not con-
stant in the successive webs of any individual spider, but varies from day
to day (although within a narrow limit), is also against this hypothesis.
It has already been intimated that the notched zone serves an important
end in bracing the radii while they are yet in outline. This appears dis-
_ tinetly while observing the above described behavior. The first
Forming yadii that are inserted bend and sway under the weight of the
Notched _. : ;
Fons. spider, which, as she clambers over them, suggests the idea of a
carpenter engaged upon a_ scaffolding in its first crude state.
In some cases the aranead stops at the guidon, after having placed the first
few radii, and swings her spinnerets around their bases as though to
strengthen them. This act may be repeated several times; and in fact the
spider whenever she comes to the centre is apt to make two or three of
these gyrations. However, when all the radii are inserted she proceeds to
complete the notched zone, laying in the spirals thereof from the centre
outwardly. These vary in number from four or five to ten or even more.
This variation holds in webs of the same species; for example, in seven webs
of Argyroepeira hortorum, the spirals in the notched zone numbered, suc-
cessively, 8, 10, 10, 10, 6, 8, 5. I have counted as many as twenty in the
web of Epeira gibberosa. In the group of Orbweavers, of which Epeira
‘insularis? is the type, the number of notched spirals is quite persistently less,
commonly five or six. The width of the notched zone is about equal to, or
a little greater than that of the free zone, and about twice that of the hub.
In at least one example noted (an orb of Tetragnatha extensa) three wide
notched spirals were first spun before the others were laid in. These ap-
peared to be the analogue of the spiral scaffold, referred to in the next
section; but this is not the ordinary rule of construction.
Mr. Romanes* quotes Dr. Leach as giving, on the authority of Sir J.
Banks, a case of a web-spinning spider which had lost: five of its legs,

‘Insect Architecture, page 313.

* This familiar and beautiful spider Dr. Thorell declares quite identical with the Epeira
marmorea of Europe. I have no specimens of E. marmorea with which to compare, but
have no doubt of Dr. Thorell’s identification. However, I retain Hentz’s name in the two
volumes on Habits, and will endeavor to adjust the nomenclature of this and other species
in the final yolume.

5’ Mental Evolution in Animals, page 209.

?
.

78 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

and as a consequence could only spin very imperfectly. It was observed
to follow the habits of the hunting spider, which does not build a web,
but catches its prey by stalking. This change of habit was only tem-
porary, as the spider recovered its legs after moulting.* Mr. Darwin also
alludes to this incident.

My observations are wholly contradictory of this. I have placed upon
my vines an Epeira domiciliorum that had lost all the legs on one side, and

found it to weave a serviceable web, although necessarily some-,
Spinning what imperfect. It hung upon its snare and trapped flies with
Senet fair success. I have often noted similar defects in various spe-

cies always with the same result. Mr. Romanes’ inference as
to the plasticity of instinct needs a little more confirmation. Indeed,
the inference was long ago fully exploded by the observations of Dr.
Heineken, a surgeon in the Island of Madeira during the early part of
this century. This gentleman, in order to test the ability of orbweaving
spiders to spin after mutilation, removed at intervals, successively, the legs
of various individuals, with the following results: Epeira (Argiope) fasciata,
with all the legs removed except the second and last on the left side and
the last but one on the right side, thoroughly mended its web when two-
thirds of it had been torn away. It maintained the same position and
attitude as before mutilation, and in every respect had the manner of an
Orbweaver.

Another Epeiroid spider had all the legs removed except the first on
the right side and the second and last on the left side, leaving the spider
with but three legs. On the following day, filaments appeared in several
directions. These were constantly added to, and in the course of two weeks
a geometric web was formed equally perfect, but more sparing in quantity
than one made by a spider in the same species and under the same mede
of confinement, but healthy and unmutilated. The entanglement and taking
of flies, and the conduct of the two spiders was in every respect similar.
They were confined in large glass jars. A number of individuals were
experimented upon with the same result. In the case of one tubemaking
spider, the number of limbs was reduced to two, and the web entirely de-
stroyed. Even then enough web was spun to cover the spider imperfectly
and occasionally to entangle an exhausted fly. It lived for five weeks after
mutilation. ?

' Transactions Linnean Society, Vol. XT., page 393.
* Dr. Heineken, On the Reproduction of Members in Spiders and Insects. Zoological
Journal, Vol. IV., page 428. 1828-29.

Crea HR Mv.
THE ARMATURE OF ORBWEBS: VISCID SPIRALS.

I,

THE next step in orbmaking is to prepare for the spinning of the con-
centric lines or spirals. This is done by starting a line at or near the
notched zone and carrying it around spirally toward the circum-

cee ference, attaching it by the spinnerets to the intersected radii.
val Scaf- ny - -¢ sae eres : ,

This forms the spiral scaffolding. The distance between these
folding. :

ines is about equal to the width of the notched zone, the space
between which and the first scaffold spiral is in fact the free zone. The
absolute width differs of course according to the size of the web. In large
orbs of Epeira domiciliorum from which the explanatory figure (Fig. 77) was
drawn, the distance was about an inch between any two of the eight spirals
(I-VIIT) except between I-II, where it was
about three-fourths of an inch. These wide
spirals, as will presently be seen, are the
scaffolding upon and by which the true
spirals are laid in, and from which they
differ by being destitute of viscid beads.
Before the beaded spirals are spun,
however, which is the completion of the

snare, a preliminary act some-
Corner

times occurs. Very many orb-
Loops. : ;

webs are not perfect orbs; in
some the entire space circumscribed by the

foundation lines and the foliage or other
Fic.77. Spiral scaffolding. LinesI-VIare objects to which they are attached, is filled
the scaffold ; ix, a section filled in; x, cor- Fy i - aes 2 .
ner loops. with true viscid spirals, thus nearly elimi-
nating the Foundation Space proper. In
other orbs only. the lower part of the snare is netted with spirals to the
very foundation lines. In others again the angles formed by the interior
margin of the Foundation Space (the inner foundation lnes) represented
by letters ix and x, in the figure, are filled with spirals. In such cases
these corners or angles have usually been covered first. For example, in
the orb at Fig. 77 the animal first spun the spirals which fill up the
angle ix. She then passed to the right hand corner x which was in like
(79)

80 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

manner covered; and so moved around the web until all the corners (at
x) were filled in, leaving the open circular space occupied by eight scaffold
spirals.

The lines thus covering the angles are not strictly “spirals” although
they belong to the spiral space, and have precisely the characteristics of
the true spirals from which often they cannot be separated by the eye,
without close attention. They are put in by “loops;” that is, the spider
passes back and forth over the ends of the radii, as at x, 1x, carrying her
thread, and looping it at the extremities of corner spaces. ‘These lines
have therefore been designated corner loops. In point of fact the concen-
tric lines are complete circles only when the framework of the snare
allows an unobstructed movement entirely around the centre. This exam-
ple is not the invariable rule of procedure, for spiders vary their modes.
Some start at once upon the spiral concentrics and make loops (particu-
larly at the lower part of the orb) before the
final finish. The case is simply illustrative of
the ordinary method of dealing with the cor-
ners and angles.

In the act of spinning the spirals the spider
moves from the circumference toward the cen-

_ tre, precisely the reverse of the direc-
Spinning tion taken when placing in the spiral
es scaffolding. The rapidity with which

the spiral line is spun and the pecul-
lar manner in which the spider’s eight legs ap-
pear to be intermixed, make it extremely diffi-
cult to observe and describe the actual method.
But the process, as it is ordinarily pursued, is substantially as follows:
The two hind legs are used exclusively to aid the spinning fingers in the
work of spinning. ‘The other legs are used for locomotion alone. The
moment one string is fastened at the upper point upon a radius, which
is done by the application of the spinnerets thereto (see Fig. 79), the
spider lifts its abdomen, thus of course drawing out after her a thread,
one end of which is the last point of attachment (x, Fig. 78) to the
radius (R 2), and the other the closed spinning fingers. The hind foot
(4 0) nearest the spinnerets is now bent under and grasps this thread,
which, as the spider moves, it holds and appears to pull out with great
rapidity. Next, the inner hind foot (4 i) is bent under and seizes the
thread, which it holds aloft, stretching it out until it is almost double its
proper length, as represented in Figs. 79 and 80. If the distance between
the radii be great, and the spiral string therefore much lengthened, the
two hind legs will be used alternately several times to draw out the line.

In the meantime, the outer hind leg, which had first aided the spin-
nerets In paying out the thread, is reached downward towards the radius,

Fic. 78. Starting a spiral string.

THE ARMATURE OF ORBWEBS: VISCID SPIRALS. 8]

which the spider all the while has been rapidly approaching

g, and grasps
it with the claws just beneath the point where the new string will cross.
This then is the attitude of the spider at this point of her operations.
Fig. 79. One hind foot (4.0) grasps the radius near and below the point
(xx) Just opposite the last point of

attachment. The other

Paying hind leg (4.i) is reached
out the

out beyond and above the
Thread. /

spider’s abdomen, hold-
ing the new string (ns) so that the
two parts form an angle. Now the
abdomen drops towards the radius.
The raised foot lets go the stretched
string at the very moment that the
spinning fingers grasp the radius
(at xx) and clamp the string there-
to. The string being released at
the same moment, contracts with
a sudden snap, and thus forms the
little interradial or portion of the
spiral lne between the two radii. Fig. 80 shows the first action in this

Fic. 79. Clamping a spiral string.

process. The strings I I, II II, are sections of a finished spiral line, and
III x III is a string in the act of being spun. The line x is caught up
by the claw, cl, upon a tarsal spine, ts, (apparently) or a metatarsal spine,
ms, and pulled out from the abdomen to which it is attached by ab. The
foot (here greatly exaggerated) moves rap-
idly towards ab, and the line is fastened at
the point III, indicated on the right hand
radius, r. The large tarsal spines which arm
the terminus of the tarsus of Argiope coph-
inaria are continually used by that species
to hold the beaded string as it is thus
drawn out. In the meantime, of course,
the remaining limbs of the spider have

been carrying her forward. The

The legs on the side towards the cen-
Forward

tre of the hub reach upward and
Progress.

grasp the spiral scaffold (ss) if

Fic. 80. Drawing out a beaded spiral. The
leg much exaggerated.

the scaffold happens to be within reach.
This is frequently the case during the
whole process of spinning; but frequently also during the placing in of
the first spiral strings included between two scaffold lines the spider is
unable to reach so far, and therefore must go around the radius, as will
be described presently. The legs on the side of the body towards the

82 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

circumference of the orb grasp the radius as it is approached. This
describes in a general way the method of locomotion. In other words,
the legs towards the circumference reach forward toward the approached
radius. At the immediate instant when
the spinnerets clamp the new made string
upon the radius the whole body is at rest
and is balanced by the legs in the posi-
tion just described (Fig. 79), that is, on
the upper side supported by the two fore
legs; on the forward side (towards the
head of the spider) by the other
The two fore and third legs, holding
String 3
Gintaped. to the radius ; and on the lower
side by the hind foot, which
also grasps the radius just below the point
of intersection. Of course, this period of
CS he aR ee re ee while spin- poise, as & tule, is so brief that<at as
scarcely noticeable. At times, however,
when the spider appears to be moving more sluggishly, for one reason or
another, the moment is sufficiently prolonged to permit the observation.
I have often seen that the spider would make a quite noticeable pause
before the hind foot let go the new spiral string, permitting it to snap into
its position between the two radii. Sometimes the position of the spider
will differ from the above in detail; for example, when the beaded strings
have been brought up close to the scaffold line,
they can be fastened while the spider hangs “ / ,
with her sides nearly parallel with the scaffold.
In such case the legs on one side will hold on
to the scaffold, while at least two legs on the
under side remain free, and grope about with

the restless motion of feeling after something,
heretofore described. In these operations the
scaffold line is generally well bent downward
instead of being taut as shown in the cuts.
The general line of progress of the Orb-
weaver’s body while spinning the spirals is il- WZ,
lustrated at Fig. 81, where R represents the LASS ="
radii, SF, Sx, SFy are spiral scaffold lines, N
and SP true beaded spirals. The spider en- = a

gaged upon the spiral A fastens it to the me. 82. Dropping action on the down-
radius IR at the point of contact; then the Sao Het 2e
course of the body is upward along 1R to the spiral foundation SFx ;
thence across the section B thereof; thence downward along radius 2R,
until at the point C opposite A she can tighten and fasten the line

THE ARMATURE OF ORBWEBS: VISCID SPIRALS. 83

which she has carried around with her. This makes one section or string
of her beaded spiral. The next string, C-D-E, is completed in the same

way, the general course being in the direction of the arrows.
Course of 4." the space between the newly made viscid spirals (as A
Spider. : | agin the east rs

and the next occurring foundation spiral (SFx) is diminished,
the spider does not need.to walk along the intervening radii, 1R, 2R, ete.
The distance between the spiral foundation and the new points of opera-
tion is then short enough to allow her to grasp the former with her fore
feet; and thus she strides along, oscillating between the viscid spirals and
the foundation spiral, and between the two radii separating the beaded
string which she is weaving in. Very often, indeed, there is no need to
walk along the radius at all, but from the beginning to the end the
spider is able to accomplish her work by the simple process of reaching
to the spiral scaffold. In that case, of course, the dotted line and arrows
of Fig. 81 only represent in a general way the course of the body.

In ascending the orb, as well as in crossing from one side to another,
the aranead must plod through all the course which has thus been imper-
. _ fectly indicated; but when she is on the downward course she
Dropping. i. not compelled to stride along the radii and spiral scaffolding,
and therefore simply drops from the point of attachment last made to the
next radius. (Fig. 82.) This sheer descent of her web is made when those
radii are reached which cross from the centre laterally to the circumfer-
ence, when it is manifest (see R1, R2) that all required is that she should
drop from the radius last intersected (R2) to the one next in order (R83).
This is the usual course of the spider, and not until she makes the turn
and again proceeds laterally across her orb is she required to renew the
more tedious process described.

It is obvious that those Orbweavers which make vertical webs must,
from necessity of the case, vary their mode of proceeding while spinning
the spiral lines, according to the position which they may chance
at the time to have upon their orbs. This fact may be illus-
trated at Fig. 83, which represents diagramatically the progress
of the spider around an entire concentric. The web is represented with the
radii, R, R, in place, and the spiral scaffold, 8, located. The spider had
already begun upon the viscid spirals, and had laid in one circular course
of the series. Let us suppose that she starts at the point x on radius marked
R1, to lay in her second spiral concentric. The ordinary course would be
to stride along the radius to the spiral scaffolding (S) and so to the point
x2, where she would fasten her new string. But it is obvious that such a

Swinging
the Circle.

course would be wasted time and energy, and that her purpose would be
accomplished more readily by dropping directly from x on R1 to R2, and
carrying her line to the point of junction x onthe last named radius, This
is precisely what the spider does, and this is her habitual method on all
parts of her orb where such a direct drop is practicable.

84 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Thus, to follow her course from R2 she would descend to the next
radius, R38, by such a direct drop. When her string is attached to the
point x, on this radius, she will pursue the ordinary method and
pass around to the spiral scaffold at its point of intersection (z)
with the radius. Here now it is again possible for her to drop
from z to x, on the radius marked 4. From this point onward, while pro-
ceeding across her orb, and during the ascent from R4 to R16, her habit-
ual method is to swing around the radius to the spiral scaffold, and so
down the next radius to the points of intersection, x. When she has

Varying
Methods.

Fic. 88. Swinging around the circle.

reached radius No. 16 it is again possible for her to proceed by dropping
directly from her last point of intersection to the radius next below.

It will be observed that an alternate course of progress is possible for
the spider at certain sections of her orb. For example, between the radii
3 and 4, and 4 and 5, instead of moving from the point of intersection,
x, along the radius to the spiral scaffolding, and dropping from the point

z or swinging along the radius of the scaffold, she may pass
Walking from
Beaded
Spirals.

x8 directly along the line n, supporting herself by the
beaded spiral last wrought in. ‘This she sometimes undoubt-
edly does. Blackwall expressed the opinion that the last made
viscid spiral line is also used as a support while spinning the next spiral

THE ARMATURE OF ORBWEBS: VISCID SPIRALS. 85

in order, in cases where the spiral scaffold is not easily accessible.! I have
occasionally observed this action, but cannot certainly confirm the observa-
tion as habitual. At all events, the diagram will show this alternate move-
ment as it may be made between the radius 5 and radius 6, or again be-
tween radius 6 and radius 7.

From this point onward, while crossing laterally the lower portion of
the orb, and again while ascending, the striding movements which have
been described and illustrated by the previous figures become necessary.
Usually, however, upon the downward course, she drops from one
radius to another, and thus proves herself, like any human la-
borer in mechanics and architecture, both able and willing to
make the best use of her time and strength by varying her ordinary habit,
and availing herself of natural conditions. I have described what is the
habitual course, as it may be seen by any careful observer. But there occur
exceptions, and I have sometimes had occasion to note the fact that some
spiders allow themselves to be so swayed by habit that they persist in
crawling around the sides of all the sections, instead of relieving them-
selves by the direct drop after the manner of their congeners. I suppose
that even in Spiderdom there is room for the ultra conservative consti-
tution.

Mr. Blackwall thus describes the mode of spinning the spirals, which
correctly summarizes the detailed account which I have given. From the
circumference of the orb the spider passes along a radius to the outer
line of the spiral scaffolding (having fixed a viscid thread to the end of
the radius)—along which she goes to the adjoining radius, drawing out
the thread, in her transit, with the claws of her hind leg nearest the
circumference. She then transfers the thread to the claws of the other
hind leg, and passing down the radius at which she has just arrived to the
circumference, she places the foot of her hind leg previously employed in

drawing out the threads on the point in the radius to which

Place her filament is to be attached, and bringing her spinners to the
wall’s De- ee nai : : ;

Sie spot there makes it secure. The precise place in each radius at
scription.

which to fix the thread is always ascertained by the situation
of the foot of the hind leg, and this is determined by touching with the
feet of those legs nearest the circumference, the marginal line, or when
the structure of the net is further advanced, the last formed circumyolu-
tion of the viscid spiral line.?

The spider advances, as we have seen, by a zigzag movement, partly
striding, partly swinging, catching alternately upon the opposing founda-
tion spirals and the next radius. Every radius crossed, at every crossing,
is touched as above described and the spiral caused to adhere. In some
orbs whose radii number forty or fifty, and the spirals as high as sixty,
the number of attachments is very great—2500 or 3000, and they are

1 “Nets of Geometric Spiders,’ page 183.

86 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

made with a rapidity which often prevents the eye from following the
motions of the foot and spinnerets.

When the innermost spiral is reached the aranead swings or strides to
the hub, takes up her position head downward and bites out the flossy
euidon, which she takes within her mouth.t~ Whether or not it is finally
rejected I cannot say, but it is certainly retained for some time, and I
believe is dissolved within her mouth, and swallowed.

What becomes of the unbeaded scaffold lines which the spider uses for
weaving in her system of beaded spirals? ‘They are not seen among the

concentrics when the orb is finished, and the secret of their dis-

sae q 2Ppearance is only to be unfolded by watching the architect as
caffo ;
Removed, She proceeds with her work. It will thus be found that as she

spins her way from the outer margin toward the centre she
bites off her scaffolding and permits it to drop away, rolling it up usually
within her jaws. It has served her purpose by giving her footing while
engaged in forming the essential part of her structure, and when she
needs it no longer she removes it, precisely as the mason when “ point-
ing” his stonework takes down his wooden scaffold as he works from the
top toward the bottom of his wall. I have observed this process repeat-
edly, as others have done.?. Mr. Emerton® speaks of “a few turns in the
centre” apparently confounding what I have called the “notched zone”
with the special scaffolding, as his figure also shows. The latter is
not simply a continuation of the former, but is rather an independent and
permanent part of the orb, having a wholly different use and is separate-
ly spun. Blackwall says that the “innermost circle” of the spiral scaffold
is permitted to remain; but my observations, on the contrary, are that all
the concentrics are removed and the beaded spirals carried to the very
margin of the free zone. Possibly the habit is not invariable in its
details; and on the whole presents a good example of intelligent exercise
of the spinning function.

ale

The efficiency of an orbweb for the capture of prey depends chiefly
upon its viscidity and strength. The former quality pertains to the spiral
lines which differ from the other parts of the web in being
covered at close intervals with minute viscid beads. To these
the value of the snare as an instrument is chiefly due, for they
adhere to and melt upon the wings, limbs, and hairs on the bodies of
insects that strike the web, and thus fatally entangle them. Rennie has

Spiral
Beads.

' Kirby and Spence, Introduction to Entomology, page 413, are quite correct in their allusion
to this fact, but the biting away of the cotton like tuft is not necessarily accompanied by
the opening up of the hub. Blackwall suggested the probably true reason why the central
space is without viscid beads.

2 Blackwall, op. cit., page 183.

* Emerton, American Naturalist, ii., 478; Packard’s Guide, page 646; Structure and Habits
of Spiders, page 64.

THE ARMATURE OF ORBWEBS: VISCID SPIRALS. 87

certainly made a mistake in saying that the suspensory lines are as often
studded with beads as the spirals.t- The radii are often found more or
less beaded, although this is a rather exceptional and incidental condition ;
but I cannot recall, among the vast number of orbwebs, a single instance
of beads upon the suspensory or foundation lines. The dewdrops gather
on those lines, however, and perhaps Rennie, like some other observers,
was deceived by them.

Under the microscope the beads show as beautiful objects, not unlike
pearls strung upon a cord. Indeed, were a jeweler to reproduce in exact

_ form and suitable magnitude a geometric web, substituting pearls
Size of A z

Basds for beads, he would have a necklace of surpassing beauty. The

beads vary in size according to the size of the orb and its maker;
they vary also upon the same orb and
line. Some have a thickness little greater
than the diameter of the line; others are
several times greater, say in proportion of
6, 38,4, and 2. The larger ones commonly
alternate with the smaller, two or more of
the latter succeeding the former, and this
sequence is tolerably constant, but it is by
no means absolute. Immediately after for-
mation the beads are uniform in size, and
the change in size is afterward caused prob-
ably by the interblending of two or more
of the original beads. (See Fig. 84.)
They are forthe most part semitrans- 1% Relative size and shapes of viscid
beads. The space beaded at IV is shown

parent or translucent. Frequently there ata, natural size.

occur what appear to be opaque _ beads,

showing quite black upon the line; these are simply particles of dust,
around which a delicate coating of the spiral gum has gathered. Small
spherical objects, grains of pollen and the like, also are seen, and the orb
soon becomes well sprinkled over with minute extraneous particles, espe-
cially if the wind blows or the location is dusty. Under the microscope
the beaded line shows through the substance of the globules, which is
evidently aggregated around it. Indeed, one may scrape off the beads and
leave the line intact. Fig. 84 shows a few of these viscid beads as they
appear under a microscope. The sections I, IJ, III are from a snare of
Cyclosa caudata examined afield. Section IV is drawn from a snare of
Argiope argyraspis spun while in confinement. It shows the beading
along a space of nearly five millimetres as marked off at a; and also indi-
cated upon the magnified line. None of the beads upon this snare were
longer than about one-tenth of a millimetre. In shape they were ovoid,
more or less pointed at the poles; many were globular and some had

1 Insect Architecture, page 313.

fete) AMERICAN SPIDERS AND THEIR SPINNINGWORK.

irregular forms. To the naked eye or under a common hand glass the
beads often show as quite regularly arranged globules of two or three
sizes. (Fig. 85.)
These two opinions are very deeply seated in the popular mind: first,
that spiders are able to shoot out from their spinnerets lines or rays;
second, that they are able to retract within the abdomen the lines
Elasticity which they spin. In the former case the delicate filaments are
OF spral ejected from the spinning tubes as liquid silk, but the movement
Lines. are : :
of the air is the means by which they are borne swiftly aloft or
outward from the spinnerets. There is no ground in fact for the latter
opinion, although it is not strange that casual observers should be deceived,
as the optical illusion, for such it is, is very complete. The illusion is
occasioned by two causes: the first is the action of the spider which in
ascending a dropped line, for example, gathers up the thread under her
“snoesdecoredesOrrietecooe jaws, as she goes, in a little, flossy ball so delicate
Soe oreo as t® escape ordinary observation, ‘Nhe other icause

02010()-00-0000-00-000-0000-00—

s00e0se0ee00s0ve0ev00— is the extreme elasticity of the line, which may be

00-0-00-:000-0-00-0000000000- E 5 : li . f li ] f ape
ee sacseeseces extended greatly by the application of a slight force,
Bese es cece Onstaz- and on its removal will contract proportionately.
070v0-0-000-00000000— c rn
Fe EONS One who has carefully watched the movements of
20-00 0-00-0.000-re— Orbweavers while laying in their spirals must have
ro0-0-000000-90O-00-

observed, what Blackwall has already noted,! that in
-©000920000900G000- passing from one radius to another the viscid line
00OocOncOccocog. 18 usually drawn out to a much greater extent than
Fic. 85. Appearance of beads 18. necessary to connect the two. Taking the last
tohescye: spiral cross line, after its formation, Fig. 80, 111—111
prolonged, as the base of a triangle, the lne is actually drawn out before
it becomes taut and is fastened as at iii—x, ab, occupying thus two sides
of the triangle. I have seen the line thus stretched until it certainly was
nearly if not quite twice the length finally assumed. This elasticity is of
course of immense advantage in the preservation of the snare under the
struggles of vigorous insects entrapped within it, as well as before the vio-
lence of wind, and beneath the weight of dew and rain. One may easily
assure himself of this elasticity by touching some object to a single viscid
string and drawing it out until it snaps. He will find that the united
length of the two lines thus expanded will often be as much as four, six,
or even eight times the length of the original line.
But there results from this elasticity another advantage which I believe
has not heretofore been noted. It presents in part an explana-
Forma- tion of the formation of the beads, a point which has been
tion of ; : ; = ; P
aa. much discussed and never yet fully explained. The spiral line as
emitted from the spinnerets is covered with the viscid matter
of which the beads are composed uniformly distributed over its surface.

1 Spiders of Great Britain and Ireland, Intr., page 10.

THE ARMATURE OF ORBWEBS: VISCID SPIRALS. 89

When drawn out by the foot of the spider into the position of x-ab,
Fig. 80, how is this viscid matter affected? In order to test the effect
of expansion and sudden contraction upon viscid matter spread along a
line, I covered thin bands of India rubber with mucilage, and then sud-
denly stretched them. The result was that invariably globules or beads
were formed similar in shape to those upon the spiral of an orbweb. A
twist of the band, by rolling it between the finger and thumb, caused the
globules to mass equally around the band, a position which they would
doubtless have kept permanently, as do the spider’s beads, could the muci-
lage have hardened as rapidly as the viscid secretion from the spider does.
This tendency would probably be greatly increased were the spider when
emitting the viscid matter to give the line a sharp twist or even impart to
it a vibratory motion. At all events, we know that an elastic line drawn out
in the above manner and suddenly released is set into vibration, the mechan-

ical effect of which would certainly be in the direction here indicated.
However, it is probable that a natural contraction or crystallization of
the viscid matter itself would follow when exposed to the air, and thus
produce the beads without any mechanical agitation, which

Natural nevertheless would undoubtedly assist the action of aggregation.
Crystalli- ,,_. ; : i Beke abd 3 ir
Sein Various experiments showed that an elastic line, or elastic band,

when covered with mucilage and then stretched, soon becomes
threaded with a series of beads not unlike those on the web of the geo-
metric spider. The natural tendency of the material is evidently to gather
into these minute globular masses. If we suppose this to represent a gen-
eral tendency of viscid liquids, we have at once the reason why spiral
lines covered with viscid secretion as they are emitted, should soon present
the appearance of strings of beads.
Incidentally it may be said that the elasticity of the beaded spiral en-
ables the spider to so graduate the interradials that they are all taut.
The fact that the radii converge upon the centre compels a

Equaliz- reat difference in length between a string drawn at the outer
ing Inter- margin and one at the interior. Does it not imply a great de-
radials. i see aise | ‘i : ply a great

gree of mathematical skill to pay out the requisite amount of
line as the distances gradually and continuously diminish? I suppose that
the whole matter is solved chiefly by the elasticity of the spiral thread.
If the spider were to draw out an equal length of line in every case it
would bridge the wider interspace at the circumference and the narrower
one at the centre with equal facility.
What is the condition of the spiral thread as it escapes from the spin-
nerets? Does it show at once the appearance of viscid beads?
How Or, is it smooth upon the surface, and do the nodules gradually
Beads are RA hie oe ae ee :
NIA As. form after emission? The difficulty of finding a spider at the
exact point of spinning necessary for this observation is in itself
considerable; to find a web so located as to allow study under a glass of

90 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

sufficient power to separate the beads, is yet more difficult; and the exces-
sive rapidity with which the spiral lines are spun forms the greatest ob-
stacle of all to a successful observation.

However, I was able to obtain the required favorable conditions by
colonizing a number of spiders of various species, especially the Basket
Argiope, upon honeysuckle vines which cover a fence and arbor in my
yard. I thus learned that the spiral thread issues apparently from the an-
terior spinnerets and that they issue as a pure white line, the whiteness
being equally distributed over the thread, and presenting quite a contrast
with the bluish whiteness of the lines which are used for the radii and
foundation. Frequently I saw a minute globule of glistening liquid ap-
pear on the emitted thread at the space of four or five millimetres from the
spinning tubes; but this was immediately spread along the line by the
brushing movement of the fourth leg, or naturally distributed itself.

After various efforts to observe the character of the line as it issued
from the spinning spools, in which I was only partially successful on ac-
count of the rapid movements of the spider, I fixed my attention upon a
selected portion between two radii which had just been attached; and
then upon the next and the next string toward the moving spider. By
using a magnifying glass of moderate power I was enabled to see that
in a short space, varying in different spiders, and indeed varying on the
web spun by the same spider, the process of crystallization, as perhaps I

may call it, or aggregation, began. Here and there along the
Breaking Jine there would first show points of roughening in the out-
into : E ss
meade. line. From these several centres, on either side, the roughened

condition would spread, presenting somewhat the appearance of
the spiral threads of a screw. Gradually the detached points assumed
figures more or less oval, and subsequently the globular or subglobular
forms which are most common in the beads. By shifting the lens I could
see this process going on all along the strings most recently spun. At
one end of a string or interradial the beads would be forming, while
at the extremity nearest the spider’s spinnerets the line would be perfectly
smooth.

Beyond the string under observation the parts spun a few moments
earlier were covered with beads of normal shape. This observation was
repeated a number of times, and these matters are now definitely settled :
first, that the viscid material is placed upon the spiral thread contempo-
raneously with its emission; second, after a string has been placed be-
tween its two radii it naturally undergoes the process of aggregation
common to yiscid liquids in like position; and finally, it assumes with
greater or less rapidity the forms of oval or globular beads gathered
around the thread.!

1'The two sorts of material are evidently secreted from two different glands, and per-
haps also emitted through different spinning tubes.

THE ARMATURE OF ORBWEBS: VISCID SPIRALS. ot

Thus Fig. 86 will represent a section of a snare upon which an Orb-
weaver is spinning in her spirals. She has finished her task along the
beaded line, BL, and is working upon a line L. Just beyond it, imme-
diately behind her, the string numbered 5 shows a white unbroken surface ;
No. 4 is shghtly ruffled; in the string No. 3 a few points of segregation
have begun to appear; at No. 2 the beads are nearly perfected on the part
nearest the spider and quite finished on the further half. On string No. 1
the beads are completely formed. The figure, although sketched from na-
ture as far as it is possible to draw such swiftly changing objects, is neces-
sarily in part diagramatic. However, it accurately expresses the facts.

The beads when newly formed are of a white color, translucent and
glistening. They are uniform in size, or nearly so, but there is a constant
tendency in the first-formed minute beads to undergo a further process of
ageregation, thus making
larger beads. These large
beads will often be found
at the crossing of the lines.

The effect of rain upon
the beads is to blend sey-
eral into one until quite

large globules are
ee d formed, in good a
by Rains, Part mixed with . B

water. If the rain Fic. 86. Diagram illustrating the crystallizing of beads. SF, spiral

5 3 E foundation; BL, beaded line; L, line just spun; 2, 3, strings on
be continued it dissolves the which beads are forming; SP, the spider.

viscid material, and the

portions which do not drop off remain as large beads. These also soon
pass away, leaving the snare without the ordinary armature for efficient
service. I have frequently tested this matter during and after heavy or
long continued rains; and neither by tongue, nor touch of finger, nor con-
tact with other objects, nor by glass could the beads be discovered on many
of the spirals; and often the whole web is disarmed. This accounts for
the fact that spiders find it necessary to construct new snares after pro-
tracted rains. The rain also dissolves, but not quite so freely, the thick
white shield and zigzag ribbon on the snares of Argiope.

In this connection I introduce the explanation of a phenomenon which
long greatly puzzled me. While wandering in the woods of Delaware
County, I observed on several separate occasions, always in the
snare of the Orchard spider (Argyroepeira hortorum), a novel and
striking variation in the arrangement of the spirals, which is rep-
resented at Fig. 87. It will be seen from this figure that the spiral space
is divided into two distinct belts, of which the outer one contains about
half the number of lines in the inner one. Of two specimens showing this
appearance, the inner belt had sixteen and the outer eight, the difference

A Pecu-
liar Orb.

92 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

being just two to one in
both cases. This regu-
larity of proportion add-
ed to my perplexity in
seeking an explanation
for the appearance. Why
should the spider have

HN

I)
il};

=
SS

made such a_ peculiar
division in her spiral
space? Was I on the

\

track of some new and in-
teresting departure from
the fixed habit of this
species? The snares were
figured and described,
and for a number of

years I sought in vain
Fic. 87. Effect of rain upon an orb. The open marginal space was a . : ae
spun before, the remainder after, a shower. for an explanation of the
peculiarity, which, how-
ever, I saw but once again, and that in an Orchard spider’s web.
At last I found the explanation. On the honeysuckle and ampelopsis
vines growing in considerable profusion in my manse premises, I had colon-

ized a number of Orbweayers, including several examples of Ar-
Effect of

Rai giope cophinaria. One morning in September, just after a warm
ain. 3

shower, while going the rounds of my colonists, | observed on
several orbs that a series of spiral lines had been spun from the margin
inward, covering about one-half the ordinary spiral space. No other beaded
spirals appeared; and looking a little more carefully I observed that those
upon the web were all greatly deltated and much more widely separated
than usual. In fact, I came to the conclusion that the Argiopes had been
engaged upon this part of their snare when overtaken by the shower; that
they had abandoned their work, fled
to their refuge, and in the meantime
the beating raindrops had twisted the
spiral lines already spun, until they
presented the appearance described,
and which is shown at Fig. 88.
An hour thereafter I left my study
to reinspect the colonists upon the

vines. The rain had eeased : the sun Fic. 88. Section of Argiope’s orb interrupted by a
noe : shower.

was shining pleasantly, and I was sur-
prised to observe that the partly completed webs had now been finished.
But instead of cutting away the portions originally wrought in, and which
had been partially disabled by the rain, the spiders had taken up their spin-

ve)
Se)

THE ARMATURE OF ORBWEBS: VISCID SPIRALS.

ningwork at the point where it was abandoned and finished it in the usual
manner, so that the orb presented the appearance shown at Fig. 87. The
spirals were not only greatly deltated by the action of the rain, the crossed
lines being merged and twisted together at the middle part, but the beads
upon them had been taken up by the raindrops, a number united into one,
so that instead of the ordinary condition of a vast number of minute beads

spread entirely along the line there appeared a much smaller

Interrupt-jumber of beads of larger size, that distinctly showed to the
ed Bead- Beane Ty tl -plained sterv of tl a0) s-hard spider’s
ing Fin. eked eye. 1en the unexplained mystery of the Orchard spider’s

ished. peculiar snare flashed upon my mind! At once the mystery

was solved, and that in a most simple and natural way. The
peculiar appearance of the orb was simply the result of the spiders resum-
ing arrested work upon the spirals after the same had been abandoned on
account of a shower, and which in the meantime had been twisted and
deltated by the action of the elements, and the size and grouping of the
beads changed. As the renewed work was spun in, in the ordinary way,
both as to the position of the lines and the size of the beads, the con-
trast with the larger beads and the more widely separated spirals of the
earlier belt was very great. It was not the first time that I learned the
valuable lesson that natural phenomena are often to be explained by the
simplest and ordinary causes, while we are vainly speculating and_philoso-
phizing over some supposed occult and mysterious reason.

Tit.

Mr. Blackwall remarks that “the estimate of the number of viscid
elobules distributed on an elastic spiral line in a net of Epeira apoclisa of
a medium size will convey some idea of the elaborate operations
of the Epeiroidee in the construction of their snares.”! This quo-
tation evidently indicates that Blackwall supposed the viscid glob-
ules to be the result of “ elaborate operations” on the part of the Orbweaver, in
other words, that they are formed by direct and intentional action. This
has been the well nigh universal belief. But in the light of the
true mode above recorded, it is necessary to diminish by so much
the credit heretofore bestowed upon this child of Arachne.

It would be an extremely laborious, if not impossible task, to ascertain
the exact number of beads upon an orbweb, but I reached a near enough
approximation by the following process: A sector of a snare was taken, that

Number
of Beads.

An Hrror
Corrected

is, a complete section extending from the hub to the circumference between two
radii, and the number of beads thereon was carefully counted.
This sector was then measured and the superficial area calculated.
The superficial area of the entire beaded space having been obtained

Number-
ing Beads.

in like manner, the number of beads upon the whole web was readily calcu-

? Jour. Linn. Soc., 1829, Vol. X VI., page 477, and Ann. Mag. Nat. Hist., Vol. XV., page 239.

94 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

lated with approximate accuracy. The example chosen was a snare of Epeira
sclopetaria five inches long by three inches wide, and the calculation showed a
total of 140,800. This is an orb of only medium size; in many webs the
number is certainly much larger, in some several times greater, although in
others it is doubtless greatly less. Blackwall calculated that a net of Epeira
apoclisa from fourteen to sixteen inches in diameter contained upwards of
one hundred and twenty thousand viscid globules. “‘ Yet it will complete
its snare in about forty minutes if it meet with no interruption.”!

That the viscidity of the spirals depends upon the beads, and that the
latter are placed upon the former, is of course proved by the effect of rain,

which separates the beads from the spiral lne. But it may be also
Adhesive: shown by scraping or rubbing off the globules with which the line
ness of - aes ae : ; ‘ ;
Beads, 18 Studded. This leaves an madhesive line, apparently of the

same constituency as the radii and other parts of the snare. An
easy way to demonstrate the fact is to insert a bit of glass beneath the
viscid portions of a web. The beads will adhere to the glass, if carefully
handled, so as to show distinctly the spiral strings in their proper relations
to the radu. By a little gentle manipulation with a camel hair brush or
other small object, the beads will be separated from their strings and melt
upon the glass, showing the string in the midst of the glutinous matter as a
straight silken thread.

I feel well satisfied that the viscidity of the beads varies on webs of the
same species at different times, and it is probable that the degree of
viscidity is determined by the condition of the spider. When it is well
fed the secretions are abundant, but after long periods of fasting the
viscous quality of the secretion seems to be weaker, or the secretions being
less in quantity the amount distributed upon the lnes is greatly dimin-
ished, and hence the effectiveness of the spiral strings is decreased.

When exposed to the desiccating influence of the sun, and air briskly
agitated, the nets of geometric spiders lose their adhesive property ;
but when formed in situations from which the lght is excluded, and
where the atmosphere is not liable to be perceptibly disturbed, they retain
their viscidity for a long period. Blackwall says that upon a net of
Epeira diademata constructed in a glass jar, which was placed in a dark
closet, where the temperature was not subject to great or sudden fluctuations,
the globules preserved their adhesive power almost unimpaired, and the
last formed spiral line its elasticity for more than seven months.?

I placed a snare of Argiope argyraspis in my study October 3d, 1882.
It was spun within a wooden breeding box, the front of which was covered
by a sliding glass door, the back by wire cloth. It was thus exposed to
light and air, in a well heated room. Examined as late as April 17th,
1883 (five and a half months after construction) the beads were found to

' Brit. Assen. Reports, 1844, page 77. “Spiders of Great Britain,’ page 10, Introduction.
2 Transactions Linn. Society, 1829, Vol. XVI., page 479.

THE ARMATURE OF ORBWEBS: VISCID SPIRALS. 95

retain perfectly their viscidity. They appeared to have thickened, and
were of an amber color. At various angles or points of juncture between
the radii and spirals, larger globules or masses of viscid matter had formed
as though several beads had run together and settled there. I kept a
snare of this Argiope until September, 1888, nearly six years, at which
time the general form of the orb remained perfect, though of course all
the viscidity had disappeared, and the web lines were covered with in-
numerable motes of dust, vegetable fibre, etc. On the contrary, a snare
of Epeira thaddeus kept under precisely the same conditions as above, had
in three months almost wholly lost the adhesive quality of the spirals and
scarcely a trace of the characteristic beads could be observed.

Dr. Vinson! while hunting in a forest of Réunion (Africa) became
entangled in the huge snare of a Nephila. While detaching from his lips
the sticky threads pasted upon them, which he found to be
bitter, he made the reflection that at some future day, no doubt,
a medicine would be made from such threads, and formed into
pills would serve as a substitute for sulphate of quinine in cases of inter-
mittent fever. Spider webs have been frequently used in that way, although
the medical uses of that substance are commonly thought to be limited to
that suggested by the redoubtable Bottom in Shakespeare’s play, viz., to
stanch the flow of blood. The web which has been most commonly used
in this country? for such purposes is that of a tubeweaver, Tegenaria
medicinalis. A bolus of “Telea aranea,’ or spider web, used to be a not
infrequent prescription in Philadelphia. Perhaps the somewhat revived
interest in this odd remedy may be profitably directed toward the Orb-
weavers’ snares as well.

The gum of which the spiral beads are formed has a slightly acrid
taste, and it probably is of an acid nature. An associate in the Philadel-
phia Academy of Natural Sciences, Mr. Gavin W. Hart, said that
on one occasion while hunting in the woods he was frequently
arrested by the webs of a large Orbweaver. Wishing to avoid
the unpleasant contact with the viscid material, he used his gun to strike
down the web, pushing the barrel ahead of him as he passed among the
trees. In doing this, of course, some of the threads adhered to the gun
barrel. Three or four hours afterward he found that the barrel was quite
gummy, and where the thread was thickest it had removed from the gun
barrel the bluing, as it is called. Where the thread was thickest, the bluing
was removed the most. Several friends, who accompanied Mr. Hart on this
expedition, found that their guns were affected in the same way.

Medicinal
Property.

- The Bead
Gum Acid

1 Araneides des Isles Réunion, etc., page 22.
?See Dr. Chapman’s “ Elements of Materia Medica and Therapeutics,’ Philadelphia, 1825,

OA Te I Hike ae
ARGIOPE AND HER RIBBONED ORB.

Jt.

In the United States the genus Argiope is represented by two species
whose large size and beautiful markings have drawn to them the attention
of most familiars of our autumn fields. They are the Basket
Argiope (A. cophinaria Walckenaer), and the Banded Argiope
(A. argyraspis Walck.) These resemble each other closely in
their habits and spinningwork, but some striking differences will appear.

The Basket Argiope is the largest of our northern Orbweavers and is
equaled in size by the genus Nephila alone, whose habitat is limited to the
Gulf States and southern California. This species is widely distributed over
the United States. I have examples extending from New England, through
the Middle and Western States to Lincoln, Nebraska, the Rocky Mountains,
and to the extreme southwestern point of our Pacific coast at San Diego, Cali-
fornia. It is also distributed throughout the South, where Hentz saw it.
Professor Wilder found it abundant on the seaboard of the Carolinas, and
I collected specimens as far southwest as Austin, Texas.

Cophinaria is, therefore, a veritable “ continental,” and is able

Distribu- i6 adapt herself to the climatic extremes lying between our northern
tion and : Be Paani 3
Habitat. and southern borders without any apparent specific change. It is
interesting to know that her habits remain uninfluenced by this
distribution, as far as present information, variously collected, can determine.
Her snare and cocoon everywhere bear the same characteristics, showing
that the chief forms of her industry are unchanged by varying environ-
ment. The specific name ,which Hentz gave this spider (riparia) indi-
cates that he considered the banks of streams favorite places for her snares.
Certainly, I have often found her in such localities, but there seems to be
no special fondness therefor, as is shown by her wide distribution over the
prairies and plains. She builds in low bushes, tufts of grass, clumps of

Full Orbs.
Argiope.

weeds, and like positions, and is fond of low and moist locations, but fre-

quents lawns and fields, and, indeed, in the vicinity of Philadelphia, is

quite commonly known as “the large garden spider,” thus acquiring in

America the popular title so long borne by the British cross spider, Epeira
(96)

ARGIOPE AND HER RIBBONED ORB. 97

diademata. Her orbs are frequently very large, but in this are wholly regu-
lated by site. A good figure of one of these orbs with details accurately

drawn is given at Fig. 47.
The peculiarity which first strikes the observer is the oval shield
of white silk tissue which quite covers the hub. This is thickest and
closest in the centre, and grows thinner and more open towards

ene the margin, where it gradually merges into the radii which
: are attached to
and Band.

it. In the adult
spider it is usually about
two inches long by one and
a half wide.t Attached to
the shield above and_ be-
low, and extending upward
and downward between two
radii, is a zigzag ribbon of
white silk, an inch or more
long and one-fourth of an
inch or more wide. It
traverses the whole central
space and extends down-
ward about two inches un-
til it is lost in the spirals
of the lower half of the orb.
These upper and lower
ribbons yary in their de-
gree of regular-

The Use ity; they are gen-

of the

i erally stretched
, Zigzag.

between two ra-
dii to which they are at-
tached on either side; but
sometimes they overspread
three radii wholly or in ai) WNT |
part. Sometimes they are Fic. 89. The orb of Argiope. The spider is represented at the
simply irregular patches or Bight eb dg cpa he mate mere Oe
strips and often are wanting above the shield; but the lower ribbon is
rarely wanting. This variety in the character of the shield appears to
be influenced more or less by age. The shield is generally less prom-
inent in the young than in the adult spider; nevertheless, it appears
often on the orbs of the very young. This is also the case with the
zigzag ribbon, and I have seen a perfectly marked zigzag both above and

1The shield represented at Fig. 52 measured two inches long and one and a half wide ;
another example was one and three-fourths by one and one-half inches.

98 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

below the shield space upon the web of the spiderling Argiope, in the
early part of June, when the little creature evidently had been but a few
weeks, probably a few days, out of the cocoon.

The purpose of this zigzag is an interesting problem; it evidently has
no special purpose in the daily life habits of the spider; at least, close
and continuous observation of many species colonized upon my premises
have uncovered nothing. I believe that it serves to strengthen the shield
in its position at the hub, staying it by the broad bands which bind to-
gether and support the radu. The great weight of the spider is thus

Fic. 90. The central part and upper foundation lines of Argiope’s snare.

distributed over a much larger part of the orb. It probably answers a
similar purpose when the spider is engaged in swathing the large insects
which often serve it for prey, the strong zigzag cord and central shield
forming a secure attachment for the binding cords, thus keeping the net
intact against the struggles of the victim.

This zigzag on the snares of Argiope is the nearest approach in nature
to that “winding stair” up which the cunning old spider in the school-
book rhymes of “The Spider and the Fly” dragged his “silly” victim
“into his dismal den.” Argiope certainly does pass over it to the lower
part of her snare; but the ordinary open radii on other orbs are also thus

ARGIOPE AND HER RIBBONED ORB. 99

used. However, in one snare noted, built within a lodge across the angle
of two walls, the zigzag was prolonged into a series of lines like the rounds
of a ladder, spun across the corner quite down to the floor. This was used
as a gangway, by which on one occasion, at least, the occupant descended
to the floor and thence escaped from the room.

The entire system of spinningwork thus described, shield and ribbons, is
often five inches in length, and extends across the Free space, dividing it
into two nearly equal parts. The spider hangs at the centre upon
the shield which thus covers the lower part of her body. Her
legs are well extended, but the corresponding pairs, the two fore
legs and the two hind legs, are approximated so that these members are
arranged somewhat X-shaped. The feet, however, are usually turned out-
ward, the points of contact of the legs being at the tibia.

The main purpose of the shield I believe to be protective. It certainly
may serve as a strong screen against attack of enemies from the under or
ventral side of the animal. Asa rule
that side of the shield which looks
outward from the site is occupied by
her; but at times the animal hangs
also upon the opposite face, next the
leaves or shrubbery. I have often
seen an alarmed spider scurry through
the open space from the outer to the
inner face of the shield. Again, the
spiders which on one day were found ™% ®. | The abdomen
Oe aa ee haneing to the inside of the shield, of Teeipaitiored aki
ning the sheeted hub.

Spinnerets open encain, Would be seen clinging to the outside ay

ningwork drawn out. on the next day; and, again, some on one side and some
: a “onthe other, Ihave fully satisfied myself by experiment
that a threatened danger will be avoided by placing the shield between her-
self and the apprehended peril. This is done by a dextrous movement, part
swinging, part crawling, through the free zone.

The central shield and zigzag lines are not of slow growth, but are made
immediately after the spinning of the web. The manner of spinning is as
follows: When the orb is finished in the ordinary way, as heretofore de-
scribed, the spider goes to the hub, cuts out the temporary central anchor-

ages which she puts into her mouth, and proceeds to weave in the
Manner of shield. She holds on with her feet to the lines of the notched zone,
Spinning Mea a
Shield. throws the abdomen upward and backward as far as convenient,

the spinnerets being flared or extended to their utmost width
instead of being closed upon each other. The threads, which issue from
all the spinning tubes in streams of delicate filaments, are, of course, attached
to the shield and drawn out by this motion and the action of the hind legs.
(Fig. 91.) The abdomen is then dropped down against the shield space,

Use of the
Shield.

100 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

a motion which causes the threads to rapidly contract and gather into a
little ball of loops near the surface of the web. (Fig. 92.) The spider then
swings her abdomen well to one side of this flossy hump of loops, as at
Fig. 98, drawing after her a ray of milky filaments. Next, she draws back
her abdomen, which is held close to the shield space, pulls the taut lines
over the flossy mass (Fig. 94), and the spinnerets are then
moved back and forth with a lateral motion like the
spreading of mortar by a mason’s trowel, thus pushing,
beating, or spreading the loops against the cross lines of
the hub. The spider repeats these motions, at the same
time shifting her position occasionally, thus revolving her-
self by her feet around the circle of the shield. As the
spinnerets, of course, revolve with the body, the weaving
process is continually repeated, and the shield gradually
Fic. 93. A third position. formed. The movement of the spinnerets is from the
The abdomen thrown 3

to one side, drawing centre of the hub outward, and it follows that as the
out a second ray of oreatest quantity and thickness of silk issue -at the first
spinning lines.

expulsion and gradually diminish, the centre receives

the heaviest coating, and this decreases toward the margin. The fact that
the shield is more closely woven in the centre is thus accounted for.

This describes the ordinary method by which Argiope’s shield is spun,
but there are other modes. One continually finds, in studying the new made
webs of this species, that the zigzag ribbon entirely traverses the hub, in
which there is no trace of the shield except afew straggling lines. In this
‘ase the ribbon has evidently been spun first. Again, one sees the same
extended ribbon, and, in addition, on either side are woven one or more
zigzag bands, arranged in arcs of circles, which occupy the
space usually taken by the shield. In the course of time
these would be overspun, so that the hub would be occu-
pied by the thick shield which is common to the species.

When the hub is covered over, the spider proceeds to
insert her zigzag ribbon. She moves downward to a point
a little below the shield. Dropping her spinner-
ets to one of the radii, she attaches all the num-
erous filaments at once, say at the point 1, Fig.

95. She then raises her abdomen and begins to ascend, Diets wera netics
moving slowly, and dragging after her a band of silk. to the looped masses,
: a : which the spinnerets are
As she mounts, she swings her spinnerets across to the Oppo- peating and squeezing
site radius, drops them at the point 2, and attaches her down.
ribboned dragline thereto. Of course, the upward movement of the spider
and the simultaneous lateral motion of her spinnerets give to the ribbon a
will be higher

Insertion
of Zigzag.

diagonal course, so that the second point of attachment, 2,
than the first point, 1. So also when the abdomen is swung back again, the
spider meanwhile still climbing, the third point, 8, will be higher than the

ARGIOPE AND HER RIBBONED ORB. 10]

preceding attachment. The figure represents the species in the act of ascend-
ing the line and swinging her abdomen from the point 3. The natural
uplift of her body, combined with the crosswise motion of the abdomen, will
cause the direction to be along the dotted line towards the point 4, where the
next attachment will be made. After that attachment the abdomen, still
manipulated in the same way, will be carried across and upward to the
point, 5,and so on until the band is completed. As the spinning is thus
repeated alternately from side to side, and the ribband first fastened to one
radius and then to its opposite, there nat-
urally results the peculiar zigzag formation
known to all observers of this web.!

The habit of spinning the white shield
and zigzag ribbons is deeply imbedded in
the species. One sees it continually in very
young spiders, and at all the ages of the ara-
nead until its death. It is extremely persist-
ent, and it is rare to find any individual
under normal conditions that does not make
the whole or a considerable part of this char-
acteristic spinningwork.

I venture to give some extracts from
notes of observations upon the daily move-
ments of Cophinaria. ‘They were made at

: my request, by a gentleman, Mr.
aor Benj. H. Hunt, resident in Frank-
F1G. 95. Manner of spinning the zigzag ribbon. ford, one of the outer wards of

Seer eee aan tee feat see. Philadelphia.? Since this journal was made

make 3-4, swinging the abdomen across from i have been able to follow the life of tl is
3 to 4 while she climbs the radial lines.

species through long periods, even up to
her death, by means of colonized individuals. But at that time I was not
so situated as to make such consecutive observations, and I insert these notes
of a “lay observer” because they are not only accurate and piquant, but vary
the point of view and thus add value to the study.

The spider was reported as first observed on August 30th. I will take
up the journal at a little later date. The spider was at the time fully mature

‘This description is the result of a number of observations. It was several years after
I had described before the Philadelphia Academy of Natural Sciences the manner in which
this spinning was done ere I was able to see the actual operation. It was pleasant to find
that I had anticipated the mode with absolute accuracy, and thus again shown that the
naturalist can at times truly “ predict.”

* Mr. Hunt became interested in one of these spiders observed on his premises, reported
the fact to me, and following my instructions was able to place in my hands several new facts.
Many persons living in rural parts and suburbs could render valuable service to natural history
by thus taking up one creature and following its behavior closely and continually, taking care
to record everything seen, with such rough drawings as might be possible.

102 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

and was doubtless a female. “September 7th.—The web is of the ordinary
form, consisting of irregular concentric polygons, suspended from a strong
breastwork of thick thread which forms the base of a triangle, the other two
sides consisting of the two garden fences. A diary of the spider’s move-
ments would be rather monotonous. Nearly all the time she would seem
to sit quietly in the centre of the web. One morning she was absent for
an hour or two, and I supposed she had fallen a victim to some of her
enemies, either the ‘thick or thin billed birds that gladly eat them,’ or a
solitary toad which has lately appeared about the place. But the next time
I visited the web she was in the centre again.

“The rain seemed to be her greatest enemy. After a violent shower which
took place a few mornings ago, about three or four o’clock, I found that
the bit of zigzag lace had entirely disappeared. In the course of
the morning she began to repair it, and when I found her at
the work she rapidly ran off to the extreme end of the breast;
work. However, before two o’clock, she had entirely replaced her
bit of lace, though it was less straight and symmetrical than before. Since
then she seems hardly to have moved from her position. I had supposed
that the violence of the rain had swept the bit of lace away, but I
now think that the rain acts chemically upon it and dissolves it. This
morning it rained gently for a couple of hours before five o’clock. Directly

after that hour I went to see the spider, and found that half of
tthe lace strip above the centre of the web, and also above the

spider, had disappeared entirely at the top, and nearly disap-
peared close to the spider’s abdomen, which is always uppermost. Below,
the parallels and zigzag were but little impaired. She also seemed uncom-
fortable from the wet and was scraping her legs and body, somewhat as ¢
fly does, until at least one drop of water fell. There are no wasps about
the place, and if the sparrows had been inclined to eat the spider they
would have done it before now. She hangs too high for the toad, fights
between whom and spiders I think are oftener read of than seen.

“Monday morning, September 11th, 1876.—The spider has replaced the
zigzag strip for the sixth time, four times after rains, and twice on morn-
ings when no rain had fallen over night. In the latter cases little cottonlike
tufts were left, which seemed to form her bed (shield). Possibly, the strip,
on these two occasions, had been destroyed by the dew, though it was by
no means heavy. Each renewal of the strip is more imperfect than its pred-
ecessor. ‘This morning it is very slight indeed, of inferior architecture,
and not three inches long. She always forms it very rapidly, not by
drawing out single threads, as in making the web, but by producing little
bands, one-sixteenth of an inch wide. The difference between the
threads and the bands is similar to that between the ‘roping’
and the yarn turned out by the old fashioned hand cotton spin-
ning wheel in use fifty odd years ago. The ‘roping,’ it will be remembered,

Repairing
the Zig-
zag.

Effects o
Rain

Spinning
the Shield

ARGIOPE AND HER RIBBONED ORB. 103

was formed of the cotton rolled together and twisted a little, the rolls being
too short to be spun into yarn without the intermediate roping process.
The use of the strip I cannot see. Not a fly has been caught in it, while
the web catches a few flies and many mosquitoes and gnats, which two latter
insects I do not perceive that the spider notices. Yesterday I saw a fly
struggling in a part of the web, distant from the centre; the spider did not
move towards it while I was looking, but a few minutes afterward I found
her devouring it. She replaces her strips, on an average, in less than five
minutes.

“Wednesday, September 13th.—Something, apparently a cat, jumped
through the lower half of the spider’s web yesterday morning, of course
carrying away the meshes and part of the zigzag strip, deranging the rest.
The spider did nothing all day, seeming to be discouraged; and I found
her still sitting on the remains of her rumpled bed! (shield) early this
morning. But during my absence for some fifteen minutes she had removed
these rumpled remains as rubbish, and had begun to repair damages. She
was replacing her bed by bringing forth congeries of very minute fibres,
and kicking? them into place with her foot. This work was very soon fin-
ished. There is nothing architectural, so to speak, about the bed; it is a
mere tuft.

“She then let herself down about two inches and a half below the bed,
fixing a thread to the web as she proceeded, and then turning about began
to crawl up again, arranging behind her as she went her zigzag
strip. This is not confined, as I first thought, between parallel
threads (radii), but is attached on one side to the thread made
in descending, and on the other side, to the general mesh.* The strip is
irregular in width, just as all the late ones have been, and when the spider
had brought it up and attached it to the lower part of her bed she did
not, as heretofore, continue its reconstruction above the bed, but, turning
round, settled herself quietly into her old position, head downwards, possi-
bly somewhat exhausted by the late demands on her spinning resources.
I omitted to say that since five o’clock yesterday afternoon she has replaced
a portion of the web carried away by the cat. The long strong thread from
which the whole depends, and which was broken by the cat, she has not
replaced, but only mended, and it is now a little out of line.

“Thursday, 14th.—A cat again jumped through the web last night, dam-
aging it badly, breaking the main beam, which throws the web quite off
its balance. I found the spider, early this morning, prospecting among

The Zig-
zag Strip.

1T have several times seen the crumpled remnants of an old shield left, like a rude boss,
on the outside of a new one, which had been woven underneath it. This is probably the
“rumpled bed” alluded to.

2 The rapid motion of the hind leg to and from the spinnerets in seizing and pulling out
the thread, has certainly the appearance of “ kicking.”

8’ This is sometimes, but not always, the case.

104 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

the morning glory leaves which cover the board pile, apparently for the
purpose of making fast to something in order to place her main beam.
But she soon gave over and went back to her bed, seeming discouraged.
Towards noon I found her with a miller or moth in her clutches, wrapped
in what seemed to me a scrap of her bedding. As I looked, a fly became
entangled about three inches from her. She directly went towards it, but
in no great haste, no doubt because sure of her prey, and when
near enough she reached out, hauled it into close quarters, and
before I could see how, the fly also was wrapped in a bit of
white gauze.1 She took it to her bed, and I suppose fed on it and the miller.

“In the afternoon I found her on her bed on the inside of the web,
exactly opposite to her old place on the outside, and there she remains
this evening. Perhaps she thinks the inside the safer place of the two
in the dilapidated state of her dwelling. This spider is certainly subjected
to great trials.

“Friday morning, September 15th.—There was a heavy rain last night,
with wind, and the spider has disappeared. I have shaken the convolv-
ulus leaves roundabout, but find no sign of her, and the wreck of the
web has the appearance of being utterly deserted.”

The journal here ended, and I heard nothing more of the creature
whose life and trials had been followed with so much interest and intel-
ligence by my Frankford correspondent. The above quotations throw some
interesting side lights upon the humble daily life of this representative
of the spider world.

It may interest the reader to know what ‘caused the sudden disappear-
ance of the Argiope at this point. The date (September 15th) is the co-
cooning season; and no doubt Cophinaria had retired to some shaded
nook among the leaves or adjacent lumber, to spend the last forces of life
in weaving the beautiful basket shaped cocoon of the species, within which
the young are reared.

The Central Space of the Basket Argiope’s snare consists of the hub
and its adjuncts, as described, and several (there are four in Fig. 89) un-
beaded spirals. These are more widely separated as they ap-
proach the beaded spirals, and they occupy nearly the entire space,
so that there is little or no Free Zone. Some of the notched
spirals are nearly always covered by the shield, and when the spinning-
work thereon is light they may be seen beneath it. The fact that they are
without viscid beads explains Mr. Hunt’s wonder that no insects were en-
tangled in this part of the web.

The architecture of the entire snare is shown at Figs. 47, 89, 90.

An interesting feature in the construction of Cophinaria’s snare is that
which I have called “ protective wings”

Swathing
Insects.

Notched
Zone.

or fenders. These are outlying
‘The swathing of the insect is often done rapidly, by one outgush of silken filaments
from the spinners, and a quick motion of the feet revolving the captive.

ARGIOPE AND HER RIBBONED ORB. LO5

lines spun on either side or in front of the orb at the distance of one or
more inches from it. In certain positions these wings are thrown on either
side of the orb, as represented at Fig. 96, where the web is

ote hung within a conical or pyramidal mass of cross lines, a retite-
or Pro- ;

larian web, in fact. In this snare both the upper and lower sec-
tective

Wings. tions of the orb were attached to strong foundation lines set

within this mass, which was itself attached to the surrounding
foliage. This structure appears to be common as to the upper half of the
orb, but the lower part is frequently fastened directly to the foliage or
other objects of the site. Such an arrangement adds to the elasticity of
the snare, and must materially contribute
to its powers of resistance. When _ the
webs of Argiope are spun in such a posi-
tion as to expose the spider from either
side, the wings are thrown out on both

>

sides, as in the figure. But in a great

number of cases only one side is thus de-

fended, and it will be found in such cases mx

rA

that the other side is protected by the ~
foliage against which the orb is spun.
These fenders or wings are by no means
universal. Indeed, I haye examined scores
of snares on the same day and for several
successive weeks without noticing one ex-
ample. The Banded Argiope makes the
same kind of protective wings, and I have
found several half grown individuals of
this species on the seashore of Cape Ann,

Massachusetts, whose webs were all thus Fic. 96. Protective wings or fenders of
characterized. Sometimes the fenders are ne hema aah of
wholly separated from the spinningwork of the orb itself, and are thrown
out well upon the flank, and attached to projecting parts of the foliage.
They then commonly consist of very strong thick lines resembling those
spun for-the foundation of the snare.

The purpose of this outlying spinningwork is probably protective.
The scaffolding of crossed lines is thrown over both faces of the orb like
wings, chiefly over the middle and upper parts, thus covering the point
where the spider domiciles. The wings are several inches distant from

the orb. Any large hostile insect or other enemy hovering around
Uses of

: the web must first touch the outlying wings, whose agitation
Wings. Mf |

telegraphs a warning to the occupant. The detention resulting,
trifling as it would be, might yet allow sufficient time, in many cases, for
the occupant to escape. The protective wings might even happen to ward
off wholly some assailants. On such provisions as this often hangs the

106 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

preservation in nature of the individual
.and even the species. The wings do not
appear to impair the efficacy of the orb as
a snare for trapping the natural prey of
the spider. Such insects break upon and
through the web with an elan bred of un-
consciousness of danger quite different
from the perceptible caution and hesitation
which mark the conscious approach of a
hymenopterous foe.

In the snare figured above (Fig. 89),
the number of radii was twenty-five. The
number of spirals in the lower part of the
orb was twenty-six; in the upper part it
did not exceed nine. The hub was thus
placed well above the geometrical centre of
the orb. ‘This snare was spun by a female
colonized upon a young tree. After the

Fic. 97. Rudimentary web of female Argiope.

ordinary preliminary prospecting, she spun
a rudimentary web, Fig. 97, consisting of a few perpendicular lines looped
and crossed, upon which she hung in the natural posture. She remained
thus until evening and then spun her characteristic orb. This manner of
resting upon a few straggling ratlins is quite habitual. The male of Cophi-
naria appears very small by the side of his adult mate. He is not very
active in his predatory habits after ma-
turity; at least the snares upon which
I have always found him appear to be
poorly adapted to the capture of insects,
although I have occasionally seen a_ fly
entangled in one of them.

The drawing of one of these rudiment-
ary webs, given at Fig. 98, was made from

_ a pencil sketch kindly furnished
‘Webs of

me several years ago by Mr. Em-
the Male. ear Bee :

erton, and is a fair representa-
tion of the ordinary character of the web
upon which I have found the male Coph-
inaria. It may be noticed that the snare
quite closely resembles the meshed hub
spun by the female before the shield is
made, and which is characteristic in most
orbs of the genus Epeira. However, there

is a good deal of variety in the form of

: Fic. 98. Male of Argiope cophinaria on a
the male webs, and some of them are much rudimentary web.

ARGIOPE AND HER RIBBONED ORB. 107

more elaborate than that shown at Fig. 98, having well defined radii and
a spiral system at least in the lower part; but I have never seen one
that extended beyond the bounds of what in a perfect orb is the central
space. ‘The zigzag ribbon is present, but scant and ill defined. The habits
of the male and another drawing of his snare will be found in a subsequent
chapter.

The following are measurements of several webs of Cophinaria: No. 1.
tadii, 385; notched spirals, 13; beaded spirals, 24. Specimen half grown.
No. 2. Radii, 26; notched spirals, 13; beaded spirals, not counted. No. 3.
tadii, 50; beaded spirals, 16 above the hub, 31 below; the orb 12 inches
in length, 10 inches wide.
Shield and ribbon 5 inch-
es long. A strong fender
placed three inches from
the spider. Eight notched
spifals partly covered by
the shield. The ribbon en-
tirely traverses the shield
space. No. 4. Radii, 35, 18
on one side of the ribbon,
17 on the other, including
the radii inclosing the rib-
bon. Notched spirals 13, nearly filling the open space. Beaded spirals
24. Width of orb, 8 inches. Zigzag ribbon, 38 inches, including the
shield, which is about five-eighths inch.

Fic. 99. Central decorations on orbs of Argyraspis.

IT.

The Banded Argiope (A. argyraspis) is an abundant species, at least in
Pennsylvania and the adjacent States to the south and east. The female

is generally somewhat shorter in body length than the Basket Ar-
Banded ;

sie giope, and otherwise smaller. The abdomen tapers gradually

from the middle part toward the apex. The spider is of a gen-
eral whitish gray color; her abdomen is covered above with a bright silver
gloss, and is crossed longitudinally by two pretty yellow bands, and _later-
ally by a number (thirteen or more) of black lines unbroken, alternated
with interrupted ones,!
Argyraspis is seen most frequently in the later summer, from July until
November, nested upon hedges, shrubs, bushes, and in tall grasses and
weeds. Her snare is substantially the same as that of Cophinaria, see Fig.

‘Argiope argyraspis is closely related to the well-known Arg. fasciata Fabr. of Eu-
rope. See Koch’s “Die Arachniden,” pages 159, 160, and Tab. ccexciv., Fig. 954. It is not
strange that Hentz should have supposed it to be the same or near thereto. It is dis-
tributed generally throughout Central and Southern Europe and Northern Africa. A
quite full synonymy may be found in the works of Walckenaer and Simon.

108 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

47, but I have usually been able to determine it, when found without an
occupant, by the following features: The sheeted hub is not as large and the
tissue is not as thick, indeed it is sometimes expressed by only a faint puff,
or simply by a serrated or nodulated cord, as at Fig. 99,1. In short, a well
defined shield seems to be a permanent characteristic of the Basket Argiope’s
orb, while Banded Argiope rather inclines to omit it or express it by zigzag
cords. These cords are often thrown in ares around the hub as at Fig. 99,
ii and iii, and give a pretty and striking effect to the web. However, I must
confess that my confidence in these distinctions is not very great; and to
the untrained observer the differences between the two webs would hardly
be apparent.

It is significant, as illustrating the community and persistence of habit
in a genus, however widely separated, that a spider (Epeira mauritia Walck.)
closely allied to our Argiope
argyraspis is found in the is-

lands of Maurftia,

An Afri- pueoe

Réunion, and Mada-
can Con- z
gener gascar (Africa), with

precisely the same

habits. Vinson! describes the
snare of this aranead with its
peculiar zigzag decorations,
with the X-like position of
the legs as she hangs upon
her snare, and the cocoon in
its site, in language which
might be used with equal pro-
priety of Argyraspis. With
shght change the figure of the
African Argiope as given by
Vinson might stand for a draw-
ing of our American species.
A third species of Argiope, which appears to be the Argiope argentata?
: of Koch, is found abundantly in the extreme Southwest of the
poe United States. I have many specimens from Southern Califor-
fata, nia, where it abounds, spinning its large, beautiful webs every-
where in the neighborhood of San Diego. It extends southward

through Mexico, is widely distributed thoughout the states of South Amer-

Fig. 100. A snare of Argiope argenteola.

1 Araneides des Isles Réunion, &c., page XIIT., 198, and Plate VIIT., Fig. 2.

2 Argiope argentatus, Koch, “Die Arachniden,” t. 5, page 388, pl. 154, Fig. 360. Also
A. fenestrinus, id., Fig. 155. The Epeira argentie (EK. argentata) of Walckenaer, figured
Pl. 18, Fig. 3, Atlas, Apterés, is with little doubt the same spider or a close variety
thereof. Vol. II., Apterés, page 115. I first introduced this species to the Philadelphia Acad.
Nat. Sci. as new under the name of Argiope argenteola. It is possible that the spider will be
found specifically different from A. argenta when specimens can be had for comparison.

ARGIOPE AND HER RIBBONED ORB. 109

ica,! at least in the northern tier. Eastward it has been located in Texas
and at Tampa Bay and Key West, Florida, and is found scattered through-
out the West Indies? and the Caribbean Sea Islands.? Mrs. Eigenmann,
from whom I have notes and specimens, describes the snare of Argentata as
about one foot and a half in diameter. The foundation lines are very
strong; the centre irregularly meshed and the notched spirals eight in num-
ber, the three outermost of the series being about twice as far apart as the
others. The spider rests at the hub of the orb in the position character-
istic of the genus as above described. The snare is decorated with zig-
zag lines and other thickened lines like those of Cophinaria and Argy-
raspis.

One of the specimens sent me, a mature female, survived shipment
through the mail and spun three successive webs for me in a trying box
or jar. In these the hub was sparsely meshed and the orb other-
wise of the usual Epeira character, with one remarkable excep-
tion, which, as it occurred in every one of the three snares
spun, appears to suggest that it may be a permanent characteristic. In
ordinary orbs, it will be remembered, there is an open space or free zone
between the spiral space and the notched zone; but in these orbs of
Argentata sections of the spiral space immediately above and below the
hub were continued through the free zone to the hub. Thus between
radii 1-5, Fig. 100, the spiral lines were prolonged to the hub; and
similarly between radii 10-15 in a position nearly opposite, at the lower
part of the orb, the spirals were prolonged upward. Is this a new
form of orbweb? Were the three successive examples simply abnormal
modes of working in the notched zone, caused by the unnatural condi-
tions under which the web was made? These questions can be answered
only by those who may be able to study the spider in its natural home.
The open section thus peculiarly intercrossed composed substantially the
‘part over which the legs of the spider were spread as she hung upon her
orb. Her abdomen hung free from the hub, to which it was attached by
a thread from one-fourth to three-fourths inch long. The spider's hind
legs clasped successively the radii 1 and 4; the third pair held by a little
pyramidal pull up between radii 1-17 on the side, and 6-7 on the other;
the two fore feet on one side grasped radius 9, and the two other side radii,
13 and 14 respectively, extending well down the spiral space.

Argenta-
ta’s Orbs.

‘Specimens received from Venezuela through the kindness of Professor Peckham.
2 Specimens received from the late Mr. William Gabb.
3 Specimens received from Mr. Charles H. Thompson, Swan Island.

ORWACE Ain: Vou
EPEIRA AND THE WEAVERS OF ROUND VERTICAL WEBS.

iE

Tur orbwebs most frequently seen in the Middle, Northern, and Atlan-
tic States are made by a group of spiders closely related in structure and
almost identical in economy. Among the most abundant of these

Hpeira are the Furrow spider (Epeira strix), the gray Cross spider (E.
Meshed : =e , Bae f Ek
ae sclopetaria), Epeira patagiata, the Domicile spider of Hentz (I.
benjamina Walck.), and Epeira trivittata. Next to these, per-

haps, are Epeira insularis,' and more rarely the Shamrock spider (E.
trifolium). There is little or no difference in the character of the snare
made by these araneads, but Insularis and Trifolium invariably, and fre-
quently Domiciliorum, are found in leafy nests with a trapline attachment to
the hub of the snare. Strix and Sclopetaria and sometimes Domiciliorum
nest in rolled leaves, but do not maintain as decided a trapline attachment.

In the typical orb of these species, represented at Fig. 101,? the hub is
commonly meshed. This is not always so, but in spite of the occasional
exceptions, I regard the meshed hub as a characteristic. One will rarely
fail to identify unoccupied orbs of the type figured as belonging to one of
this group.

The notched zone has from four to six concentrics, rarely more; the
number of radii and spirals varies, but has a pretty strong tendency to
keep about twenty-one. They are found in all manner of sites where in-
sects abound.

The Furrow spider is one of the most numerously and widely distrib-
uted of our indigenous Orbweavers. I have taken it as far north as Mon-
treal and the Thousand Islands on the St. Lawrence, and as far to the

1The Epeira insularis of Hentz and Ep. conspicellata of Walckenaer. I have Prof.
Thorell’s authority (to whom I sent specimens) that the species is quite identical with the
Kuropean Ep. marmorea. I have, however, in the absence of specimens of the European
species, concluded to continue the name of Hentz at least in the two volumes on Habits
and Industry. For the same reason I retain Hentz’s name Epeira domiciliorum, for what
seems to me without much doubt to be Walckenaer’s E. benjamina.

* For the original photograph from which this engraving was made I am indebted to
Mr. Horace P. Chandler, of Boston.

’The average of 11 snares counted was 215, the lowest number was 18 radii, the high-
est 28 radii, and 25 spirals.

(110)

WEAVERS OF ROUND WEBS. eG

southwest as Texas. It abounds along the Atlantic seaboard from Maine
southward at least to Delaware and Maryland; and Hentz found it in Ala-
bama; he named it from the scalloped or furrow lke markings

The on the dorsum of the abdomen. In appearance and habits it
Furrow ne et . i, 's
hider resembles Epeira cornuta of Europe, and is not improbably a

variety of that species.1 If this be so the species has a vast dis-
tribution, and retains its peculiarities in all countries, latitudes, and condi-
tions with undisturbed persistence.

Fic. 101. Typical orb of Epeira. Half tone engraving made from a photograph.

None of our Orbweavers more habitually shuns the light. She is rarely,
except when very young, found upon her snare during the day; but occu-
pies a neighboring crevice, tubular tent, or rolled leaf, concealed within

1T have compared with the habits of E. cornuta as described by Menge in his Prussian
Spiders. The spinning, nesting, and cocooning and general habits of the two well agree.

1 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

which she remains until nightfall. She thus shuns the hymenopterous ene-
mies who hunt in the sunshine, and is in position to capture the night
flying insects, among which chiefly she finds her prey. So per-

Noctur- sistent is this habit that Strix will rarely leave her hiding place by
nal Activ- cae Santee Nae : :
ity day even to take the insects that become entangled in the snare.

When the night begins to fall she may be seen swinging in the air
against the darkening sky, laying in the foundations of her net and spin-
ning her orb. It is surprising how many of these creatures start into
activity in sites where their presence is not suspected. The skipper of a
yacht on the St. Lawrence River, during a fishing trip, complained to me
that the spiders were a great nuisance to him; that he brushed away num-
bers of cobwebs every day, but that in the morning he was sure to find the
vessel again fringed and laced with their webs. He could never make out
where they all came from, or how they got aboard the ship.

I was able to solve the man’s perplexity. A few days before, while
coming down the river in the passenger steamer about twilight, I had no-
ticed my aranead friends dangling from various parts of the boat, engaged
in their tentative efforts at web building. Thereupon I examined the under
parts of the railing and the cornices of projecting parts of the deck, and
discovered a large number of Orbweavers, principally Epeira strix, young

and old, male and female, curled up against the woodwork or

Spider = domiciled in silken nests. I called our skipper’s attention to sim-
Stowa-. 24 & : 5 : :
a ilar localities on his own boat, which were occupied in like man-

ner, and his wonder at once ceased. He had innocently thought
that clearing away the webs had disposed of the weavers. He never imag-
ined what a colony of unbidden passengers or “stowaways” he was carry-
ing, who kept to their dens by day, and at night, when the yacht was laid
up, turned out, spun their webs, and were back to their retreats before the
good sailor men were astir the next morning.

This example illustrates and explains a mystery in spider manners that
has puzzled many housekeepers, viz., “ Where do the cobwebs come from ?”
The query should be, rather, “ Whither do their spinners go?”

When the snare is spun the Orbweaver takes position at the hub with
her head downward. The artists do, indeed, persist in putting her upon

y the web with head upward, but facts are against them. The
Position Qrbweaver never assumes that position except when she turns to
a : run to her nest or to take prey, in which cases she may remain

stationary for a few minutes, but will soon resume her inverted
posture. As the nest or retreat of the Epeiroid is usually above the median
horizontal line of the orb, one would think that the head upward position
would be the safer one as affording an easier approach to her refuge in
case of danger. But on the contrary the naturalness of the inverted
posture appears from the fact that when the spider is within her tent,
as she generally is except at night, the head is then turned downward

WEAVERS OF ROUND WEBS. 113

toward the web. The posture at the hub, therefore, is the natural one
taken when, upon disturbance of the snare, the aranead runs down the
trapline to the centre. Convenience and habit combine to fix the posture
as we find it.

Moreover, the majority of vertical orbwebs have the longer part of
the spiral surface available for capture of insects below the median
horizontal line, a fact caused, as has been seen (Chapter V.) by

aie the corner loops that stretch downward beyond the concentrics.
su file Thus the habitual posture of the spider really gives the widest

Natural, command of the snare,

being the best posture
from which to sally forth against
entangled insects.

Still further it may be said,
that the nest does not necessarily
afford the readiest or even safest
retreat in case of assault by ene-
mies. It is much easier for the
spider to fling herself from the
web and drop to the ground than
to mount to her nest. Not only
is this movement executed with
marvelous dispatch, but, as I can
well testify from my experience
in collecting specimens, the con-
cealment afforded by the grass,
leaves, etc., at the surface is very
complete, especially as the ani-
mal instantly curls herself into
a ball and lies in the foliage FiG. 102. Position of Tee ee hub, to show command
with the rigidity and_ stillness
of death. On the whole the inverted posture of the Orbweaver, however
unnatural it may seem to us, is precisely the one which nature has made
most advantageous to the spider.

The legs of the Orbweaver are rarely, never habitually, I think I may
say, spread out equally over the hub. The two fore feet on each side

are approximated, and spread out from the body at an angle

et more or less acute. (See Fig. 102.) The two hind pairs of legs
mand the "— ae
are similarly placed, although the short third pair is more
Snare. . ;

likely to be extended directly from the body. The approxima-
tion is sometimes so close that the legs are arranged X-shape. If the
claws be closely examined as the spider thus hangs, they will be seen
very generally to clasp the lines of the hub at or near the points where
several radii unite, or to hold on by little pyramidal clusters of threads

114 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

whose basal extremities touch the united radii, the apical ends being con-
verged within the claw. (Figs. 102, 103.) Thus the agitation made at any
point of the snare is communicated through the radii to the feet, made
extremely sensitive by the numerous delicate hairs and spines which
clothe them. The eight claws of the spider, each one of which is in
communication with three, four or more converged radii, together com-
mand the whole number of radii, and through them also the
Under interwoven spirals. By this arrangement Madam Arachne, like
Her Tee . .
Thumb, ® 200d housewife, may be said to have the whole of her house-
hold establishment literally “under her thumb.”

The Orbweaver while thus in waiting is chiefly supported by the
claws, and apparently by those of the hind feet. But the spinnerets also
aid in maintaining the weight, by means of a thread or threads which
may be seen issuing from them and attached to the hub beneath by a
minute white dot of silk.
The frequent formation of
these attachments, as Menge
has observed of Epeira di-
ademata, on the return from
her various excursions after
insects or on housekeeping
duties, sometimes causes the
hub to be dotted over by
white specks, especially in
the region underneath the
spinnerets. This is espe-
Fic. 103. Feet of Orbweaver while in position at the hub, to show cially apparent on a thinly

Hare gio ee net sheeted hub of Argiope.

The Furrow spiders, like others of their genus, are found near running
streams and still water, where the congregations of insects are usually

largest. I have seen multitudes of them upon the railings of

Natural the old Gray’s Ferry Bridge over the Schuylkill before the rest-
Sitesof |, . aeaag =.
Snares, SS Innovations of human creatures had set up the new struct-

ure; and on the famous Long Bridge over the Potomac at Wash-
ington they were domiciled in legions. This species will often be found
upon the shrubbery and trees of yards, lawns, and orchards, and in such
locations frequently selects a site for her snare which forms for it a beau-
tiful background of leaves, tendrils, and flowers. Such an example is Fig.
104, snares spun among lilies and sprigs of coxcomb in a flower garden in
Eastern Ohio. But more than some others of the especial group to which
she belongs Strix is a wood spider. I have often found her in forests,
groves, and fields, building upon the branches and nesting among the foli-
age. In color Strix varies much; the young specimens are often found
quite black; in maturity the prevailing color is yellowish, with. reddish

WEAVERS OF ROUND WEBS. 115

rings upon the legs, and bands upon the cephalothorax. I haye some

adults with whitish abdomens.
Epeira sclopetaria (Ep. vulgaris Hentz), the gray Cross spider, I have
not found abundant in wooded spots, but more frequently near bodies of
water. Immense colonies are domiciled near and upon the boat-

ee houses, taverns, and outhouses at the inlets and boat landings of
sclope- mie é as
a Atlantic City and Cape May, N. J. They grow to great size,
tarla. - : ey,

feeding upon the swarms of green head flies and other insects
that frequent those places. The cellars, open and latticed spaces under the
porches, stables, and out-
houses of the cottages and
hotels of these watering
places are also favorite
resorts. The proprietors
would do well to encourage
their presence and propaga-
tion as at least some check
upon the flies and mosqui-
toes.

In South Carolina, where
Hentz first observed the spe-
cies, she is seldom found
far from the gardens. This
partiality to human homes
he supposed due to the ad-
ditional safety thus afford-
ed from the terrible Sphex,
though on what ground I
cannot conceive. In South
Carolina she is subject to
such variations in color and
markings that it is quite
difficult to distinguish be-

tween these and _= several

Fic. 104. Snare of Epeira strix among the lilies.

other species. Hentz once

found in the nest of a mud dauber (wasp) seventeen variations of this spe-
cies, each differing more or less from the others. In this latitude (Philadel-
phia) I find no such difference as to color, which is a quite uniform gray;
but there is some tendency to variations in the markings of the abdomen,
especially among the young. The species is distributed! from South Caro-
lina northward to Maine, and westward through New York and Pennsylvania
to Wisconsin, including Canada, at least along the St. Lawrence River.

' Of course in all these allusions to geographical distribution it is understood that the
reference is to that known by the author to date.

116 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Closely related to Sclopetaria is the well known species Epeira patagiata.
It is distributed throughout Europe, and is one of the common species of
Syria. Its round snares must have been familiar objects to the
ancient Palestinian prophets, and are as likely as any other to
have suggested the several Scriptural metaphors drawn from the
spider’s web. It is an abundant species in parts of the United States,
especially in New England along the seashore, and in the Adirondacks
and northern sections of New York. I have studied its habits and spin-
ningwork in these parts, and find that they differ in no respect from those
of Sclopetaria. I have little doubt that the two spiders are one _ species,
and indeed one finds it difficult toseparate them into
even two well defined varieties.
Epeira benjamina Walck., the Domicile Spider
(peira domiciliorum, of Hentz), has a very wide dis-
tribution. Hentz found it in Alabama; Em-

EHpeira
patagiata

The ; : :
... erton in New England; I have collected it

Domicile 2 ?

Spider. 12 Massachusetts, Pennsylvania, Canada, New

York, Ohio, New Jersey; and Mr. Peck-
ham in Wisconsin. Dr. Marx has specimens extending
northward and westward from Rhode Island, through
Minnesota, Nebraska, Colorado, to Spring Lake, Utah ;
and southwest as far as Fort Graham, Texas. It thus
has been traced over the entire United States to the
tocky Mountains. In Colorado it has a vertical dis-
tribution of 12,000 feet. In the South, Hentz says
that she is often found in dark places, and even spins
her web in dark apartments not much frequented. I
never found the species, though abundant in this
latitude, in any such sites—but usually upon bushes

Fic. 105. Temporary ribbon : i
central of Epeira domicili- and trees, in yards and woods, commonly bright and

orum.

sunny places. In one case I found several adult fe-
males hanging upon their large webs, which were spread against a frame
house, in the full blaze of a September sun. They kept the position
throughout the entire day. Such a difference in habit is certainly note-
worthy. After a heavy summer shower I once found two webs of this spe-
cies temporarily marked by what is a quite fixed characteristic of the webs of

Argiope. (Fig. 105.) Below the hub the notched zone was crossed
Tempo- by a disk of thick, sheeted silk which extended downward be-

rar Fe i oe ;
See tween two of the radii, uniting them. A similar band united
Decora. two of the radii above the hub. I conjectured that these had

tions. been thrown out from the spinnerets to strengthen the web

against the weight of the rain; or as a protection, a sort of
umbrella, between the spider hanging on the side toward the bush and
the shower driving from the opposite quarter. Several specimens of Epeira

WEAVERS OF ROUND WEBS. 117

trivittata were found with a like peculiarity in Connecticut. Yet, I cannot
regard it as other than incidental.

One might indulge the conjecture that this accidental feature of a
snare of Enpeira offers a clue to the reason for the permanent features of
a like character upon the webs of Argiope, Acrosoma, and Uloborus. The
difference or differences which have caused the characteristics to become
fixed in the last named genera are at present unknown. I venture only
to suggest that my observation shows that these genera quite habitually

remain upon their orbs continually, whereas the

Domicile spider and her 2M, congeners usually retire
from their orbs in day YA

\

time, and have nests or
dens to which they can resort in foul weather or
in case of attack. I have frequently found Domi-
cile in a leafy tent, but oftener without one; her
habit in this respect seems to connect Sclope-

taria whom I have never seen in such an abode,

Bee
ZN

Ss:

FiG. 106. Nest and snare of Epeira insularis.

and Insularis who is always so found. On one occasion while driving
along a New Jersey road, I observed an orbweb spun upon the tall grass
beneath a young tree. The foundation lines and supports reached upwards
to the lowest branch, about twelve feet above the surface. Having climbed
out upon the branch I observed a spider nested within a curled leaf and
holding to a trapline that extended entirely to the orb beneath, the longest
trapline I remember ever to have seen. ‘The nest was collected and the

; occupant proved to be Domiciliorum. Closely related to the Dom-
Epeira

Aare icile Spider is Epeira trivittata. ‘The two are very similar in gen-
trivittata. a I :

eral appearance and markings, the latter, however, being some-
what smaller. Their webs and general habits are the same.

118 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

In the group of Epeiras with hub meshed snares, the most remarkable
in appearance is Epeira insularis. The bright yellow markings upon the
back of the abdomen, and the orange legs with their brown rings
The Insu- distinguish her as one of the most beautiful of her genus. She
ae attains even greater size than Strix and Sclopetaria, and in the
insularis, late summer and fall, when the female is full of eggs, appears
quite formidable. Hentz named her from the fact that he dis-
covered her upon an island of the Tennessee River. She is however widely
distributed, having been traced as far south as Georgia and South Carolina,
through the great Middle-Western and Middle States, as far to the northwest
as Wisconsin, and throughout New England. She is very abundant in Ohio,
Pennsylvania, and New Jersey, in woods, groves, and out grounds, and invar
riably domiciles upon shrubs, bushes, and bushy trees, commonly choosing
a well elevated site, within seven or eight feet from the ground. If we
admit the identity of this spider with the European Epeira marmorea, the
distribution is vastly widened, and this fine species must be enrolled among
those which probably inhabit the entire northern hemisphere.

The snare of the adult is a large orb of the type heretofore described ;
several measurements of which are as follows (in inches): 13x11, 14x14,
20x14, 14x14, 8x6. That which especially distinguishes In-
sularis from the foregoing group is the well nigh unvarying habit
of living in a nest of rolled leaves situated above the orb, and
attached thereto by a trapline. This varies in length according to the
size and situation of the snare; it will frequently be found about seven
inches long. At one end it is held by the spider’s outstretched claws as
she sits within her tent; at the other end it is fastened to or near the
margin of the hub, or notched zone, by a little delta of diverging termini.
These slightly pull up the centre of the web and thus tighten the radi;
the traphne itself being held quite taut, the motions of struggling insects
are readily communicated to the vigilant watcher within her leafy sentry
box. Just beneath the nest, and serving to brace it, may often be found a
wide and irregular netting of lines, communicating with surrounding objects
but rarely extending far downward toward the snare.

The Shamrock spider, Epeira trifolium, received its name from the tri-
foil or clover like markings upon the back of the abdomen, which is a

whitish, whitish gray, or purplish color. The legs in the typicat

Snares of
Insularis.

ae form are ringed with black, and most species are so marked, but
1am- F 5 : 5
Oe I have taken specimens in which the legs were a uniform orange

Spider, Color. The abdomen of the adult female becomes strongly marked,

especially along the sides, with bright red. One individual was
collected whose abdomen was quite white, but after a period of confinement
gradually turned to a dull brown. Another was well marked with black
patterns, but also finally came out with shades of red and yellow. The
Shamrock spider is somewhat more robust in form than her above named

WEAVERS OF ROUND WEBS. 119

congeners, 1. e., the abdomen more nearly approaches a globular shape. In
Massachusetts I found one specimen with a white abdomen ; two with yellow
abdomens; one with bright strawberry or burnt sienna marks; one Tri-
folium that was blackish, the markings on the abdomen being white or
silvery. These were all found in nests of several leaves, fastened together
in the ordinary ways. A similar variety in coloring characterized specimens
found in huckleberry patch-
es and wooded hillsides just
back of the bay, at Niantic,
Connecticut.

In habit and spinning-

work Trifolium resembles
Insularis, living in a curled
leaf with a trapline attach-
ment to her snare.t Hentz
in his description, based
upon a specimen from
Maine, says that the spi-
der is found in houses and
near dwellings. Mrs. Mary
Treat reports the same
characteristic of the indi-
viduals seen by her in New
Hampshire. On the con-
trary I have rarely found : : :
a specimen except in the [QRZ am SAN 6 jy (lil
open fields or among shrub- Ls !
bery and often quite remote
from human habitations.

A summer (1888) spent
on Cape Ann, Massachu-
setts, gave me an admir- .
able opportunity to ob- . /

Se
Ww
hy

BM) HIF) i ‘oS
aia il
\M it

serve the habits of this Fic. 107. Orb and nest of the Shamrock spider, Epeira trifolium.
species. Those who are
familiar with New England hedge rows know how they are

Tents in .
Hodes formed ; granite boulders and blocks, brought from the meadow
Bowe, or elsewhere, are piled along the boundaries between field and

road into low stone walls or fences. On either side of these
walls grow in unchecked profusion the native plants and wild flowers of
New England. There are shrubs of various sorts, golden rod, great ferns,

1 Fig. 107, measurements: Orb, 14 x 14 inches; hub, 1 inch; notched zone, $ x 4 inch,
irregularly placed; 4 notches below; central space nearly 3 inches. Vineland, N. J., on

the bank of a run.

120 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

red raspberries, countless bushes of wild roses in full bloom, elder with
its white blossoms or purple fruit clusters, and many other flowering plants,
intermingled with weeds and grasses. This interesting bit of tangled plant
life is a favorite camping ground for innumerable spiders, among which I
found in August many of the leafy domiciles of Trifolium.

This species lives from Maine southward; I have found it in Massa-
chusetts, New Jersey, Pennsylvania, and Ohio; and have specimens as far
to the northwest as Wisconsin. Dr. Marx’s specimens carry her range to
Bismarck (Dakota), Minnesota, Colorado, and Wyoming. Its distribution is
probably coterminous with that of Insularis although possibly more limited
southward. Trifolium closely resembles the European Epeira quadrata both
in appearance and habit. It is not at all unlikely that they may be regarded
by future students as simply varieties of one species. There is indeed a very
close relation between these two species and Epeira marmorea, and the entire
trio might without violence be classified as varieties of Epeira quadrata
Clerck.

Among various species sent me from California is one which I have
heretofore described as Epeira vertebrata.’ It is evidently a very common

species on the Pacific coast, judging by the number of repre-

meee sentatives always found among collections from that quarter.
verte-
Baars A few notes as to its habits were sent to me by Mrs. Eigen-

mann; but a fortunate event enabled me to study the species
on my own premises. Mrs. Smith sent me from San Diego, in the month
of May, 1888, a number of cocoons from which hatched out a vast colony
of young. These I placed in an arbor in the manse yard, hoping that
they might there become domesticated.

I was surprised to see how slow they were in leaving the home nest,
clinging fast to the cocoon, and then in little clusters above it for more
than a month. I left my home for a summer vacation on the 8th of
July, at which time the young Vertebrate were still hanging in clusters
and apparently had not grown a particle. I returned September Ist, and
found five full grown specimens, all females, comfortably domiciled in dif-
ferent parts of the yard on honeysuckle and ampelopsis vines. Three of
them were quite near each other, within a few feet of the spot where
the cocoons hung. Other individuals may have migrated into adjoining
premises, but these five remained with me and gave me quite full knowl-
edge of their spinningwork. The following year a number of young
appeared, and it is not improbable that the species may become perma-
nently fixed in this section.

Its snares are identical with those of the Domicile spider, and in
its general habit it differs little from that species. It occupies a leafy
nest for much of the time, but not so persistently as Insularis and Tri-

! Proceedings Academy Natural Sciences, Philadelphia, 1887, page 342.
oS ’ ’ b, oD

WEAVERS OF ROUND WEBS. 121

folium. The nests, moreover, were not as carefully formed as with those
species. Vertebrata makes its orb early in the evening, and thereafter
hangs to it pretty closely, unless disturbed. The traplines by which the
webs are connected with the nests are much deltated at the point of
union with the hub, and diverge at the point where they are united
with the nest. So that the spider, instead of clasping a single line as is
usual with Trifolium, really has its feet upon several lines. I have seen
this peculiarity in traplines of Domicile spiders that had spun on iron
fences. Vertebrata appears to be a very diligent weaver, working with
steadiness and energy at the daily renewal of her snare, until early Oc-
tober. She then begins to show less activity; the sluggishness increases
rapidly, the webs are rarely renewed, and
soon the spiders disappear within the
leaves and die.
Epeira displicata is an interesting little
spider which makes a round web, usually
somewhat inclined. I have found

Epeira it in New England, woven against
displi- : 2

a leaf whose edges were curled
cata.

up and formed the support for

the foundation lines. I know little of its
general habits, but it is distributed quite
extensively throughout the United States.
Among the most interesting of our
spider fauna is that group of the genus
Epeira which may properly be

Diadem

ee ee termed the Angulata_ group.
i The individuals are distinguished

Spider. als ¢ stinguis

by two processes, more or less de-
cided and pointed, upon the base or front Fic. 108. Snare of Epeira displicata. From
part of the dorsum of the abdomen. They ne Eee ee
are situated near the margin and overhang the sides and the cephalotho-
rax. They are not hard or leathery like the spinous processes upon Acro-
soma and Gasteracantha, but have nearly the consistency of the abdominal
integument. To this group belongs the Diadem Spider, Epeira diademata,
so familiar in European landscapes, and known popularly as the Cross
Spider or Garden Spider. I have specimens of this species collected in the
United States, one as far to the north and west as Minnesota. The spider
undoubtedly has found lodging upon our shores, probably as an importa-
tion by immigrants from Europe, but is very rare as yet.

Others of this group are Epeira gemma, a fine large species, which
inhabits the Pacific slope, and as far eastward at least as Utah; also
Epeira cinerea, a large gray species, in many respects resembling E. gemma,
which ranges the Northern Atlantic slope and the Adirondack Mount-

2 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

ains.t To the same group belong Emerton’s Epeira sylvatica, and my E.
bicentennaria. The species are closely related to each other and to the
European Epeira angulata and E. bicornis. Systematists may
hereafter unite them all into two or three species. The habits of
the entire group, as judged by the species which I have studied,
are like those of Insularis and Trifolium as above described. They dwell
in silken tents or nests of rolled leaves, and spin webs of the type shown
at Figs. 101 and 107.

Epeira stellata is remarkable for the formation of its abdomen. Around
the sides are inserted a number of spines, one of which projects promi-
nently over the cephalothorax, which gives the creature a striking and
weird appearance. I have taken it, especially the young, in Pennsylvania.
New Jersey, and Connecticut. In the last named State numbers of the
species were seen occupying orbicular snares, which were spun low upon
grass, ferns, and golden rods on the margin of a meadow near a_ stone
fence. They were of the general type of that group of
which Epeira strix is a representative. The spiders hung
at the centre with legs bunched up against the body, the
half grown individuals looking like seeds of certain plants.
The dull grays and grayish browns of its color helped to
make it inconspicuous against the background of the brown-
Fic. 109. Figure of ing foliage on which their snares were spun. At the least

Radteracantha, "disturbance the spider dropped suddenly to the ground, or
ran for refuge to the fohage at one end of the web.?

Among the Orbweavers constructing full vertical orbs is Gasteracantha,
a spider whose remarkable shape has attracted the attention, of many ob-
servers. Fig. 109. I have received numerous specimens of Gaster-
acantha cancer, and perhaps several varieties of the same, from
Mrs. Rosa Smith Kigenmann, which were collected in the neigh-
borhood of San Diego, California. On the Mesa land near the Mussel
Beds, and also along the bay shore in that vicinity, a great number of
specimens were found. The orbs of the spider were usually spread at a
considerable angle, occasionally nearly horizontal, and sometimes almost

Angulata
Group.

Gaster-
acantha.

*It was first made known by me in the Acad. Nat. Sci. Phila., under the name Epeira
harrison, after the lady from whom Mrs. Mary Treat (who sent me specimens) received it.
Emerton subsequently gave a detailed description and obtained priority.

*The measurements of one snare of an individual about half grown are given as fol-
lows: Orb, 63 x 6} inches in dimensions. Central space, 1} x 1}. Notched zone and hub,
{ inch in diameter, of which the hub itself was 33, inch. The notched zone contained 8
spirals. The hub was slightly meshed. From the notched zone to the spiral space the dis-
tance was 4 inch. The interspaces between the last 3 spirals of the notched zone were
much larger than those of the rest of the series, being ;, inch. The spiral space itself cov-
ered from 3 to 33 inches. The radii numbered 35. The spirals were 26 below, 20 above,
and 21 at the sides of the hub. Another web was 5 inches in diameter, and was nearly
round in shape; had 18 radii and 18 to 19 spirals.

WEAVERS OF ROUND WEBS. 123

perpendicular. The heavy spider hanging on the under side of the close
meshed hub pulled the net down at its centre as the snares were swayed
by the wind. The upper foundation lines were quite strong and usually
of great length, being from three to five feet, and in one case twelve feet
long. The orb itself is often about eighteen inches in diameter, and is a
conspicuous object to one driving by it upon the road. The concentric
spirals are numerous and placed in with great beauty and regularity.
They extend entirely around the snare, giving it a more circular appear-
ance than is common with
those webs which have
looped spirals below the
hub, thus giving the orb
an elongated form. For
the most part the hub is
closely meshed, but in one
case was found open.

My own observation of
the snare of Gasteracantha
is limited to a single indi-
vidual seen in Texas in
the neighborhood of Aus-
tin. This web was spun
within a triangular space
of two feet or more in
length from top to bottom.
This space was marked off
by foundation lines, which
were decorated in a pecu-
liar manner, as represented
in Fig. 110. This decora-
tion consisted of tufts of
flossy white silk from one-
eighth to one-fourth inch
long. They were spread
along the outer foundation lines throughout nearly their entire length.

Fic. 110. Snare ot Gasteracantha, to show the flossy tufts.

Several were also placed on the two inner supports of the orb. Two
radii, one above and another below the centre, were similarly

ates decorated, and several tufts were grouped around the hub, which
ufts on — : : ‘ :

was open. The number of these flossy tufts on one foundation
Webs. I .

line was twenty-one; on the other fifteen. The spider hung at
the centre of her web, which was vertical, and consisted of twenty-three
radii regularly crossed by spirals, many of which presented the deltated
appearance usually produced by the capture of insects. The figure here
given is drawn simply to indicate the exact position of the flossy tufts

124 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

and of the orb within the triangular foundation lines. The other details
are only approximately accurate.

My notes do not show the complete form of the web, but Mrs. Eigen-
mann’s observations abundantly establish the fact that the orb of Gaster-
acantha has the notched zone and free space as is the case with the webs
of Epeira, which it closely resembles. None of the California webs, how-
ever, had anything like the tufted decorations which I observed in the
Texas individual. Whether or not other examples in the same vicinity
exhibit the peculiarity which I have described I am not able to say.!

The interest in the problem here presented is much increased, although
the problem itself is brought little nearer solution, by facts concerning the

snares of this genus recorded by M. Vinson.? He observed the
African same characteristic noticed by me in the Texas example, in the
Sey cer webs of Gasteracantha bourbonica of certain African islands.

This spider spins a vertical web a metre or more in diameter.
The snare is often suspended across the path in forests. The threads are
different from those of other spiders; they show little cottony tufts (ren-
flements cottoneux) distributed at intervals, but quite nearly approached.
The spider hangs at the centre. She is active when she moves; but when
one touches her she throws herself from her place, holding on by her
thread, by the aid of which she is able to replace herself upon her snare.

In another part of his book M. Vinson records the same observation
in this language: The Gasteracanthe of the Isle of Réunion introduce
into the variously stretched lines [foundation lnes]|, in the midst of which
they establish their regular nets, a finishing-up (“confection”) altogether
special. As these lines are isolated, quite separated one from another,
they are differently wrought from those of the interior net, and show at
short intervals little cottony puffs (“renflements”) which cause them to
appear as though interrupted from point to point. These puffs give the
web, of necessity, very great strength and elasticity.®

The same author, however, introduces another observation upon this
species, which brings us face to face with the same curious diversity, if

not divergence, in the habit which I have shown in the Gas-
Webs teracanthe of our country. M. Vinson declares that the Gas-
Without k 5
Tufts. teracanthe of Madagascar, which are both larger and more

numerous than those of Réunion, do not follow the custom of
decorating their webs with cottony tufts as do those of the last named is-
land, but spin their vertical snares in a manner altogether similar to those
of the common Epeira.

‘As I was at the time intent upon the study of the natural history of the agricultural
ants, I was compelled, often at great sacrifice of my feelings, to resist the attractions every-
where around me to observe and seek out the habits of the spider fauna.

* Araneides de la Réunion, Maurice, et Madagascar, page 238.

% Op. cit., Introduction, page xvii.

WEAVERS OF ROUND WEBS. 1295

How shall we reconcile or explain these strange unities and diversities?
It might be said, in view of the numerous observations made by Mrs.
Eigenmann in California, that my own description of the Texas species,
which was based upon observation of a single web, was that of an abnor-
mal act, a freak, an accident, an individual peculiarity. When, however,
we see spiders of the same genus, so widely separated in their habitat,
presenting in both America and Africa on the one hand the same curious
habit of web decoration, and on the other the same adherence to the nor-

yp sM “We Rt wn A
TTR SE SAR
i AN

nN

WO
Ni i TAU Sy
| FL

Fic. 111. The orb of Acrosoma rugosa. The outline of the entire frame is shown at the right.

mal type of snare, it seems impossible to account for the web observed by
me on the ground of a freak or individual peculiarity. At present I can
only record the facts, without venturing to suggest a theory to explain
them. I am not even able to say what differences, if any, may exist be-
tween the species which spin the several webs. The difference is certainly
not very great. A future observer will doubtless find a simple explanation
of the phenomenon; and whatever it may be it will probably be found
similar to that which causes individuals of Argiope and Acrosoma to twist
and string ribbon decorations around the central parts of their orbs.

126 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

ine

The third group of Orbweavers making vertical webs is composed of
those which retain the open hub. Among these are our indigenous species
of the genus Acrosoma. These are found in the neighborhood of
Orbs with Philadelphia, and are distributed very generally throughout the
oe Middle, Northern-Middle, and Southern States, east of the Rocky
Mountains. The favorite site for their snares is a large open
space between two bushes or trees, or between the diverging branches of
the same. I have most frequently found them in the margins of an open
grove, wood, or forest. As a rule they swing their nets at a considerable
height, so that one’s face comes in contact with them while passing through
the woods. The foundation lines are frequently of considerable length, four
or five feet, or even more. The delicate orb swung between them is a very
pretty sight as one sees it outlined against the sky, showing through the
vista of the opening trees. (Fig. 111.)

The three species common to our neighborhood are Acrosoma rugosa,
spinea, and mitrata.! They are all characterized by abdomens which present
upon the dorsal surface spines of greater or less length and hard-
ness. ‘These spines are more decidedly developed upon the first
two named species. In the last named species, the Mitred spider,
the spinous processes are small, and the integument is not so tough.

All the three species make substantially, and I might say almost pre-
cisely, the same sort of web. The shape of the snare is usually quite orbic-
ular, nearly always approaching a circle more nearly than that of most
species of Orbweavers. The number of radii is very great, amounting at
times to as many as eighty, and the number of spirals is corre-
spondingly large. The orb itself is not very large, generally
being within six inches in diameter rather than above. It re-
sults, therefore, that the spiral space presents a remarkably close texture of
checkered openings between the cross lines. The free zone, which in the
typical Epeira net contains no lines crossing the radii, is always occupied
in this genus by the lines of the notched zone, which wind in three or four
comparatively widely separated concentrics through the entire free zone.
These take the place of the notched zone of the Epeira orb, whose con-
centrics are wound close up to the hub.

The hub, as has been stated, is always open, and within it the spider
is usually found hanging with its legs outstretched, grasping the marginal
circumference of the hub. Spinea and Mitrata hang in a position closely
resembling that of the ordinary Epeira, that is to say, with the head

Favorite
Sites.

Character
of Orb.

1 As I have heretofore shown (Proceed. Acad. Nat. Sci. Philada., 1888, page 5), the names
of these species as given by Walckenaer are entitled to priority. They will probably be
known respectively as Acrosoma gracilis (rugosa), A. saggittata (spinea), and A. reduviana
(mitrata).

WEAVERS OF ROUND WEBS. 12

downward and sustained by the feet, the difference being, as already noted,
that the Epeira clasps with her feet the meshed terminations of the radii
within the hub, while Acrosoma supports herself by the margin of the open

hub. In the case of Rugosa, the method is
the same but the position of the spider a little
different. 'The two hindermost legs are clasped
to the upper margin or to the bit of ribboned
lace that frequently runs upward from the hub
of the spiral space. The back or dorsum of
her abdomen thus hangs towards the ground.
The spinnerets are turned upwards and _ assist
to support the spider by a little dragline. The
head in this position is of course depressed,
and at an angle say of forty-five degrees, more

or less. She supports this part of her body not
only by the first and second pair, but
also by the third pair of legs, which,
contrary to the custom of Orbweavers
generally, are thrown forward on either

Position
of Third
Legs.

side of the face. Generally the third pair of F'6. 112. Acrosoma mitrata suspend-

legs is correlated with the

5 ed at the hub of her orb.
fourth pair, and

the second with the first, but here the third is associated with the first two.
The fact is doubtless in some way connected with the peculiar

Long
Fourth
Legs.

character of the fourth legs, which in the genus Acrosoma are as
long as or longer than the first legs. The length of the fourth

pair is an evident convenience to the spider when walking; for
the ventral part of the abdomen is an inverted pyramid or cone, at the apex

Fic. 118. Acrosoma spinea in position
at the hub of her orb.

of which the spinnerets are placed. The ad-
ditional length of the fourth legs thus serves
to raise these organs above the ground as the
spider moves. ‘The same reason, viz., the
length of the fourth legs, together with the
open hub, influences the position of the third
legs. These organs are not long enough to
clasp the marginal ring of the hub near the
feet of the fourth legs, and as there are no
cross lines in the hub to grasp as in the case
of Epeira, they must necessarily seek the
nearest place of rest, and thus are stretched
straight out from the body to the side of the
hub, as is common with Mitrata (Fig. 112)

and occasionally with Spinea; or else are bent forward in the direction of
the first and second pairs, and grasp the circumference of the hub, as does
Rugosa habitually and Spinea frequently. (Fig. 113.)

128 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

In the same group with Acrosoma, among the spiders haying an open
hub and vertical snare, may be placed Cyclosa caudata or the “Tailed
Spider,” and her closely related congener of Florida, Cyclosa bifurca. The
snares of this species are never very large. They are hung, as a rule,
within a system of secondary foundation lines, as represented in Fig. 111,
thus giving them, as with Acrosoma, a considerable degree of elasticity.
The spirals of the notched zone, instead of clustering close around the
hub, wind through the free space, and the number of radii and beaded
spirals is usually very large. The hub in the normal condition is open,
and the spider may be found hanging therein with its feet attached to a
ribboned string which extends upward through the free zone. The ribbon
runs below the hub as well as above it, and the two bands are fre-
quently connected by an irregular strip of spinningwork, thus giving the
hub the appearance of being meshed or even sheeted. It is, however,
properly placed with the group with open hubs, to which I have here
assigned it.

A striking peculiarity of the Tailed spider is to attach her cocoons to a
line extending upward from the hub to the circumference of the orb. In
accomplishing this the surrounding spiral lines and sometimes one
or two of the radii are cut away, giving to the snare the appearance
of the sectoral orb made by Zilla. This, however, is simply an
accident of the cocooning habit. The species has also the custom of hang-
ing flossy pellets of silk upon her orb at various points; and these are
often to be found mingled with the remains of devoured insects. This
habit is common among very young specimens of Caudata. In the mature
spiders the detritus of insect remains is attached to the cocoon. This habit
is considered at length in Vol. II. in connection with Maternal Instincts and
Industry. I have occasionally seen similar nodules placed upon the snare of
Acrosoma rugosa, but the habit does not appear to be fixed in that species, but
in Caudata it is permanently established.

The genus Meta has its chief representative in the geographical district of
Philadelphia, and indeed throughout the Eastern United States, in the species
Meta menardi. The snare of Meta does not differ from the full
orb webs of Epeira. Meta segmentata of Europe, according to
Cambridge! invariably spins her orbicular snare at an inclination
to the plane of the earth; he had never found one extended perpendicularly.
The hub of the orb is open, in this respect approximating the snares
of the spiders which make horizontal webs. Like Tetragnatha extensa,
it has the habit of extending the first and second pairs of legs in a line
with the body. This species is quite catholic in the selection of its orb
site, as there is scarcely a conceivable situation among herbage, bushes,
heather, on heaths and commons, where it may not be found.

Peculiar
Habits.

Meta
menardi.

1“Spiders of Dorset,’ Vol. II., page 241.

WEAVERS OF ROUND WEBS. 129

Another European species, Meta merianze, approaches in the general trend
of its habits our Meta menardi. This spider is found in the corners and
windows of outhouses, verandas, and greenhouses, also under overhanging
banks and rocks, and in other damp, dark situations. This quite accurately
describes the habit of our Meta menardi. I have found the webs at the
foot of the Allegheny Mountains in Central Pennsylvania, quite generally in
dark and shady positions. Indeed, I collected quite a number of species

_ within Sinking Spring Cave. These had established their snares
asain "from one to two hundred feet from the opening of the cavern,
and had swung them against the face of the rocky sides. From
the point at which I collected the spiders, I could see the mouth of the cave,
which is not large; and beyond it the dim light of the ravine through which
it is approached. But no light penetrated to the spot, at least not enough
to make it possible for me to collect specimens or examine the snares. My
observations were made by the light of a torch. I found a few specimens
in sheltered positions outside the mouth of the cave. It is probable that
the spiders drifted within the cavern when they were young, or may haye
floated within it upon the waters of the stream that enters it. But it is
evident that a location within such a darkened domicile is agreeable to this
aranead, and a tendency to this habit is manifestly a characteristic of the
genus Meta.

According to Emerton Meta menardi lives in cayes and other damp
and shady places in New England, and he reports specimens obtained from
caves in Kentucky and Virginia.! It is thus manifest that through
a wide extent of territory, the habits of the species preserve the
same characteristics.

Blackwall describes the species under Walckenaer’s name, Epeira fusca.?
Emerton, following Thorell, accepts the specific name menardi of Latreille.*
If, therefore, we accept the American and European species as substantially
' the same, we shall find that this tendency to seek obscure places characterizes
both the American and the European species. Blackwall says that in
North Wales the principal haunts of the species are caves, cellars, over-
hanging banks, and other obscure places.4

Loving
Darkness.

'“New England Epeiride,’ Transactions Connecticut Academy of Arts and Sciences.
Vol. VI., page 328.

* Hist. Nat. des Insect. Apt. Vol. IL., page 84.

3 Gen. Crust. et Insect. Vol. L., page 108.

+ Spiders of Great Britain, page 259.

OCHEACE n= Wak:
COMPOSITE. SNARES AND SECTORAL ORBS.

il

In the following chapter I have placed the spinningwork of two groups
of Orbweavers that appear to me, in spite of some marked differences, to
haye many points in common, namely, those which habitually make a
composite snare and those which spin an orbweb, lacking one sector. Com-
posite snares combine the round web of Orbweavers with the netted maze
of lines which marks the typical Retitelarian. Two spiders which most
prominently associate with their
own snare that of the Lineweavers
are Epeira labyrinthea and E. tri-
aranea. Of these two, the habit
is most permanently fixed in the
former, which is rarely,
if ever, without its maze,
while with the latter it
is sometimes very scant.
Triaranea’s orb is habitually sec-
toral, Labyrinthea’s snare inclines
to the orbicular, but, as will be
presently shown, appears to be a
transition form between the orbic-
ular and sectoral. In the meth-
ods on which it is®constructed it
properly is grouped with the sec-
toral orbmakers.

The web of the Labyrinth spi-
der is perhaps the most remark-
able example of the composite

Fic. 114. Snare of the Labyrinth spider, seen from behind. gyare. Its orb is spun at one side
The leaf tent is shown in the maze.

The Laby-
rinth
Spider.

of a mass of yariously crossed

lines, designated as the maze or labyrinth, from which it is separated

by a small but quite distinct space usually of about an inch. To the

centre of the orb is attached the trapline, a ray of several threads which
(130)

COMPOSITE SNARES AND SECTORAL ORBS. 131

slants upward into the labyrinth to the point where the spider is domi-
ciled. The domicile is a small, bell shaped, silken tent, which is usually
protected above by a withered leaf; or is simply a slight silken canopy
spun within or against the lower end of the leaf. In the cocooning
season this shelter tent is sometimes spun against the lowest one of the

Fic. 115. Labyrinth spider’s snare, to show the maze of intersecting lines above the orb.

several cocoons which the spider habitually makes. (Fig. 114.) The retite-
larian snare or maze of netted lines, which happily suggested
The Laby- Fie

rinth, of . . : ee
Timon side of the orb, which it somewhat overlaps. It is irregular in

ntz’s specific name, labyrinthea, is situated above and to one

shape, but often rudely pyramidal, sometimes making a bulk of
spinningwork from ten to twelve inches wide and high, and six to eight
inches deep. For example, Fig. 115, a snare spun in a fir tree measured

ile) AMERICAN SPIDERS AND THEIR SPINNINGWORK.

twelve inches wide, twelve inches high, seven inches deep. The shape and size
are of course modified, as with all webs, by the particular features of the site.

There is a decided space between the labyrinth and the orb, except
that the orb is, with rare exceptions, attached above by its foundation
lines to the labyrinth. This is seen in the side view shown at Fig. 116.
The spider is there nested under one of her cocoons. The side attachment
of the orb is apt to be upon some of the long guy lines by which the laby-
rinth is held in form. It generally extends downward as far as the middle,
or a little below the middle point of the orb.

The maze serves its little proprietor and factor
the following uses: First, it is environment and
support for her tent; second, it gives convenient

points of suspension for her orb; third,
erties it provides a safe and convenient nur-
rinth, ‘ery within which to hang her cocoons ;
and, fourth, proves an admirable field
upon which the young can find exercise and for-
age. I have seen the little fellows, late in the
season, scrambling up and down among the inter-
lacing lines, picking out here and there minute
entangled imsects. Fifth, the labyrinth serves as
a true snare as well as domicile for the adult
spider, for I have seen her capturing small insects
that had been caught within the maze, cutting
through the lines for that purpose. Her chief
dependence for food is, however, upon the orb.
wees Moreover, sixth, the labyrinth must have value as

Fic. 116 Side view of Labyrinthea’s : : .
snare, to show the space between & protective environment for the occupant against
orbhand tener: raiding mud dauber wasps and other enemies, and
for her cocoons against various parasitizing foes, since the tangle of crossed
lines certainly raises a formidable barrier against approach of winged in-
sects. It might be added, seventh, that in the pairing season the males
appropriate the labyrinth for purposes of temporary rest in their gradual
approach when courting the female. They pull down the lines by their feet
as they hang back downward until they form the ribs of a sort of araneal
groined arch. I haye seen three males hanging upon one web at the same
time. Labyrinthea rarely makes great changes in this portion of her snare,
although the orb, as is usual with Epeiroids, requires frequent

5 vicelal renewal. Indeed, the maze has greater natural strength than the
of the

Laby-
ane pletely beaten down and dissolved the latter did not affect the

former, and in such cases the occupant abode within her reti-
telarian bounds for a day or two without reproducing the orbweb.1

orb, for I have observed that winds and showers which had com-

'On this point see further in the chapter on Engineering Skill.

COMPOSITE SNARES AND SECTORAL ORBS. 133

The orb of Labyrinthea is a delicate and beautiful structure. It is not
large in size, usually measuring six or seyen inches at the longitudinal axis
and five or six at the lateral. The largest web I ever saw was
twelve inches in diameter.' Within this space are disposed a
large number of finely spun radii and spirals, the former some-
times numbering as high as seventy-five, the latter exceeding eighty. The
spirals, as is common in orbwebs, are more numerous below than above the
hub, but this difference is very marked in the web of Labyrinthea, some-
times being as great as three to one, and even six or seyen to one.? The
spirals in the lower part of the orb are not complete circles, but are looped
in, the lines terminating at the sides. This feature is sometimes seen
in full orbwebs, and is habitual in sectoral orbs. (See Fig. 121.)

The diminished number of spirals at the top of the orb is in part
due to a peculiar feature of the snare, which at least suggests that com-

bination of characteristics of full orb and sectoral orb al-

The Orb
Described

ay ready alluded to. This fea ture results, first, from the posi-
tral Space tion of the spider's domicile behind the orb, making it nec-

essary that the
the snare in order to give
its outer surface ; and, sec
direction of the trapline
opening than would oth
is illustrated at Fig. 117,
of the orb from behind
view to the connection
hub, and its relations to
seen that the unbeaded
zone are cut off above, leaving a triangular open
space somewhat like the aia aE ace free radius of a sectoral
orb. This opening is larger or less according
to circumstances; it may be increased by the trapline impinging upon
the spiral space, thus leaving but a few continuous spirals at the top of
the orb. The spider when seeking prey runs through this opening, under-
neath the overspun arch of spiral lines, to the outer face of the orb upon
which the insects are ensnared. It returns along the same path to the
tent with the captured insect.

trapline should penetrate
the spider admission to
ond, from the slanting
which compels a_ larger
erwise be required. ‘This
which shows the centre
and above with a special
of the traplne with the
the spirals.? It will be
spirals of the notched

OTRO

‘The following measurements in inches show ordinary sizes: 7 inches long by 6 wide ;
Grxsor GrxdO 9x 736 x 4s 12 Le

2 The following counts will illustrate this: No. 1, radii, 55; spirals, 81 above, 82 below.
No. 2, spirals, 8 above, 55 below, 47 at the sides. No. 3, radii, 75; spirals, 80.

’ Measurements of Fig. 117, orb 9 in. long by 7 wide; hub } in. long, { wide; centre
of hub 2} in. (about one-third the length of the orb) from the top margin of the orb.
The hub is meshed, oval, narrowed at the top. The notched spirals fill the Free space,
three being close to the hub, the others widening as they wind. Traplines about 24
in. long.

134 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

The trapline of the Labyrinth spider differs from that of Trifolium
and Insularis in being composed of several threads instead of a single
line. Fig. 118. These threads usually diverge at the nest, with
which they are united, and again sometimes at their attachment
to the hub. Most frequently the trapliné is a ray of threads
converging upon the hub. The hub is characteristically meshed (Fig. 117),
the sides of the meshes being in part the ends of the radii as continued
within the hub, where they are of course greatly contorted. This feature
is also observable in the notched zone, where the lines of the radii are
often broken or zigzagged, and much bent out of their course, as may be
seen at Fig. 119.

I have observed the Labyrinth spider in the act of spinning her maze.
The process appears to be a simple one to the observer, although it is diffi-
cult to describe and yet more difficult to figure. The strong foundation lines
are first spun, and these lines, after having been once made, will be pre-
served carefully for a long pe-

Trapline
and Hub.

sae Bete
Spinning riod of time. Indeed, unless
the eye : } e 1 viol

ena roken by external violence, a

spider might preserve this sort
of household prop-
erty through an en-
tire season. From
these lines, by drop- yc. 119, Bent radii in the
ping and carrying notched zone of Epeira laby-
aot rinthea.
draglines, by crawl-
ing around upon the foliage, by establish-
ing here and there central intersecting

rables, and then by dropping and striding
from one to another, the labyrinthian
maze of crossed lines is in the end evolved.

However, the complete condition of the maze is a matter of growth
through a longer or shorter period. When a comparatively few lines
have been spun, the spider will take her place at the central part therein.
She begins here to spin out a few short lines, which in the course of a
few moments present rudely the appearance of the dome of Linyphia. By

; pushing her body and her spinnerets against the top and sides
Framing ¢ . . . ae :
the Tent. this domelike framework, she gets it into a somewhat con-
sistent shape. This is the foundation or scaffold upon which
eventually is built her silken tent, which acquires. consistency of tissue
as the threads are gradually spun up against it. Here now she estab-
lishes herself, and from this point stretches out her traplines and_pro-
ceeds to spin her orb, swinging it upon the strong cables or foundation
lines of her retitelarian system. Her method, as far as I have been able
to judge, is precisely the method of Theridium and other true Lineweavers,

Fic. 118. Multiplex trapline of Labyrinthea.

COMPOSITE SNARES AND SECTORAL ORBS. 135

and, indeed, may be described as the method which Agalena also uses when

spinning the retitelarian supports of her long sheeted snare.
The peculiar snare of Labyrinthea and other spiders making a composite
web appears to be a larger development of a habit which is seen to a greater
or less degree in the genus Argiope. In considering the particular

are Sid spinningwork of this genus I have already called attention to the
Habit. fact that both Cophinaria and Argyraspis suspend the upper foun-

dation lines of their orbs to a series of intersecting straight lines
which are spun with more or less consistency to the overhanging and sur-
rounding foliage. This sys- j

tem of crossed lines is very
frequently carried downward
to one side of the orb and
sometimes upon both sides,
so that it forms what I have
called the protective wings or
fenders. If the reader will
compare the more perfect and
permanent spinning habit of
Labyrinthea and Triaranea with
that which is described and fig-
ured as the work of Argiope, he
will see the close resemblance be-
tween the two. One may therefore
say that what appears as a rudimentary
habit, or a habit more or less developed in
the case of Argiope has appeared as a per
veloped and fixed habit in the spinning behay
rinthea. There is a marked peculiarity in the fa

Zp fectly de-
yO cies Es
\Y ior of Laby-

vorite site that

_.Labyrinthea chooses for her snare. This Q)| — is noticeably a
ee dead and leafless bush, or a leafless part of \\ a tree or dead
branch. The habit is quite persistent, and I \\/ have seen it in

every well established habitat of the species. It is true \\{ that she will
spin her snare among leaves, but her preference is for a |\ locality not so
obstructed. In such sites she is often seen in little }\} groups or colo-
nies. In one such colony at Radnor, Pennsylvania, I ( counted thirty
adult spiders, whose snares were spun upon a dry Fic. 120. Codp- brush heap
within a space six feet long, six wide, and five ‘tive howse hich. To

- ; Ge te keeping by two
this “clearing” every individual settler had no Labyrinth spi- doubt been

attracted by the same fayorable conditions for an un “** obstructed
habitation. Perhaps the instinct which induces this choice is under the
same influence as that which urges many Theridioid species to seek similar
sites for their retitelarian snares, which exactly resemble the maze of Laby-
rinthea’s web. Certainly, it is interesting and curious to find these two

136 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

habits existing side by side in the Lineweavers and an Orbweaver which

affects a lineweaving spinningwork.
On one leafless bush I found two individuals established whose several
premises had been merged into one by the blending of the two labyrinths.
(Fig. 120.) It was quite a case of codperative housekeeping ; or,

seo to make a closer analogy, it suggested the double houses one
ative 0 : 6 : 5
House. Often sees in city architecture, with united party wall and com-

keeping, Mon porch separated by a rail. The cross lines of the two

mazes completely blended; one spider was domiciled under a

leafy roof, the other under a woven tent; one orb faced toward the front,
the other toward the side of the united labyrinth.

The Labyrinth Spider has a very wide distribution through the United

States, and will probably be found to inhabit our entire territory. It has

been traced from New England south and westward to Colorado

ae , and California, and I have specimens from several States of
raphica ; :
anata South America. These last, ike numerous examples from South-

Hone ern California, differ from the more northern fauna in being

larger and somewhat more brightly marked. Their cocoons are
also larger, and probably their snares are more formidable; otherwise, they
are substantially the same species. It, therefore, must be added to that class
of our aranead fauna whose physical elasticity enables them to occupy with
equal facility a far northern and far southern home. However, in questions
of geographical distribution, the factor of vertical distribution ought not to
be forgotten. A far southern species may have a practically boreal habitat
by elevation upon a mountain range. I cannot speak positively as to this
point concerning South American Labyrintheas, but the specimens from
Southern California were taken from the seashore and the ordinary level
of San Diego.

i.

One of the most abundant of the small group of spiders that weave
sectoral orbs is Epeira triaranea, so called because of its composite snare,
which combines with that of the Orbweaver a decided retitelarian
web, and a quite good approximation to that of the tubeweaver.!
I have found the orbs of this species, from June Ist throughout
the summer, on bushes, shrubs, trees, hedges, on and between fences, and in

Epeira
triaranea.

1 This spider was first noticed by me under this name in Proceedings Academy of Nat-
ural Sciences, Philadelphia, 1876, page 201. Subsequently, in the same journal, 1878, page 127,
I gave a full description of the animal and its spinningwork, with figures, under the name of
Kpeira globosa, a spider closely resembling my species, which had been described by Key-
serling, Verhand. d. zool.-bot. Ver., X-X., 1865, page 820. I had the name changed at that time
in the page proofs of my paper, but being now less certain as to the identity of Keyserling’s
species I follow Mr. Emerton in returning to my original name. It is not improbable that
Keyserling’s name will be finally given priority.

COMPOSITE SNARES AND SECTORAL ORBS. lee

great numbers on the lattice work and open slats of the corn cribs and
other outhouses of farms. In the last named site very many young spiders
were seen in the first week of June, having but recently issued from the
cocoon. They were distributed along the lattice work for several yards,
forming a goodly colony. As late as June 21st a similar colony was found
in like position, the spiders being from one-half to two-thirds grown. In
July and August I found many individuals located within the interstices
of a stone fence near the
seashore, at Cape Ann,
Massachusetts.

Triaranea persistently
makes a web with an
vo ah open sector and
ag VN free radius, that -

Ry Radius.

x 4/PRa Ry i
ae, Shy by is, a prolonged
SNA BZ line not crossed by viscid

N beads, which, although it
may occupy
the position
of a radius,
is free from
the general

Fic. 122. Epeira

h \ Bi, radial — sys- triaranea (glo-
J 8 TT} mn Ai 2 tem. Exam- ™™:
pt 7 ’ = q
vin \\ | Ki ples occasionally occur,
a\\' D ‘
\\) NU particularly among adult
of MN webs, in which the spi-
V2 AN aes - eee
vA e rals entirely cover the
i} ES
\ orb space, but the gen-

eral habit is otherwise.
| Among young Triaraneas
I have very rarely no-

ticed such an exception.
For example, in the col-
ony just alluded to I counted consecutively fifty-two snares, every one of
which had the free radius. The same fact was true of the colony of June
6th. In these young webs the radius was always entirely free, with four
exceptions, in three of which there was one thread stretched across the
opening near the top of the web, and in the other case there were two
lines so placed,

Occasionally I have found a colony in which the tendency to a full
orb was much stronger than usual. One such was noticed at Niantic,
Connecticut. In the interstices of a stone wall bordering the beach of
Niantic Bay, on the country seat of one of my brothers, many Triaraneas

Fic. 121. Tent and sectoral orb of Epeira triaranea.

138 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

are established. Their tents are woven against the upper surfaces of the
round rocks and their snares fill the openings. In a number of these,
made by adults (August), the proportion of full round orbs was much
greater than sectoral orbs. I am not able to account for this remarkable
difference, as nothing in the site gave a clue. It would almost seem that
the species is in a state of transition from the one habit to the other ;
the habit of weaving a sectoral orb being now in the ascendant, but the
power to spin full orbicular snares remaining intact and sometimes be-
coming dominant.

The wedge like open space always occupies the upper semicircle of the
snare, but has no fixed posi-
tion therein. I conceived the

idea that the orien-

Orienta- tation of the open
tion of i E

sector and_ trapline
Sector.

might have some
special relation to the econ-
omy of the spider, or even to
its structure. But, after mak-
ing an immense number of
notes and sketches of webs, I
concluded that the matter is
largely dependent upon the
convenience of a site for pitch-
ing the shelter tent. Some-
times the sector opens directly
upward as in the typical snare
at Fig. 128, sometimes to the
left, or again to the right.
Much the greater number of

Fic. 123. Triaranea’s snare. 0, orb; m, the maze; g, guy lines openings noted by me were on

supporting orb; d, den or tent; f, free radius; c, central. the right side of the web (fac-
ing the object), and next to that the favorite position was at the middle.
The sectoral opening usually occupied about the space of one-eighth of the
surface of the orb. I have measured sectors covering respectively about one-
fifth, one-sixth, one-eighth, one-tenth, and one-fourteenth of the same. Or,
the proportions may be yet better understood by these measurements. Let
ab (Fig. 124) represent the diameter of several orbs and cd the width of
the sector at the circumference. In No. 1, ab = two and a half inches,
cd = six-eighths inch, three-tenths the orb space; No. 2 (Fig. 124), ab=
two and a half inches, ed = one inch, two-fifths the orb space; No. 3, ab =
two and a half inches, cd = one-half inch, one-fifth; No. 4 (Fig. 125), ab =
two inches, cd = three-eighths inch, over one-fifth; No. 5, ab = two inches,
ed =three-eighths inch, one-fifth orb space; No. 6, ab—=two inches, ed =

COMPOSITE SNARES AND SECTORAL ORBS. 139

three-eighths inch, one-fifth the orb space. These were all webs of young
spiders. It will thus be seen that there is no fixed rule by which
Triaranea is guided in this outlay of her web, and that she allows herself
a wide range of variation, although the greater number of orbs show
a sector of about one-fifth the orb space.

Through the open sector passes the free radius or trapline, for such

Fic. 125.

Illustrations of the orientation of the trapline, and width of
the open sector.

it is, its use being precisely that of the trapline Fic. 126. Bell shaped tent in which
in full orb making spiders. Near the point of Pee ee ee
attachment to the hub this is deltated, diverging into several lines that
are fastened at various points to the meshes of the hub. The
other end of the trapline enters a little bell shaped silken tent
swung amid a retitelarian maze, where it is held by the spider. (Fig. 126).
Sometimes several spiral lines will cross the upper part of the open
sector (Fig. 127); again one may see the variation shown at Fig. 128, where
two radii (dr dr) detached from the hub (H) are lifted out from the
plane of the orb, leaving an open space (QO) through which the trapline
(T) passes. Another variation differs from this in having but a single de-
tached radius (dr) to which cross loops (cl) pass from the marginal radii
R, R. (Fig. 129.) When weay-
ing in the spirals this spider does
not pass entirely around the orb,
as is the case with the full orb
‘makers in the major part of their
snare, but moves back and forth
between the radial borders (Fig.
125, c and d) of the open sector,

Trapline.

spinning her spirals in successive AAS
me: Fig. 127. Fic. 128. FIG. 129.
: _ horseshoe loops. This Au) 7
Spirals in .- Variations in the open sector; detached radii.
is the method observed
Loops.

by Zilla, and all sectoral orb makers in fact. The necessity for it
is at once apparent. Of course, in this case the term “spiral” has only
a technical application to these lines. (Fig. 130.) |
The number of both spirals and radii varies greatly. The latter are
more numerous, often far more numerous below than above the hub,
which frequently is situated well above the geometric centre of the orb.
Thus, in an orb six inches wide by seven long the spirals in the upper
part of the snare numbered nineteen, in the lower thirty-two. The lower

140 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

spirals were thus drawn in shorter loops with much less curve, and the
centre of the hub was well toward the top, two inches therefrom. In an-
other adult web the orb measured eleven inches long by eight wide, the
number of radii was forty-one, of spirals forty-five, of notched concentrics
nine. The centre of the hub was five inches from the topmost. spiral.

The following measurements give some idea of the size of Tri-
Web aranea’s orb: Web No. 1, about four inches diameter; radii
meres) forty-three; spirals thirty-five. No. 2, radii twenty; spirals

twenty. No. 5, diameter six and a half inches; radii thirty-five ;
spirals thirty-five. No. 4, seven inches long by six wide. No. 5, six and
a half long by five and a half wide. MRadii forty; spirals, forty-eight
below, twelve above. No. 6, forty-one radii; forty-five spirals. No. 7, two
and a half by two and a half. No. 8, eleven by eight inches, central five
inches from top, three and one-fourth from
side; radii forty-one, spirals forty-five, notched
zone nine.

Triaranea is frequently found in the neigh-
borhood of human habitations, around barns
and various outbuildings of farms, but also
loves the field, and is frequently found therein.
It does not appear to have in so marked a de-
gree as Labyrinthea a preference for nest sites
naked of foliage, when such can be conven-

)

Fic. 130. The looped spirals, L.S., in iently procured,

Zilla’s orb. The maze or snare of netted lines in the
web of Triaranea is, on the whole, not quite so prominent as that of Lab-
yrinthea, but in some cases it is very heavy, and generally is decidedly

he marked in the adult spider. The variation in this portion of
earecer the snare may be seen from the following extract from my note
book, made during one day: No. 1, retitelarian lines not heavy ;
No. 2, little or no retitelarian lines; No. 3, shght retitelarian lines above;
No. 4, retitelarian lines quite abundant in a protecting wall behind and
above but not before the orb.
These, like other differences in webs, may often be accounted for simply
by the fact that they exhibit different stages of completion. Spiders do
not invariably finish secondary parts of their web at the same

Cause of time that they spin the primary one. The nest or tent, for ex-

Differ- : Mi gine “ae :
ample, will sometimes be a matter of growth, and it is probably

ences. = Y

the case that the netted cross lines of composite snares are
developed in the same way. Young spiders also differ from adults in the
degree of attention which they pay to the secondary parts of their snare.
The principal part, however, the orb in the case of Orbweavyers, is invari-
ably completed, if circumstances will permit it, before the spider settles
herself to the pursuit of prey. .

COMPOSITE SNARES AND SECTORAL ORBS.

141

It is certainly interesting to find these Orbweavers possessing in so
marked a degree the spinning habit of the tribe most closely related to

Affinities. not be possible to

munity of habit and the com
of these snares and their weav
the weavers of the Retitelarian
hereafter when I come to con
of the Basilica spider; but it
that they both possess very de-
cidedly the Epeiroid character-
istics,
In the meantime, there is
another interesting peculiarity
of Triaranea’s web which
needs to be noted, namely, the
bell. shaped den or tent of
white silk hung amidst the
maze (Fig. 181), and connect-
ed with the trapline. <A struct-
ure of this kind, within which
the spider constantly dwells, is
not confined to this species.
Many Orbweavers have a sim-
ilar tent or some flossy uphol-
stered crevice, hole, or leafy
nest, within which they con-
ceal themselves frequently or
habitually. Triaranea often
‘shows a remarkable addition
to this ordinary bell shaped
tent. There is an open and
quite distinct tube attached to
the mouth of the
tent, from which it
to the centre of the
free radius is fasten
runs through or along the floor
ally kept taut, and is clasped
fore feet of the spider. This
fect, shortened, or even whol
ly found as in Fig. 152. In

Tube-
weaving
Tendency

Fic. 131. A snare of Epeira

themselves in general structural characteristics, although it may

trace a close relation between the com-
munity of structure. The affinity

ers with the spinningwork and
tribe will be more fully traced
sider the Domed orbweb
may be here remarked

—

=

reaches almost

orb to which the

ed. The free radius

of this tube, is continu-

at the upper end by the

gangway is at times imper-

looped spirals and elon- ]y omitted, but is frequent-
gated lower part of the ;

orb. this bell shaped den and _

triaranea, showing the

connecting tube one may see a germ or modification or suggestion of the

typical snare of the tribe of Tubeweavers.

We thus see that our spider

142 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

represents in her spinningwork three separate tribes of spiders, namely,
the Orbweavers, to which she herself belongs; the Lineweavers, whose
spinningwork she imitates in her netted maze of crossed lines; and the
Tubeweavers, whose snare is represented by the structure just described.
See also Fig. 123, g.

The distribution of Epeira triaranea has not been very satisfactorily
determined; but it probably inhabits all the northern, central,
and northern-southern portions of our continent between the two
oceans. It has been located by collection in New England, the
Middle and Western States, Utah, and Santa Cruz, California.

Among the spinners of sectoral orbs is Epeira
thaddeus Hentz. In size aS and habit it closely re-

; sembles ‘Triara nea and weaves a_simi-
Hpeira f .
ane es a lar orb. As far as my observations ex-

tend it affects wooded locations more
persistently than Triara nea, or at least shuns the
habitations. It is inclined
curled leaf or within a
sites spins a strong silken
it dwells, holding to the
maze of right lines in the
hangs her bell shaped
web of Thaddeus. These

Distribu-
tion.

neighborhood of human
to screen itself beneath a
leafy tent, and in such
tubular nest within which
trapline of its snare. The
midst of which Triaranea
nest is wanting from the
are the chief variations in general habit and spin-
ningwork between the two spiders. Thaddeus is
a 5 : Fic. 132. Tubular gangway (n.c) S
widely distrib between the tent and orb of Uted, its southern loca-
tions being A] ‘Traranea. g-l., guy lines sup- ahbama, South Carolina,
as far as to En 7 =” terprise, Florida; north-
ward it has been found in New England, Wisconsin; and in the Middle
States at least to the prairies. It probably has range over the entire At-
lantic slope and Mississippi Valley.

Distribu-
tion.

Til.

During the winter of 1882-8 Mrs. Rosa Smith Eigenmann sent me from
San Diego, in the extreme southern part of California, a few spiders, among
which were several of a species which proved to be Zilla x-notata.
ous In subsequent correspondence I ascertained that the snare of this
Snares of ae :
Zilla. aranead was distinguished by a free sector, and several cocoons
were forwarded, from which I succeeded in raising fine broods of
younglings. These I located upon plants and various elevated objects within
a warm room, and as they freely spun their characteristic orbs I soon had
a number for study, of which an example is figured. Fig. 183 was spun
underneath the handle of a small basket, and is drawn natural size. The

COMPOSITE SNARES AND SECTORAL ORBS. 1438

spirals were carried around in loops, quite as represented; the hub was
meshed and surrounded by a notched zone. <A bit of cotton cord that
clung to the handle had been utilized as a support for the foundation lines
on one side (on the right of the cut), and within a scant series of cross-
lines at the top a slight nest had been woven in which the little Zilla
rested. Her feet clasped a trapline attached to the hub by a deltated

ihen oI

Fic. 133. Sectoral orb of young Zilla x-notata, woven under a basket handle.
Natural size.

terminus. The free space was decidedly marked, as it was in most of the
orbs made,

My first opportunity to study Zilla in a natural site (uncolonized) hap-
pened to be upon the grounds of Mr. F. M. Campbell, at Hoddesdon, Hartz,
England. Later I noted the snares of great numbers of the genus in the
highlands of Scotland, particularly in the neighborhood of Loch Achray
and Loch Katrine. One especially interesting colony was _ lo-
cated at the sluices which regulate the flow of water from Loch
Katrine.’ A footwalk crosses the stream, along which are short
iron posts and an iron rail, Vast numbers of Zilla had settled along the
cornices and panels of these posts, and from their nesting places had

A Scotch
Colony.

144 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

stretched their characteristic webs diagonally across to the hand rail. It
thus happened that as many as a dozen or fifteen snares would be built
out from the same cornice or moulding, their upper foundations occupying
the same horizontal plane, but diminishing in length as they approached
the angle made by the post and the hand rail. The wedge shaped space
thus defined was almost completely filled with spinningwork, the orbs vary-
ing a good deal in size, but being alike in structure.

The ‘position was a good one for trapping insects, which fly in vast
numbers over the surface of the streams, but I could not but wonder
whether some of the spiders occupying the interior snares were not sore
put to it to pick up an honest living, and might not have been constrained
to resort to cannibalism. However, I saw no raids “ower the border,”
notwithstanding the traditions of the Scottish site, but all the aranead
clans seemed to be dwelling in peace.

I had a fine opportunity one summer of studying the spinning habit
of Zilla atrica at Annisquam, Massachu-
setts. Many of this species were colonized
upon the spacious grounds and
surroundings of the place where
I was lodged. They were domi-
ciled upon the chicken coops and outbuild-
ings, upon the shrubbery, and in consider-
able numbers upon the boat house on the
very verge of the inlet. In the latter po-
sition their snares were swung just above

Fig. 134. Fi. 135. the point of high tide, and they were very

“of Zilln, & thesplien; Bh uttealonie busy capturing the insects that flew around
and above the water, and defending them-

selves from vigorous colonies of Epeira patagiata domiciled in the same site.

I noticed an occasional tendency among these Zillas to spin a full
round orb. For example, in one colony of fourteen, all the nests were
sectoral except one. In another of fifteen, fourteen were sectoral, and one

had a complete orb. I could obserye no obvious reason from
Excep- the nature of the location why this difference should appear. It
tional a cE eee : =
Baad evidently is characteristic of the genus. Zilla callophyla, a
Webs, uropean species, can usually be recognized among the British

Orbweavers by the open sector, which characterizes its web.
This peculiarity, however, does not always exist, as webs formed by young
individuals, probably of the same brood, are occasionally found within a
short distance of each other

Zilla
atrica.

, some with the characteristic free radii, others
constructed after the usual Epeira type.1_ There appears, thus, in both
hemispheres to be a tendency in this genus to revert to the typical round

1 Staveley, “British Spiders,” page 247.

COMPOSITE SNARES AND SECTORAL ORBS. 145

web of the Orbitelariz; or, shall we say, a tendency to run tangent from
its own typical form into that of the established type of Epeira? On one
small bush, where perhaps a dozen Zilla atricas were domiciled, I found
no less than four orbs with completely rounded webs. In one of these, a
very rare circumstance indeed, I found that the trapline occupied a sector
below the median line of the web. In this interblending of spinning habit
Zilla shows the peculiarity already noted in the closely related species of
the genus Epeira, Epeira triaranea.

This colony afforded some very interesting illustrations of the strong
tendency to variation in the manner of forming the trapline. Ordinarily,
as has been shown, the trapline of orbwebs consists of a single cord, which

connects the hub of the orb with the feet of the spider lodged

ie in her retreat above and at the side of her snare. As a
aria- foe: Bo
fide rule, the end which is attached to the hub divides into

several branches, obviously giv
in the way of telegraphy. Sometimes
will be observed near the feet of the spi
the traplne. But generally
holds the single line within
Labyrinth spider, the trap
threads which diverge near
by the foot, and converge
the ordinary rule in the gen
is probably the one most
series of drawings presented
depart from this habit. Fig.
trapline with a number of

ing greater facility
one or more branches
der, where she clasps
one fore foot reaches out and
the claws. In the case of the
line consists of a number of
the point where they are clasped
toward the hub, and thus reverse
us Epeira. The single trapline
commonly used by Zilla, but the
will show how widely she can
154, for example, shows the
diverging lines toward the foot

of the spider at S$, the whole ‘es system forking about the mid-
: . m . Fic. 136. Branched anys r NTS A Ee ies
dle of the line, T, and being “tyapiine system of SUPported by another Y-shaped
line still nearer to the hub, — Zilla. At Fig. 185 the trapline has

assumed the rude outline of an hour glass. Five or six deltations grasp
the meshed hub, and these lines converge about the middle of the trapline
system, from which point they diverge toward the spider’s nest and the
surrounding leaves, upon which the snare is supported. The feet of the
spider at S are extended beyond the leafy nest, and grasp at least two
lines of the system. Fig. 186 shows still further divergence from the
original type. Here the hour glass, if I may continue the figure, appears
to have been cut into two, and the ends well separated by a bent line, in
the midst of which is a triangular patch swung to adjoining leaves. The
two fore feet of the proprietor are thrust from her tubular nest and grasp
the principal diverging lines of her system.

I have observed similar arrangements in the trapline system of Epeira
domiciliorum whose orbs were swung upon a barbed wire fence inclosing the
grounds of Woodland Cemetery. The question, of course, naturally arose,

146 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

what has caused this divergence from the typical single line? I am
rather inclined to think that it is accidental, resulting probably from the
breakage and pulling out into irregular forms of the original thread, and
the efforts of the spider to repair it without reconstructing her snare. Its
telegraphic efficiency is probably thereby impaired.

LWe

Nephila plumipes! is the largest of our indigenous Orbweavers, and is,
perhaps, our most decided representative of tropical spider fauna. Some
examples of the genus Nephila in the
collection of the Academy of

Distribu- Natural Sciences of Phila-
f | } | ate delphia, from Africa,” have
y 4 f = plumipes. reached an immense size.
, be j Their webs are formidable
impediments when stretched across
cl paths and among forest trees, even
i, to human passengers. I know of but
Y one species in the United States, and
: for much of our knowledge of this we
are indebted to the intelligent studies of Pro-
fessor Bert Wilder, M. D. While stationed
on the Southern Atlantic coast as an army
surgeon during the war of the Rebellion, he
became especially interested in this creature,
and published various papers descriptive of
his observations. The chief habitat of Ne-
phila, as Prof. Wilder found,* is Long Island,
a low, narrow uninhabited strip of land about
f five miles southwest of Charleston, South Car-
olina, covered with palmetto and pine trees,

f surrounded on all sides by creeks, and in the
Fic. 137. Wilder’s Nephila. Fe- midst of a great salt marsh. During a two

male, natural size. 5 : 5 5

years’ stay on the coast and in the interior of

South Carolina and Florida he never met with any traces of Nephila else-
where than near this island, except a specimen found upon Folly Island,

\
\

and a cocoon found in a tree on James Island. He had not observed it

1Prof. Thorell expressed the opinion, on the strength of specimens sent to him, that
our American Nephila is a different species from N. plumipes. I propose for it the name
of N. wilderi, in recognition of the gentleman who has made its habits so well known,
should the suggestion prove to be well founded.

2Collected in Zululand by Rev. Mr. Grout; some also from Liberia.

’ Proceedings Boston Natural History Society, Vol. X., page 205, 1865.

COMPOSITE SNARES AND SECTORAL ORBS. 147

on any of the adjoining islands, although there appears no physical rea-
son why the species should not occur all along the seaboard.1

The female is a beautiful, as well as large, spider. The body is over
an inch long and the longitudinal spread of the legs is nearly four inches.
The cephalothorax is jet black above, but covered, except in spots, with
silver colored hairs. The abdomen is not oval but cylindrical in shape, the
length much greater than the width. In color it is olive brown, a light
yellow above, and variously marked with yellow and white spots and stripes.
The legs are yellow, with dull red annuli and feet. The first two and the
fourth pairs have at the tips of the femur and tibia strong hair brushes
or feathery tufts to which the best known species of the genus owes its
name—plumipes, featherfoot, or plumefoot. The male, like that of Argiope,
is very small in comparison with his mate, who is four or five times larger
than he. He is not more than a quarter
of an inch long and is of uniform dull
brown color.

Prof. Wilder found the spiders in for-
ests spinning their webs between trees and
Nephila’s shrubs, sometimes within reach,
Speacen but oftener ten or fifteen feet

or eyen more from the ground
where the sunlight could strike them. The
orb varies from one foot to three or four
feet in diameter, as large as a wagon wheel.
It is composed of two kinds of silk, of
which one is white or silver gray, inelas- Fic. 138. Section of the orb of Nephila.
tic and perfectly dry. To this belong the po ee
radii, foundation lines and retitelarian supports. The spirals, on the con-
trary, are‘a bright yellow or golden hue and very elastic. This
is a remarkable peculiarity, which I have never seen but once,
in an exceptional case of the web of the Furrow spider woven
in captivity. This had a bright, golden yellow color, which continued
throughout several months, during which I preserved the web. I attribute
this phenomenal appearance to some abnormal condition of the spinning
organs, by which the glands that furnish the flossy, yellowish silk used
for blanketing the cocoon and for winter covering, had been required to
secrete material for snare weaving. But with Nephila the yellow secretion
appears to be habitually used for the viscid spirals. This color marks the
webs of the genus generally, as described by Vinson (of African spiders)
and others.

The spiral scaffolding, however, is spun of white silk, and is not re-
moved after the completion of the spirals, an exception to the habit of

. Golden
Strands.

‘IT have had specimens from Florida.

148 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Orbweavers. Each concentric of the scaffolding, which is marked by the
arrows in the figure (Fig. 138), makes a marked division between the in-
termediary spirals, which are thus divided
into groups or bands, adding much to the
peculiar form of the snare.

Wilder states! that the free sector or
space uncovered by beaded spirals in the
snare of Nephila, in natural site is equal
on an average to about one-sixth the sur-
face of the orb. He, however, gives a
drawing of a web made by a spider in
captivity upon a circular wire frame, which
has a free sector equal to two-thirds of the
orb.2 (Fig. 189.) No doubt this abnormal

NAB E

SOc «form was due to the artificial conditions

FiG, 139. Snare of Nephila, woven ona wire ynder which the spider pled her industry.
hoop. (After Wilder.) 5 : ee oon 6 5

Prof. Wilder is sufficiently explicit in his

description to allow us to present the diagramatic or restored web, Fig.
140, as approaching the characteristic form in natural site.? It thus closely
approximates that of Epeira triara-
nea and Zilla. The spirals do not
form complete circles, but are looped

“\
if NGS Kn
ii il 6: p i uit ;
: Wk ORE nT

across the radii, in a manner already
described, and in spinning them the
spider does not move around the
web, but returns upon her course
from one side to a corresponding \
point on the other. The web thus
made is strong enough to support ]}
a light straw hat when hung up-
on it.
Gosse speaks of the immense
snares of Nephila as one of the
obstructions to free travel

Jamaica .- BE Te dies
Nophila : in the woods of Jamaica.
Gone These, he says, are in-
fested with the great long aE
; = Fig, 140. A diagramatic snare of Nephila, composed from

bodied spider with brush tufted the descriptions and sketches of Prof. Wilder.

1 Proceedings American Association, 1873, page 265.

This has led Emerton, Structure and Habits of Spiders, page 66, to the erroneous state-
ment that her snare “consists of loops running round about quarter of a circle.”

’ Prof. Wilder, in his paper, Proceedings American Association, 1878, page 272; also
Galaxy, page 111, 1869, and on the Triangle Spider, Popular Science Monthly, page 658,
1875, gives an outline cut of Plumefoot’s orb, which corresponds with that of Fig. 140.

COMPOSITE SNARES AND SECTORAL ORBS. 149

feet, Nephila clavipes. If one succeeds in pushing his way with much
difficulty through the briers, his face is pretty sure to come into contact
with the strong threads of these spiders, which are spread over the bushes
and between trees along the roadside. The web is perpendicular, the part
on which the spider sits, head downward, is geometric, but this is sur-
rounded on all sides by a vast array of irregular lines, the frame of which
consists of compound threads, stretching from the surrounding trees and
shrubs. Some of these threads are twelve feet long, of a yellow color, and
nearly as thick as sewing silk; Mr. Gosse found them able to resist a
great pressure without breaking; but thought it utterly improbable that
the rapid and powerful flight of even the most minute hummingbird could
be for a moment arrested by the web of this or any other spider.

1p. H. Gosse, “ Naturalist’s Sojourn in Jamaica,” page 240.

CAP iy ex:
HORIZONTAL SNARES AND DOMED ORBS.

if

THe Orbwebs heretofore considered all belong to the general division
described as vertical orbwebs. The snares to be considered in this chapter
are known as horizontal orbs. The horizontal orbweb in all es-
alae sential particulars is woven like the vertical orb and differs chiefly
berosa, im the fact that it is usually hung wholly or partly in a
horizontal position.

In the species making vertical webs, the habit is so firmly fixed that
the spiders rarely deviate therefrom, and never, except under circumstances
which constrain a departure. Nevertheless, it is interesting to remark that
sometimes they do spin orbs that more or less approximate the horizontal.
Occasionally these orbs are entirely horizontal. For example, I have
known a brood of young Epeira sclopetaria, freshly escaped from the co-
coon, to spin upon the same object minute orbs, some of which were ver-
tical, while others were as truly horizontal as though they had been made
by a species that habitually weaves an orb of that sort. Fig. 141. It was
not difficult for me to determine that these individuals were influenced to
an abnormal act by the conditions under which they wrought. It was
comparatively easy for them to get foundation lines so placed that a hori-

zontal web almost inevitably resulted ; while, on the other hand,

eee the frames for a vertical web could not have been obtained
10ns 1n ° ‘op °

the Orb except with the greatest difficulty. Yet, in the case of a few of
Pinca the same brood nearly as great difficulties were overcome, and a

vertical web was made. For example, the little fellows in the
cut (Fig. 141) found it easy to weave an orb horizontally around the metal
frame that supports the lamp chimney, and this they did. But others fol-
lowed the specific habit and sent down lnes to the table, making a
triangular frame and a vertical orb within it.

So, too, it may be said that spiders which make horizontal snares are
sometimes constrained by difficulties of the site chosen to deviate more or
less from the horizontal plane. Indeed, I have seen the orb of Tetrag-
natha inclined at almost every angle, and occasionally have found it spun
in an absolutely vertical position.

(150)

HORIZONTAL SNARES AND DOMED ORBS. 151

Such are the facts in the case. Whether this accidental tendency on
both sides to vary the habitual position of the snare may have laid the
foundation upon which has been developed the permanent habit which we
are now to consider, is a point which others, perhaps, may be able to
settle, to their own satisfaction at least. To my mind, the diffi-
culties of originating a fixed habit from such an _ accidental
variation are so formidable that they seem practically insur-
mountable. In ad-
dition to these is
the difficulty of ex-
plaining why the
same accidental va-
riation, appearing
with equal frequen-
cy in many species,

Develop-
ment.

should have suc-
ceeded in fixing it-
self upon a few
species alone ?

In the United
States the spiders
which habitually
are found upon
horizontal — snares
are Argyroepeira
hortorum, Epeir
gibberosa, and the
various species of
the genus Tetrag-
natha, and the sey-

eral species of Uloborus. For reasons which
will hereafter be explained I do not include
the last named species within the group to
be described in this chapter.

Fig. 141. Varied orbs of a colony of
Argyroepeira hortorum, or the Orchard spiderlings.

spider of Hentz,’ is one of the most beautiful of our indigenous species,

presenting in its varied green, yellow, and metallic silver colors
Orchard

Bridger all the characteristics of some of the brightest tropical species.

It is widely distributed, probably throughout the entire United
States, and is thus equally at home in the cold climate of New England
and the winterless regions of the South. Its web is usually found in low

1 Epeira hortorum Hentz, “Spiders of the United States;” Argyroepeira hortorum

9o
Oo.

Emerton, “New England Epeiride,”’ page :

£52 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

situations, spun upon branches and stalks of tall weeds and grasses, or in
the lower branches of shrubs, bushes, and trees. The orb is frequently
quite round, indeed is habitually round when spun in open spaces where
the spider’s action is unfettered. An adult spider’s orb has an average
diameter of from eight to nine inches. The spirals and radii are closely
placed and average in number about thirty. The hub is open and the
spider has its position just beneath, clinging back downward to the margin
of the hub or to the notched zone immediately surrounding it. The abdo-
men is often turned upward almost at right angles to the cephalothorax,
and is stayed by a line attached to the orb above. Fig. 142.
From the foundation lines of the orb downward there usually extends
a mass of crossed lines, which may be called the apron. These are thick-
est upon two sides, although sometimes they extend entirely

Protect- around, giving the whole mass of spinningwork the appearance
ive Rs : ;
Seren of a hemisphere with the circular plane upwards, or of an in-

verted cone. The purpose of this apron is evidently protective,

as it must shield the spider from assaults of enemies that would be
inclined to strike her as
she hangs beneath her orb.
Spiders occupying vertical
orbs which for the most
part are swung upon foli-
age and other objects which
form a background, are tol-
Fic, 142. Position of Orchard spider on its orb. erably secure against attack

from that quarter at least.

But the weavers of horizontal orbs have no such natural local protection.
Hence it is the more needful that they should manufacture one for
themselves. The apron may also stay the foundation lines that support
the delicate work of the orb itself, and perhaps protects it from the ap-
proach of insects who would break through without giving the spider
an opportunity to catch them. It doubtless also serves for the arrest of
insects, as I have found flies entangled upon the threads. It may thus, as
in the case of the Labyrinth spider, be of some benefit to the occu-
pant in the way of providing food. But for this the principal reliance is
of course upon the orb, and the chief supply is from those insects that
strike it as they fly downward. The outside foundation lines, to which
the horizontal orb is hung, are sometimes of considerable length; I have
found them thirty-six inches long. Fig. 148 is an accurate representa-
tion of the foundation system of the Orchard spider, and also a section of
the snare showing the spiral system as well as the central space. The lines
are drawn vertically, but, of course, the reader will understand that they
are to be considered as spun horizontally as they were in nature. A little
better view of the central space is shown at Fig. 144 where the delicate

HORIZONTAL SNARES AND DOMED ORBS. 153

arrangement of the unbeaded and notched spirals (n) is represented. If
one will imagine a web thus constituted throughout the entire orbicular
space, and hung in a pretty
site among meadow plants
or wild flowers, he will have
a true conception of the del-
icate beauty of this work of

aranead art.
In appearance the orb
resembles that of Acrosoma.
The open hub,

Orb the numerous spi-
ene rals, and the nu

43 "aAlS, al 1e -
teristics. = 2 -

merous and deli-
cately spun radii and bead-
ed spirals are characteristic
of Hortorum, as they are
of Acrosoma. But I have
never seen in Hortorum any
of the ribboned decorations
which mark the spinning-
work of Acrosoma. The free
space also is decided in Hor-
torum, but small or lacking
in Acrosoma. When dis-
turbed the spider usually

runs along the dragline to Fic. 143. Section of foundation lines and orb of the Orchard
which she hangs underneath aaa ae aa

the hub, to the remotest part of her foundation lines, with which the drag-
‘line is generally connected. She remains stationary at her point of refuge,
or hides beneath a leaf, or sometimes drops to the earth.

I have never seen the snare of Hortorum in a vertical position, and
have rarely noticed it inclined in any degree from the horizontal; but have
record of one web that inclined about forty-five degrees. In this orb the
foundation lines were attached to the leaves of a plant eighteen inches high,

= upon which the snare was hung. From these,

| THIS
ee TE

lic. 144, Central section of Or- : . . : se , .
chard spider’s orb. f, free space; distance of five or SIX inches. | his Is the ordi-
n, notched zone; c, open hub.

retitelarian lines were earried downward to an
adjoining tree, making a rude appearance of an
inverted pyramid. ‘This apron was not carried up

close to the orb, but separated from it about the

nary position of the apron, and in this respect is
quite analogous to the corresponding situation of orb and labyrinth in the
snare of Epeira labyrinthea. Indeed, it may be said as a general fact that

154 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

in all orbweaving species which make a composite web, either habitually
or occasionally, the mass of crossed lines is separated by a little space from
the orbicular part of the snare. This is the case with the protective wings
of Argiope, which are always so placed as to leave free action for the
spider as she moves back and forward between the orb and the retitelarian
lines on either side.

Epeira gibberosa, the Hunchback spider, closely resembles Hortorum in
the sites selected for her snare. Like Hortorum the species is probably dis-
tributed throughout the entire United States. I have collected it
in Florida, in the border and Middle States, and in New England,
and have specimens from Wisconsin, but none further to the
west or northwest. Its snare rarely diverges from the horizontal plane, and
is like the Orchard spider’s in every respect, except that I have never found
it with the apron or protecting maze of
crossed lines. Instead of this, however, the
spider has the habit of making for herself
a netted hammock of lines stretched between
leaves of the plant up on or near which her
Orbis sspun. (Wig. 145.) This hammock
between the pulled up
may be seen figured
Nesting Habits. Un-
mock the Hunchback
holding to a trapline
which is attached, at the opposite end, to
the central part of her snare. In this respect
her habit is related to —«-Fi¢. 145. The hammock nest of the that of the Shamrock

: Hunchback spider.
and Insular spiders

Eipeira
gibberosa

is sometimes woven
edges of one leaf, as
in the chapter upon
derneath this ham
hangs back downward,

and others of that
group. Sometimes she forsakes this position and hangs like Hortorum
underneath her orb, and sometimes I have found her thereon
~without any such associated hammock nest. Gibberosa appears
to be less timid in disposition than Hortorum. At least, when
touched by my pencil, the Orchard spider would invariably swing away
from her position or crawl off to the outlying foundation lines. The
Hunchback, on the contrary, instead of forsaking her position, would only
turn around, shake her body, or jerk her trapline in a neryous manner.
Gibberosa lacks the bright silver markings of Hortorum, but keeps the
general green hue of legs and body, the color, however, being somewhat
darker.

IT.

The genus Tetragnatha furnishes some of the most familiar and inter-
esting species of spiders making a horizontal snare. Our two most common
species in the Eastern United States, and probably throughout the whole

HORIZONTAL SNARES AND DOMED ORBS. 155

continent, are Tetragnatha extensa and T. grallator. The former species
has been supposed to be an importation from Europe. It is impossible, of
course, to determine whether this is so or not, for the species is
so widely distributed, over the greater part of the continent in
fact, that the probabilities are that its life in North America
antedates the period of European communication. My collections and
specimens range from Canada, Connecticut,
and Massachusetts to Florida, on the east-
ern shore; to Texas on the south and
southwest ; and on the Pacific coast as far
northward as Vancouver Island, and south-
ward to San Diego, at the extreme border
of California. Emerton has collected it on j.. 145 idea ainaleetenaey ok wees
the White Mountains of New England and
along the seaboard, and Dr. Marx has specimens ranging from Fort Simms,
Labrador, to Florida, and westward and northwest through Kan-
sas, Alaska, and the Aleutian Islands. As the species is widely
distributed throughout the continent of Europe, and is probably
found in Asia as well, it is easy to see that it might have been transported
without the aid of human ships, simply by the agency of the winds, either
from America to Europe, or from Europe to America. The original centre
of the species, if one is to suppose an original centre at all, cannot, there-
fore, be positively determined. It is a spider of delicate greenish and yel-
low colors, and appears to be rather delicately organized, notwithstanding
the formidable jaws which characterize it in common with its congeners,
and to which its generic name is due. (Fig. 147.) Nevertheless, it has
been able to find and hold a habitat amid the most
diverse climatic extremes, and in establishing itself has
crossed continents, lofty mountain ranges, and oceans.

Tetragnatha extensa is a spider which when once seen
‘annot easily be mistaken for another. It well deserves
its name of “extensa,” or the extended spider, for its
abdomen is in the shape of a rather narrow cylinder, is
greatly extended, as compared with the cephalothorax,
and it has the habit of stretching its front legs forward,
Fic. 147. Thejaws ana 1s hind legs backward until, together with the long body,
mouth parts of Tet- the entire spider is drawn out into a straight band and
ragnatha. 7 aie ° .

forms a peculiar vision, which the observer is apt to bear

in mind. The colors of Extensa vary a good deal, but for the most
part the cephalothorax is pale white and yellowish. The abdomen is
delicate yellow, tinted with shades of green, and has a fine branching
black line running down the middle of the dorsum. The sides are finely
reticulated, and the under part has a dark band down the middle with
green on each side.

Tetrag-
natha.

Distri-
bution.

156 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

It loves the neighborhood of water, but is found distributed widely
throughout the meadows and in the foliage of bushes and low trees. Its
snare is of a delicate texture, finely spun, as a rule, but oftentimes short
and straggling. It is placed either in a vertical, horizontal, or inclined
position, but its general habit is horizontal, and with this class of Orb-
makers I have placed it. It is armed with a pair of formidable jaws, whose
immense teeth and long fangs would appear to give it a great advantage
in its conflicts with enemies and efforts to secure food.

In construction the orb of Tetragnatha extensa, as well as all other
species of the genus, corresponds very closely with that of the Orchard
spider. The hub is open, and a series of notched concentrics follows; then
comes the free space; then the spiral space, the foundation space, and the
foundation lines.?

The position of Tetragnatha is underneath the central part of her
snare. Her body is usually stretched across the open hub. The legs do
not radiate from the body at open

angles, but are drawn very

mecca close to the cephalothorax
oe ° at the fore part, and to the

abdomen at the hinder part
of the body. The fore feet clasp the
‘radii at or beyond the notched zone,
or one foot holds fast to a line which
is stretched to the under part of the
web and bows downward to the foot.
Fic. 148. Tetragnatha outstretched beneath the hub The abdomen, as in the Case of the
Seats Orchard spider, is hitched by a sim-
ilar line to the orb. In this position the spider sometimes swings almost
free from direct contact with her snare. The fore legs touch or approx-
imate near the middle, and the feet are curved. outward. In spite of its
somewhat awkward appearance, Tetragnatha is remarkably lively in its
movements.

When alarmed, Extensa runs down into the weeds or grass, and stretches
herself along the stem on which she has found refuge. Her legs hug
her body closely, even more closely than when suspended to her web as
just described. As her entire body is of a greenish yellow color, not
greatly different from that of the plant, it is somewhat difficult to distin-
euish her from the stem on which she rests. This peculiarity is well

known among observers of the species wherever it is found, and is cited
as one of the examples of protective form mimicry.

1 Description of Orbs. No. 1. Vertical; 5x4in.; n. z, 4x4 in.; fz. #x #in.; hub irregu-
lar meshed work. No. 2.5.x 5 about; f. z, 3 to }in.; hub open, with few irregular threads.
No. 3. Nearly vertical; 3 n.sp.; r. 16; sp. 21 below, 15 above. No. 4. Horizontal; 43 x 5 in.;
tx 4;f.z.,.3x%;open hub. Nos.5, 6,7. Orb inclined about 45°;

small, 3 to 5in. in diam. Several orbs 2 in. diam,

r. 22, sp. 13 and less above ; n. z., ?
, ,

HORIZONTAL SNARES AND DOMED ORBS. 157

The next most common species of Tetragnatha is the Stilt spider,
Tetragnatha grallator Hentz.t_ In color the adult is not so brilliant as
Extensa, being a dull gray; but in its general form, habits, and
the structure of its web it corresponds with Extensa, but is
larger, darker, and less attractive in appearance when adult. It
differs, also, in its greater fondness for a location near or over water. Its
webs are frequently seen stretched above the surface of running streams.
In pools, in the quiet nooks of brooklets and creeks, where branches droop
down from the banks and overhang the water, I often find a colony of

The Stilt
Spider.

‘i

i hs
URI WV

oH Wi

I'tG, 149. Horizontal orb of the Stilt spider, stretched above a brooklet (Doe’s Run).

Stilt spiders that have spun their horizontal orbs upon the leaves and
twigs close down to the water’s face. As the wind moves the branches
to and fro the webs almost dip into the stream beneath. Here the crea-
tures hang and prey upon the insects that always frequent such sites in
great numbers and hover over the stream. (Fig. 149.)
Another favorite position is underneath the boards and cross logs of
1T. elongata Walck., Nat. Hist. d. Ins. Apt., ii, page 211. Dr. Thorell has little doubt

that Hentz’s species T. grallator is identical with Walckenaer’s T. elongata. See “ Araneze
of Colorado,” Bulletin U. 8S. Geolog. Sury., 1877, page 479.
S :

158 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

mill races. I recall one such site at Bellwood in the Allegheny Mountains,
where very many Stilt spiders were thus located, and had found it so
admirable a feeding ground that they had grown to large proportions.

Some of the orbs were fourteen inches in diameter. (Hig. 150.)
With this fondness for the water are associated some most interesting
habits which especially adapt the Stilt spider for its favorite site. One of
these was observed in individuals of the Bellwood colony above

ee mentioned. The webs were stretched between boards laid on
he

narrow beams as a gang way across the mill race near the sluice
Water. Sarees ; ‘

vate, and also from these boards to the sides of the race itself.
While studying them I was often compelled to disturb the spiders. ‘They
d oD d

Fig. 150. The Stilt spider’s web beneath logs.

ran from the centre of their large orbs and took shelter on the sides of
the cross beams or underneath the boards. If still further disturbed, they
would sometimes drop by a dragline from the lower surface of the plank
and hang with their legs stretched out straight, fore and aft, in the charac-
teristic position already described as assumed by them when resting along a
branch or other surface. In this posture they would hang motionless for
some time. (See Fig. 151, left hand of cut.)

On one occasion, while attempting to seize one of these individuals,
she dropped downward suddenly for several feet. I was not surprised at
this motion, for it is the one resorted to by alarmed Orbweavers when

HORIZONTAL SNARES AND DOMED ORBS. 159

they precipitate themselves from their snares to the ground. I prepared
to draw my specimen upward by her dragline, feeling sure that I would
certainly capture her, when, to my amazement, she threw herself upon
the surface of the water, a distance of eight or ten feet. I looked to see
her drown, or at least to be swept away through the open sluice gate by
the fast rushing stream. Neither of these things happened. The
moment our Stilt spider struck the water she reached upward
one hind leg, clasped the dragline in her claw, and began to
scurry over the mill race toward the shore.

I watched the movement with exceeding interest, and was delighted to

A Spider
Sailor.

see the adventurer reach her destination. (See Fig. 151, right hand figure.)

é

The dragline, partly by its natural elas-
ticity, but also because the spider prob-
abiy reeled out thread as she traveled,
continued to stretch as the spider moved
toward the shore. It thus held her firmly
anchored to the surface of the plank to
which her dragline was attached, so that
the force of the current, thus counteracted,
did not sweep her through the open sluice
over the shoot. In the meantime her feet
were kept in motion, and she appeared to
me to be walking the water in the man-
ner of certain so-called “ water spiders,”
belonging to the genera Dolomedes and
Lycosa of the Citigrades. It certainly is
an interesting fact in the natural history
of an orbweaying spider, that it possesses
a habit so closely resembling one charac-
teristic of a tribe widely separated from it

: ‘1G.151. Tetragnatha hanging extended, and
in n arly every other respect. Fic. 151. Tetragn ath 2 h anging extended, anc
. ¥ running on water.

The outspun filaments that serve the
spider for navigating the air are also utilized for propulsion over the

; water. In one case they serve as a balloon, in the other as a
Navigat-

sail. This discovery was made on a pleasant October day while
ing Water - :

walking along the shore of Deal Lake, Asbury Park, New Jer-

sey.1 I stopped before a clump of tall grass that grew upon a little
tongue of land that jutted into the lake, in order to shake down from the
foliage any spiders who might for the time be domiciled thereon. The
especial object of my search was water frequenting species, particularly
the common Dolomede (Dolomedes sexpunctatus), whose mode of run-
1 October 21st, 1881. I believe that I have the honor to be the first person who ob-

served, or at least announced, this interesting behavior. See a note published in “ The
Continent,” Philadelphia, August 2d, 1882.

160 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

ning over water, and behavior when cast upon water, I wished to observe.
The beaten marsh grass yielded me no Dolomedes, but instead several
half grown Tetragnatha vermiformis, Emerton, dropped upon the surface.
To my surprise they seemed not the least disconcerted, but immediately
recovered themselves and with one exception ran to the shore precisely
as do the Lycosids. The excepted individual had been thrown out from
the bank farther than its comrades. For a moment it paused, its body
bowed and held upward upon the eight legs which were spread out so
that the feet marked the outline of a rude circle upon the surface. Then
it started rapidly across the mouth of a tiny baylet between a tongue of

the land and the main shore, traversed the intervening space,
and pulled itself to the land by the overhanging grass. My
attention was attracted by the remarkable fact that during
this transit there was no appreciable movement of
the legs. That an Orbweaver should be able to glide
so rapidly and gracefully over water was a fact

= in itself sufficiently new to me; but that one
i should do this without any physical exertion
7 a whatever amazed me. Could the action of the

air upon the body have been the impelling force ?

I addressed myself eagerly to the solution
of this mystery. A second clump of grasses
was beaten, and a Tetragnatha fell upon the
lake. She ran over the water to the shore,
using apparently her fore legs as paddles. Be-
fore she climbed into the grasses I
thrust my cane under her body,
gently lifted her up, and reaching
outward as far as I could, gradually
sunk the tip of the stick into the
water without causing any ruffling
of the surface. The spider was thus
eased off the stick and placed upon
the surface undisturbed. As soon as she felt herself fairly launched she
made a few strokes with her fore feet, then suddenly paused and thrust the
apex of her abdomen down to the surface. Directly, the abdomen was
raised from the water and turned up until it made an angle of about 60°
with the surface. Next a long streamer of silk filaments was emitted from
the spinnerets, precisely as in the case of aeronautic spiders when about to
ascend, and immediately the spider began to scud at a great rate over the

Fic. 152. Silken sails: Tetragnatha navigating a lake.

water. The mysterious motor was thus revealed—the silken threads served as
sails upon which the wind played, propelling the vital craft across the water.

The discovery into which I was thus accidentally led was so interesting
that I devoted the remainder of my day to the full investigation of the habit

HORIZONTAL SNARES AND DOMED ORBS. 161

of navigation by means of filament sails. The first experiment was re-
peated a number of times with various details upon several spiders, and al-
ways with the same result. The gossamer thread was undoubt-

saa edly used as a sail, and the action of the wind bore the little
ara navigator to the shore. I frequently blew the tiny craft out to

sea, either with my breath or by fanning with my hat. My stick
could at any time arrest the thread by placing it a foot or more above the
spider, and having entangled it, I could draw her thereby in any direction.
The filament was plainly seen floating above the spider, waving to and
fro, generally bending above her back.

The legs during motion were raised upward and bowed, thus holding
the body well up from the surface, exactly in the attitude of a spider about
to take aeronautic flight. They were kept quite rigid and motionless. The
feet were spread out, describing the outline of an irregular octagon. I fancied
that they were united by threads and that thus the spider sat upon a delicate
raft of silk. Before spreading her sails the first act of the spider was to
drop the abdomen to the
surface, at which moment,
I inferred, an attachment to
the legs was made. I can
hardly bring myself to be-
lieve that the threads were
attached to the water, al-
though it may so have been.

While the spider was un-
der sail the feet made a very noticeable ripple of wavelets as they were
hurried along. She could accomplish short distances from the shore by
running, without spreading sail, but when put well out she always re-
sorted to the latter mode. However, any floating object which she met
‘during the voyage was pretty sure to be taken advantage of as con-
venient harborage. A downy seed which fell upon the water and drifted
within reach of one of my.aranead sailors was immediately seized by the
creature’s fore feet, the spinnerets were set in motion, and the seed was
overspun with a delicate floss, which converted it into a sort of float.

In this connection I record an incident which may throw some light upon
the development among Orbweavers of this interesting water habit. A large

female Epeira sclopetaria was collected, along with an abandoned
Epeira = cocoon, behind which it had spent the winter, at Atlantic City.
and Her __,,, . é : :
Float. The spider was accidentally dropped into the Inlet, together with

the flossy ball of the cocoon. She immediately threw out threads
around the ball (Fig. 153), to which she remained attached as to a buoy,
and thus the two drifted along safely under the floor of a boat house
and so out of sight. One associates such an action with the water walking
and navigating of Tetragnatha, and wonders whether Epeira could ever,

Fic. 153. Epeira using her cocoon as a float.

162 AMERICAN SPIDERS AND THEIR SPINNINGWORK.-

under favorable environment, develop like behavior. Moreover, the query
arises, Whether from some such accidental occasions, often repeated, may
not have sprung such a perfect navigating habit as that attributed to
Dolomedes fimbriatus, who makes for herself a raft of leaves united by
threads of silk, and so navigates the fens of Northumberland, England, in
search of prey.

Like her congener Extensa, the Stilt spider has a wide distribution over
the United States. It is dispersed throughout the entire belt of
Eastern and Middle States; and the collections of Dr. Marx locate
it in Empire City, Colorado; Fort Bridger, Wyoming; Kanayah,
Aleutian Isles; Sitka, Alaska, and as far to the northeast as Unga Bay, Lab-
rador.

Distribu-
tion.

1a.

The remarkably extended geographical distribution of these species of
Tetragnatha, and especially of T. extensa, necessarily raises the question as
to the effect of environment upon structure afd habits. Through-
Distribu- out the wide area alluded to, the habits of Extensa, as far as I
oom have been able to learn, are absolutely identical. I have studied
and Habitthe spider at widely separated points in the United States, and
have made some observations of its habits in Great Britain. I
have also compared my observations with all recorded by European ob-
servers to which I could have access. There is no essential variation in the
testimony. The structure of the animal herself remains unchanged. The
character of her web is everywhere the same. Her cocooning habit, her
pairing habit, and in short all her life economy appear to be wholly unaf-
fected by change of climate, food, site, and elevation. It must be allowed,
indeed, that much remains to be done in the way of carefully noting the
habits of the species in the various localities at which it has been collected ;
but the spider has been known for more than a century, and, in Europe
particularly, has been studied by all arachnologists, and has had as much
attention given to her as to any other species, with the exception, perhaps,
of Epeira diademata. The above conclusion, therefore, may reasonably be
regarded as accurate.

In this respect, Tetragnatha extensa is not alone. I have shown that
in the case of our large representatives of the genus Argiope (A. cophi-
naria and A. argyraspis) precisely the same facts obtain. (See
Chapter VI.) From the rugged winters of New England to the
perpetual summer of Southern California, throughout the mount-
ain regions of Pennsylvania, and on the broad stretches of the American
plains, these spiders have been traced, and are found everywhere the same
in structure and habit.

To these may be added a large group of the genus Epeira, all of which
are distributed over Europe, North America, portions of Asia, and probably

Other
Hxamples

HORIZONTAL SNARES AND DOMED ORBS. 163

throughout a great part of the northern hemisphere. The spiders of the
southern temperate regions have not yet been sufficiently studied to enable
us to decide whether or not this group is represented there. It certainly
would be a valuable addition to our knowledge could it be known whether
they are as widely distributed in the southern hemisphere as in the
northern ; and especially if it could also be determined whether or not the
peculiar conditions of the torrid zone have prevented distribution of these
species across that area. No doubt this would throw light, as far as spiders
are concerned, upon the power of certain species to originate and maintain
life independently in certain natural geographical areas.

Among this group of Epeiroids may be named Epeira insularis or E.
marmorea, Epeira cornuta or E. strix, E. diademata, E. quadrata or E. trifo-
lium, E. sclopetaria, and E. patagiata. In the case of some of these species

the records do not show quite as great extremes of climate and
Power to elevation in their distribution. But the facts concerning them
Resist : ; ;
Environ. @! contribute to the general conclusion that certain araneads have
tivcuat an immense power of resisting the external influences of their

environment; possess a remarkable elasticity of temperament,
which allows them to adapt themselves to widely different conditions of
life. In the midst of all this, so thoroughly fixed are their habits that
they resist all those centrifugal influences of varying surroundings which
are supposed to be so potent to overcome the conservative tendencies of
natural behavior,

Environment does influence the distribution of some species. The spider
fauna of the tropical regions when placed alongside of those of the tem-
perate zones show marked individuality. There are certain groups that
have found lodging along the warm regions of our Gulf. States, throughout
Texas and Southern California, but have neyer been able to push their

way farther to the north. The genus Nephila, for example, is
. Climate Jimited to the southern belt of States; and although in geologi-
Limits . ne .
Distribu- ‘al time, as early at least as the oligocene or the tertiary, the
on genus was established as far north as Colorado, in the region of

Florissant and South Park, it is not now found above the par-
allel of Charleston, which in a general way indicates the limit of its north-
ern distribution. What are the influences that prevent it from breaking
through this barrier? One must hesitate to answer; but they ate prob-
ably climatic, inasmuch as the genus has immense development in various
species throughout tropical regions.

Another example is the genus Gasteracantha or Crab spider, distin-
guished by its round or circular abdomen, upon the margins of
which are fixed various spinous processes. (See Chapter VII.)
In this most striking characteristic, namely, the presence of spines
upon a leathery abdomen, Gasteracantha certainly resembles the genus
Acrosoma ; yet that genus has several representatives in our northern spider

Gaster-
acantha.

164 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

fauna, while Gasteracantha has never been found farther north than the
southern areas of our Gulf States. Both these genera, like Nephila, appear
to be more especially characteristic of the tropical spider fauna, among
which they also have a great variety of prolific and peculiar species.

One’s curiosity is sorely puzzled to know why our three northern repre-
sentatives of Acrosoma have been able to find and hold a place among
the fauna, not only of the temperate, but of the more northern areas,
while other species, and the genus Gasteracantha in all species, have ceased
their northward march at the line already indicated. Or has the progress
been in the reverse direction—from the north towards the south? And
are our indigenous species of Acrosoma the survivors of a fauna that once
held sway throughout the regicn stretching from New England to the
Pacific ?

IV:

Closely associated with spiders making a horizontal snare is the Bas-
ilica spider, the sole known representative of species that spin what I have
ralled a Domed orb. The
history of this species,
which I have heretofore
recorded, is as follows:}
In the month of June,

1877, I was en-

Sa camped upon
ee the hills of the

Epeira x ,

basilica, Colorado River

of Texas, a few
miles southwest of Aus-
tin, studying the habits
of the agricultural and
cutting ants.2 A limited
portion of my time was
given to observing spi-
ders, in the course of
which the object of this
sketch was discovered.
Her snare was hung about
two feet from the ground,
upon a bush which stood

; . in the midst of a grove
lic. 154, The dome shaped snare of the Basilica spider. r, the reti- t a tS

telarian snare; d, the dome. ot young live oaks. This

' Proceedings Academy of Natural Sciences of Philadelphia, 1878, pages 124-1382.

* Observations upon the former species are recorded in a volume entitled “The Agricul-
tural Ant of Texas,” J. B. Lippincott Company, Philadelphia. For some account of the
Cutting Ants see “Proceedings Acad. Nat. Sci. Phila.,” 1879, page 33, and Chapters XIII. and
XIV. in my popular work entitled “The Tenants of an Old Farm.”

HORIZONTAL SNARES AND DOMED ORBS. 165

snare had the composite structure imperfectly represented in Fig. 154.
The general form of the snare was that of a pyramid the upper part of
which, r, was a mass of right lines, knotted and looped and crossed in
all directions. Within this mass was suspended an open silken dome, d d,
constructed of a vast number of radii crossed at regular intervals by con-
centrics after the manner of the common orbweaving spider. The radii
were about one-sixteenth inch apart at the bottom or circumference of the
dome. The concentrics extended entirely and with equal regu-
larity to the summit. They did not cross the radii in circular
lines, but presented that notched appearance which characterizes
the notched zone in the ordinary webs of Orbitelariz. The meshes formed
by the radii and spirals had thus much the shape of the meshes in a fish-
erman’s net. The diameter of the dome was from seven to eight inches
at the base, and the height nearly the same. It was suspended in the
midst of the retitelarian lines by silken guys of
like character, which thor gay oughly steadied the del-
icate structure, and per fectly preserved its form.

Beneath the dome, from two to three inches
removed, was a light sheet of cobweb, ¢, irregularly

meshed by wav ing and straight lines.
rei It had a decid ed convexity upward, and
Bisor was supported, like the dome above it,

and of which it seemed to be a protecting
curtain, by silken threads or guys, so stretched as
exactly to meet this pur pose. This curtain may
have been simply the col .. 1. «ne Basilica ae lapsed remnant of an old
web, which had been strip a, side view of body; c,ceph- ped downward, or aban-
foned: iz} orders ito: com "an eet struct a fresh snare above
it. But it presented the appearance of a special structure, intended to
serve a special purpose.

Of the many specimens of spinningwork which I have studied, I have
never seen one quite so beautiful as this. It was with real regret that such
a rare piece of spider architecture was destroyed, after it had been sketched,
in order that the architect, herself one of the most beautiful of her
kind, might be collected for the cabinet. The species was named Epeira
basilica.

It would be an interesting study to the architect of human habitations,
to uncover the principles upon which this silken basilica was reared. He
would doubtless find admirable adaptation of means to ends; he
would be likely to meet methods quite familiar to himself; and
perhaps to stumble upon some of which he is yet ignorant. He
certainly would have occasion to marvel that a structure so stable could be
wrought out of such fragile material as spider silk, and that the delicate
dome could be so poised in the midst and by the help of silken threads as

The
Dome.

Architec-
ture.

166 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

to preserve its perfect form. Perhaps he would rise from the study with
a higher appreciation of the quality and character of despised Arachne.

Nor would he find the creature herself unworthy of admiration as she

hangs inverted within and just below the summit of the dome. The term

beautiful is rarely associated with individuals of her order, but it
The Arch- ee ae set Ase an si See
aesck: may properly be used in this case. There is a combination of

crimson, various shades of green, yellow, snow white, and black
colors, which might prevent the most fastidious lady from raising the cry
of “horrid spider!” against a creature bearing such delicate hues and
dwelling in such a fairylike domicile. However, the main point of interest
in the Basilica spider is neither its architectural skill nor its fair colors.
Its chief importance to the arachnologist is that it seems to form a perfect
connecting link between the orbweaving
and lineweaving spiders, in the character-
istic spinningwork of the two tribes.

In order to perceive this statement it is
necessary to recall what has been written in
the last chapter about certain Orbweavers

that make composite snares, as
A Con” for example, Epeira labyrinthea
necting a : ps : :
Link. and EK. triaranea. These species,

it will be remembered, not only
spin the typical orbweb of the tribe to
which they belong, but combine therewith
a mass of right lines intersecting one an-
other in different planes and at various
angles, the whole combination forming at
once the home and snare of the animal.
The maze is an exact retitelarian snare, as
has already been shown, and will be readily
recognized by any ordinary observer of the cobwebs, for the most part made
by Theridioids, which form the bulk of those infesting the angles of the
walls of our stables and outbuildings. Thus our first connecting link be-
tween the spinningwork of Orbweavers and Lineweavers is established at the
typical web of the latter, as shown in the snares of the family Theridioide.

The second link, which itself constitutes in the web of the Basilica spider
a complete interblending of the groups, is seen at the snares of the Linyphi-
olde. ‘The genus Linyphia is one of the largest and most impor-

Fic. 156. The bowl shaped web of Linyphia
communis.

Linked to :
. tant among the weaving gener yrder to show the steps by
eine. t ng the Lineweaving genera. In order to show the steps by

which the two groups approach each other in habits, some expla-
nation of the spinningwork of the Linyphians is necessary. Their web differs
from that of the Theridioids substantially in the addition of a sheetlike
web to the web of intersecting lines. Indeed, the lines take a subordinate
or subsidiary place, and the sheet appears to be the real snare. There are

HORIZONTAL SNARES AND DOMED ORBS. 167

three common variations of the form: First, a plain sheet of thin silk
attached to the under part of leaves or suspended between branches as in
the webs of Linyphia costata. Second, the snare of L. communis, represented
at Fig. 156. It has a mass of right lines, r, to which is suspended a bowl
like sheet, b, beneath which again is a dish shaped sheet, d, of more open
spinningwork with the concavity upward, as in the bowl. The snare from
which this figure was drawn had a total height of from twelve to fourteen
inches. The diameter of the bowl was from
six to seven inches, its depth one and a half
to two inches.

Linyphia communis hangs inverted to the
lower surface of her bowl, and is thus pro-
tected from assaults by the underlying floor
or dish or curtain, d.

A third variation is that of the beautiful
snare of Linyphia marginata (lL. marmorata
of Hentz), which is in form precisely like
that just described except that the bowl
becomes therein a dome. That is to say, )
the sheet, b, has the concavity downward //,/-]
instead of upward, and the dish or cur-
tain undergoes a similar change. In
other words, the web of Marginata
has the exact form of Basilica’s
web, except that in the latter the *=*
dome, d (Fig. 154), is constructed =\
of open regular meshes formed by ENS
the intersection of radiating ribs :
of silk with notched concentrics,
while Marginata’s dome is woven
of irregularly placed threads into
a thin sheeted web. The lower curtains, and the upper retitelarian web are
substantially the same in both. In other words, the typical character of
an Orbweayer’s snare, namely, regular radiating lines regularly crossed by
spiral concentrics, appears in the web of Basilica without any other change
from a fixed generic Linyphian web. In the figure (157) the three netted
domes were apparently made successively by one spider, and abandoned
for some undiscovered reason. The ordinary web contains only one dome.
It is probable that the curtain usually found beneath this is the compressed
remains of a former dome, above which a new tent is reared. Something
of the same habit may be seen in certain Orbweavers, who, however, push
the rejected material to the outer margins instead of beneath the web.

We may trace this interesting analogy from another point in the group
of Orbweavers, and find yet further coincidence. The typical orb of the

Fic. 157. The snare of Linyphia marginata.

168 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Orbitelariz is vertical, but the corresponding section of the web of the Bas-
ilica spider, Fig. 15, d d, might be properly described as horizontal, or
rather as a blending of the horizontal with the vertical. In other

ae words, if a horizontal orb attached at the circumference in the
jira oF” usual way were to be lifted up by a thread fastened in the centre,

it would assume the shape of the dome in the web of the Basil-
ica spider. In point of fact, this effect might be produced from the charac-
teristic snares of those species which have been described in the opening of
this chapter. If, for example, one were to fasten a thread to the central
point of the orb of Tetragnatha or the Orchard spider, and gradually lift
it until the orb should assume the dome shape, he would have a snare very
strongly resembling that of Basilica. The principal difference would be that
the apron of intersecting lines beneath the dome of the Orchard spider ap-
pears in Basilica’s web as the underlying curtain; and in addition thereto
a similar mass of spinningwork appears above the orb. Another difference
is that the spiral concentrics all have the notched appearance of the few
central concentrics which compose what I have named the notched zone.

Several years after I had observed and published the description of Bas-
ilica’s web and its relations, substantially as described above, I was greatly

delighted to have my study confirmed by the observations of Dr.
Observa- George Marx, of Washington, D. C. He had received my ac-
tions Con- : aa ’ ie ; caste
firmed, count with much skepticism, as indeed did other arachnologists.

Unfortunately, my description of this entirely new form of orb-
web, and the remarkable deduction therefrom, were based upon observations
of a single example both of spinningwork and spider making it. I had no
doubt of the accuracy of my notes and sketches, which were made with
care and painstaking, for at the first glance I apprehended the importance
of the discovery. Nevertheless, I greatly desired to find other examples,
but searched in vain in the neighborhood of my camp.}

It was, therefore, with unusual satisfaction that I learned from Dr.
Marx that he had observed several specimens of Basilica in the shrubbery
on the beautiful parked grounds surrounding the Agricultural Department
and other public buildings of the national capital. He confirmed my de-
scription of the character of the web, and added thereto an obser-

ration of the manner in which the dome is reared. The hypo-
‘thetical case, given in my original paper, of the manner in which
the domed orb of Basilica might be (substantially) erected out of the hori-
zontal orb of the Orchard spider, proved to be a fortunate anticipation of
the exact method of the spider. Dr. Marx says that the orb is at first a

Building
the Dome

1T had gone to Texas with a special purpose, namely, the study of the Agricultural
Ants; and it was absolutely necessary, in order to follow my line of study and experiments,
that I should limit the time given to other observations. I have often regretted that I
could not haye spent a day or two in searching the surrounding district for other examples
of Basilica,

HORIZONTAL SNARES AND DOMED ORBS. 169

horizontal one; and that it is lifted up gradually by attaching lines at
various points upon the upper surface and drawing them taut, one after
another, until the whole is lifted up into the domed structure represented
in Fig. 154. I may add that Dr. Marx was also able to collect cocoons of
the species, and describe the manner in which they are hung in the neigh-
borhood of the web.!

The manner in which this change is wrought was determined by Dr.
Marx, and he has kindly placed at my disposal his notes upon the same.
When first observed by him (at 8.30 A. M.), the snare lay in a horizontal
plane, as shown at Fig. 158, and had more than fifty radii. It was hung
between the tips of the branches of a bush. At 12 M. the borders of the
snare were bent downward, causing it to assume the form of a shallow
dome. At 4 P. M. the transformation had so far progressed as to bring the
web to the structure represented at Fig. 159. The work was carried on in
this wise: At the marginal edges were outgoing lines, as ¢ b, Fig.
158, used to support
or brace the snare, as
is usual with hor-
izontal orbs. On

Fic. 158. Basilica spider’s mode of transforming a horizontal
into a domed orb.

these at certain points (c) were fastened lines (c d),
which were attached to a branch (d) some distance
below and to one side of the plane. These lines
(c d) were gradually borne downward until they
sition of the dotted line, ab. This action caused the depression of
the edges; and by continuing this manipulation of the outside or
foundation lines, the orb was forced first into the shape of a shallow dome
flattened at the pole, and then into the form of the’ typical web as above
described. (Fig. 159.) This action was seen “repeated over a dozen times.”

But it was manifest that some other method had been brought to bear’
than that already explained. The position of the snare in its original
horizontal form had been exactly located by a fork (f, Fig. 158), in the
branch to which the stay lines were attached, which was on a level with
the horizontal axis of the orb. Now, however, the edges of the web were
not only drawn below the level of the fork, but the central part was raised
at least three-fourths of an inch above the fork. (Compare f, Fig. 158,
with f, Fig. 159.) The manner in which this had been done was readily
seen by a glance at the various lines, perpendicular and inclined, which

assumed the po-

‘See Vol. I., Chapter on Maternal [ndustry.

170 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

extended upward from the exterior of the dome to the inclosing and sup-
porting labyrinth of crossed lines. Evidently the little engineer had com-
pleted the work, so well begun in the depression of the edges of her orb,
by elevating the central part through the same method of applying force,
but in an opposite direction. So well had the power been graduated that
the proportions of the dome were beautifully preserved.
We have thus traced the analogy between the spinningwork of this
species of Orbweavers and that of Lineweavers in these several particulars:
_ First, in the dome shaped snare and dwelling place, which cor-
Spinning- responds with that made by a species of the Retitelarian genus
ore Linyphia. Second, in the mass of intersecting lines placed around
gies. and above the dome, which is the characteristic web of the Retite-
larian genus Theridium and of many other genera. ‘Third, in the
sheet like curtain beneath the dome, which in form resembles the thinly

Ad

Fic. 159. Position of Basilica’s web after the horizontal orb has been transformed. The meshed
structure is only indicated. The original plane of the orb is shown at f.

sheeted web of many species of Linyphia, as, for example, L. costata; and
which in both position and form corresponds with the underlying curtain
or dish of L. communis and L. marginata.

Thus, Epeira basilica is seen to possess all the leading characteristics of
the principal families of the Retitelarize, namely, (1) the maze of crossed
lines, and (2) the sheeted web in exact detail, and (8) the dome shaped
web in outline. It also possesses the chief characteristic of the Orbitelariz,
namely, the geometric web, or radiating lines regularly crossed by concentrics.
Moreover, it combines in its dome structure the vertical and horizontal forms
which are the prevailing ones in the orb of its congeners. The Basilica
spider may, therefore, be regarded as well nigh, if not completely, bridging
the space between the spinning economy of these two great tribes of the
Aranee.

HORIZONTAL SNARES AND DOMED ORBS. tit

In this connection it should be remembered that there is a general resem-
blance in structure between the Orbweavers and Lineweavers; and it may be
stated, moreover, that this resemblance is more marked in the case of the
genus to which Basilica is closely related, Meta; and also in some of those
species which have the habit of making a composite snare. ‘This is so strik-
ing in Koch’s genera Meta and Zilla that they have been classed with both
sections. On this point Dr. T. Thorell has remarked, “As Zilla shows an
analogy with Steatoda of the Lineweavers, so does Meta form a transition
to Linyphia of the same tribe.”! These relations may be more fully con-
sidered in the systematic part of this work, but in the meantime we are
justified in saying that in the case of the above named species, we find the
tribes of Orbitelariz and Retitelariz approaching each other in structure
as well as in the interblending of their spinning habit.

1“QOn European Spiders,” page 61.

CAL UB ex:
THE FEATHERFOOT SPIDER, ULOBORUS PLUMIPES.

ils

THE remarkable genus Uloborus is represented by at least two species in
the United States, namely, Uloborus mammeatus Hentz, and Uloborus
plumipes Lucas (Phillyra riparia Hentz). These spiders closely

Uloborus jyesemble each other in structure and, as far as I know, have no
Distribu- ,. ae : ee ae , e ; a
eee difference in habit. The genus, in both its species, is widely

distributed over the United States, probably covering the entire
area. I have traced its distribution from New England, tm the States of
Massachusetts, Connecticut, and Rhode Island, southward to New Jersey,
through the District of Columbia, to Florida. Moving westward, along the
Gulf States, it was found by Hentz in Alabama, and by myself in Texas.
Specimens have been sent me from Wisconsin, where the Peckhams have
observed it, and I have collected it at various points in Eastern and Cen-
tral Pennsylvania. This record of distribution would indicate that the
spider probably occupies the whole area of the United States, with the
possible exception of the Pacific coast; and I have no doubt that it will
be found there also. Plumipes is found in Europe, as are other species of
the genus. Uloborus is not of modern origin, as the family, at least, is
represented among the fossil spiders of the amber.

My studies of Featherfoot’s local habitat show some decided prefer-
ences for moist, low, and well shaded sites, but indicate a quite miscella-
neous taste. In Connecticut I found its snares in the decayed
hollows of old stumps or cavities beneath their roots, and spun
Orb Sites, Near the ground upon the low underbrush of thickets. One very

large colony of young spiders was found on laurel bushes at the
foot of Brush Mountain, Pennsylvania, above one of the branches of the
Juniata River. Their snares were swung at the height of four feet and
less above the surface. In the neighborhood of Philadelphia I have found
them quite low down, swung between the stalks of a blackberry thicket,
and once only within a shallow cavity among the stones of an abandoned
mill dam. I have always happened to observe them in moist places near
running streams. In Texas I found Uloborus, probably Mammeatus, in

bushes on the uplands south of Austin, above the deep gorge of Barton
Creek.

THE FEATHERFOOT SPIDER, ULOBORUS PLUMIPES. 173

Hentz observed the species on limestone rocks on the banks of Cyprus
Creek, and in moist places in North Alabama. Its congener, U. mamme-
atus, he found dwelling most frequently in cavities, among large logs, and
in hollow trunks of trees. Emerton found Plumipes between loose stones
or low bushes in New England. Mrs. Peckham almost invariably found
this species building in dead branches, six out of seven being thus located.?
She gives an apt abstract of its habits. In form and color it resembles
a scrap of bark; its body is truncated and diversified with small humps,
while its first legs are very uneven, bearing heavy fringes of hair on the
tibia, and having the terminal joints slender. Its color is a soft wood

\ ¢ Stan oo .

Fic. 160. Orbweb of Uloborus, spun in the opening of a hollow stump.

brown or gray, mottled with white. It has the habit of hanging motion-
less in the web for hours at a time, swaying in the wind lke an inani-
mate object. The strands of its web are rough and inelastic, so that they
are frequently broken, and this gives it the appearance of one of those
dilapidated and deserted webs in which bits of windblown rubbish are
frequently entangled.

Baron Walckenaer says that the closely related European species, Ulo-
borus Walckenaerius Dugés, generally spins its horizontal snare between
the stems of rushes in dry and warm places, which resembles that of
Epeira in form, but of looser tissue.* Hahn found the species in the

1 Phillyra mammeata. “Spiders of the United States,’ page 129.

2“ Protective Resemblances in Spiders.’”’ Occasional Papers of the Natural History So-
ciety of Wisconsin, Vol. I., 1889, page 77. By George W. & Elizabeth G. Peckham.

> Aptéres (Suites 4 Buffon), Vol. IL, page 229.

174 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

neighborhood of Nuremberg on the edge of forests, building its snare be-
tween young pines. Simon says that the species lives upon dry brambles
or in the cavities of old walls, that it is always found stretched
Uloborus jenothwise beneath its snare, and is readily confounded with
W alck- es ae F ae tee os
enacrius, *Woiming objects. Uloborus Walckenaerius is one of the
spiders inhabiting Palestine, being among those lsted from
Syria by Mr. Cambridge.
I have never seen the orbs in any other than a horizontal position.
They measure from three to four and five and a half inches in diameter.

as

' \ \S)
\ \ Vl

H

MSN ee i 4,

aR _— \
Nae,

rll qT mM A || mT a

b << Se

SUNN AON
i g et

CUCL

UNUM

Fic. 161. The orb of Uloborus on a laurel bush. The curled spiral thread is represented, and the remnants
of a former web pushed back to the margin.

The hub is generally closely and beautifully meshed, like the snare of the
Labyrinth spider, and the central space is entirely filled up by concentrics,

corresponding with those composing the notched zone in the or-
Charac- dinary webs of Orbweayers. The radii diverge in the ordinary
ag way, but seem to be of a rather delicate material. In the Juni-
Snares. ? °

ata colony above named many of the webs were surrounded by
what appeared to be the collapsed remains of a former snare. The spiders

AD)

1“ Arachnides de France,” Vol. IL., page 169. 2 Proc. Zool. Soc., 1872, Part I., page 279.

.

THE FEATHERFOOT SPIDER, ULOBORUS PLUMIPES. 175

appeared to have cleared away and pushed back the old broken webs so
as to make space for new ones, and the fragments occupied the margin of
the orb space close up to the points at which the foundation lines were
attached to the adjacent foliage. (See Fig. 161.) On one of these webs I
counted thirty-six radii and twelve spirals, not including among the latter
the concentrics which fill up the central space. The hub measured a
quarter inch in diameter, and the distance between the concentrics was

one thirty-second of an inch. Beneath the orb there extended

ee a mass of retitelarian lines, somewhat after the manner of the
easure- - :

Orchard spider, but not so abundant. The central spirals grad-
ments.

ually opened as they approached the true spiral space, and were

separated by distances ranging from one-eighth to one-fourth inch. A
notched ribbon about an inch long was spun on each side of the hub,
gradually terminating in a point. The central spirals crossed the ribbon
at the points of its angular scallops. The hub was one-fourth inch wide.
Snares of Uloborus found upon the banks of Bride’s Run, at the out-
let of Bride’s Pond, near Niantic, Connecticut, were
spun in the cavities of old stumps, or upon the ferns
and grasses near the banks of the stream. The hub
was checkered or meshed somewhat lke the notched
zone of Epeiroids. The notched or central spirals
seized the points of the little ribbon that extended
centrally through the hori zontal orb. The spirals of
one orb were twenty-two in Fie. 162. Piecéof the number, the radii thirty-
2 ml : scalloped ribbon on :
nine and forty. The spirals — , orortloborus, COntinued close up to the
margin of the notched zone, without any interspace, and
the web was about four and a half inches in diameter. (See Fig. 160.)
A striking peculiarity of the orbs of this species is the ribbon decora-
tions which are quite characteristic, and unite the spinningwork of the
genus with that of such genera as Argiope and Acrosoma. Per-

Ribbon haps the most frequent form of decoration is a scalloped band
Decora- : : : : . a
tions, 2bout one thirty-second inch in width, which crosses the central

part of the orb, being scarcely perceptible at the hub, and grad-
ually diminishing towards the circumference of the orb. Where the spirals
cross, this ribboned spinningwork is pulled into points, thus giving the
band the toothed or scalloped appearance represented at Fig. 162. The
distance between the spirals was from one-fourth to one-eighth of an inch;
the distance across the band from point to point about one thirty-second
of an inch.

Another form of decoration shows simply the addition on one side of
the hub of a second ribbon, which makes an angle with the first. In this
snare the spider hung beneath the hub, with its fore and hind legs re-
spectively attached to the points where the ribbon joins the hub.

The most remarkable decorations of this sort I found upon the orbs of

176 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Uloborus mammeatus in Texas. They formed interesting and beautiful ex-
amples of this character of spinningwork, which is more easily illustrated
than described. Fig. 163 represents one web. The upper ribbons, travers-
ing nearly the entire area of the hub, were very much the same as the
last described, except that on one side the spinningwork was greatly
thickened at the termination, giving a club shaped appearance. On each
of the other sides of the hub were thrown two parallel semicircular bands
shightly separated from each other. In another snare, represented very im-
perfectly, indeed, at Fig. 164, the longitudinal bands were lacking, but in-
stead of them a series of four or five circular bands encompassed the hub.
My sketches, taken upon the spot, do not show that these bands were con-
centrics, though I have been inclined to think that such might have been
the case. At one side of this orb was stretched a ladder like structure lead-
ing from the hub to the outer foundation lines. This was a very peculiar

—
S

/

Fic. 168. Decorated orb of Uloborus mammeatus.

formation, and reminded me somewhat of the zigzag band characteristic of
Argiope cophinaria, but the rounds were not continuous as with that spider.
The purpose of these ribbons I have never been able to determine
satisfactorily. I have called them decorative, not because I imagine
that the purpose of the spider in placing them upon her

Use of web is in anywise analogous to the human = sentiment ex-
Decora- . : :
naka pressed by that word, but simply as a convenient term to in-

dicate the character of the spinningwork as it presented itself to
my own mind. Certainly it did greatly enhance the beauty of the deli-
cate structure. It is probable that these decorative ribbons or bands serve
to protect the spider herself, and may also be of service in strengthening
the web. But I have sufficiently expressed my opinion on this subject
when treating of the snare of Argiope. (Chapter VI.)
No one who has studied with any care the spinningwork of the Orbi-
telariz can doubt that the web of Uloborus is that of a genuine Orb-
weaver. In its round shape; in the arrangement of lines radiating from

~I

THE FEATHERFOOT SPIDER, ULOBORUS PLUMIPES. 17

the centre; in the structure of the hub; in the preliminary spiral scaffold ;
in the central concentrics, which correspond with the notched zone; in
the form and distribution of the spirals; in the character of the

A Gen- sibbon decorations; in the manner in which the snare is swung
uine Orb- 3 : : : ; :
weaver, (© foundation lines in whatever site it may be placed; in the

position of the spider underneath the web ;—in all these points
the spinningwork of Uloborus is analogous to that of Orbweayers, espe-
cially Tetragnatha, or of the Orchard and Hunchback spiders.

There is, however, one important difference. The spiral concentrics, in-
stead of being composed of single lines covered with viscid beads, as in
typical snares of the Orbitelarize, are composed for the most part
of several very delicate filaments, although in certain parts the
thread is single. To threads and filaments alike are often at-
tached a number of minute objects, opaque, and for the most part amor-
phous; but many of them being very small globes of a yellow color, per-

No Viscid
Beads.

Fic. 164. Circular ribboned decorations on the snare of Uloborus.

haps the pollen of flowers. They adhere to the single threads, but more
. fully to the portions containing several distinct filaments. These opaque
objects have so much the appearance of beads that a careless observer is
likely to be deceived by them; at least, I was thus led astray in my first
studies of the Uloborus snare. There are, however, no viscid beads upon
any of the lines, although the thread is certainly very adhesive, chiefly
I suppose by reason of the delicacy and flocculence of the fibre. The
smooth point of a pencil touched to it does not adhere; but when my
finger was laid upon a spiral it adhered as in the case of a beaded web.
In this respect the snare of Uloborus resembles that of the Triangle
spider, Hyptiotes cavatus, and also certain species of the Clubion-

See idee, such as Dictyna philoteichus and other species of that genus.
of Floc- : :
Pitted This flocculent web was discovered and described by Blackwall,

Spirals, @d is produced by special organs known as the cribellum and
‘alamistrum. The calamistrum is located upon the metatarsus
of the hind pairs of legs. It resembles somewhat in form the flyers upon

178 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

an old fashioned spinning wheel, and is apparently used to separate into
a flossy mass the threads of silk as they issue from the spinning glands.
Bertkau, in an article on the cribellum and calamistrum, has shown cer-
tain secreting glands at the ends of the fine tubes which have their
outlets in the former organ. It is not improbable, in view of this dis-
covery, that the viscidity of the flocculent spirals
of Uloborus and other spiders possessing this
K-70 organ is caused in some measure by a slight
Zé secretion from these glands.

It is the possession of cribellum and cala-

mistrum by Uloborus and Hyptiotes which has
_ led various arachnologists to separate
Calamis- these two genera from the Orbweavers,
SSS ene Emerton, for example, following Black-
= =/\\y Cribellum “* Gy ae eae: ) s aes
a) wall, Keyserling, and Bertkau, assigns
ee ee them to the Clubionidee. Without entering at
showing the cribellum, cb. P, pos) length into the reasons, based upon structure, for
peer Sa ones dissenting from this opinion, I have felt con-
eee strained, on the grounds of their spinningwork
alone, to place both these genera among the Orbitelarize, where indeed such
a distinguished systematic arachnologist as Professor Thorell has already
placed them, and continues to keep them, notwithstanding all the objec-
tions that have been advanced by the able naturalists who have espoused
the other view.

Mr. Emerton has made some studies of the web of Uloborus Walek-
enaerius, the common species of Northern Europe. I reproduce his figure
(Fig. 167), which represents an unfinished web of this species
seen in France. It shows the central part still occupied by the
preliminary spirals or scaffolding, while the outer part is covered
with curled threads, and the smooth spirals cut away (or not yet inserted),
leaving thickened spots or ribbons on the rays. In the finished web most
of the spirals pass regularly around, but the outer ones are often more or
less irregular, as in Epeira webs, according to the shape of the space in
which the web is made.

According to this author, Uloborus, after inclosing her eggs in the co-
coon, becomes careless about her web,
and repairs it only enough to keep the
cocoons in place, so that many imper-
fect and irregular webs are found at
the cocooning season. The only web Fic. 166. Curled thread of Clubiona.
of Uloborus plumipes seen by Emerton Vip aoe ag
was imperfect from the above cause, but was evidently the remains of a
nearly round web, the rays meeting somewhat nearer the upper than the

EHuropean
Species.

lower edge.

THE FEATHERFOOT SPIDER, ULOBORUS PLUMIPES. 179

The same author says that the spiral lines of Hyptiotes and Uloborus
have a strong, smooth thread through the centre. That of Hyptiotes, which
he examined fresh, had the finer
part arranged in reg-
ular leaves or scallops,
in which the separate
fibres could not be distinguished.
The thread of Uloborus, at least
when old and dried, had the
loops longer and less regular, and
he had not been able to distin-
guish the separate fibres except
at the edges of the band. To
my eye the spiral seemed to be
a single continuous flocculent fil-
ament without any supporting
thread, thus differmg from Hyp-
tiotes. But of this I am_ not
confident. Under a common
hand lens it has a milky or
filmy hue.

The position of the spider upon her snare is very much like that of
Tetragnatha. I have found her stretched out underneath the hub, with
the legs extended fore and aft almost in a straight line with the
ribboned decorations to which the feet clung. Sometimes, how-
ever, she turned and hung beneath the hub at a position at
right angles with the ribbon.

One young specimen, captured upon her snare, I saw repairing the
broken margins of her web. It was done line after line, one
radius and one spiral at a time, precisely in the manner common
to other Orbweavers. The broken lines were cut out, and new
ones substituted, or were picked up by the spider’s feet, spliced, and
stretched into position. She worked very deftly and rapidly. I saw her
capturing a small insect, a gnat. The two hind legs were used for rapidly
pulling out the enswathing thread, while the second and third legs re-
volved the insect and held it to the web. According to Hentz, Uloborus
has the habit of vio-
lently shaking — her
web when threatened.
But when at rest he
always found it in an
inverted position underneath its orb, with its hind legs extended in parallel
lines like Tetragnatha. This record of habits, imperfect as it is, indubi-
tably places Uloborus among the weavers of orbwebs.

Spiral
Thread.

FIG. 167. Unfinished web of Uloborus Walckenaerius.
(After Emerton.)

Position
on Snare.

_ Repairing
Snare.

Fic. 168. Uloborus hanging beneath her orb.

CHEAP Eni Xo
THE TRIANGLE SPIDER: THE ORB SECTOR.
i

Tue snare of Hyptiotes cavatus, the Triangle spider, has awakened
deep interest among naturalists on account of its peculiar construction and
manner of operation. The little spinner is equally interesting to the sys-
tematist, because of its relation to other individuals of its tribe; and in-
deed because of the question, which has divided arachnologists, as to what
tribe in the order Aranez it truly belongs.

I have no hesitation in assigning it to the Orbitelariz, where it seems

to me that its spinningwork undoubtedly requires it to be placed. On the_

grounds of structure, also, I follow Dr. Thorell and give it the
same position,! although it must be allowed that the authorities
are well worthy of consideration who place it among the Clubi-
onide. As in the case of Uloborus, this is done almost exclusively upon
the grounds that Hyptiotes possesses the cribellum, a special organ for the
exudation of spinning material, and the calamistrum, by which such ma-
terial is manipulated or hackled until it presents the appearance which
will be further described hereafter.

The snare is a sector of a circle, including about forty-five degrees of
the area, and with a radius varying from twelve to twenty inches or less.
It is thus, as to shape, in strong contrast with the typical orb of
Epeira, which is a full circle, and with the sectoral orb of Zilla,
which is a circle lacking its upper sextant, while the net of
Hyptiotes is just about a sextant or sixth of a circle. In the language of
Professor Wilder, who has pointed out these relations, to use a more
homely comparison, the net of Epeira is an entire pie; that of Zilla or
Nephila is a pie with a piece cut out; while that of Hyptiotes represents
the missing piece. In algebraic language, Zilla + Hyptiotes = Epeira.?
(See Fig. 170.)

The snare is habitually spun in a vertical plane, although it is subject
to some variation, and I have occasionally found it more or less horizontal.
It is hung in all sorts of positions between the» branches of trees and

System-
atic Place

The
Snare.

1On European Spiders, page 69.
2 Professor Bert G. Wilder, Triangle Spider, “Popular Science Monthly,” 1875, page 653.
(180)

THE TRIANGLE SPIDER: THE ORB SECTOR. 181

found it abundant among the mountain pines of Central Pennsylvania,
as well as among the flat, sandy, pine barrens of New Jersey, and in
pine groves on the seashore at Ipswich Bay, Massachusetts. But
I have frequently seen it in other positions, among shrubs and
evergreens on the lawns of country residences; in groves of deciduous trees
in Connecticut; in the underbrush of Woodland Cemetery, Philadelphia;
on the banks of the Schuylkill, and in shady ravines in Fairmount Park.
Mrs. Mary Treat found it in New Jersey dwelling among flowering peas,
having its snare attached to the dry sticks upon which the vines were sup-

The Site.

ice
a

ate
[siege TA
’ HSC Iw AWN

thi

Fic. 169. The snare of a Triangle spider, spun on a dry bush by a New England stone fence.
One-half natural size.
ported. While Hyptiotes thus shows a disposition to domicile on any
sort of bushes or foliage, its favorite location may be said to be groves
_ of pine. In this respect it corresponds with its European con-
Favorite ary : 1: ap eee cae . .
Net Site, 2°mer Hyptiotes paradoxus, which Professor Thorell found in
the neighborhood of Stockholm during July, August, and Sep-
tember, principally in woods of trees of the fir kind, especially in pine
woods.
Our Triangle spider, like Paradoxus, seems to choose most freely the
dry bare branches of the pine or other trees; but this is by no means a

182 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

universal preference, for I frequently find the snare spread among the
green needles of the pine boughs and stretched amidst the green foliage
of other plants. The nest site is generally low down. I have rarely
noted it more than three or four feet above the surface of the earth.
As the lower branches of pine trees are always dry, it would follow as
a necessity, without any special preference on the part of the spider, that
her habit of swinging her net low down would compel her in such
positions to spin between dry limbs.

The spider is probably distributed over a wide geographical area. I have
traced it from New England on the northeast, from Maine to Massachu-
setts, through New York, New Jersey, as far south as the District
of Columbia and Alabama. I have also taken it in Ohio, and
as far to the southwest as Texas. It thus shows a considerable
range of climatic extremes. It will probably be found wherever forests
of fir and pine flourish.

Hyptiotes is very small, being little over an eighth of an inch in body
length, with rather short, stout legs. It is a dull grayish brown color,
with occasional brighter tints of red intermixed. It thus strongly resem-
bles the color of the branclies
to which its snare is oftenest
hung. This identity of color
makes it difficult sometimes
to find the animal; but I can
hardly think that it presents
a case of protective mimicry,
as does Mrs. Treat, who also concludes that Hyptiotes recognizes color,
and that its habitual resting place is a matter of intelligent choice.t On

the contrary, as I have just stated, it is supposable that the

Distribu-
tion.

Fic. 170. Zilla plus Hyptiotes equals Epeira.

General position is simply a matter of convenience, as it gives the best
Appear- 144...
ees attachment for the trapline of its peculiar web; and, moreover,

since the spider domiciles in all sorts and parts of shrubs, hving
and dead, it is certainly reasonable to think that a bright green would
have been as great a protection to it as the dull brown and gray which
prevails.

The appearance which the snare presents to the observer is that of a

circular sector, attached at the open or outer end to surrounding objects,

and at the apex to a straight line of varying length, similarly
Construc- anchored. The number of radii is always four, never more nor
tion of F : eo Bee ast é
Web. less, and in this number, of course, is included the two outside

rays. The two central radii are crossed by lines which may be
regarded as the equivalent of the spiral ines which intersect the radii in
ordinary orbwebs. The manner in which these several parts of the snare
are constructed will now be pointed out.

1“My Garden Pets.”

THE TRIANGLE SPIDER: THE ORB SECTOR. 183

The mode of spinning the foundation lines or frame has never been
observed, as far as I know, by any naturalist. A careful study of a number
of webs, however, has led me to con-
clude that it is spun as follows: In
the first place, the spider stretches

between two points a sin-

Making gle line, which we may rep-
= resent by the dotted li
Frame. eee gee

PB, in Fig. 171. She then
proceeds to attach to this line, say at
the point A, another thread, which
is carried along the original line, Fis. 171. Making the frame of the Triangle spider's
PB, to the place of attachment, B. (te
Thence up the branch or other object to C, where the carried line is
drawn taut and fastened. There is thus produced the line AC, and the
original foundation line having been drawn
upward by pulling upon AC, has assumed
the curved form of AB. The two outer
radii of the snare are thus in place. Now
the spider drops from the point CB, carry-
ing with her a thread, which is attached at
B, and becomes thus the base line of the
triangle CABC. Proceeding along the line
BA, carrying with her a thread as before,
she makes another attachment at E, returns
upon her course to B, and thence upward
to E, on the base line where the carried thread is straightened, fastened,
and the third radius, EE, completed. In a similar way the fourth radius,
DD, is stretched. This, of course,
does not express the exact order in
every case, but the general method.

It will be observed that these
radial lines do not meet in a com-
mon point. This is in-
deed contrary to most
Pra published descriptions of
Point? the appearance of the

snare. For example,
Thorell speaks of these threads in Fie. 173. Natural arrangement of radii, to show the order
the net of Hyptiotes paradoxus as sane ot
forming “equal angles with the original thread, and each other.”' Em-
erton speaks of the apex as “the point where the rays meet.”? He again

= ;

Fic. 172. Frame or radial lines of Hyptiotes’
snare, as in nature.

Have

1 European Spiders, page 70. 2New England Spiders, Family Ciniflonide.

184 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

speaks of the four branches as radiating from the extremity of the sector.1
Fig. 171, with the exception of the dotted line, is drawn from nature; so
also are Figs. 172 and 173. These show, better than any worded descrip-
tion, that the interradials are attached in the manner which I have repre-
sented, and are not drawn out from a common apex or point.

According to my view, the position of the first line spun is indicated
by the dotted line (AA, Fig. 172). Afterward the first radius (Ir) was
formed by attaching that line to AA, thus drawing it up until it assumed
the position of Aa, Aa. To this again were successively fastened the lines
2r and 38r, which completed the radial framework, ready for inserting the
spirals. So also, at Fig. 178, one sees the same order of progress as shown
by the numbered lines, viz., the dotted original line drawn up to make the
trapline and first radius (Ist) by the attached thread, which constitutes the
second radius (2d). The base line (8d) comes next in order, and there-
after the two additional radii (4th, 5th) in their order.

No doubt, the radial lines may be at times found meeting at or near the
same point; I have certainly so found them, but I believe that this is not
characteristic of the spinningwork, but is simply an accident thereof. In
other words, the spider having made her first main line, attaches the three
succeeding shorter ones to a convenient point thereon without much regard
to whether they meet in a common angle or not, but in fact ordinarily
places them at different points along the line.

The framework being thus prepared, the spider proceeds to place in her
spirals. For the manner in which this is done we are «indebted to Pro-

fessor Wilder. His account is based upon two personal observa-
Mode of tions of the mode of spinning. He says: “Let us suppose that
ries the framework of the net is completed, and that the first or

longest interradial line (Fig. 174, I4) has also been made. In-
stead of beginning the second interradial at S* she begins at 4; and in-
stead of climbing up the interradial or the strong and convenient base line
(BB), she runs to a point (2) on the lowest radius near the apex, crosses
the two intermediate radii from 2 to 3, and passes along the upper radius
to the attachment of the first interradial (S1). On reaching this, she turns
and moves for about her own length toward the apex. Contrary to the
usual habit of spiders, during this roundabout passage from 1 to 4 she
spins no thread. She now spreads her spinnerets a little, and presses them
upon the radius, keeping them so while she advances again about her own

: length. This forms the attachment of the second interradial
eet, ( [?). The spider then lets her abdomen fall somewhat, support-

ing her body and advancing upon the line by means of her
first, second, and third pairs of legs. The fourth pair are apphed together
to the spinnerets with great rapidity, at least five times in a_ second, or

1 Structure and Habits of Spiders, page 76.

THE TRIANGLE SPIDER: THE ORB SECTOR. 185

three hundred times in a minute, and in so doing they draw out a
double line.

“The spider moves slowly along the radius until she reaches a point (5)
where she can step across to the next radius. While so doing, she ceases
to draw out the double line, and carefully keeps it from contact with
either of the radii. She then reverses her course and moves along the
second radius to a point (6) nearly under that whence she started. The
double line has shortened itself considerably; any slack she draws in, and
then turning about, with her head toward the apex, she makes a second
attachment with her spinnerets close pressed against the radius. This
done, she again hangs from the radius, draws out the spiral line, and ad-
vances toward the apex, crosses at 7 to the third radius, returns thereon to
8, and makes a third attachment. She then repeats the same
process upon _ the third radius, and in Fig. 7 is repre-
sented (at 9) as { having finished about one-half of the line.”

The number
of crossed lines
when the work =
iscompleted ya- fh = 6
ries, according =
to Wilder, from
six to sixteen.
The European
Paradoxus, ac-
cording to Thorell, spins from sixteen to twenty-two.
According to my own count the number is not constant,
but the prevailing number is nearly sixteen. I have counted
five, fourteen, nineteen, and twenty-two on snares in the same
general site. The number is not constant even with the same
individual. A female that spun fourteen spirals on one day had nineteen
the next; and like differences showed in the other parts of the snare.
Evidently there is no mechanical necessity in the constitution of the ara-
nead that compels it to a machine regularity of product.

These lines are not single threads, covered with viscid beads, as in the
case of most Orbweavers, but resemble those of Uloborus, as heretofore
described. That is to say, as they exude from the spinnerets and cri-
bellum, they are teased, or to borrow a word from the flax manufac-
turer, “hackled,” by the calamistrum into a somewhat irregularly widened
flocculent mass. ,

Wilder speaks of the spiral thread as simply double lines, the two
strands being from one five-hundredth to one two-thousandth of an inch
apart. Emerton says that it “has a strong smooth thread through the

Fic. 174. Mode of spinning floc-
culent spirals of Hyptiotes. The
Spider’s progress from 4 is shown by
the course of the arrows. (After Wilder.)

~
~
~

Iss

1 Op. cit., page 649, note.

186 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

centre,” and “has the finer part arranged in regular loops or scallops (see

Fig. 176, a,b!) in which separate fibres cannot be distinguished.”
The spiral lines, according to my own studies,
when examined under an ordinary hand _ lens,
present a milky appearance, as though composed
of very thinly spun material. With a little
higher power the supporting spiral thread is seen
passing through this milky mass. Placed under
a microscope, the line is seen to consist of three
strands, namely, the central spiral thread, and
two curled lnes, which alternately cross and _ re-
cross each other above and below the centre,
forming the loops as represented at Fig. 177. In
Fic. 175. Calamistrum of Hyptiotes, this respect Mr. Emerton has correctly represent-
(ter Wilder.) tarsus and met- ed the spiral line of dyptiotes. The two curled

atarsus of fourth leg; b, the claws, é és

open; ¢, cross section of the meta- lines seemed to me to be sometimes composed of
tarsus, showing liscavityinwhich 4 flocculent instead of a smooth thread, and it is

lie the muscles; also a single : 5 z
curved bristle upon the side, a this which, seen by the eye, or by a lens of low

art of the calamistrum; e, a sim- ; ; ;
flar calamistrum bristle stil mans POWer, gives the milky appearance described.
enlarged; d,f,two feathered bris) ‘The above results I obtained from freshly spun
tles from near the joints. : x
webs, whose clean silk was unmarred by use.
Other studies of this cross line, made from older
3

rz
snares, showed that it consists of one, two, or three — <i.
a “pb

separate threads, around or between which

Floccu- : : = Fic. 176. Thread of Hypti-
sn the fine flocculent material was twisted or Aree Moist onnrane
Thread, 1#Stened somewhat as in Fig. 178. The lat- sides. (After Emerton.)

ter presented a milky appearance, and was spread out so fine
that often no traces of independent filaments were observed. In short, it
was a very delicate, cottony mass, much wider at some parts than at others,
presenting in miniature something like the appearance of the woolen rolls
which, as a boy, I used to watch with intense interest as they passed into
the flyers of an old fashioned spinning wheel.
In this cottony mass one frequently observes a
number of particles of dust, pollen, and various minute
amorphous objects, which have been caught

S gscesessescssegy ce ey upon the sticky material as they drifted be-
end- so :
| _ ee fore the wind. As in the case of the web
Fic. 177. Section of Hypti- : = 2 y
otes’ snare, to show the ar- of Uloborus, they present to the casual ob-
rangementoftheflocculent server, even when looked at by a common magnifying

thread. Greatly magnified. t y
lens, the appearance of beads upon the ordinary thread

of Epeira. It is not strange, therefore, that many have been deceived and
led to suppose that the Triangle spider makes a beaded web. The true

1Cobwebs of Uloborus, Am. Jour. Sci., 1883, page 205. Also New England Spiders of
the Family Ciniflonidee, Pl. XI.

THE TRIANGLE SPIDER: THE ORB SECTOR. 187

character of the spiral can only be satisfactorily determined by taking it
upon a suitable frame and observing it under the microscope.

The spiral lines, where they cross the two interlying radii, are not con-
tingent to the radius at one and the same point, but present precisely the
appearance of the concentrics in the notched zone of a common full orbed
snare. The entire snare of Hyptiotes is thus notched, and in this respect
it corresponds with the domed orb of the Basilica spider as I have de-
scribed it.

The length of the snare proper varies a good deal. I have measured
one five and a half inches in length, another two and a half, and another
thirteen inches, measuring from the apex to the base line. The
spiral space itself will measure two and a half inches, three and
three-fourths inches, rarely more, often less. The length of the
base line, which represents the width of the snare at the open or widest
part of the triangle, also varies much. I have measured one twenty-six
inches in length, the longest of which I have any note. The radii are
not separated from each other by equal spaces at their points of attach-
ment to the base line. For example, one
snare measured two inches in the upper -7AAy fB_fAy _ ay
space, between the first and second radii; ““—~—=* += =
in the middle space, one and one-fourth Se ae eae or oe eee
inch; in the lower space, one and one- ent thread are broken up and hang irreg-
fourth inch. At the point nearest the apex, “8"*
where the spiral lines terminated, the width across the snare between the
two outer radii was three-fourths of an inch.

The distance from the apex of the triangle to the point where the
original line is attached I have called the trapline, and this also varies in
length. I have the following measurements: One and one-fourth inch, one
and one-half inch, one and six-eighths inch, two and one-half, five, and
thirteen inches. The snare drawn at Fig. 169 gave the following measure-
ments: trapline, two and a quarter inches; number of spirals, fourteen,
separated from each other by distances varying from one-eighth to one-
fourth of an inch; the spiral space, two and a half inches long; distance
across the web at the origin of the spirals (the point nearest the trapline),
two inches; distance across the web at the termination of the spiral system,
four and one-half inches. The three radial openings measured at the base
line respectively, two, one and a half, and one and three-fourths inches.

A fine large snare spun by a male Hyptiotes gave the following meas-
urements: number of spirals, twenty-three and twenty-two; the spiral space
occupied three and three-fourths inches in length; the distance across the
snare at origin of the spiral space, one inch and _ five-eighths; distance
straight across a, the end of spiral space, five and one-half inches. From
the point of the triangle to the origin of the spiral space was two inches.
There was a quite long trapline, about thirteen inches. The base line of

Dimen-
sions.

188 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

the radii was also very large. The space between the several radii, meas-
ured at the termination of the spiral space, was about equal in all to one
and seven-eighths inches. Across
the snare at the beginning of the
spiral space the distance was one-
half inch in all.

When the web is completed,
the spider takes a position upon
the trapline, sometimes
very close to the apex,
but more frequently
removed from it by a varying
space. Sometimes she is close
Fic. 179. Position of Hyptiotes on her trapline, T. The coil, tO the apex, at other times well

cl, is shown in the upper figure, and at sl in the lower. removed therefrom ; sometimes
she hangs upon the line between the apex and the branch to which the
line is suspended, and again is found close up to the branch, even rest-
ing her abdomen against it.

Position
of Spider

mM:

The position of the spider upon her trapline is very peculiar, and
worthy of careful study, for it gives a clue to the curious phenomenon
which is now to be described. Her face and fore feet are

Using the towards her triangular snare. The trapline is held within the
ee! first two pairs of claws, which are placed near each other (see
Fig. 179, upper figure), and is drawn so tightly that every por-

tion of the wedge shaped
web is perfectly taut, as rep-
resented in Fig. 180. Upon
applying the lens to the
spider as she thus hangs
with back downward, it will
be seen that between the
second pair of legs and the
third pair of legs, the line
is also taut. ‘This is its
condition according to most
of my observations, but it

seems that sometimes it is

Fic. 180. Hyptiotes’ snare drawn taut.

shghtly slackened, as shown
in the lower figure in the cut. (Fig. 179.) Carrying the lens along to
the short third pair of legs we see that they are bent at the knee, and the
claws approach each other at the trapline, which they firmly clasp. Glance-
ing at the fourth or hind pair of legs, it is observed that these are stretched

THE TRIANGLE SPIDER: THE ORB SECTOR. 189

backward, and also clasp the trapline in the approximated claws. But be-
tween the third and fourth pairs of legs the trapline presents a peculiar
form. Instead of being drawn taut or held loosely, it has the

Coil’ of appearance of a coil, and this in fact it is. About three-fourths
Slack a= - ; ; ae ;
Tene of an inch of the trapline, or a portion equal to four times the

entire length of the spider, is rolled up above the spinnerets and
the hinder part of the abdomen, between the third and fourth pairs of legs.
(Fig. 179, cl.) Behind the spider the trapline is in the same taut condi-
tion that it presents in front of the spider.
The net is now in perfect condition for operation. The whole front
part of it, which includes the snare proper, is drawn taut in every cord
_ , and fibre. (See Fig. 180.) The trapline behind the spider is in
caeraaeed the same tense condition. The only portion that is relaxed is
the bit of coil between the last two pairs of legs, and occasion-
ally (perhaps) the — short
stretch between the front
legs and the third pair. We
will now suppose that an
insect strikes the snare, al-
though the same effect can
be produced by touching the
spider herself or by tickling
the fibres of her web in a
manner to imitate the move-
ment of a fly. She is not,
however, easily deceived by
the latter trick; at least, I
have rarely been success-

Fic. 181. A relaxed snare of Hyptiotes, after the snap.

ful enough to compel her to spring her net by mimicking the movye-
ments of an insect, and when I desired to make the observation, was
compelled to touch her gently with a pencil. As soon as the spider per-
ceives that her prey is trapped, she unclasps simultaneously all the fore
feet holding upon the trapline, and those of the third pair of legs which
keep relaxed the coil of slack line. Instantly the entire snare shoots
forward (Fig. 181), and by a principle of inertia which needs no expla-
nation, the spiral lines are thrown forward around the insect (Fig. 182),
whose entanglement is thus secured. With a rapidity so great that the
eye is not able to follow the details of the movement, the snare is tight-
ened ; the spider momentarily assumes the previous position of expectancy,
and again springs her net. This may be repeated several times, Wilder
having observed six successive springings of the net.

In this movement the spider appears to shoot forward with her snare,
but in point of fact she has remained stationary, or at least has advanced
but a trifle. But now, crawling to the apex of her snare, she seems to

190 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

ascertain the exact location of the fly by pulling upon the radu. Having
satisfactorily decided this, she runs along the loosened radius and some-
times, when the prey is small or hopelessly entangled, contents
herself by pulling it up by means of the lines about it, and car-
ries it to her accustomed station, to be eaten at leisure. More
frequently she moyes along the trapline, and almost entirely destroys the
triangular section which forms the web. This action is thus correctly de-
scribed by Professor Wilder :—

Before reaching the apex the spider cuts with her jaws the apex line,
but as she maintains her hold in front of the cut by her first and second
pairs of feet, and has a communication in the rear through the lne which
most spiders always attach to a point behind them, she does not fall,
neither is the net loosened beyond a certain limit; it usually seems to
recoil about an inch; this recoil tends to entangle the prey like yy

Securing
the Prey.

the original snap of the net. The spider again advances, gathers Yh P
the radii togeth \ #] er and cuts them all, still keeping the line \ WW)

WAY \ RY)
drawn out be- |W NW

hind; again the i
net recoils and | fy
collapses. Again i
she advances

and cuts the |

radii the net y Y Fig. 182. Condition of Hypti-

j otes’ net when sprung upon a
is now hardly fly. (After Wilder.)

distinguishable as such, and is falling together
about the devoted fly; the spider now spreads her :
legs, gathers the net between them and flings it like a
blanket over her victim. Struggles are in vain; but “to make
assurance doubly sure” the spider grasps the mass, transfers it to
her third pair of legs, and with them turns it over and over as |
a ball, hanging the while by her front legs; and with the hinder ™
pair, used alternately, draws out from the expanded spinnerets broad sheets
of silk which, relatively to the power of the fly, are like steel bands upon
a man,

Having in this way reduced the prey to a rounded ball, in which its
limbs are hardly distinguishable, the spider takes it in her jaws and mounts
to her place. <A single fly of ordinary size seems to occupy a whole day
in the eating. When finished, the remains are cast down as a pellet, so
perfectly deprived of moisture that it is probable that this species, like
Nephila and perhaps all Epeiride, sucks out the gum of its old net and
reclaborates it for use in making a new one.!

My observations of the feeding habits of Hyptiotes correspond with
those of Professor Wilder, She is very deliberate in her mode of proceed-

1 Op. cit., page G51.

THE TRIANGLE SPIDER: THE ORB SECTOR. 191

ing; slowly rolls the insect in swathing thread until it assumes the ap-
pearance of a round flossy ball. One female that I observed was a
long time in thus preparing for her banquet. The spirals of
her web had been broken in

the capture, a single thread

alone remaining. In another example Tu

observed the entire interradial system ee a
was obliterated.

This, however, is not, as Wilder
supposes, a peculiar habit. I have fre-
quently noticed Epeiroids doing pre-
cisely the same thing. The only differ-
ence is that in the case of the latter a
space consisting of two, three, or four
radii’ would be cut out, leaving thus a large circle or wedge shaped gap
in the snare. This gap corresponds almost precisely to the appearance of
the Triangle spider’s net after she has cut out the entangled fly and com-
pleted the enswathment preparatory to feeding. Of course, however, as
Hyptiotes makes only a sector of a circle, she has nothing left of her snare
after the insect is thus prepared; whereas spiders making circular webs
have a goodly portion of their orbs intact and ready for service after one
sextant is destroyed. Substantially, then, we may say that the same thing
occurs with the snare of Hyptiotes and the snare of Epeira when the en-
tangled insect is captured, cut out, and enswathed.

I noticed what seemed to me a remarkable peculiarity in the manner
of swathing and feeding upon a gnat taken by one of these spiders. Hyp-
tiotes hung to her trapline by the two fore feet, which were stretched out
quite at length from either side, as represented in Fig. 184. Her jaws and
palpi appeared to me (although I could not quite make this out) to be
,supported upon the trapline. At least they overreached that line and
grasped the partly enswathed insect, which lay over the line on the side
opposite the spider’s body. The palps reaching upward from one side and
the third feet reaching beneath from the other side revolved the insect,
while the hind legs paid out the
silk and manipulated the swathing
as represented at Fig. 184. The atti-
tude was an extremely odd one, and

Feeding
Habits.

Fic. 183. Outlines of a relaxed net after service.

had the savor of that grotesqueness
which seems to me always to mark
the appearance and behavior of this
aranead.

When the fly was sufficiently secured it was carried back to the trap-
line, whereupon Hyptiotes rolled herself over beneath her line in the ordi-
nary posture, laid hold of the trapline by the two hind pairs of legs, and

Fic. 184. The Triangle spider swathing a fly.

192 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

gathered up between them the ordinary coil of silk thread. Then she
stretched forward the two fore legs upon one side of her body and grasped
the trapline just in front of her face, and bent the other two fore pairs of
legs around toward the ball within which the insect was swathed and
which was held well elevated within the mouth. The two bent fore legs
evidently assisted in manipulating the food while the spider made a meal.
This seemed as odd a posture as that assumed during the swathing of the
fly. (See Fig. 185.)

When the snare has been sprung and the spider wishes to tighten it,
she does so by apparently first drawing upon the trapline with the fore
feet, accomplishing the movement after the manner of Epetroids
by placing one claw before the other, as a sailor ascends a rope
hand over hand. At the same time, or immediately thereafter,
she executes a similar movement with the two hind feet, only reversing
the direction. It should be said that during the process of snapping the
net, the hind pair of feet hold to the trapline and never let go until the
spider abandons her position to visit the snare in search of prey. The
third pair are also held in position, so that when the hind feet begin to
pull backward, shoving hand over
hand, so to speak, under the trapline
towards the point of attachment, an
amount of slack is formed between
these feet and those of the third
pair, which very soon rolls up into
the coil of slack line which has just
been described. It is thus quite pre-
pared for another spring of the snare.

I have observed the same peculiar use of the hind legs when the
spider had occasion to raise herself from beneath upwards. Epeiroids
ascend a dropline head uppermost, pulling themselves hand over
hand, and allowing a coil of thread to accumulate between the
palps and the jaws. Hyptiotes, instead of turning and ascend-
ing head foremost, mounts tail foremost, keeping her claws attached to
the trapline and drawing herself up hand over hand, following the method
by which she draws herself backward in order to tighten her snare. It
presents a very odd appearance to see her ascending a dropline in this
position, literally “backing” up it, although one is not so much struck
with the oddity of it when he sees her recovering after snapping her
snare,

The Triangle spider has the habit of violently oscillating her web,
just as do many of the Orbweavers; that is to say, she not only draws
“it back and forward by snapping her trapline, but shakes it up and
down or to and fro.

According to Professor Thorell, the males of Hyptiotes are extremely

Use of
the Feet.

Fic. 185. Hyptiotes eating an insect.

Backing
up Cables

THE TRIANGLE SPIDER: THE ORB SECTOR. 193

rare, although the females are pretty common during the summer months.
Mrs. Treat found the males of our Triangle spider at home with the
females during two seasons. They were not in webs of their
own, but always in the upper corners of the nets of females
where the foundation lines are fastened to the trees. They were thus
opposite their mates, who were waiting beyond the apex, and apparently
were watching all their movements with great interest. This is the custom
with males of most Orbweavers during the pairing season. It is a mis-
take, however, to suppose that the males do not spin snares. I have fre-
quently found them upon webs of the same construction and operated
in the same way as those of females. At one time, I found in a fir tree
a group of ten males, with their snares spun close together.

A curious behavior was noticed in a Triangle spider observed in a pine

wood in the Allegheny Mountains. Numbers of snares were there found

on hemlock trunks and dead standing saplings. I cut the trap-
Hele eee f f these webs to see how it would affect the spider.
Rigidity, [ne of one of ebs to see \ . I

She was hanging at the time with her hind legs quite near the
trunk of a tree. Instead of dropping downward when the support of the
fore part of her body was broken, she simply settled backward a little so
that the end of her abdomen rested against the tree. In this position her
body extended straight out from the trunk in a line at right angles thereto.
The fore legs were slightly bent and held but a remnant
of the trapline, which was greatly ruffled in the man-
ner of a taut string when suddenly untwisted. Both
pairs of hind legs in the meantime were holding tightly
to two short cords, one in each pair of claws, which were
attached to the tree by little conical clusters of threads :
firmly glued to the bark. The spider in this attitude fic. 186. Muscular rigia-
presented an odd figure, the like of which I have never ha a
-observed in any other species. (See Fig. 186.) Her body was perfectly rigid,
although there was nothing to maintain it in position except the bracing
which resulted from the hold upon the lines above described. I watched
her for a long time, and she showed no signs of wearying or relaxing her
attitude.

The amount of muscular vigor displayed by the spider in maintaining
this position must have been very great, but certainly not greater than re-
quired to preserve the attitude which she assumes when holding her snare
ready for prey. This attitude she will maintain, without the slightest ap-
pearance of muscular tremor or weariness, for a long period of time. I
have never had patience to see how long she would thus hold out if not
interrupted by insects striking her snare; but I can readily believe that her
patience will endure not only for a day but probably for more than a day.

We thus have a tolerably full natural history of this interesting species.
There are few animals whose habits better repay the student; but one who

Males

194 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

wishes to know the secrets of Hyptiotes’ daily life must be content to bear
patiently many disappointments, endure many discomforts, and attend,
through days of tedious waiting, with unruffled temper and unflagging
zeal, upon the slow unfolding of the record. The spider is one to be looked
after, not stumbled upon; its form is so inconspicuous, and its home in
such obscure sites, that the naturalist will need to seek for it. No doubt
much yet remains to learn of its behavior; its cocooning habit, for exam-
ple, is wholly unknown, and the cocoon which Professor Wilder supposes
to be hers is by no means well identified. The little mother has persist-
ently denied me, in spite of numerous endeavors, the pleasure of settling
this question. I cordially wish some of my readers better success in unrayv-
eling this and other unwound threads of the Triangle spider’s life.

CEVAP EER XCF.

THE RAY SPIDER AND HER SNARE: ACTINIC ORB.

I,

In the vicinity of Philadelphia, June 14th, 1881, I found a number
of spiders grouped not far from each other on orbicular webs, which
proved to be of a type previously unknown, and which I called the Ac-

tinic or Ray formed orbweb. At the time of my discovery
Nameandy considered the spider new to science, and gave it the name
Position, © Considered the sj ; g

of Epeira radiosa in a paper containing a careful and detailed
description of its spinning habit.! I then intimated that it would prob-
ably be assigned to a new genus, and subsequently in a verbal communi-
cation proposed for it the name Actis radiosa. Emerton, in his monograph
of the New England Epeiride, created for the spider the genus Micro-
epeira. ?

Subsequent investigation led me to believe that the spider belongs to
Cambridge’s genus Theridiosoma,? and probably is identical with the
European form Theridiosoma gemmosum of L. Koch.4 | This genus has
marked resemblances to Epeira, as Cambridge himself allows; and on the
ground of structure appears to be at least equally related to the Epeiroids.
Count Keyserling, however, in his extended and admirable monograph
of the American spiders,® retains the species among the Retitelarie, where
it had previously been placed.

But the spinningwork shows conclusively that it must be placed with
the Orbitelariea. To that position, therefore, I have assigned it,® and it
becomes necessary to transfer the genus Theridiosoma from the Retitelariz
to the Orbitelarie, and to make for it a new family, for which I have
proposed the name Actine.?7 The systematic position and relations of the

' Proceedings Academy Natural Sciences of Philadelphia, 1881, pages 163-175.

2 Trans. Conn. Acad., Vol. VI., 1884, page 320.

* Rey. O. Pickard-Cambridge. Theridiosoma argenteolum: Annals and Magazine of
Natural History, 1879, page 193.

*Theridium gemmosum: Verzeichniss der bei Nurnberg beob. Arten, page 69.

° Die Spinnen Amerikas: Theridiide, yon Graf E. Keyserling, Zweiter Band, page 218.

® Proceed. Acad. Nat. Sci., Phila., 1889, page 180. “Note on the True Systematic Position
of the Ray Spider.”

7 Actis, axric, a ray.

(195)

196 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

species will be considered more
fully in the appropriate part
of this work.! At present we
may devote our attention to
the remarkable and most in-
teresting character of the
web.

The locations in which I
first discovered the snares, and
where afterward I found them
to be quite abundant, had been
for several years a familiar
and favorite hunting ground
for spiders. It illustrates the
fact that some of the most in-
teresting discoveries that await
future observers may be found

Fic. 187. The Ray spider seated on her snare, just before near their own well known
Seine ee haunts, and upon ground that
has been often searched by other workers, or even by themselves.
The first examples of the species collected by me attracted little atten-
tion so far as the snare was

: concerned, because
Discov-

they seemed to be
ery. ;

simply a new spe-
cies, or the young of an old
species of Orbweaver, hang-
ing upon the remnants of
webs greatly broken by or-
dinary wear and tear in cap-
turing insects. But the rep-
etition of the form, partic-
ularly the peculiar character
of the open central, struck
me as strange. How could
the nets of several spiders
possibly happen to be twist-
ed into the same shape, and
that shape so strikingly odd

as that which I observed ?

rm. Fig. 188. Interblending of rays upon one axis. H, hub, or
This caused me to make a central point; T, trapline.

1 Dr. Thorell, to whom I sent specimens, has recently written me that he considers my
Radiosa quite identical with Theridiosoma gemmosum (L. Koch), and agrees with me that
on structural grounds alone it may be well ranked with the Orbitelarie.

THE RAY SPIDER AND HER SNARE. 197

more careful examination of the spinningwork of these little strangers. As
the snares were hung invariably within the interstices of rocks forming
the remains of a ruined dam, or in cavities underneath roots of old stumps
of trees, or in recesses of the overhanging banks of a little brook or run,
everywhere shadowed by shrubbery and thick foliage, it is not strange that
the peculiarity failed to attract attention, and was only developed by more
careful research.

On account of the continually changing form of the snare, it will be
necessary to present it from various points of view, and as seen in differ-
ent stages of its diurnal changes. Fig. 187 presents a view of the
Snare . : i Arh Sas fis ;

snare in a partially relaxed condition. ‘The spider is seen seated
Described . Sea re ee

in the centre of a series of rays, i, U1, 111, iv, v, which are grasped

by the third and fourth pairs of legs. There is no hub, properly speaking,

os

Fic. 189. View from front. Web taut. Perspective not shown. Central opening exact.

but the axes of the rays may be seen at times united upon a central
point, as at H, Fig. 188. The general tendency is to four or five main
divisions or rays, as may be seen by studying the figures presented. But
there is more or less variation, and in the course of the day’s usage in
capturing prey two sections will become interblended upon one axis, as
appears to be the case in Fig. 188 and also in Fig. 191.

The central space is a large, irregular opening, constituting about one-
third of the entire snare, whose diameter is usually from three to five
inches, as at Fig. 189, which is drawn natural size. The central circle,
meshes, and notched spirals which so generally characterize orbwebs are
thus wholly wanting in the Actinic snare,

198 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

The orb may be said to be
If Mage td 194 composed of a series of inde-

pendent rays or sectors, each
ray consisting of several spi-

A>

rally crossed radii, and_ the
whole series united into an
orb by cross lines or spirals
like those which unite the ra-
dii. In the shifting of the
section lines above referred to,
this separation of the orb in-
to independent rays is always

e Uifyy
ie “Ly D ° ml a 3
HY, K quite evident. The spirals are

Want

covered with viscid beads, as

in most orbwebs. The radii
YI iw ¥pp ee / do not all pass to the hub or
5 RR LT centre, as do those of orbwebs

FiGc. 190. Side view of Ray spider’s snare when drawn taut or generally, but converge for the
bowed. Seen within a cavity. a S =

most part upon the axes of
the rays as represented at Figs. 187, 188, 189. Thus at Fig 189 the
various radii of the several sectors converge consecutively upon the axes
i, li, iii, iv. These axes themselves converge upon a single strong thread
or trapline, T, which is attached to some part of the surrounding surface
of rock, earth, or plant.
When the snare is flat or
relaxed, as was the case

tite) Ne
with the one drawn at Fig. MMs Ait
188, and as appears in Fig.
187, the trapline is often
about perpendicular to the
plane of the orb, having
the relative position of the
handle to the rays of an
open Japanese umbrella.
This, however, depends
somewhat upon the envi-
ronment; a convenient
point for the attachment
of the trapline will cause
the animal to divert the
thread more or less from

the perpendicular.

We may now suppose

the spider placed as in Fig. 191. Ray spider’s snare when bowed. Viewed from behind.

THE RAY SPIDER AND HER SNARE. 199

Figs. 187 and 189, at the point where the rays converge, grasping the axes
with the four hind feet. She has the posterior part of her abdomen
toward her snare, thus reversing the attitude of all her tribe. Moreover,
her back is turned upward. The two front feet seize the trapline and
draw it taut. Then, precisely as a sailor pulls upon a rope, “hand over
hand,” the little arachnid’s feet move along the trap-
line, one over another. As she moves, going, of course,
away from her net, the axes of the rays,
held firmly in the hind feet, follow her; the
centre of the snare bears inward, the other
parts are stretched taut, and the web at last has taken
the form of a cone or funnel as at Figs. 190, 191.
In this position the snares continually suggested an
umbrella with ribs reversed by the wind and the coy-
ering stripped loose from the top of the handle. Fig.
190 gives a side view of the web when thus bowed or
drawn taut; another snare is shown at Fig. 191, as seen
from behind. These snares were located within cavi- jyg. 192, Ray spider seat-
ties formed by the dropping away of stones from the — ¢4 upon her foot basket,

- = ¢ back upward.
ruined dam breast in which they were first discovered.

In the example shown at Fig. 191 the spider has moved quite down
the trapline to the surface of the little twig projecting into the cavity to
which it is attached. It will thus be seen that the snare is more or less
a plane surface, or more or less conical, according to the position of the
animal upon the trapline and the degree of tension thereof.

Bowing
the Snare.

Il.

When an insect strikes the snare, the spider has two modes of operat-
ing. The first somewhat resembles that of the ordinary
Orbweaver, in that the insect is simply permitted to en-
_ tangle itself, and is then taken, swathed, re-
Operating, | . wrk 8
turned to the centre, and eaten. There is,
the Snare. tas, ;
however, this difference: before the spider goes
, g
to the insect, the axes of the snare are twisted or knotted
by a rotary action of her body and movement of the
legs, so that the parts of the orb unbroken by the captive
remain taut. Fig. 188 represents a snare thus “ locked,”
or, perhaps I might more properly say, “keyed.” The
trapline is now relaxed, although its elasticity is such
Fic. 198. Position on that the change can scarcely be noticed. The spider
foot basket with head then moves upon her victim, quite habitually cutting out
bent downward. 3 . : 4 y
the spirals with her mandibles as she goes. When the
insect is ensnared well towards the circumference of the web, and indeed,
for the most part, in other cases also, it results that the ray or sector

200 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

upon which the entanglement had occurred is quite cut away. The spider
thereupon proceeds to operate the remaining parts of her snare, which, in

time, is thus destroyed by sections, as will be fully illustrated hereafter.
The second mode of operation resembles that of the Triangle spider,
Hyptiotes cavatus (Hentz). It is at this point that the habit of our Ray
spider becomes particularly interesting. ‘The Triangle spider makes a tri-
angular web, which is in fact an orb sector, composed with

ee unvarying regularity of four spirally crossed radii converging ap-
ance to : ; : aoa :

: yroximately upon a single line. Upon this line the spider hangs
Hyptiotes! y UE 8 I I 8

back downward, grasping it with all her feet, and having a por-
tion of the line rolled up slack between her two hind pairs of feet. Thus
the forward and back parts of the trapline are taut, while the interme-
diate part is slack. The spiral parts of the snare are also taut. When
the web is struck by an insect,
the spider suddenly releases
her hind feet, the slack line
sharply uncoils, the spider
shoots forward, the whole web
relaxes, and the spiral lines
are thrown around the insect.
This is repeated several times
before the prey is seized. (See
description and cuts in Chap-
fers excle)
Precisely the same action
characterizes the Ray spider.
Her ordinary position, or at

Fic. 194. Ray spider (greatly enlarged) in position, back down- ‘ ; qos. ;
ward, on a taut snare. To show the slack line coil, Sl. The least the one in which I most

positions of the feet on the foot basket are marked by nu- frequently observed her, is a
merals; a, b, c, the axes of several rays. sy
sitting posture, back upward,

as shown at Fig. 187. The axes of the rays are held in the third and
fourth pairs of legs, the fourth commanding the upper, the third the lower
series, quite habitually, as it appeared to me. A sort of “ bas-

pias ket,” or system of connecting lines, shown at Figs. 187, 195,
on the : ; = ;
ie unites all the feet, seeming to converge toward the fore feet (per-

haps, upon the second pair), where they grasp the trapline. It
is upon this foot basket that the spider sits when her net is bowed.

This, however, is not the invariable posture; in the reconstruction of
the rays and shifting of the axes, as the day’s work tells upon the snare,
the spider will vary her posture to that of Fig. 191. The trapline gen-
erally has a direction downward rather than upward, so that the head
and fore feet tend to be depressed below the abdomen, Figs. 192, 193,
and this depression may gradually result in the complete inversion of
the animal, so that she assumes the natural position of Orbweavers. I

THE RAY SPIDER AND HER SNARE. 201

have even seen individuals with the back turned downward, Fig. 194, as
is the habit with the Triangle spider and with all those species who make
a dome or horizontal orbweb, as the Basilica spider and the Orchard
spider. (See Chapter IX.)

If now the feet of the spider be carefully examined with a good glass,
a coil of slack line will be seen, precisely as in the case of the Triangle
spider. This is illustrated at Fig. 194, where a, b, c, are the axes of
several rays, grasped in the third (3) and fourth (4) pairs of legs, and Sl
is the coil or slack line curled up between these and the fore pairs (1 and
2), or simply between the pair of fore legs; that is, between the two first
and the two second feet. As the spider does not exceed one-eighth of an
inch in body length, and the position of the snare is within cavities and
interstices of rocks, where the light does not bring out the delicate tracery
of the fine webs, the observation of
these and other points of like char- |
acter, is a matter of some difficul-
ty. But, although the exact relations
of the coil to the feet were some-
times in doubt, and indeed seemed
to vary somewhat, the existence of
the coil and its general relations
were determined beyond doubt. It |
is also certain that the slack line
sharply uncoils and straightens when
the spider releases her grasp upon
the trapline, and that the web un-
bends and shoots quickly forward.
It is instantly changed from the
bowed or conical form of Figs. 190 Fie. 195. Ray spider in position, back upward, show-

a 2 ing slack coil and foot basket, ii; axis of a ray
and 191 to the circular plane of Figs. grasped by third foot, 3; trapline grasped by fore

187 and 188. sac

The following points, however, long evaded my observation, before
webs were found which presented the conditions for successful study. But
at last I was well satisfied. The “springing” of the snare is
caused by the sudden releasing of the trapline from the fore
feet, instead of the hind feet, as with the Triangle spider. The
polarity of the two arachnids relative to their webs is reversed, Hyptiotes
having her fore feet, but Theridiosoma her hind feet towards the snare.
The slack line is therefore coiled between the two fore feet or between the
fore and hind feet of Theridiosoma, but between the two hind pairs (as
a rule) of Hyptiotes.

I have already explained the manner in which Hyptiotes is affected
when her two hind feet are released from the trapline. The coil straight-
ens, and the whole body of the spider shoots forward, If now we turn to

Springing
the Snare.

202 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

~

Theridiosoma, as represented at Fig. 194, or again, as shown at Fig. 195,
we observe that if the fore feet, 1, 2 (Fig. 194) are released suddenly from
the trapline, T, the whole body shoots backward, although still toward the
snare, as with Hyptiotes. This was the ac-
tion which I observed.

The determination was finally accomplished
by first carefully sketching the arrangement
of the basket stretched between the feet (2,
3, 3, 4, 4, Fig. 195). With this chart in one
hand, and in the other hand a magnifying
glass focused upon the feet, I watched until
favored with several successive and unsuc-
cessful springings of the net. As the spider
only leaves her seat when she thinks that an
insect is well entangled, and again bows her
net by pulling on the trapline if no prey be

ensnared, the above conditions enabled me to
Fic. 196. Ray spider. Action when an 7 :
insect is taken. S, spider; In,insect, COMpare my chart of the basket, with the
basket itself as seen under the glass. I found
that the outlines on the paper and the lines under the animal’s feet ex-
actly corresponded. There had therefore been no change in the relative
positions of the hind feet, mandibles, and palps, and perhaps also of the
second pair (2) of feet. There had been an actual (not seeming) motion
of the body with and in the direction of the snare, and this had been
‘aused by releasing the first pair of legs (1) from the trapline. The only
actual motion, therefore, was the slight hitch forward produced by the
elasticity of the axes of the rays and other parts of
the snare behind the aranead.

The importance of this determination seems greater
from the fact that I had at first concluded that the
Ray spider actually operated her snare by sections.
That is, instead of springing the whole orb at once,
as above described, she simply sprung the ray struck
by an insect, by unclasping the foot holding the axis
of that ray. Thus, ray u, Fig. 195, would be sprung
by releasing the axis of ii from the third foot, No.
3. This is probably not done when the snare is in
complete form (as at Figs. 187, 189, 190), but I be-

i : J Fic. 197. Ray spider’s snare
lieve that it is done when the web has been par- after usage in taking prey.

tially destroyed, and is reduced to two rays or sec-

tors, as at Fig. 197.

The spider is at the centre,
holding the rays “ locked.”

The fragmentary condition of the Ray spider’s web after contact with
insects has already been referred to. The snare is gradually obliterated, a
conclusion to which the spider herself very curiously contributes. When

THE RAY SPIDER AND HER SNARE. 203

an insect strikes the snare, as at Fig. 196, ray I (broken ray), Theridio-
soma first “keys” the snare by twisting together the foot basket and the
parts adjoining (C), including the end of the trapline. This

= eae maintains the compact condition of the snare after the spider has
He ah left the central point at which she has held all parts together in

Wreb. the manner heretofore described. Then the insect is sought.

Creeping along the axis of the ray upon which the prey is en-
tangled, she cuts away the cross lines as she goes, leaving the bare skele-
ton of radii, as shown, Fig. 196, I, marked “broken ray.” ‘The insect is
then brought back to a point (D) near the centre, but (in this case at
least) above it, where it 1s eaten. While the feast goes on, not unmindful
of future supplies, the spider (S) clasps the adjoining axis and (C D) the
connecting lines, which appear to be in condition for operating somewhat
in the usual way. When the insect is eaten, the for-
mer position is resumed, the trapline clasped, and
the net bowed and tight ened.

After a morning’s trap
been plenty, and general
the afternoon, the snare
one or two rays or frag
seen it reduced to a bare
one ray (I), and two frag ments of two others, are
united into a new ray, and these are placed in
opposite parts of the orb. Fre.198. Rayspider. Halfot Again, one-half of the

snes orb eliminated and a new ITN: nce °

orb may be eliminated trapiine, Th, formed. Ta, (Fig. 198), leaving two ra-
dii (i, 11) to operate with. position of old trapline; i, ‘he Ray spider was also
observed to construct or adopt a new trapline, thus
changing, so to speak, her base of operations. This action is illustrated
at Fig. 198, where Ta is the original, and Tb the new trapline. This is
not a frequent occurrence, as the necessity for changing the original line
does not appear to arise very often.

ping, if the game has
ly towards the middle of
will be found reduced to
ments of rays. I have
skeleton. In Fig. 197,

TIE

Not the least interesting and valuable feature of the Ray spider’s indus-
try is that it constitutes a connecting link between two forms of snare
..._. Which stand at the very opposite poles of the spinningwork of
Affinities. pr bb

the Orbweavers. At the one extreme is the familar circular
snare or full orb of the ordinary garden spider. At the other is the orb
sector of the Triangle spider. A glance at these will show how far they
are apart in structure. The same separation appears in the habits of the
two araneads. As opposed to Hyptiotes, the spiders of which Epeira is a
type hang head downward in the centre of the orb, with their feet grasp-
ing small groups of the radii; or sit in a silken den, or crevice, holding

204 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

to a taut trapline which is connected with the centre. There is no slack
coil, and no springing of the net as with the Triangle spider.

The industry of Theridiosoma is united to that of the full orb makers,
on the one extreme, by its orbicular character and its beaded spirals; but
with that of Hyptiotes, on the other extreme, by the independent character
of the rays, the nature of the trapline, and the entire mode of operating
the snare. The facts necessary to trace these affinities I have already
given.

Some of the striking differences I have also recorded, and they may
thus be summarized. The web of Hyptiotes is a single sector; that of

Theridiosoma has four or more sectors united. Hyptiotes com-

Differ- mands one line with her feet, the trapline and its continuation;
ences aie :

en eee Theridiosoma commands several axes, which are connected with,
Ae ae but not continuous of, the trapline. Hyptiotes has her head,

Theridiosoma her abdomen towards her snare. Hyptiotes habit-
ually hangs to the trapline, back downward; Theridiosoma generally sits
upon a foot basket of lines, back upward. Hyptiotes shoots forward when
her net is sprung; Theridiosoma shoots backward; but both spiders move
toward their webs. Hyptiotes holds her slack coil between the two hind
feet; Theridiosoma between the fore feet. In these differences, the points
wherein Theridiosoma varies from Hyptiotes show a quite apparent ap-
proach to the behavior of the full orb makers. Thus the distance which
heretofore had separated between the far away extremes of the spinning-
work of the Orbitelarize, has been bridged over by the industry of our
little indigenous aranead—the Ray spider. It is to be remarked that
while structurally the Triangle spider is as widely removed from Epeira
as economically, the Ray spider is more closely allied structurally to the
latter than the former.

In correspondence with arachnologists, concerning the true position of
the Ray spider, the question was raised as to the accuracy of the statement,
in my paper of 1881, that the interradial lines of Theridiosoma

Viscid sys . .
are covered with viscid beads. The question is certainly one of

eee great importance. Mr. Cambridge, in establishing the genus,
which he regarded as a connecting link between Theridium and Epeira,
alludes to the fact that Dr. Koch describes the snare as consisting simply
of a few lines spun from plant to plant. “This habit,” he declares, “ to-
gether with some structural considerations, exclude it from the Epeirides.”
Thus, it would seem that the spinning habit of the creature bore quite as
strongly as its structure in determining its systematic position. Had Mr.
Cambridge then been familiar with the real spinningwork of the species
he might have had no hesitation in relegating it to the Orbitelarie.

The question was raised, whether the spiral lines of my Ray spider
might not have been covered with flocculent strings, somewhat after the
manner of the snares of Hyptiotes and Uloborus. As the spider is desti-

THE RAY SPIDER AND HER SNARE. 205

tute of the calamistrum and cribellum, which are always associated with
this character of spinningwork, it was hardly possible that the spiral arma-
ture could have been of this sort. However, I was not able to testify on
the subject with that assurance which seemed to me desirable. It is cer-
tainly possible for one to be deceived by even an ordinarily careful exam-
ination. The webs of Theridiosoma are so habitually placed in
dark cavities and shaded locations, and in positions that often
extremely embarrass the observer, that on this ground alone one
would be liable to mistake. Again, I have often noticed that even the
simple lines of Theridium will be found covered with particles of dust
and the spherical grains of pollen, which at a casual glance present very
much the appearance of beads. More than once I have been drawn into
a Second and third examination by this deceiving resemblance. Moreover,
I had limited my original examination to the use of a hand lens, and had
not made the more careful microscopic test which would haye placed the
matter beyond doubt. I therefore resolved to reéxamine the subject before
a final expression of opinion.

An opportunity to do so did not present until the 8th of July, 1889.
In the vicinity of Wallingford, Pennsylvania, in a shaded ravine covered
with a wild growth of natural

Grounds
for Doubt.

plants that overhang a stream of R

clear running spring water (Doe’s =
‘5 S i

Run), I found a number of this C2BsoGQsscossOsoe> 5
. ez!

species, and made a thorough © COS CDs Goce S2GrrGocs H

study of the point in question. I
took with me apparatus by which
portions of the web could be sep- Fie. 199. Beaded spirals on the snare of Theridiosoma
: ¢ gemmosum. (Magnified.)
arated and placed under the micro-
scope. Thus tested, in three separate snares, I was able to determine be-
b ?
yond doubt that the spiral line of Theridiosoma is precisely like that of
Epeira. The beads upon several strings, that is, the several portions be-
tween two radii; were counted, in one case numbering sixty-four. I was
) g :
able to make satisfactory drawings of these beads, Fig. 199.
The behavior of the web upon the frames and glass cups was_ pre-
cisely like that of Epeira, the beads melting upon the surface of the
glass, and the string remaining as a simple line in the midst of
The Spir- the
als are
Viscid.

viscid mass. The beads reflected light; in appearance ex-
actly resembled those of Epeira, and in some cases the cord upon
which they were attached was distinctly seen running through
them. Further, I examined portions of the snare upon which small insects
had been caught, and these showed in every respect the manner of entan-
glement which I have so frequently observed with the true Orbweayers.
(Fig. 200.) Previous to removing the sections from the webs, I tested
them with the tip of a blade of grass, to which the lines adhered very

206 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

closely ; indeed, the viscidity of the beads was not only equal to that of
Epeira, but greater than that of some species, as, for example, that of
Labyrinthea.

In order to have separate and independent testimony to this fact, I
requested my private secretary, Mr. Edwin S. Gault, to examine the various
points submitted, and give an impartial report upon the same; first, as to
the snapping of the snare; second, as to the recovery of the trapline by
pulling upon it; third, as to the character of the web itself, whether it
was a round web, resembling the Orbweavers’; fourth, as to the character
of the spiral, whether it was beaded or unbeaded; fifth, as to
the manner in which insects were entangled upon the web, name-
ly, whether they presented the appearance of having been caught in
ordinary beaded snares of Epeira. In all these points
Mr. Gault entirely corrobo rated my investigations.

It may therefore be con sidered as established be-
yond doubt that the snare of Theridiosoma gemmo-
sum (or radiosum) as it appears in America is not

only an orb of the character above de-
Theridio- scribed, but is armed with viscid bead-

The Con-
clusion.

soma an : bene
Orb ed spirals. ‘This fact alone, in view of the
wwoaver! kHown relations between spinningwork and

structure, would compel us to place it with
the Orbweavers. But when Fic. 200. Insect entanglea we find that the indica-
tions of structure are quite 5Pe" anes RaysPk sufficiently in harmony
with those of habit to jus tify such a decision, we
can no longer hesitate. I may venture the prediction that a careful study
of the spinning habit of the European species will show that it entirely
conforms to that of its American congener. It is greatly to be desired
that such a study be made.

Ve

The first specimens of the Ray spider taken by me were hung in large
openings left between the breastwork stones of a ruined mill dam. The
wall had crumbled and quite fallen away in places, leaving large
cavities, within whose moist, cool shelter, among ferns and mosses,
this species had domiciled. The brook poured over the middle
part of the wall, making a pretty waterfall; briers, bushes, ferns, and various
wood plants grew out of the wall and stretched over a deep pool twelve or
fifteen feet in diameter, into which the water dropped. On the lower bushes
and branches above the stream, and continually agitated by the splashing
of the water, was a colony of Stilt spiders, Tetragnatha grallator, stretching
their long legs along their round webs, and dancing with the motion of
the waves; the beautiful nets of the Featherfoot Uloborus (Uloborus plu-
mipes), nets of Tegenaria persica, Linyphia communis, Linyphia neophyta,

Natural
Habitat.

THE RAY SPIDER AND HER SNARE. 207

Epeira hortorum, and of one or two species of Theridioids, were in close
neighborhood. ‘The whole pretty scene was embowered in a grove of young
trees. A more charming habitat could not well have been found.

Another colony, not far away, was established within the cavities formed
underneath the roots of a large fallen tree, and beneath the ledges of some
rocks over which the roots turned. In several similar positions were found
the same snares, and also among the rocks in a wild ravine through which
ran the stream, Lownes’ Run.

Further explorations of the surrounding country showed that the spider
was largely distributed, and in similar conditions. I found numbers in
ravines, on the broad leaves of the skunk cabbage,! whose snares were
stretched above the brooklet, and beneath the shelving banks. They were
also found among the rocks of Crum Creek over the beautiful drive to
Howard Lewis’ mill. Subsequently I collected the same spider in Eastern
Ohio (New Lisbon, Columbiana County), where it was domiciled in a deep,
cool ravine, Mineral Spring Glen. A runlet that cuts across the escapement
of a hill on its way to Little Beaver Creek, has worn out the rocks into a
series of descending steplike platforms, over which the stream flows, form-
ing one or two waterfalls of some height. On each side of the stream,
and particularly under the ledges of the rock platforms, the snares of
Theridiosoma were placed. The habitat of the Ray spider may therefore
be described as moist, cool, shaded cavities and recesses among rocks and
roots, beneath banks and foliage, over or near running water. I haye com-
pared my specimens with some of Mr. Emerton’s collections, made in va-
rious parts of New England, and find them identical. A specimen sent by
Dr. Koch to Count Keyserling had been collected by Dr. Brendel in Peoria,
Ilhnois.

The distribution of the Ray spider is thus greatly enlarged, and no
doubt it will be found in many other parts of America. One might venture
the opinion, based upon its peculiar habitat, that the species will
also be found in Canada. Accepting the species as identical
with Theridiosoma gemmosum, of which I have no doubt, we are
able to place this interesting aranead also among those American species
that have an intercontinental and possibly a cosmopolitan distribution.

Distribu-
tion.

1Symplocarpus (or Ichtodes) foetidus.

© Melia chek eet
ENGINEERING SKILL OF SPIDERS.
AE

Ir is a generally received opinion, even among well informed natural-
ists, and is certainly a fixed popular tradition, that Orbweaving spiders
construct a web that is perfectly true in its geometric arrange-
Imperfect ment. This has highly redounded to the praise of the little
Geomet- weaver, particularly as she may spin by the sense of touch with-
ric Ar- . EAE “. cpewrene :
aes out the aid of sight.! It seems a pity to destroy any notion
ont that may throw around despised Arachne a greater measure of
respect in the popular mind, in which her standing is, as a rule,
anything but favorable. However, in the interests of truth it must be said
that concerning this point the popular opinion is only true in a general
sense. There is much irregularity in the execution of many geometric
webs.

The radii are not laid out with absolute mathematical accuracy, but
are separated from each other by distances varying considerably. If, for
example, one carries the eye around the circumference of this large orb,
he will find here two radii terminating upon their marginal foundation
lines at points half an inch apart, and there two others three-fourths of
an inch apart, and in yet another place two others separated by one and
a half inches. It is true that all orbs are not laid out as irregularly as
this from whose measurements I have quoted, but more or less irregularity
will be found on almost every web, particularly upon those spun by adult
spiders. Again, the radii will be found blending with one another at
various points instead of converging regularly upon a central point; and
more or less departures of a like kind from mathematical accuracy char-
acterize the spiral concentrics. However that may be, the actual facts in
the case are sufficiently striking, and the general regularity of plan and

the frequent close approach to geometric accuracy in special orbs

ea are remarkable enough without resorting to exaggerations. In
ry no she Sin es ae
Fissentia), ct it may well be doubted that absolute regularity, in the

sense of symmetry, would be the most desirable for the uses of
a web. The departures from mathematical accuracy may mark, and I
have reason to believe do mark, a higher measure of utility, and

! See Wood’s “Homes without Hands,” page 321.
(208)

ENGINEERING SKILL OF SPIDERS. 209

show a continuous power to adapt the spinningwork to its environment.
This seems to be done almost unconsciously. If this view be true the lack
of mathematical symmetry may prove the presence of a higher skill rather
than the reverse.

The query was started in my mind whether spiders dwelling along the
seashore or in wind swept heights might not have developed some special
habit of resisting the extraordinary danger to their snares by some extraor-
dinary protection. But I have not found evidence favoring such a sug-
gestion. I have only one example that looks at all in that direction.

Fic. 201. Orbweb (A) among rocks, braced against sea wind. B, braces; C, C, connecting line
or trapline to the den, D.

Among the rocks around the lighthouse at Annisquam on Ipswich Bay,
Massachusetts, I found a large orb of Epeira sclopetaria spun within a
few feet of the surf, and stayed in the peculiar manner which is repre-
sented in Fig. 201. The snare was in a sort of gully or canal between the

granite boulders on the shore, through which the wind blew

A Wind strongly as through a funnel. Across this little gully and exposed
Swept ma : : : ; ;
es to the full force and suction of the wind the orbweb was built

and stayed upon the side of one of the rocks, as at A. Farther
along, a few lines were stretched across the opening, fastened to rocks on
either side as at B, and upon this a line, CC, was suspended, attached at one

210 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

extremity to the centre of the orb, and at the other to a cavity in the
rocks, D, at which the aranead had her den. The hne CC undoubtedly
served as a trapline and a sort of bridge along which the spider moved
from her snare to her nest. But its general appearance and structure sug-
gested the idea that it was braced by the line BB, and acted as a stay to
the orb itself. ‘

I was inclined to think that this peculiar spinningwork showed an
effort of the spider to brace a snare pecularly exposed to winds. It may
be, however, that the line B was an abandoned foundation line, or was one
of those tentative threads which spiders are often spinning, and that its
connection with the trapline was either an accident or afterthought. Per-
haps, indeed, it might have been intended to increase the communicating
power of the trapline.

The fact is, one is very apt, by an unconscious anthropomorphism, to
attribute to the humblest creatures of the fields methods of reasoning and

principles of action which have no existence in the inferior ani-

eels es mals, and are simply the reflections of a higher intellect upon
omorph- ; :
ae P™ the works of a lower one. The naturalist must continually be

on his guard against thus attributing to the creatures whose
habits he is studying methods which in like circumstances would have
been suggested to his own mind.

An illustration of this is quite in point. I have at various times met
suggestions that especial engineering skill is shown by spiders in_ protect-
ing their snares from the effects of wind or other violence of the natural
elements, by the use of sundry objects as counterpoises. Although I had
little faith in the theory, it seemed to me entitled to careful examination.

Once while walking along a graveled path bordered on either side by
shrubbery, I saw what exactly corresponded with reports of so called en-
gineering spinningwork. A large orbweb blocked the entire pathway be-
fore me. The foundation lines were strung across the walk and supported
upon the bordering shrubbery, but a large pebble hung to the bottom of
the web. It was nearly two inches above the surface of the ground, and

my first thought was, here now is a case that confirms the opin-
A Case ofion that spiders support their orbicular snares with weights in
Counter- ; . . eG
noiee: order to balance them against the wind! Kneeling upon the

ground, [I made a careful survey of the premises, and came to
the conclusion that there was no special intention in the case at all, but
that the uplifting of the pebble was a matter of accident. The spider had
run down her supporting lines to the ground, as is her invariable custom
when spinning in a similar site; but, not having a tuft of grass or like
material whereon to fasten the lines, she stuck them upon one of the
pebbles scattered over the walk beneath.

Now the pebble lay but loosely in its artificial matrix, and when the
wind rose and played upon the orbweb, bellying it somewhat, and when

ENGINEERING SKILL OF SPIDERS. 211

in addition the spider began to run up and down

her snare, the pebble was simply lifted up by the
tightening of the upper lines of the snare. This
result was probably assisted by the natural con-
traction of the elastic threads, and by the pulling
of the shrubbery under the force of the wind.
My conclusion was, therefore, that the spider had
balanced her
orb in the
usual way,
but discover-
ed that, al-
though it was
“founded up-
on a rock,”
her house was
rendered in-
secure by the
simple fact
that the rock
was not able
to keep its
place against F1G. 202. Sectoral orb of Zilla counterpoised by a fallen ivy leaf.

the strain.
Mrs. Eigenmann sent me from Southern California some
cocoons of Zilla x-notata, from which I succeeded in raising
a number of broodlings, who domiciled in my

+ ’ . .
Zilla’s library. Many tiny snares were woven upon a
Leaf ‘ :
potted ivy plant, and one of these gave an ex-
Counter- . , =x : :
poise. ample of ready adaptation. The stay lines of

the orb were attached to sundry leaves, and the
upper and side attachments proved secure. But the leaf
to which the whole lower system of supports was fastened
fell off and stretched them downward, giving the snare a
peculiar, elongated shape, which I have never seen quite
approached. (Fig. 202.) This swinging pedestal amply
served the purpose of the wee architect, whose frail web
(drawn here natural size) was well balanced even by so
light a weight. The weaving went on upon this new
basis, radii were spun down into the elongation, and
when the spiral loops were put in, that part was not
omitted. Thus, the net space available for business was
a good deal enlarged, and what was lost by the free
sector at the top was quite made up by the netted

212 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

prolongation at the bottom. The free space exscinded about one-fifth of
the orb. The trapline branched at the hub end, and was held at the
other end by the spiderling, which was backed against the axil of the
leaf, surrounded by a tiny open booth of delicate cross lines. This leaf
was braced to one behind it by various cords.

The late Rev. J. C. Wood, a good observer in many things, indorses the
current opinion that if spiders find that the wind stretches their nets to a

dangerous extent, they hang pieces of wood, stone, or other sub-
Epeira’s stance to them, so as to obtain the needful steadiness. He de-
ieee clares that he had seen a piece of wood which had been thus

used by a Garden spider, and which was some two inches in
length and thicker than an ordinary drawing pencil. The spider hauled
it to a height of nearly five feet, and when the suspending thread was
accidentally broken the little creature immediately lowered itself to the
ground, attached a fresh thread, ascended again to the web and hauled the
piece of wood after it. It brought this balance weight a distance of five
feet along the ground before reaching the spot below the web. There
were eight or ten similar webs in the veranda, but only in this single
instance was the net steadied by a weight.1 I cannot pretend, in view of
the indefinite nature of the record, to explain on more natural principles
the action of this spider. Had the stick been attached to the bottom of the
web, I could have more readily drawn the inference that the purpose was
to stay the orb against the violence of the wind; but I cannot imagine
what use it could have been at the top, where it ought to have had a con-
trary effect. However, the inference which the ingenious and interesting
popular writer has drawn from the incident is in any case entirely too
sweeping.

Mr. Wood’s incident does not stand alone. In “ Hardwicke’s Science
Gossip,” an admirable repository for general observations made by natural-
ists and nature loving persons in Great Britain, I find several records of a
similar character, which I here note.

A large Diadem spider had begun a web by fastening threads to the
eaves of a corridor roof about seven feet high. The extreme points of
the outer stay lines were about four feet apart, and these were
united at a distance of about three feet from the roof, thus
forming a triangle. From the point thereof a single strand was
carried down to within two or three inches of the ground. ‘To the end of
this strand was suspended a small triangular stone about half an inch
across and one-fourth of an inch thick. It is evident, says the observer,
that the stone must have been fastened to the glutinous web as it lay upon
the earth, and was subsequently drawn up. As the wind caught the web
it eaused the stone to vibrate gently, and the motion thus communicated

A. Stone
Anchor.

1 Wood, “Homes Without Hands,” page 319.

ENGINEERING SKILL OF SPIDERS. 7is

to the geometrical part of the web was scarcely perceptible.t The fact is
not questioned, but the inference here made that the spider purposely drew
up the stone as a counterpoise is wholly gratuitous.

Another correspondent ? contributes a similar case observed by a lady
in Scotland. She was walking through a wood when she suddenly noticed
at some distance from the ground a small stone apparently
poised in midair, but which, on closer examination, was seen
to be suspended by a long thread from a _ spider’s web, built
between two trees.

Yet another fact is recorded in the same journal, although it is quoted
from an American magazine.* A gentleman, while passing along one of
his garden walks in Brooklyn, saw, upon a cherry tree, a spider’s web
which was spun within foundation lines that stretched from the trunk to
fastenings that ran out upon a large limb. The web rose at an angle of
perhaps thirty degrees from the earth. The spider had by some means

formed a corner downwards and suspended from it a little stone
An Amer about half an inch long, three-eighths wide, and one-eighth
ican Ex- : aaa :
rip Ai thick. This was well secured, and hung some eight or ten
inches below. This weight kept the web taut, and swung
slightly as the wind affected it, and there it remained for several days.

Still another correspondent declares that, like many other persons, he
has observed a small stone suspended from a spider’s web, but expresses
his doubt as to the suspension being an intentional act of the
spider, and gives what I regard to be the true explanation, name-
ly, that by the shrinking of the threads, or some change in the
position of the web supports, the stone had been raised from the ground.+
In all the above cases it will be observed that the evidence for intentional
engineering is simply the fact of the stone’s position, which is equally ex-
plained as above.

Professor Pavesi has recorded a similar experience in his “Spiders of
the Canton Ticino.”® His attention was first called to the fact by a friend,
and he was at the outset incredulous, but had confirmed his original obser-

vation. He begins with a statement which I can corroborate,

A Scotch
Case.

A
Doubter.

= .,. viz, that when Epeira makes a web in the path of a garden or
avesi’s hss
Gnas other sites between trees, it is her custom to drop a thread from

the lower angles of the polygonal foundation lines of her net,
which lines converge upon this single cord. Further, he declares (which is
contrary to my experience) that upon this cord the spider ties a counter-

1 John Hepworth, “Science Gossip,’ November, 1868, page 262.
J. F. D., id., page 283.

8 J. R. 8. Clifford, “Science Gossip,’ April, 1869, page 94. Quoted from the “ New York
Gardener’s Magazine,” 1841.

* George Guyon, id., page 118.

> Ragni del Canton Ticino: Annali Mus. Ciy. Di Genova, Ser. 1, IV., 1873, page 39.

be

214 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Yj Yy Y poise, which may be
ee A} a dry leaf, ia little

piece of wood or oth-
er like material, but
commonly is a small

xO eee
ZEN pebble or gravel from the

Vee

Ye path. In one such case,
Youn. when he had taken away

the spider descend by the ver-
tical thread to ascertain what
had happened, and, having ar-
rived at the ground, she fastened
the line to another pebble.
It will be observed in this case
that the pebble to which the thread
was fastened lay upon the ground,
and this fact itself compels me_ to

aN i doubt Professor Pavesi’s conclusion. I
FAO MLS tae ea ate wither eOUnLER: cannot resist the thought that in this,
poised snare. (After Parona.) as in other cases where the pebble was
found lifted above the ground and acting as a counterpoise, it had orig-
inally been in the same po sition upon the garden path, and had
been raised by the elasticity of the thread, the mechanical action of
the wind, the motion of the spider, and the swaying of the trees.
Another observation has been made by Professor Parona of It-
aly, and recently communi cated in a paper entitled, “‘ A Peculiar-
ity in the Habits | of Meta meriane.”! In October, 1886,
Meta’s he observed in a villa at Baccione, on Lake Orta, a web
ee of Meta merianee, spun in the entrance of a short arti-
ficial gallery exca vated in solid earth. The orb, as is
customary with nets woven in like positions, was stayed by a series
of lateral lines, which were suspended upward against the arching
vault, and were prolonged downward toward the walk. The snare
was about sixteen inches wide (forty centimetres), and was ex-
posed to the sweep of the wind. The thread prolonged from the
outer margin to the ground was about twenty-seven inches (sixty-
seven centimetres) in length. At the end of this line was hung a
fragment of soil identical with that of the vault, and about as
large as a seed of Indian corn (di grano turco). (Fig. 203.) The
soil was compact and heavy, and the pellet acted as a counter-

AN

poise, holding the web fully “Wgy@ extended, so that it was sufficiently

‘ Particolarita nei Costumi della Meta merianze, Scop. del Prof. Corrado Parona. Annali
del Museo Civico di Stor. Nat. Di Genova, Ser. 2, Vol. VII., 1889, pages 250-5, Tav. VI.

the counterpoise, he saw,

Eee

7
we! ten

ENGINEERING SKILL OF SPIDERS. 215

taut to capture prey, as indicated by the number of victims entangled in
its meshes. It was so firmly implanted, and so opportunely repaired, that
Prof. Parona was able to observe it continuously for eight days. The in-
terest of the observer was so much enlisted in what seemed to be an inter-
esting and novel fact, that he made various inquiries and researches as to
previous records.

Among others, he communicated his observation to the veteran arach-
nologist, Professor Thorell, requesting his opinion thereupon. The ques-
tion was submitted by Professor Thorell to myself, as lying
within the line of my special studies of life habits, and I re-
turned for answer substantially some of the facts which have
been recorded in this chapter. Nevertheless, Professor Parona has done
well to place his observation upon record, and he has fortified it by like
observations from other authors. Among these is the experience of Pro-
fessor Pavesi, in part as above. He quotes a second observation in the
same line made by Ninni, on the web of Epeira umbratica, as recorded in
the Acts of the Society of Natural History of Veneto-Trentina.! This

spider wove her snare under the roof of a beehive, and gave it

Professor
Parona.

nee stability by carrying down a thread to the soil and wrapping
a ra it around a pebble which was raised to the height of about

seven inches (about eighteen centimetres) from the ground. De-
siring to know if such ingenious work were confined to that case, the
author destroyed the web and waited to see how the spider would behave
in the face of the difficulty that it had previously overcome. Three days
afterward he saw the web built in the same manner as before, but more
perfectly finished. As though conscious that without another point of at-
tachment the construction of her snare would be impossible, the spider
carried down a thread which was maintained in a taut condition, not with
one pebble as before, but with two pebbles and a straw. From this line,
as an initial foundation line, she constructed the framework of her orb in
the shape of an isosceles triangle, within which the orb was spun, in a
position well sheltered from wind and rain. In order further to test the
matter, the author destroyed this second web, but awaited the spinning of
a third one in vain, as Umbratica abandoned the site.

It is to be observed that in this case also the testimony is defective,
in that the observer did not see the spider actually using the pebble as
Cui bono? = counterpoise ; that is to say, in the act of suspending it upon

the line. In point of fact, what possible benefit could have
been obtained from staying the orb by a pebble hanging above the ground,
when an attachment to the solid earth below in the usual manner, or to

‘Sopra la tela dell’ Epeira umbratica: Atti Soc. Veneto-Trentina di Sc. Nat. Padova ;
1876; Vol. 3, pages 204-5; Tav. VI.e VII. I regret that the particular number of this jour-
nal in which the reference is made does not happen to be in the library of our Academy
of Natural Sciences, and I have not, therefore, been able to consult the original.

216 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

a pebble fixed therein, would have been more advantageous to the spider?
This is equally true of all known cases of counterpoise.

After haying cited my opinion, as communicated in my letter to Dr.
Thorell, Professor Parona expresses, though with some reserve, his belief

eeea t= - |
AICO J

Fig. 204. Swinging nest of the Shamrock spider, Epeira trifolium.

that the act recorded by him was an intentional one on the part of Meta.
The counterpoise could not have been lifted up from the garden path,
as no such material entered into the composition thereof. It
had evidently come from the vault above, as it was of the same
material, and retained living tufts of a moss that grew upon
the overhanging vault. Moreover, if I correctly understand Professor Parona,

Parona’s
View.

=. iS

ENGINEERING SKILL OF SPIDERS. 217

the distance of the web (counterpoise?) from the ground was about a
metre and a half, which would seem to preclude the theory that it had
been raised up from the ground by the elasticity of the web, or the

mechanical impact of the wind.
Nevertheless, I am constrained to believe that in this case also the
explanation of intentional engineering must be dismissed. The pellet
had evidently been separated from the vault by the erosion

peste ,. of the atmosphere, and had either been lifted up from the
a ground, where it had fallen, in the manner I have described,

or, which is more probable, it had entangled within the web
as it fell; had been prevented by the foundation cords from dropping
entirely to the ground; had been held above the surface by the viscidity
and natural elasticity of the threads; and while thus hanging, accidentally
poised, it was made use of by the spider as a point from which to re-
attach her foundation line. As long as it remained in poise, undisturbed
by the wind or passing objects, it would be available for the purpose
of staying her web; and in this position it was the fortune of Professor
Parona to see it.

However this theory may accord with the facts, I am perfectly assured
that the spider could not have cut off from the vault a particle of soil so
large, and then have transferred it to the position where it was seen.
Such action is so wholly foreign from all that I have observed of the
habits of Orbweavers, that I cannot possibly allow myself to admit it as a
reasonable explanation. On the whole, my judgment is that none of the

‘instances heretofore observed, in the form at least in which they are re-

corded, afford sufficient testimony to permit us to believe that Orbweavers
have the engineering ability to counterpoise their webs against the action
of wind and the natural shrinkage of the web material, by means of peb-
bles or other objects attached to marginal lines.

Indeed, if such action were really proved, it would seem to me an un-
wise and not a cunning exception to the general habit in like web sites,
which is to carry the principal supporting line quite down to the firm
earth. Nothing could be gained, and much would be lost, by exchanging

this for an unstable counterpoise. Would the spider be apt to pause

within an inch or two of the ground, which was thus clearly within its
reach, to make so unprofitable an exchange? The only special

Counter- wisdom that can be allowed the spider in the case is that
oisin ; :

2 & which accepts an undesirable situation as at least available, and
Useless.

adapts her spinningwork thereto; and that is certainly to be rec-
ognized, and it is sufficiently remarkable.

IT.

It is not to be doubted that spiders do show considerable powers of
adaptation in adjusting their spinningwork both to peculiar situations and

218 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

special exigencies. Most of the above examples and perhaps all are illus-
trations of this. Another case in point was furnished by a Shamrock

Fic. 205. Furrow spider’s extemporized den of sawdust.

and proceeded to spin her snare directly
below the opening. She attached her trap-
line to the hub, and thus in her hanging
home continued to wait for prey.! (Fig.
204, page 216.)

Another somewhat similar case of adap-
tation in nest making was due to an acci-
dent in the environment of the web. A
half-grown Epeira strix had wovy-
en a snare in the hollow of a tree
(at New Lisbon, Ohio), within two
feet of the ground. <A colony of Pennsyl-
yania carpenter ants (Camponotus Penn-
sylvanicus) had quarters in the tree, and a
squad of black workers were busy excavat-
ing their wooden galleries. These dumped
their chippings from openings just above
the spider’s orb, whose viscid spirals re-
tained a goodly quantity of the brown
sawdust. In course of time a ball of chip-
pings as big as a walnut had accumulated,

A Saw-
dust Nest.

spider, Epeira trifolium, that
exhibited a remarkable ability
to adapt her domi-

Special Gile to very peculiar
Adapta- ie) ‘

: circumstances. She
tion.

had placed her nest
in the curled leaf of a grape
vine, which becoming detached
from the stem fell and entan-
gled within the lines of the orb
beneath. Whereupon the oc-
cupant, in nowise disconcerted,
adjusted her tent, stayed it
above and at the sides with
guy lines, braced it beneath,

BSS

——

\. ~

= mS UH = : at ; i NY /
see - Re ST Nee :
Soh bay ai .
Koa)

hd \:

SAE IN

Fic. 206. A blockaded path.

' The incident occurred at Vineland, New Jersey, and notes and measurements for the
figure were furnished me by Mrs. Treat. The incident is also recorded in that author’s

“My Garden Pets.”

ENGINEERING SKILL OF SPIDERS. 219

or, perhaps, had been purposely massed by the spider. However that may
be, the ball was utilized as a nest; its centre had been pierced, a spher-
ical cavity formed by silk lining the interior, which was entered by a
circular door bound around the edge by spinningwork. This quaint dom-
icile was pendent from one of the strong upper foundation lines, and
herein Strix rested, while the emmet carpenters worked away above her,
continually dropping chips over the roof of her nest and the orb be-
neath, until one side of the snare was quite covered with them. In
this case the position of the nest, as well as its form, was exceptional,

) Ge

& A iv
\\ Mt ee? “eee
Ale, eel,

A, M4
ms
Zt

4
{

\ ,
ay

Mi fi, MW,

\ a: Va
he 2 | ,
We yi i ( Z

ae
Was IAW, be, 7:

Fic. 207. A meadow orbweb braced to an overhanging branch of a tree.

as the nest site of Strix is well nigh invariably beyond the limits of the
web, sometimes, indeed, several feet. In these points the spider was evi-
dently led to an intelligent variation of her nest building by circumstances.
(Fig. 205.) A series of interesting illustrations of the same elasticity of
habit in the nesting industry of the Furrow spider may be found in the
subsequent chapter on Nesting Habits, and might, with almost equal
propriety, have been introduced here.

Another case of adaptation may be cited, without impropriety, as a good
example of Epeiroid engineering. While walking through the pine woods at
the head of Deal Lake, New Jersey, I found a narrow path blocked by a

220 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

structure which is represented at Fig. 206. It is easy to explain the mode
of forming this remarkable framework, if we suppose that the spider was
perched upon the twig, a, and emitted from her spinnerets a
From thread which was carried out and upward by the wind, and
Treetop : P 2 rane :
to Path, Cutangled at b, thus forming the prime foundation line, ab.
Thence she could have moved to the point between d and a,
whence she would have dropped to the ground, a distance of ten feet,
and hitched a second lne to a tuft of grass. <A third line might readily
have been secured by dropping from the point d, the natural swaying
of the spider, increased by a breeze, carrying her to c. This line, de,
could easily have been pulled in by the cross lines above and below the
orb. A convenient frame being thus obtained, the spinning of the orb
would be a simple mat-

y RSS Can
ter. The entanglement === ee = he Ahsilaan thse M.A if

to the side shrubbery at
c, ¢, may also have been
made by aid of the
breeze in part.

If, in the absence of
direct observation, one 4
were to deny the use «
of air currents, then it
must be supposed that
the spider carried its
line along the tree to
the tip of the branch, b, i
which was twenty-five !
feet above the ground ; tc a
and after that it would
be difficult to conjecture
how she could have proceeded. In fact, in this case the “carrying around ”
theory alluded to in a foregoing chapter appears to me quite incredible.

Fic. 208. Trusses on a fractured snare of Agalena necevia.

If we admit that the moving breeze materially aided the spider in her
work of construction, and that she was thus in part dependent upon
chance, yet there remains a pretty wide field for intelligent selection and
adaptation. One would suppose that it required a really nimble witted
creature to seize an unexpected opportunity like the above and turn it to
such good account.

Nor is this an exceptional or even rare example. One often meets,
in his walks through our fields and woods, the snares of Orbweavers
woven upon the grasses or bushes bordering a meadow path (Fig. 207),
or the low undergrowth of an open wood or grove, while the nesting
tent and the upper supporting lines are attached ten or fifteen feet aloft
upon a branch or dead limb of a tree. It would be as idle to suppose

ae

ENGINEERING SKILL OF SPIDERS. 221

that a wire suspension bridge is swung across a valley or stream without
engineering skill, as to think such spinningwork structures are wholly
without handicraftmanship of some sort.

The Speckled Tubeweaver (Agalena neevia), which is probably the
most abundant familiar spider of our fauna, affords admirable illustra-
tions of this facility. In a stable at Almora, Wallingford, the
following form of a sheeted web of this species was observed.
The upper sash of the stable window had been lowered for pur-
poses of ventilation, thus probably rending the original snare. But in one
of the upper corners of the window frame and within the space thus left
open, Neevia had renewed her web. (Fig. 208.) The tube was in the cor-
ner, and of rather feeble character, but the pouch was doubled up some-

Agalena’s
Trestles.

Fic. 209. Agalena’s web with suspension lines and trestles between the bars of a fence.

thing like a roll, and extended entirely across the window. For about two-
thirds of the way it was an ordinary sheeted snare. Then it flared upward
and was attached to the upper part of the window frame, and was contin-
ued to the opposite side of the window with rather straggling lines. As
though to support this structure at either end, a series of strong and very
straight taut brace lines was extended downward from either end as shown
in the figure. No conclusion is possible except that this was done for the
purpose of staying the drooping pouch of the snare, and this, of course,
implies intelligent engineering.

The example cited is only one of many which might be presented
from my somewhat extended and yaried studies of the Speckled Tube-

227, AMERICAN SPIDERS AND THEIR SPINNINGWORK.

weaver. Her snares are found in all sorts of positions and locations. In
the angles of houses and walls, among leaves of trees, in shrubs and grasses,
in old stumps, and caves and holes in the ground, wherever a

Trest- footing can be had and a spinneret can be laid, this univer-
ling Her _ cs . : FTP
Wigee sal occupant of outhouses and grounds proceeds to weave her

snare. Under all circumstances she shows rare ability to adapt
it to the particular site where chance has fixed her abode. If bracing is
required from above she sends upward a series of lines which support
her sheeted snare. If bracing is required from below, as we have seen
(Fig. 208), she sends out a series of trestle lines, which keep the sheet in
poise, and suggest the methods of carpenters when scaffolding a platform
or floor, or trestling a bridge. If bracing be needed both above and be-
low, as in the pouched snare (Fig. 209) woven between the bars of a farm
fence, the lines are sent
out in the very positions
to give the required sup-
ae | port. In fact, a civil en-
_ fi Sa sil ie if ‘ ‘ gineer would decide, up-
; | on examination, that his
profession could have sug-
gested no better arrange-
ment under the circum-
stances.

In the lawns and
grounds around Philadelphia, and indeed almost every-
where in the United States, Agalena’s snare will often be seen
spread like a broad white sheet upon the upper surface of
hedges and thick set plants, such as arbor vite, boxwood,
and honeysuckle. Into these she works a silk lined cylindri-
‘al tunnel, which extends to the very heart of the plant, and
often to the ground beneath. She manages, in some way, so to lash back
the stems and twigs that, in spite of the natural elasticity and growth
force of the plant, the tubular den or home is held quite in
place. Not only so, but the sheeted web will be stayed and
held in position by a series of lines that seem to display no
little skill in adjustment. She thus places a tubular bridge between her
foraging ground and her retreat.

Once while visiting a brother, the late Commander Rhoderick Sheldon
McCook, U. 8. N., at his home in Vineland, N. J., my attention was called
by him to one of these snares of Agalena built upon an evergreen bush
planted in his yard.. The comments of the sailor were striking and
characteristic, and I regret that I cannot accurately recall them now. But
I well remember the amazement which he expressed as he pointed to this
point and that in the structure of the snare, and compared it to the shrouds

Fic. 210. Tubular work of Dysdera bicolor.

Tubular
Bridges.

b]

ENGINEERING SKILL OF SPIDERS. 223

and other portions of a ship, and showed how the right lines seemed al-
ways to have been placed in the needed position. This aranead is so
common that any one who chooses to test my descriptions and observe
independent examples can easily do so for himself. (See Fig. 215.)

This is not the only Tubeweaver that shows an engineering skill that
challenges the admiration of human observers. Fig. 210 represents the
ordinary tubular snare of Dysdera bicolor, which was spun within
a paper box in which I had captured the spider, and of course
in absolute darkness. In the morning I found a circular snare
placed against the curved edge of the box, and stayed to the sides and
bottom in a way that I have attempted with indifferent success merely to
suggest in the figure. As I looked at it, and set to myself the problem of
how to weave a mass of silken threads into the corner of a room,
for example, in such a cylindrical shape that it would stand out stark
and smooth, my admiration for the cunning skill of my aranead
friend was much increased. At all events, the art that can build
and stay such a work out of such g flimsy material as the silken
lines emitted from a spider's spin ning spools, is entitled to a
high place, at least in animal 4 engineering.

The snare of Theridium is a mass of intersecting lines
suspended at all points of the outer margins by con-
verging threads attached to the surrounding site. The
spider takes her posi tion within the centre of this
mass, and in the, : course of time there is a
very strong tenden' TKN RAS Ss cy in the spinningwork
to assume the shape aia = eta _ of a nest. The lines
become thickened : aN ine Z in the centre, and
may occasionally be = found so approxi-
mated that they pre sent the appearance

. Fic, 211. Trestlework snare of a young Theridium. ,.
‘of a net, not un lke the snare of
Linyphia, but not so closely textured as that of Agalena. Beneath this
thickened centre a series of lines will often be found stretched downward
and attached at the basal extremity. (See Fig. 211.) A web suspended
between the joists of an old barn, the slats of a lattice work

Dysdera’s
Skill.

\
MAN

Therid- screen, or within a box, or other like situations which will allow
sate these supporting lines to be formed with some degree of regu-
Trestles. © 5

larity, presents a striking resemblance to the trestlework of a
wooden railroad bridge. I have observed this especially in Theridium
tepidariorum, and some very beautiful and remarkable examples in the
web of the long legged Cellar spider, Pholeus phalgioides. When such
a web is formed, the spider is found suspended to the under part of
the thickened portion, which thus becomes to her a sort of nesting place.

Fig. 212 was sketched from the snare of a female Theridium differens
woven upon a wire frame fastened with staples upon a wooden block,

224 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

The block was laid upon a rough plastered cellar window (in my church cel-
lar) much frequented by spiders, and was overspun as indicated in the figure.
The ridge of the pyramidal structure drooped between the tips of the wire

hoop, quite like the main cable of a wire suspension bridge.

oe N From this numerous diverging lines stretched on either side to
/ sa) YX a .

age SS the edge of the block and the window ledge beyond. Below
di \\ . the ridge cable and within the side guy lines a maze of

thickened netted lines was spread, from which support-
ing trestle like lines dropped down perpendicularly
to the surface of the block. The spider her-
self, with several white globular flossy co-
coons and a bevy of younglings be-
sides, was domiciled
within a series of lines
that extended from one
of the wire tips (left
4// hand of the cut) to the
ty stone window frame. The
\ g/ resemblance of this struct-
¥ ure to the wire bridges or
fi wooden trestlework of hu-
APA man engineers 1s apparent
> RSeK <<" at a glance.
aa il — [4 Wii) At times,
i, =< when the sit-
uation will al-
low, the spin-
ningwork of
Theridium
assumes even
more decidedly the form of a nest. For example, in the horse stables
of “ Almora,” the country seat of a gentleman resident at Wallingford,
the windows are protected by a wide meshed wire frame. Within the
meshes and around the window frame a vast number of spiderlings of
Theridium tepidariorum had colonized. The scant lines which

Globular formed the original snares had gradually been thickened around
Struct-
ures of

NS

NY

= LT
Re ; cme) > —— >A.

Fia. 212. Theridium’s silk suspension bridge.

the margins, from which stay lines were thrown out in all di-

: rections. In the course of time the snare assumed the globular
Therid- : a me ; Re te as Se
SEA. shape which is indicated in the cut. (Fig. 213.) Within the

centre, which was more scantily woven and more open than
elsewhere, the spider was established. This condition of the central part
was quite the reverse of what one usually sees, viz., the thickening of the
web near the spider’s habitat. The variation appears to have been caused
by the necessity of strengthening the points at which the guy lines and

ENGINEERING SKILL OF SPIDERS. 225

radiating supports seized the margins. These structures, modified as they
doubtless were by their environment and in a measure thus compelled to
their final form, evidently show considerable skill in adapting spinningwork
to circumstances.

There is no doubt that in the ordinary operations of snare making and
nest building, the Labyrinth spider continually brings into play certain
principles of operation which may be properly designated by the
term engineering. For example, in looking at Labyrinthea work-
ing up the maze of crossed lines in which her domicile is hung,
one is continually impressed with the fact that she so balances
and adjusts the lines as they are successively spun out, that the whole
spinningwork is as
well suited to its ww
purposes as is the
complex scaffolding 4
used by human car- 3 4 9"
penters in building see x eg
a house. I cannot Neen

cot ae Vinac(a
conceive in what K
manner the spider
perceives the vari- \
ous inequalities, on
this side or that,
which require spe- }
cial treatment in ,
the way of staying, %& .
tightening, adding, = GS —=
etc. Perhaps her ~ SSF ~
sense of touch is
‘so delicate that her
perception of these
necessities is accurate enough to enable her to construct her intricate snare
so as to attain precisely the same results as would have been reached had
she been guided by an engineering intention from the very first.

Again, Labyrinthea is in the habit of roofing her silken tent with a
leaf. Sometimes the leaf is used in heu of the tent, and again the tent
is woven inside of the concavity of the leaf. In order to ob-
serve the mode of treatment I once dropped a curled leaf into
a newly made snare of this spider. She at once perceived its presence by
the agitation of the maze, ran to it, and appeared immediately to perceive
its value. She fastened to it here and there a line, as though to preserve
it from falling farther and thus damaging her snare. She then ran to
the stem, attached a strong thread to it, and clambered out upon her silken
trestle for the distance. of two inches, and then fastened her line, leaving

Labyrinth
Spider’s
Snare.

Ne Se,

4

Ke

=
Fl =
tS

Fic. 213. Globular structure of young Theridium tepidariorum.

Roofing.

226 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

the leaf stayed in a most admirable way. She then took her position un-
derneath the roof, apparently satisfied with her new shelter. The only
thing which it seemed to me she might have done better was to turn the
leaf. It had fallen with the cavernous part upward, and the spider so left
it, although that part was the one best fitted for a den. I watched for
lrg awhile to see if this point would be observed and remedied by
are the little architect, but saw nothing. During the night there
Tent, was a heavy storm of rain and wind, and in the morning I found
the orb destroyed and the maze much damaged; but the leaf
remained, and the spider was nestled against it. It had manifestly been
her refuge against the storm.

LY iN Gi q
AN

Fic. 214. How a Labyrinth spider swings and stays a leaf.

The day cleared, and next morning a new and beautiful snare had been
spun. However, a site had been chosen six or eight inches removed from
the original one. ‘To this point the leaf had been shifted; and now I no-
ticed that it had been turned over so that the concave part was downward,
as at first I had thought it ought to be. This could hardly have been the
result of accident. The whole leaf was now so arranged as to make the
best shelter possible, and it was stayed within its position in the maze in
an admirable manner. Fig. 214.

To the point of the stem was fastened a very strong, thick, white line
(a, a) similar to that with which Labyrinthea suspends her string of cocoons.
This extended through the labyrinth in a somewhat waving course for
a distance of eight inches. This line was braced throughout its course

bo
bo
~I

ENGINEERING SKILL OF SPIDERS.

by various threads fastened upon the intersecting lines of the maze. From
a little corner in the upper part of the leaf a similar line, b, was stretched,
braced by two interior lines of a like character (cc and d), which

Laby- like the stem cable were also held in place by numerous slighter
rinthea’s : a Fag"
Cables cords extending through the maze. A careful study of these

main supporting cables, and indeed of all the lines used for
upholding the leaf, convinced me that, whether or not the spider was con-
scious of any principles of engineering, she had in her results proved
herself an admirable engineer. I kept this leaf under observation for
a number of days of varied weather, and it never lost its poise, or was

NY
Mi

Fic. 215. The snare and stay lines of Agalena ncevia in a honeysuckle vine.

moved from its place within the labyrinth. It endured well the strain of
one of the most severe downpours of rain that I ever saw. It thus stood
the test of actual use as well as careful observation.

In accounting for such acts as this, one is compelled to suppose the
exercise of reasoning powers of some kind by the spider. Whether the
reasoning may haye been accomplished by the processes known to man
and more highly organized animals, or whether the behavior of the spider
was the result of sensations produced by her delicate sense of touch, and a
perception of irregularities of weight and tension, which passes human ex-
perience, one need not stop to discuss. In point of fact, judging these

228 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

phenomena as one would decide upon the behavior of his fellow man, one
is not astray in attributing to the spider a rude sort of intentional en-
gineering skill. Is it any less worthy of this title because exercised with
seeming unconsciousness and without a moment’s hesitation or apparent
reflection of any sort?

In the same direction look the facts which I have recorded in the
‘chapter on the construction of webs (Chapter IV.), under the head of

alternate apposition of the radii. Indeed, it may be said truly,
Alternate that in the entire work of laying out the foundations of an orb
Appo- Se ae adicenie carci aati ot
Loe and placing in the radu, regard is had continually to the proper
Badia adjustment of the various parts, with view to their counterpoise

and adequate support beneath the weight of the operative. One
side is balanced against another side, one line is stayed by its opposite,
and so from part to part the spider moves, evidently to keep her orb
entirely balanced until it is completed.

The manner in which the ends of the radii, which terminate upon
the hub, are wrapped round about and braced by the notched zone; the
manner in. which the wide nonviscid spiral scaffold lines are
woyen in order to give vantage ground from which to place
in the close lying and permanent viscid spirals, upon which
the usefulness of the orb depends—all these, to mention no other points,
seem to indicate a very delicate perception of those modes (shall I also
say principles?) of construction which are continually recognized in the
art of the builder, the architect, and the engineer. The examples of vari-
ous orders of spinningwork which I have given above have been grouped
in this chapter to give the force of assembled and consecutive illustra-
tion to the inquiry as to the intellectual quality of araneal architecture.
In point of fact, the special industries detailed in the various chapters,
and notably the two on Nesting Habits, will furnish illustrations of equal
aptitude and force.

Spider
Intellect.

eee a” Dob Ve

MECHANICAL STRENGTH OF WEBS AND PHYSICAL POWER
OF SPIDERS.

KE

THE size of orbwebs varies generally with the size of the builders. But
location, the condition of the wind, and contiguity of other webs have
much to do in determining the matter.

The abundance of insect food may be a factor modifying both form
and size. An example of this was seen
in the colony of Epeiroids referred to,

Chapter III., as stretching their

chee nets across the water between the
upply ieee Sey
Modifies. boat houses at Atlantic City.

(Fig. 61.) There the flies swarmed
in such myriads that the difficulty of ob-
taining food was reduced almost to the
minimum. As a consequence most of the
spiders hung in the merest rudiments of
webs, as shown at Fig. 216. In some cases
these may have been the remains of more

or less perfect snares, which had become

Fic. 216. A rudimentary snare of Epeira.

reduced to remnants by struggles of in-
sects; but many of them showed no traces of any other architecture than
that here represented, and I inferred that the spiders had discovered that
the building of complete orbs was a useless waste of labor and material.
and had spun no more than the central space.

A Furrow spider taken from the railings of a bridge, where its space
was circumscribed by location and by numerous webs of its fellows, when

placed in a roomy cell spun an orb eleven and a half inches
Modified

by Site long by eight inches wide, hung upon a foundation line sixteen

inches long. The same aranead, when placed in a glass jar three
inches wide, wove a small characteristic web, or an apology for one, not
unlike the rudimentary snare at Fig. 216. Argiope cophinaria often makes
a very small web, and is quite sure to do so when the arboreal spaces
surrounding it are straitened. But when domiciled where her lines
could be carried long distances I have known her to make an orb more
than two feet in diameter.

2g

230 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Again, it is obvious that in cases where an Orbweaver is dependent upon
the wind to carry her foundation lines from the starting point to a point
of attachment, the length of that line will necessarily be deter-
mined by circumstances. The cord may float off a goodly dis-
tance before striking an object, or may entangle soon. In the
latter case, as the foundation line will be limited, the snare will be dimin-
ished accordingly. I have known a Furrow spider to make a web a
foot wide one night, and the next night, when becalmed and_ prevented
from stretching a foundation in her old site, spin an orb four inches in
diameter.

Young spiders make small webs, and invariably very perfect ones. The
irregular, abridged, or patched snares which one sometimes sees, when not

Modified
by Wind.

\\\

Ms

pall
\\ WN
WY

Fic, 217. Typical orbwebs, Epeira strix.

the result of wear and tear, are those of adults; never, I believe, of young
Orbweavers.

The following are a few measurements of the orbs of some of our com-
mon species. Kpeira insularis: inches, six by six; thirteen by eleven; four-
teen by fourteen; twenty by fourteen; fourteen by fourteen. Epeira strix:
two by one and one-half; twelve by eight; nine and seven-eighths by nine
and one-half. These are measurements of the orb alone, not including the
foundation spaces. It will be seen that only a part of the above orbs are
nearly circular; more frequently, perhaps, they are somewhat elliptical, the
vertical diameter being the longer. The central space occupies about one-
third or from one-third to one-fourth of the orb, the spiral space on either
side about equaling it in width. The hub approximates the geographical

STRENGTH OF WEBS AND POWER OF SPIDERS. 231

centre when the web is quite round, but otherwise is elevated above the
centre; sometimes is placed well to one side. (Fig. 217.) Its width, though
subject to variation, may be said approximately to equal one-third of
the central space.

The frailty of a spider’s web has passed into a proverb. Yet, compara-
tively, the silken line of an Orbweaver is very strong. According to Schaf-
enberger! it requires ninety spinning threads of an Epeira to yield one
thread of the thickness of a caterpillar’s thread; and, according to Leeu-
wenhoek, it requires eighteen thousand spider lines to make the thickness
of a hair of the beard. These comparisons are suggestive, although in a
measure deceptive, since there are vast differences in the size of the threads
woven by Epeiroids. It is probable that the extraordinary strength of the
thread is due to the superposition of a large number of extremely minute
threads. However, after the thread is woven, Meckel could not recognize
it as consisting of more than eight to ten strands. A geometric snare,
whether vertical or horizontal, must be strong enough to sustain the weight
of a spider of considerable size, such as Argiope cophinaria or Epeira insu-
laris, particularly when the female is heavy with eggs.

Blackwall thus determined by experiment the strength of a line by which
a female Epeira diademata, weighing ten grains, had sustained itself from
a twig. He attached to the extremity of the line a small piece of muslin
with the corners nearly drawn together, so as to form a minute sack, into
which he carefully introduced sixty-one grains weight in succession, being
more than six times the weight of the spider. On the addition of one-half
grain more the lne broke.?

Not only must an orb sustain the weight and movements of its maker,
but it must also have sufficient strength to hold the various insects which

strike upon it. Bees and wasps are sometimes able to break
bios Ric through the spiral meshes of a large snare, but generally the
and Dews threads are strong enough to hold them, in spite of their strug-

gles, until the proprietor can enswathe them. Moreover, the orb-
web must be able to sustain the weight of evening dews. One who has
seen such snares in the early morning, when every viscid bead appears to
have attracted to itself an encasing armor of silvery dew, and has noticed
how the spiral strings are bagged down under the weight of the same
(Fig. 218), must have inferred that the snare was able to support a com-
paratively heavy burden. The same is true concerning summer showers,
which must fall very heavily and be driven before a pretty strong wind
in order to batter down a well constructed orbweb.

Indeed, I have often wondered at the capacity of these fragile structures
to resist the force of winds. Here, for example, are webs of Epeira strix

‘As quoted by Meckel.

* Transactions Linnzean Society, Vol. XVIII, 1841, page 321.

232 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

and Epeira triaranea in the full sweep of a strong gale, blowing over a
near by bay of the sea, and are scarcely damaged. Sometimes, it 1s true,
the webs are blown away or lashed into threads wholly or in

Resists . . . .
part; but frequently they will stand all the ordinary high winds

Wind. ; : : ‘e
and even some of the extraordinary ones which blow off the

ocean. This is true even when they are spun quite near the beach, and
have little protection under the lee of surrounding objects.

An illustration of the remarkable strength and elasticity of the founda-
tion lines of orbwebs appears in a biographical notice of the distinguished
astronomer, the late Gen.
Ormsby M. Mitchell, printed

with an edition of
Strength ‘hig lectures.1.» Prof.

of Foun- witchell directed
dation

ee. his great ingenuity
to the problem of
causing a clock to record its
beats telegraphically, and at
the same time perfectly per-
form the work of a time-
keeper. The required makes
and breaks in the battery
were effected by means of a
cross of delicate wire and a
mercury cup. Many obstacles
having been overcome, there
arose the great difficulty of

procuring a fibre

ae sufficiently minute
rmsby .
and elastic to con-
Mitchell.

stitute the physical
union between the top stem
of the cross and the clock
pendulum. Various materials

were tried, among others a

Fic. 218. Section of a dew laden orbweb. (Magnified.)

delicate human hair, the very
finest that could be obtained, but this was too coarse and stiff. Its want
of pliancy and elasticity gave to the minute “wire cross” an irregular
motion, and caused it to rebound from the globule of mercury into
which it should have plunged. “After many fruitless attempts,” says
Prof. Mitchell, “an appeal was made to an artisan of wonderful dexter-
ity; the assistance of the spider was invoked; his web, perfectly elastic

‘The Astronomy of the Bible, page 35.

STRENGTH OF WEBS AND POWER OF SPIDERS. 233

and perfectly pliable, was furnished, and this material connection be-
tween the wire cross and the clock pendulum proved to be exactly the
thing required. In proof of this remark I need only state the fact that
one single spider’s web has fulfilled the delicate duty of moving the wire
cross, lifting it and again permitting it to dip into the mercury every sec-
ond of time for a period of more than three years! How much longer
it might have faithfully performed the same service I know not, as it then
became necessary to break this admirable bond, to make some changes in
the clock. Here it will be seen that the same web was expanded and
contracted each second during the whole period, and yet never, so far as
could be observed, lost any portion of its elasticity.”

De Laet,! in his Novus Orbus, as early as A. D. 1633 speaks of certain
beautiful spiders, elegantly marked by various colors, which build nets
strong enough to entrap small birds. Of others, or perhaps the same spe-
cies, he says that their webs are so tough that they can scarcely be broken.?

Sir Hans Sloane ® describes a West Indies spider, which he calls the
“Great Yellowish Wood Spider,” and which is undoubtedly a species of
Nephila, perhaps N. clavipes or N. plumipes, as making a web
strong enough to ensnare birds. ‘They have,” he says, “an
almost spiral large Web made of Yellow Spider’s Thread, like Silk,
glutinous or viscid, with which it will stop not only small Birds,
but even wild Pigeons; they are so strong as to give a Man inveigled in
them Trouble for some Time with their viscid sticking Quality.” He also
cites “Smith of Bermudas” (page 172) as describing “certain spiders of a
large size, not dangerous, but making a sort of raw silk, catching birds
bigger than blackbirds and like snipes, in their nets.”

Wallace, speaking of the spiders of the Aru ‘Islands, in the Malay
Archipelago, says that the web spinning species were a great annoyance,
stretching their nets across the footpaths just about the height of his
face; the threads composing which were so strong and glutinous as to
require much trouble to free one’s self from them.* Mr. Mosely, the

naturalist of the “Challenger,” says that at Little Ke Island,
Webs one of the same group, “ Von Willemos Suhn actually found
Heed a strong, healthy ‘glossy Starling’ (Calornis metallica), caught

fast in a Yellow spider’s web, and he took the bird out alive
and brought it on board the ship to be preseryed.”®

Vinson gives like testimony from observations made in the African
Island of Réunion. The young spiders that encamp in innumerable

Strength
of the
Snares.

1 Novus Orbus Ionne de Laet, Ao. 1633, page 29. “Aranee * * * que estate ita
validas telas nent, ut minores aviculz illis irretantur.”
2 “Qui telas nent ita pertinaces ut vix disrumpi possint.” Id., page 673.
5 Natural History of Jamaica, Vol. I., page 196, A. D. 1725.
*The Malay Archipelago, Alfred Russel Wallace, page 437.
° A Naturalist on the “Challenger,” page 382.

234 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

quantities among the large snares of Nephila swung between forest trees
are sought by the birds who, in their too eager pursuit, strike upon the
stout surrounding lines and are arrested. He had encountered these birds,
particularly the beautiful Muscipeta Borbonica of Cuvier, entangled in
these mammoth snares.?

Darwin speaks of the Brazilian forests as haying every path barricaded
with strong yellow webs of a species of Nephila similar to N. clavipes.?
The late Prof. Orton uses precisely the same language of the spiders
in the forests of the Amazon, and adds that some build nests in the trees
and attack birds.* Prof. Wilder found that the orb of the Nephila
of our Southern Atlantic coast would easily sustain a light straw hat,
whose weight is certainly greater than that of a young bird. My own
experience with such webs in Texas is that they will sustain a weight
quite equal to that, although I never made such a test. It is said by
tourists that the woods of Southern California are barricaded in the same
way as those of Brazil and the Amazon, by the webs of Orbweavers, so
that it is often difficult to pass through them.

Two well authenticated cases of birds taken by a native spider have
come under my notice in the vicinity of Philadelphia. A farmer belong-

ing to the Society of Friends, Mr. Joseph Lownes, resident in
Argiope the vicinity of Morton, informed me that he once found a bird,
as a Bird ae : ee ie
Gatcree) one of the smallest of our indigenous species of Kingster, en-

tangled in the snare of a spider, which I judged from the de-
scription to be Argiope cophinaria. He watched for some time the moye-
ments of the bird, and believing that the latter would be finally over-
come he benevolently released it from the web.

Another case occurred on the grounds of the Philadelphia “ Rabbit
Club,” near Fairmount Park, and was related to: me by David J. De
Haven, the custodian. He saw a large Argiope cophinaria (as it appeared
evidently from his description) capture in her web a hummingbird.
He watched the process of swathing the poor victim until it was com-
pletely wrapped around, when he slew the spider and rescued the bird,
too late, however, for it was quite dead.

The above examples, which might be multiplied, show beyond ques-
tion that the strength and mechanical advantages of an orbweb are suffi-
cient to enable our large Orbweavers to capture small vertebrate animals.
Whether or not they feed upon such captives one can only conjecture,
particularly in the case of our native fauna. Certainly in the last case
above cited the spider acted precisely as with all victims taken for food ;
but then, on the other hand, she might have done this and then have
cut the hummingbird out of her snare without feeding upon its blood.

' Araneides des Isles de la Réunion, page xxi.
* Voyages of Adventure and Beagle, Vol. II1., page 41.
’'The Andes and Amazon, page 304.

STRENGTH OF WEBS AND POWER OF SPIDERS.

bo
(JU)
Or

The assertion must be taken with much allowance, that nets of geometric
spiders are renewed wholly, or at least their concentric circles are replaced
every twenty-four hours, even when not apparently injured.t In
Age ofan _. J
Orbweb, Point of fact the renewal does not take place unless made neces-
sary by the destruction or serious injury of the old snare. The
reason assigned for this behavior by the same authors, viz., that the
spirals rapidly lose their viscid properties by the action of the air, is
not founded on fact, as is elsewhere shown.? The viscid beads retain
their adhesive qualities under ordinary circumstances for a considerable
time. It is doubtful if any orb becomes thus disabled in so short a period
as that assigned—twenty-four hours—except when exposed to rain.

IF.

At various times there have been placed on record accounts of the cap-
ture by spiders of small vertebrate animals, as snakes, mice, and _ birds.
Popular stories to the same effect have from time to time been
sent the rounds of the daily press, and found utterance and often
illustration, the latter sometimes of a most original and remark-
able character, in popular magazine literature. The great seem-
ing disparity in such cases between the size and vigor of captive and pris-
oner; the confusion of the various narratives in details as to the spe-
cies and behavior of the spider, and the characteristics of her snare; the
radical departure from known food habit of species that are insectivorous;
together with the fact that the accounts all have come from lay observers,
have been more or less lacking in scientific accuracy and minuteness of detail,
and wholly without scientific verification—these considerations haye caused
such records and reports to be discredited by arachnologists and naturalists
generally. But there are a few cases, confirmed by circumstantial evidence,
‘and reported by observers of good reputation and careful habit, which de-
serve notice.

The physical powers of the Lycoside, the popular running, ground, or
wolf spiders, is well illustrated by an instance recorded in the Proceedings of
the Academy of Natural Sciences of Philadelphia.* The result as reported
was achieved by pure strength and activity, without any of the mechanical
advantages of a snare. Mr. Spring, while walking with a friend in a swampy
wood, which was pierced by a dyke three feet wide, was attracted by the
extraordinary movements of a large black spider in the middle of the
ditch. Closer observation showed that the creature had caught a fish! She

Physical
Power of
Spiders.

1 Kirby & Spence, Intro. Ento., I., page 419. 2See Chapter V.

3 Proceedings, 1859. The account was presented by Mr. Lesley, from notes furnished by
Mr. Edward A. Spring, of Eagleswood, New Jersey. It was confirmed by a personal interview
with Prof. Spring, at Chautauqua in the summer of 1885, who repeated to me the details of
the incident.

236 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

had fastened upon it with a deadly grip just on the forward side of the
dorsal fin, and the poor fish was swimming round and round slowly, or

twisting its body as if in pain.! (Fig. 219.) The head of its
A Spider },Jack enemy was sometimes almost pulled under water, but the
Captures |. eee — : : , ne
Gre strength of the fish would not permit an entire submersion. It

moved its fins as if exhausted, and often rested. Finally it
swam under a floating leaf near the shore and made a vain effort to dis-
lodge the spider by scraping against the under side of the leaf.

The two had now closely approached the bank. Suddenly the long
black legs of the spider emerged from the water, and the hinder ones
reached out and fastened upon
the irregularities of the sides of
the ditch. The spider commenced
tugging at his prize in order to
land it. The observer ran to the
nearest house for a wide-mouthed

~. BAN}
SS

Fic. 219. A fish captured by a Dolomede spider.

bottle, leaving his friend to watch the struggle. During an interval of six
or eight minutes’ absence the spider had drawn the fish entirely out of
the water; then both creatures had fallen in again, the bank being nearly
perpendicular. There followed a great struggle, and on Mr. Spring’s re-
turn the fish was already hoisted head first more than half its length out
upon the land. It was very much exhausted, hardly making any move-
ment, and was being slowly and steadily drawn up by the spider, who
had evidently gained the victory. She had not once quit her hold dur-
ing the period of a quarter to half an hour of observation. Her head
was directed toward the fish’s tail; she stepped backward up an elevation
of forty-five degrees, drawing her captive’ with her.

! The figure has been drawn from a sketch furnished by Mr. Spring, who is a competent artist.

STRENGTH OF WEBS AND POWER OF SPIDERS. 237

The observers were unfortunately unable to await the issue of the mat-
ter, and therefore caught the combatants in the bottle, partly filled with
water. The fish swam languidly at the bottom of the vessel, and the
spider stood sentinel on the surface, turning when the fish turned,
and watching every motion. The bottle was set aside and visited
after an interval of three hours. The spider was then found
dead at the bottom of the jar, but the fish was alive and lived twenty-four
hours afterward. The spider was three-fourths of an inch long and weighed
fourteen grains; the fish was three and one-fourth inches long and weighed
sixty-six grains. The spider was probably bruised by the catching. The
spider referred to may have been an example of Lycosa lenta or L. fati-
fera, or more probably Dolomedes tenebrosus, all of which grow to great size

Relative
Sizes.

along streams of water.
examples of D. tenebro
the Thousand Islands in
upon various streams in the
One of the most remarkable
chanical powers of spiders is
The account is authen
ments of a number of
of the occurrence, Bata
David E. Evans found
snake, nine inches long, suspended
tween two shelves. The snake

A Spider
Ensnares
a Snake.

I have seen very large
sus along the rocks of
the St. Lawrence River, and
vicinity of Philadelphia.
records of the physical and me-
made in Silliman’s Journal.!
ticated by the names and state-
gentlemen resident in the vicinity
via, New York. One evening Hon.
in his wine cellar a live striped
by the tail in a spider’s web be-
hung so that its head could not

reach the shelf below it, by about an inch. The shelves were about
two feet apart, and the lower one was just below the bottom of a cel-
lar window, through which the rrc.220. a snake probably passed into it.
From the upper shelf there hung ee ii, 2 Web in the shape of an inverted
cone, eight or ten inches in diame a spider’s_ ter at the top, and concentrated to
_a focus about six or eight inches ‘“°” from the under side of this shelf.
From this focus there was a strong cord made of the multiplied threads of
the spider’s web, apparently as large as sewing silk, and by this cord the snake
was suspended. <A rude sketch of the serpent suspended in the web was
made by an eye witness, and is exactly reproduced at Fig. 220. <A close
examination showed that the snake’s mouth was entirely closed by a num-
ber of threads wound around it. Its tail was tied in a knot so as to leave a
small loop or ring, through which the cord was fastened, as seen in the fig-
ure. The end of the tail above (cephalad of) this loop, to the length of
half an inch, was lashed fast to the cord to keep it from slipping. As the
snake hung, the length of the cord from its tail to the focus to which it
was fastened was about six inches. A little above the tail was a round
ball about the size of a pea, which upon inspection appeared to be a green

1 American Journal of Science and Arts, XX VIL, 1835, page 307, sq.

238 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

fly, around which the cord had been wound as a windlass, with which the
snake had been hauled up. <A great number of threads were fastened to
the cord above and to the rolling side of this ball, to keep it (as
A Spider the observers thought) from unwinding and so letting the snake
ee down. It was conjectured that the cord must have extended
from the focus of the web to the shelf below, where the snake was
lying when first captured, and being made fast to the loop in his tail, was
then carried up to the fly about midway of the cord. By rolling the fly
over and over, the cord was wound around it, both from above and below,
and the snake gradually hoisted until its head was one inch or more above
the shelf. In this situation the snake hung alive for several days (three
according to one statement, five according to another), when the web was
broken by careless observers so as to allow part of the snake’s body to rest
upon the shelf below. Thus the serpent remained, unnoticed by the spi-
ders after its fall, until eight days after its discovery, when some large
ants were found devouring the dead body.

The witnesses state that when the snake was first observed “ several
large spiders were upon him sucking his juices;” that it “furnished a
continued feast for several large spiders,’ until its fall; that “during
the day no spiders were visible in or about the web, but at night there
were three, much smaller than the common fly, seen feeding upon the
body of the snake.”

One might well be excused for withholding credence from such a story,
although the acts were vouched for by abundance of respectable lay testi-
mony. Accepting the account as true, or at least probable, I would make
the following inferences: first, the description of the web, although suffi-
ciently indefinite, leaves little doubt that the snake was originally taken
in a snare of a species of Tubeweaver, and most probably by the Medicinal
spider, Tegenaria medicinalis, Hentz. The broad sheeted web of this

spider is frequently found in cellars, which are favorite haunts.

Who It builds near windows, in the angles and along the sides of
Snared eae : : : : : :
Ase walls, having its tubular den in a crack or opening laid along

Snake? an angle. The sheet is usually drawn upward until its exterior

margin is higher than the plane of the entrance of the tube.
There is thus formed a sort of pouch within which insects often fall
and so are readily captured by the spider, who mounts guard at the door
of her den. Over the door the tube frequently rises into a sort of tower.
(Fig. 221.) The webs of this species are sometimes of considerable length—
eighteen or twenty inches—and those which have been standing for some
time will be found overlaid by several successive thicknesses of silken
sheeting, discolored by the soot and dust of the cellar. A specimen of
this material may readily be taken and mounted upon white cardboard,

' Probably the T. Durhami of Europe.

STRENGTH OF WEBS AND POWER OF SPIDERS. 239

where it shows as a tissue of close texture. In the building of additions
to the web, however, the new part shows as a quite open plane of
mesh work.!

The webs of Medicinalis are often built in the angles of cellar
windows, along the sill, and in positions quite similar to that in which
the Batavia snake was caught. The strength of several snares,
found in the cellars of the Academy of Natural Sciences of
Philadelphia, was tested as follows: two webs bore up under
a pencil weighing sixty-eight grains; several small webs bore a weight
of one-fourth and one-half ounce in corks spread over the surface, but

Strength
of Web.

FG. 221. The pouch, web, tower, and cocoon of the Medicinal spider, Tegenaria medicinalis.

broke down under an equal weight condensed into a small shell. One
web bore up easily, and apparently would have carried for an indefi-
nite period, the half ounce shell. It also sustained for a short period
a weight of one ounce, and then gradually gave way by the breaking
down of the thread attachments to the wall, without any yielding of
the sheet itself.

The weight of a “striped snake,” such as is alluded to, probably
our common garter snake, Eutenia sirtalis, Linn., is accurately fifty-five

'The two webs (Fig. 221) measured: No. 1 (upper), 14 inches long across the hypothe-
nuse, by 10 inches deep; No. 2 (lower), 18 inches long across the sheeted part, 24 inches
across the meshed extension, depth 9 inches.

240 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

grains for one ten and a half inches long, and fifty-one grains for one
eleven and a half inches long. The two together weigh less than a
quarter of an ounce! Thus, a web of the Medicinal spider will
sustain with perfect ease the weight of four such snakes, will
even support six or seven readily, and will not break until
the weight of eight snakes, each larger than the Batavia specimen, has
been placed upon it. So far, therefore, the account is wholly probable.?
The mechanical torsion caused by the struggles of the serpent would
of course add to the natural effect of gravity, but would probably not
counterbalance the excess of resistance in the web as here shown. The
simple statement that a snake was suspended in a spider’s web appeals
to ideas and associations that produce at once wonder and unbelief. A
snake ?—that is a huge object! A spider’s web?—that is a very frail
thing! In poimt of fact, however, when the test of weights and meas-
ures is applied, our notions on both these points may easily be reversed ;
for some snakes are certainly very slight creatures, and certainly some
spider snares have much strength.
The above incident does not stand alone. The late Dr. Asa Fitch,
well known as an American entomologist, published an account of the
entanglement and elevation of a snake, resulting in its death.

Weight
of Snake.

Therid- The heroine of this adventure was also a New York spider,
ium :

resident in the village of Havana, Chemung County, N. Y.
Snares a

”

Snake, che is described as “the common house spider;” “an ordinary
looking spider of a dark color, its body not larger than a
common house fly.” These are such indefinite terms that they give
little clue to the scientific name of the animal, and can hardly be ex-
cused as coming from a trained entomologist. However, several details
are noted in the narrative which give good circumstantial evidence that
some species of Theridium is meant, very probably our common Therid-
ium tepidariorum.®
This spider had woven its snare beneath the counter of a village store.
A “common silk snake” about a foot long, which had been probably
brought into the store in a quantity of sawdust, took up its

dae residence on the floor underneath, two or three spans distant
en : “erie

s from the spider’s snare. When first seen the spider had placed
Lassoed.

a loop around the serpent’s neck, from the top of which a
single thread was carried and attached to the under side of the shelf,
whereby the head of the serpent was drawn up about two inches from

' Determined from alcoholic specimens in the collection of the Philadelphia Academy of
Natural Sciences.

* The difference of weight between an alcoholic and living specimen is considered by
Dr. Leidy so small that it need scarcely be estimated.

*The account is taken from the Annual of Scientific Discovery, 1862, page 334. The
original record is not quoted.

STRENGTH OF WEBS AND POWER OF SPIDERS. 241

the floor. The snake was moving about incessantly, in a circle as large as
its tether would allow, wholly unable to get its head down to the floor or
to withdraw it from the noose, while the spider was ever and anon pass-
ing down to the loop and up to the shelf, adding thereby an addi-
tional strand to the thread. Each new strand being tightly drawn, ele-
vated the head of the snake gradually more and more.

As only the neck of the creature was at first entangled, Dr. Fitch
thinks that the spider was exposed to attack as she ran up and down
the cord, and that during the early stages of the conflict the snake did
snap at the spider with its mouth. The latter, however, “with her hind
legs, as when throwing a thread around a fly, had cast one thread after
another over the mouth of the snake, so that he was now perfectly muz-
zled, by a series of lines placed vertically over the mouth; these were held
from being pushed asunder by another series “placed horizontally,” as Dr.
Fitch’s informant states he particularly observed. “ No muzzle or wicker-
work for the mouth of an animal could be woven with more artistic
regularity and perfection; and the snake occasionally making a desperate
attempt to open his mouth would merely put these threads upon the
stretch. This strange conflict issued in victory for the spider. The snake
continued his gyrations, his gait becoming gradually slower through weak-.
ness and fatigue. The spider continued to move down and up the cord,
gradually shortening it. At last the serpent was drawn up so far that
only two or three inches of the tail touched the floor, when he expired,
about six days after his capture was first noticed.

It is the above behavior, in swathing the victim with thickened strands
of silk drawn out and thrown rapidly from the spinnerets by the hind
feet, that determines the generic position of the spider with some cer-
tainty. The snare from the description was evidently not an orbweb,

and this behavior, in connection with other details, points to

Ri sand some Lineweaver as the hero of this exploit, either Theridium
um tepi- Pee a

_°P* tepidariorum or Pholeus phalangioides—probably the former.
dariorum.

Tepidariorum is a vigorous, aetive, and ferocious species. (See
Chapter I., Fig. 7.) Her web is often spread over great spaces, and is
strong enough to bear the weight of such a snake as here described. She
shows unusual courage, strength, and skill in capture of prey, taking
very large beetles and other insects, which she will raise through great
(relative) distances to the centre of her snare.

It is worthy of mention, in connection with these incidents, that the
belief that a special enmity exists between spiders and serpents is very
ancient. Pliny says that the spider, poised in its web, will throw itself
upon the head of a serpent as it is stretched beneath the shade of a tree,
and with its bite will pierce its brain. Such is the shock that the
creature will hiss from time to time, and then, seized with vertigo, will
coil round and round, but finds itself unable to take flight or even to

242 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

break the web in which it is entangled. This scene, concludes the
author, only ends with the serpent’s death.!

I had often wished for an opportunity to follow up critically one of
the recurring reports of the physical powers of spiders. This wish was
gratified in the summer of 1882. An article drifted through American
newspapers which detailed the ensnaring of a living mouse by a Ken-
tucky spider. I was fortunately able to trace the story to its origin in
the Lebanon (Ky.) ‘Standard and Times.” Correspondence with its in-
telligent editor, Mr. J. W. Hopper, brought me entire confirmation of
the report from a number of trustworthy sources. I think the incident
of sufficient importance to justify a somewhat detailed presentation. The
original account as published by Mr. Hopper is as follows :—

“A very curious and inter-
esting spectacle was to be seen

Monday afternoon in
Mouse “rthe office.of Mr) PaG
Sapa Cleaver’s livery stable

in this city. Against
the wall of the room stands a
tolerably tall desk, and under
this a small spider, not larger
than a common pea, had con-
structed an extensive web reach-
ing to the floor. (Fig. 222.)
About half past eleven o'clock,
Monday forenoon, it was observed
that the spider had ensnared a
young mouse by passing fila-
ments of her web around its tail.
When first seen the mouse had
its fore feet on the floor and
could barely touch the floor with
its hind feet. The spider was
full of business, running up and
down the line and _ occasionally
biting the mouse’s tail, making
it struggle desperately.

“Tts efforts to escape were all
unavailing, as the slender filaments about its tail were too strong for
to break. In a short time it was seen that the spider was slowly hoisting
its victim into the air. By two o’clock in the afternoon the mouse could
barely touch the floor with its fore feet; by dark the point of its nose

Fic. 222, Diagram of a mouse hanging in a spider’s snare.

‘Pliny, Natural History, Chapter X., page 95.

STRENGTH OF WEBS AND POWER OF SPIDERS. 243

was an inch above the floor. At nine o'clock at night the mouse was
still alive, but made no sign except when the spider descended and bit
its tail. At this time it was an inch and a half from the floor.
“Yesterday morning the mouse was dead, and hung three inches from
the floor. The news of the novel sight soon became circulated, and hun-
dreds of people visited the stable to witness it. The mouse was a small
one, measuring about one and a half inches from the point of its nose
to the root of the tail.”
Mr. P. C. Cleaver, in whose office the incident occurred, wrote me the
following statement: “I have two small rooms in my livery stable, one
used as an office and the other as a bedroom for my clerk. In

Mr. Clea- the front room stands against the east wall a writing desk just
ver’s Tes- : . a
‘aenony tall enough for an ordinary sized man to stand and write on.

When I first saw it the mouse was under this desk, fastened in
the spider’s web, with its head down and tail up. Eighteen inches or two
feet above the mouse was a small spider, whose body was about the size
of a small grain of sweet sugar corn, certainly not larger than would
cover the nail of your smallest finger. It was of a dark color, but not black.
I first saw it about one o’clock P. M., when the toes of the mouse barely
touched the floor. The spider kept working it up until finally it was three
or four inches from the floor, and was still alive when I left my stable
to go home at night. I can give you no information as to the web that
will satisfy you. It was long enough to reach to the floor, and there were
a good many strands of it wound in many intricate ways that I do not
understand. The web was very fine. I left the spider at work that even-
ing at sunset, with orders that it should not be touched. But the web
was knocked down that night—by some boys, I think, as a great many
were there to see the sight, and my clerk thinks it was lost in that way.
The spider, mouse, and web were all gone when I returned to the stable
‘on the following morning.” Mr. Cleaver emphatically declares the impos-
sibility of any one about his premises having manipulated the mouse in
any manner to secure its entanglement in the web. “I am as sure,” he
says, “that the spider caught and raised the mouse three or four inches
from the floor by himself without the aid of man, as though I had been
present from first to last.”

Mr. Hopper, in addition to the printed article, sent me a_ written
report of the incident, from which the following quotations are made:

“As you will see from this account, no one observed the actual

Mr. Hop- entanglement of the mouse. In a very short time after it was
per's Tes frst observed I myself was informed of it, and went to the
timony. 4

stable to examine it. This was Monday, August 22d, 1881.
The office of the stable is a small room. The desk referred to is some-
thing over three feet high, four feet four inches long, and something
over two feet wide. From the bottom of the desk to the floor the distance

244 AMERICAN

is two feet ten inches.

SPIDERS AND THEIR SPINNINGWORK.

The spider’s web extended perhaps three-fourths

the length of the desk next to the wall, and covered the bottom of the
desk to the width of about fifteen or sixteen inches. It was about three

feet long by sixteen inches wide.

“You will observe that the narrative in the news slip ends with

Tuesday morning, August 25d.
press late Tuesday afternoon.

My paper, which is a weekly, went to
The hoisting process continued all day

Tuesday, and employés about the stable say that by dark Tuesday night

the mouse was four or
from the floor. Tuesday
entered the room in the
broke the web, and the
ing, according to my re
brushed away. I greatly
not allowed to complete his
captured and_ preserved.
when I found how the
The Hon. J. Proctor
tative in Congress from
ernor of the State, was
en me by Mr.

The Hon. me from Wash

ee newspaper ac
nots letter the follow

Testi-

mony. was first called

or eleven o’clock
spider having made. its
the tail of the mouse, of
weight, gradually hoisted
barely touch the floor
was still busily ‘ hoisting
was no less vigorously en
That afternoon, perhaps
pany with Mr. Hopper,

ard, I again visited the,
ture, and found that the

four and a half inches
night a meddlesome boy
dark and accidentally
mouse fell. Next morn-
collection, the web was
regret that the spider was
work, and that he was not
I was greatly mortified
affair had terminated.”

Knott, then a represen-
Kentucky, and later goy-
one of the references giy-
Hopper. He kindly wrote
ington, confirming the
count. I quote from his
ing: “When my attention
to the matter—about ten
in the forenoon—the
thread fast to the end of
perhaps fifty times its own
its prey so that it could
with its fore paws, and
away, while the mouse
deayoring to break loose.
near five o’clock, in com-
the editor of the ‘Stand-
scene of the singular cap-
mouse had been raised so

that the top of its nose Fic. 223, A mouse suspended bya Was precisely four inches
from the floor, as I as ide nutty» by Hon: certained: by actual meas-
urement with a pocket rule. The spider was still
actively at work and the mouse still struggling. The next morning I
found the mouse dead, its nose about six inches from the floor, and
the spider still at work. The thread was attached to the end of the
tail. ‘This statement, although written hurriedly and amid_ considerable
confusion, you may use as you think proper.”

STRENGTH OF WEBS AND POWER OF SPIDERS. 245

Governor Knott also sent me the foregoing (Fig. 223) memory sketch
of the position of the mouse and the characteristics of the snare and the
entangling lines.

The testimony and observations thus obtained are of such a char-
acter as to establish beyond any doubt these facts: First, that a young
living mouse was in some manner securely entangled in the
snare of a spider. Second, that the spider, by means of silken
lines two or three feet long, hoisted the mouse through a
perpendicular distance of four or four and a half inches. Third, that
the mouse was entangled in the spider’s web by the tail alone, and
although it lived for at least ten hours, during which it struggled
vigorously to escape, was unable to free itself, and finally died. Fourth,
that the hoisting process continued during Monday from about 11 A. M.
until the night of Tuesday following, a period of thirty-four hours,
when the web was accidentally broken, and then brushed away. Fifth,
that the specific identification of the spider heroine of this exploit was
at first somewhat in doubt; and the credit seemed to lie between a Tube-
weaver, the Medicinal spider (Tegenaria medicinalis), and the common
Lineweayer (Theridium tepidariorum). The accounts of the captor’s be-
havior during the hoisting of her victim, especially swathing her victim,
and the opinions of the various eye witnesses to whom were sent descrip-
tions and drawings of both species and their characteristic webs, point to
the Lineweaver. I was much perplexed by the conflicting testimony in-
evitable in the reports of the several untrained observers. But persistent
correspondence and the kindness of Mr. Hopper and others finally pro-
cured me specimens which were declared to be undoubtedly identical
with the mouse catcher. These specimens are Theridium tepidariorum ;
to this spider, therefore, must be given the credit of the achievement.”
Sixth, a comparison of the weight of a young mouse*® with the actual
‘ power of resistance in webs of both Theridium tepidariorum and the
Medicinal spider, as determined by a number of tests, shows that the
incident on such grounds is not only plausible but much within the

The Con-
clusion.

1“The figure intended to represent the spider is larger in proportion to that insect than
the mouse is to the unlucky little rodent it is supposed to suggest. The length of the line
attached to the tail is much shorter in the sketch than in the original, where it must have
been three feet or over, as the web from which it was suspended was woven upon the bot-
tom of a writing desk, and, as nearly as I can remember, in the shape presented, but much
larger.”’—Mr. Knott's letter.

? Specimens sent to me of the spiders supposed to be identical with the one that caught
the mouse, taken from the same desk and from a web of similar construction, were the
Medicinal spider. Also, a specimen of a web somewhat similar to the one in which the
mouse was entangled, and a description with estimated measurements, of the extensive pro-
portions of the original snare, point in the same direction.

’“A mature male mouse weighed three hundred and fifty-six grains. One half grown
would probably weigh about one-sixth to one-fourth of this, say from sixty to ninety grains.”—
Note from Dr. Joseph Leidy.

246 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

possibilities of the spinningwork of those spiders. Seventh, that a series
of well and tolerably well authenticated cases, as well as observations of
the habitual prowess of spiders in taking and securing their prey, jus-
tify the inference that the capture of a mouse or garter snake lies
within the physical and mechanical abilities of both of the two species
above named.

The space given the above facts may seem to some to be in undue
proportion to their importance. But, apart from the value of positively
determining any point in natural history, the discussion has this
conclusion: The capture of small vertebrate animals by both
Sendentary and Wandering spiders is possible; the one by the
mechanical strength of their snares, the other by their physical strength.
There is thus laid the foundation, at least, for the presumption that such
animals may be or become natural food for the larger species of araneads.
This is certainly a most important fact in the life history of spiders, and
would greatly enlarge the range of their habits.

A Con-
clusion.

Caen TD BE, CVe.

PROCURING FOOD AND FEEDING.

THE Orbweaver’s snare is its tool for trapping insects. It is a notable

fact in the history of lower animals, that there is at least one order con-

taining a large group of species which possess the power, other-

Food wise the almost exclusive gift of man, to procure food by the

Sere medium of manufactured implements. The nearly universal

habit of natural life is to imbibe nutriment directly, or to secure

it wholly by means of the feet or mouth or other prehensile organs. The

Wandering spiders fall into the general course of nature, and seize their
food directly. The Sedentary spiders form an exception to this rule.

It is, of course, an interesting speculation how this remarkable habit
originated, and how it came about that such a marked exception should
exist in certain tribes of a natural order whose remaining tribes are want-
ing therein; but Nature thus far has yielded no light upon the subject.
As far as we are able to judge from fossil spiders, the structural differences
between such families as Epeirids on the one hand, and the Lycosids
and Attoids on the other, have remained unchanged from the first appari-
tion of spider life. It is a fair inference that the functional differences
have also always existed; that Epeirids have always captured their prey
through the media of manufactured tools or snares, and that the Lycosids
have stalked their prey and secured their food without any intervening
instrument.

It has already been shown how well adapted an orbweb is for its chief
purpose. Its combined strength and elasticity, its admirable arrangement
for the free motion of the spider, its location and characteristics so well
adapted to arrest the flight of insects, and its armature of viscid beads so
completely suited to retain and disable the arrested victims—these all form
an implement of tremendous facility to the aranead for procuring its nat-
ural food. The spider when ensconced within its nest holds by
its claws to the tense trapline, and thus keeps its snare taut.
When it is suspended at the hub the eight legs, stretched out
and grasping points of the radii which command the entire snare, enable
the spider at any time to contract its outlying lines around the centre,

thus producing the same degree of tension.
(247)

Handling
the Snare.

248 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

it:

In this position, when an insect strikes a snare the impact as well as
subsequent struggles set the web into violent agitation, which is at once
communicated to the spider. Her conduct will be largely determined by
the degree of agitation. Evidently the weight and size of the insect, and,
therefore, its ability to defend itself, are gauged by the force of the agita-

tion. If the insect appears to be a small one, or thoroughly

Insect — trapped, and the spider should be particularly hungry, she will
Entangle- . . ae iss os “AGAR
a rush immediately upon her victim. Ordinarily, however, the

action is different. At the first signal, the spider will turn in an
attitude of great muscular tension, as though to get the direction of the
movement. She will often make a sharp pull, the whole body moving with
muscular excitement. Sometimes only the fore legs will be thus twitched.
Then a movement will be made toward the fly, which is conducted rather
cautiously and at several stages, the spider meanwhile jerking the radi
leading directly to the entangled insect. At each pause two or three quick

Fic. 224. Mosquito
entangled by strik-

ing the net with
full spread wings. all the feet. tured by several feet.

Fic. 225. Insect entangled by

Fia. 226. A mosquito cap-

jerks are made. Sometimes, however, for various reasons, but chiefly
through excess of caution, no doubt, she will fail to make any movement
at all, and leave the insect to struggle until it is exhausted, in which case
it may either be seized and eaten, or cut from the snare and thrown away.
The Orbweaver is not infallible in its ability to determine the charac-
ter of the agitation. Sometimes the deft tickling of the web will produce
a movement so much like the agitation of an insect as to de-
Accuracy . ae : ‘ 3
of Percep-°lve @ spider, particularly if she be quite young or very hun-
a ery. A touch upon a dry insect hanging in an empty web once
drew to the spot a young spider from an adjoining snare. It
came straight to the point, as though directed by the agitation of the
neighboring web, thus showing a sense of direction, and ability to deter-
mine the originating points of the movement; but also showing the fact
that it was liable to be deceived as to the character of the movements of
a living insect. Once, while observing an Epeira vertebrata, a small insect
fell into the web. The spider ran towards it, seized it, and carried it to
the centre. While feeding, two bits of wood from an overhanging vine

PROCURING FOOD AND FEEDING. 249

dropped into the snare. Vertebrata at once rushed towards these, but find-
ing by her touch that they were dead matter, instead of leaving the ob-
: jects she drew them towards her with her feet, passed them to
Deceived. ; : eee
her lps and palps, where they were held a moment until bit-
ten entirely free from the lines. ‘Then the fore feet were reached up,
and by a sharp snap of the claws the pieces were thrown downwards
out of the web. In this case, also, the Orbweaver was deceived. But very
generally she is able to distinguish between an artificial agitation and that
produced by an insect. At least, I have frequently failed to draw a spider
from her retreat by my most skillful manipulation of her snare.

Blackwall is probably correct in his suggestion that the pulling mo-
tions which I have described are intended
to determine whether objects entangled in
the toils are animate or inanimate.! At
all events, it is true that by jerking the

radii immediately in connection

Useof with that part of the snare in
Net

, which the insects are entangled
Jerking. one

and then suddenly letting go

their hold, the spiders produce a vibra-
tory motion in the net which seldom fails
to excite action in the ensnared insect.
Guided by the struggles of her prey, the
Orbweaver runs along the most contiguous
radii to seize her victim, avoiding contact
with the viscid lines as far as possible, and
drawing out after her a thread attached to
one of the lnes near the centre of her
net, which serves to facilitate her return.
The manner in which insects are cap-

Fic. 227. Epeira revolving captured fly while
enswathing it.

tured may be observed at any time, and
yet one may venture to describe the meth-
od. When the insect strikes the viscid spirals, one or more legs and one

or other or both of the wings, or an antenna are usually first to

iat ; feel the viscid grasp of the beads. The insect, at once arrested by
ntangle- Rar eee a
iets the blow, begins to struggle, and finding itself fettered increases its

efforts to be free. Sometimes, particularly if the viscid quality of
the beads be somewhat abated or the entanglement be slight, the insect suc-
ceeds in escaping. This occurs more frequently perhaps than is ordinarily
supposed. Very often, however, the struggles only result in fastening the
victim more securely by bringing additional portions of the body into contact
with the spirals. Sometimes the insect will strike broad on in its flight, or

1 Blackwall, “Researches in Zoology,” page 289.

250 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

with wings full spread, as represented at Fig. 224, and the whole under sur-
face of the body will be first stuck to the spirals. At other times, as at
Fig. 225, the feet will be seen gathered together in a little cluster, adher-
ing at one point to the spirals. Several or all of these positions have
been illustrated in the figures, accurately rendered from nature. A mo-
mentary entanglement is all that is required, for the spider is upon its
victim ere it can succeed in releasing itself.

The mode of dealing with the entrapped insect when it is reached is

i

g LLL —_=—S
(ify EEE— =

t=

—
3
~~ Nt

4

SS
\\S

»,

SS
=

Fic. 228. Argiope swathing a captured fly by a jet of silken filaments.

not always the same. Sometimes it is immediately seized and carried to
the hub or den to be fed upon, the spider striding with it in her

ESOEs jaws over the lines of her orb. Occasionally the insect will be
ment of : : : :
Insects, ‘truck with the fangs, and the spider retreat instantly to await

the effects of the stroke. This action may be repeated. At other
times, several sharp squeezes of the fangs are given, as though to de-
stroy the insect’s life.

In the act of seizing a mosquito, an Epeira vertebrata was observed
holding to the spiral lines with one hind foot, so that her operations
might be unimpeded by contact with the viscid beads. The little cords by
which she was thus held aloof were the shape of a pyramid, whose apex
was within the claws of the spider. More commonly the victim is seized
with the claws of the two fore pairs of legs. These are so long that they
can be stretched out well forward of the spider’s body, and grasp the in-
sect without much danger.

PROCURING FOOD AND FEEDING. 251

With great rapidity the abdomen is then doubled under, and a jet of
thick, white silk issued from the expanded spinnerets, and thrown out
rapidly by the hind legs. At the same time the insect is revolved by the
united action of the short third pair of legs, the two fore legs, and not
infrequently by the aid of the hind pair also. There is much difference
in this respect, but the first, third, and
fourth pairs seem always to be used. As
the fly is rolled around by the feet the
swathing thread envelops it something
after the manner of woolen yarns as they
pass from a spindle to a reel. But some-
times the spider revolves her own body as
well as the fly, thus facilitating the rapid-
ity with which the victim is enswathed.
There is, of course, a great difference in
the amount of swathing thread used at
different times. Sometimes a few threads
suffice, so that the outlines of the insect’s
body and limbs are clearly seen through them. (Fig. 229.) Again, the
bandages will be a veritable winding sheet, and perfectly conceal the de-
tails of the victim, showing only a lumpy outline, a creature as truly
mummied as was ever one of Egypt’s sacred animals. (Fig. 235.)

Epeira trifolium was observed capturing a grasshopper. She approached
very cautiously from above, and, as she drew near the entangled insect,
threw out one fore leg and then another, drawing each back quickly as
though feeling the character of the prey. Being satisfied, she dropped to
one side and threw out two wide, thick streams of silk. These issued from
either side of the spinning rosette, and each stream was fed evidently by
the three spinnerets upon either side. (Fig. 230.) These two streams at
once seized hold upon the limbs of the entangled grasshopper, and as the
spider began to revolve the insect they were reeled
out, rapidly covering the whole insect with swathing

FiG. 229. A fly lightly swathed and trussed up.

material. These streams of silk, after the first gush,
were drawn out alternately by the two hind legs—
first one, and then the other, being used. Presently
the spider dropped below her victim, and thence

passed to the side opposite, continuing her oper-
Fic. 230. A double streamof ations until the insect was satisfactorily wound up.

ey She did not strike it with her fangs at all, but
retired to her den, dragging after her the swathing thread, which was
widely divergent where it laid hold upon the grasshopper, but gradually
converged as the spider moved away and closed her spinnerets, until it be-
came a single thread. (Fig. 231.) This mode I have observed at various
times.

252

AMERICAN SPIDERS AND THEIR SPINNINGWORK.

If any emergency arise to require it, the spider can issue a jet of silk
with such rapidity and of such volume that it is evident that strong mus-
cular contraction has been used upon the silk glands, thus
forcing the liquid material from the spinning spools without
any aid of the feet in drawing it out. That this is quite
within the ability of Orbweavers I am_ perfectly satisfied by frequent
observation of the action of Ar . g@iope cophinaria or Epeira insu-
laris when taking a_ particularly large insect, such as a_ grass-
hopper or locust, moth or blue bottle fly. (Fig. 232.)

During the action of swath ing, and without interrupting
that work, the spider takes care of the broken radii, so that they

Swath-
ing.

are joined together and fastened
ing the orb from sagging or
of the orb goes on instinctively
of conquest and capture. Some
the ends of the radii upon which
the rapid motion of the spinner
lines, but quite sufficient to main
Ordinarily the swathed victim
the jaws of the spider, who there
position and sucks the

The threads. In the mean
Banquet fen :

web, is sus :
Room.

hind feet, the
and turn the carcass
fangs are also used to
by the feet or even

The return to the
tured insect is occa
swinging outward from
the dragline which was

Fic. 231.
to a single thread.

The swathing narrowed

when she rushed down upon her victim.
the fly in the jaws, it will be fastened to the spinnerets by a short thread,
and, thus burdened, the spider swings herself along, sometimes making one
or two swings before she reaches her central point.

The feeding is done leisurely, and the juices so thoroughly squeezed
from the carcass and imbibed that, when the spider is done with it, it is a

little blackened ball of dried matter.

the fly.

to the perfect ones, thus prevent-
dropping apart. This protection
in the very midst of the passion
times it is necessary to bite out
the fly is entangled. In that case
ets closes the breach with irregular
tain the tautness of the web.

is carried to the hub or den in
upon settles herself in the usual
juices through the enveloping
while the aranead, if upon her
pended by the spinnerets and
fore feet being used to hold
while it is being eaten. The
clasp the victim as it is turned
more frequently by the palps.
hub or den with the cap-
sionally accomplished by
the point of capture upon
carried after the spider
Sometimes, instead of carrying

The white silken enswathment has
entirely disappeared, probably having been sucked in with the juices of

sharp movement of the head and jaws.

The banquet over, the carcass is snapped out of the web by a

I became much interested in the manner in which a nearly mature
female Epeira vertebrata handled a moth which she had just captured.
When the observation began, she was rolling the insect around as it hung

PROCURING FOOD AND FEEDING. 253

from the centre of her web, the lower part of which was entirely torn
away by the struggles of the large captive. When the swathing was com-
_ pleted, Vertebrata succeeded in carrying her prey to her shelter
Deporting ynder some honeysuckle leaves two feet distant. She accom-
2 aig plished this at first by seizing the mummy with her hind feet,
and partly by aid of the feet and partly by aid of the abdomen,

bore it beyond the confines of the orb. When she struck the long bridge
line connecting her snare with her den, she kicked her load loose from
her feet and attached it to her abdomen by several lines about an inch in

FiG. 232. The Insular spider enswathing a captured locust.

length. With her prey thus hanging behind, she crawled hand over hand
in the usual fashion along the line (Fig. 233), which swayed beneath its
double load. As she approached her nest she reached a series of lines
that converged upon the mouth of the den, whereupon she once more gath-
ered her prize within her two hind feet, crawled into the den by use of
the remaining feet (Fig. 234), and there began her banquet.
Evidently the principle of “laying by in store” for future use is well
understood by spiders. Not, however, in any such manner as prevails among
the ants and more highly organized animals, as Arachne’s future is but a

254 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

brief period. Here is a young Argiope which on first observation had two
insects trussed up, one on either side of her central web, near
Gee the outer margin of the orb. On the second observation, an
hour afterward, one of these was cut loose, and the spider held it
under its jaws while she rested on her shield and_ there
fed upon it. Here is another Argiope, engaged in feeding
on a large insect, and has two other insects, one on either
side of her shield, swathed and trussed ready for use.
This is an observa tion which is frequently made.
Another observa tion made upon Acrosoma rugosa will
illustrate this point. When the observation began Rugosa
had just captured a fly. A second fly
struck the web, and the spider rushed
to it, leaving fly No. 1 trussed up and
hanging by a short cord. She seized the second
victim, held it a second or two, then slowly re-
volved it, using the third and fourth

Eee pairs of legs. The fourth leg was also
pine lies used in pulling out the enswathing thread.

A slight enswathment was placed upon
the insect, and it was left hanging in the snare.
Rugosa then returned by a agpoyy y Za iy er)
dragline to the carcass of ry EA sf Le s
No. 1, and feasted upon her, i)
leaving No. 2 suspended to
the top of the central.

When fly No. 1 was finished, the threads sur-
rounding it were cut out, and the carcass was drop-
ped from the snare. No. 2 was then approached, the
spider meanwhile cautiously pulling on the radial
gangway by jerks, as though testing the vitality of
the victim or the neighborhood of an enemy. Mat-
ters being satisfactory, the fly was seized, swathed,
and brought back to the centre of the orb. When
rejected, the carcass was a charred looking
mass, out of which all the animal juices had
been squeezed.

While preying upon No. 2 a third
fly struck the web, whereupon No. 2
was at once flung out, as in Fig. 236,
and hung by a thread to the lower
margin of the hub. While waiting
for prey, Rugosa clings to the upper part of the orb by the fourth pair
of legs. While engaged in feeding, the fourth and second pairs of legs

Fic, 233. Carrying a moth by the
spinnerets.

Fic. 234. Carrying a swathed moth by the feet.

PROCURING FOOD AND FEEDING. 255

are used to cling by, while the third and first pairs are used to turn
and handle the flies.

Curiously enough the Orbweaver, although she makes her snare for
the express purpose of capturing her food, sometimes shows a manifest
unwillingness to have
to Keep.” it serve its purpose in

any other than the reg-
ular and approved manner. On
one occasion I saw an_ insect
strike the orb of a Furrow spi-
der, and on another occasion that
of a Domicile spider, when the HH
snares were only partly spun. Zep
Both animals acted precisely
alike—they seized and swathed
the flies, but, instead of feeding
upon them then and there, hung
them up for future use and re-
sumed their net building. I have
seen this act repeated many times
by various species. Another spider (Epeira domiciliorum) having caught
and wrapped up an insect that had struck her unfinished net, deliberately
and, as I fancied, with a show of indignation, cut away and cast out the
trussed captive from the snare! It was a most emphatic illustration of the
proverb, “A time to keep and a time to cast away.” I laughed heartily at
the action, which I involuntarily associated with some ultra conservative
human friends of mine, who are most unready to receive truth and other
blessings that do not come to them through the ordinary
and approved channels. Doubtless the instinct of net
building, in the above cited cases, when once excited,
proved too strong to be seriously diverted or delayed by
any ordinary conflicting sensation.

Influenced apparently by the same impulse, I have seen
a Vertebrata and also Cophinaria stopping in the midst of
laying in spiral lines to secure and swathe an insect which
had struck the orb. In these cases, instead of leaving the
, insect swathed and trussed up for future use and then
fe as returning to the work of completing the spirals, the spiders

Ay nang ow held the captured prey within | their mandibles, resumed

their work, and carried the victim around during the en-

tire process. The web completed, the quarry was taken to the centre

and fed upon leisurely. In both cases about half of the spiral space had

been finished before the insects struck the web and became entangled within
its meshes.

SS

Fic. 235. A mummied fly trussed up.

256 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

These examples indicate that the ordinary instincts of spiders are
held well under control. There are periods when certain instincts wholly
dominate action, which at other times are held in subordina-
Subordi- tion. One is not surprised to see this in such rare or unique
nation of . |. F ;
Instincts, WSstinets as the sexual impulse. But to see the same phe-
nomenon in the sentiments that control daily life, and to see
it frequently occurring, and so manifestly under the volition of the
animal, is certainly more notable. In the examples just cited it is seen
that the feeding habit is held
in subordination by the in-
dustrial impulse when net
making is in order; and a
very complete subjection it
surely is which constrains a
hungry spider to truss up a
fly or carry one about in its
jaws until a snare is finished,
or even cast it wholly out of
the web.
I once found a nearly ma-
ture Argiope cophinaria hang-
ing in the centre of
Laying her orb engaged in
by in : ie
Store, sucking the juices
from a fly, which
she kept underneath her jaws
and appeared to be handling
entirely by the use of her
palps. In the meanwhile she
held attached to her fore feet
on either side two swathed
flies, one suspended by a sin-
Fic. 237. Dwarf flies banqueting with a giantess spider gle thread, and another by a
Snes along double one. Evidently she
was troubled with what the French call an embarrassment of riches. It is
rare to see a Sedentary spider eating thus without the aid of the fore legs.
Another Cophinaria was observed with five flies, three of them large
blue bottles, fastened at various parts of her web, most of them well
towards the margin. Two of the blue bottles were completely wrapped in
white swathing silk, and were covered from one end to another with a
host of small black dipterous flies, that were trying to feed upon the car-
casses of their huge, mummied congeners. Argiope appeared to be entirely
regardless of the presence of these little creatures. They adhered so closely
to the carcass that when the spider violently shook her web they rode

PROCURING FOOD AND FEEDING,

bo
or
~J

back and forward like a group of children upon a seesaw, without being
the least disturbed. Next morning I found that all the trussed up insects
except one had disappeared; one (which I easily identified) remained in its
former position, and even then several of the little Diptera were perched
upon the carcass, apparently feeding. In the jaws of the spider was a
swathed carcass, and even on that, as the spider held it within her mouth
feeding upon it, were at least two of the little flies engaged with
Flies Ban-the greatest sang froid at their meal under the very jaws of
ae their ferocious adversary! In the meantime a third fly was
’ perched upon the middle of the abdomen of the spider herself,
apparently enjoying the situation. ‘Two days afterward I found the same
curious state of things. It may be that the very diminutiveness of these
creatures was their protection, especially as food was so abundant. It was
certainly amusing, however, to see this seeming challenge of destiny. A
few hours thereafter I saw one (or one of the same species) of these reck-
less Diptera trussed up near the spot where it had lately fed, although it
was probably not eaten.

The same behavior was subsequently observed on several occasions and
on different individuals; so that it was not the result of special sluggish-
ness or personal peculiarity. Once, when a dozen or more of these little
Diptera were hanging upon an enswathed captive, I saw Argiope brush
away with her fore feet several that were crowding about her face. The
action was most impatient—even angry—but none of the annoying and
impudent intruders were hurt. On another occasion I observed two of the
flies apparently held in the jaws of the spider. My first thought was that
they had ventured too close, had been snapped up, and were being eaten
by their giant hostess. But upon touching the point of my pencil to them,
they at once disproved my theory by drawing back a little space and shak-
ing themselves. They had not only ventured between Argiope’s palps, but
. had pushed up to the very jaws, and were sipping the juices squeezed out
by those organs! It was certainly a curious illustration of the old and
famous riddle, “out of the eater came forth meat.” (See Fig. 237.) I had
never expected to see the spider and the flies peacefully feeding together
upon the same carcass, but in nature, as in social life, it is often “the un-
expected that happens.”

ET.

The efforts of spiders to take their prey are not destitute of advyen-
tures, sometimes of a very serious sort, sometimes approaching the ludi-
; crous. For example, I chanced to get a sight of Argiope coph-
Special inaria just as she had captured a large honey bee and had
Incidents. ‘ s ;
begun to swathe it. I watched the struggles of the insect with
interest, and found that the spider got the better of her antagonist very
rapidly. Around and around the excited bee the swathing bands wound,

258 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

until at last it was completely enclosed within a silken bag. I concluded
that all was over with the luckless insect, an opinion which Cophinaria evi-
dently shared, for she laid on her final lines and clambered away to the
centre of her shield, apparently with the intention of drawing her vic-
tim towards her to take a hearty meal.

Scarcely had she settled herself, however, ere the bee renewed its strug-
gles. In a moment it succeeded in cutting a little opening at one end
of the sac, out of which first issued jaws, then antenne, then its head,
and then its body. It was free. Instead of flying away, as one would
have thought a reasonable insect ought to do, the bee turned with angry
gestures upon the little ball of white silk into which had collapsed the
enswathments out of which it had just escaped. Upon this she fast-
ened her claws, thrust her sting ferociously into it several times, and then,
as though she had satisfied her sense of justice and vengeance, spread her
wings and began to ascend.

There was an angry hum in her wings, and an ugly look in the still
outthrust sting, which led me to step back a pace or two lest I might come

in for a share of her wrath. She followed me for a little dis-

’ . . . .
aoe tance, and then, changing her mind, mounted into the air, and
scape .
pee in a moment or two was hovering over a fragrant honey-

Bonds. ‘suckle blossom, apparently solacing herself for her recent insult

by the sweets of nectar. What an escapade that was! And,
if the bee only knew it, what a story of “hairbreadth ’scapes” she might
have told to her comrades of the hive when she returned home.

But how fared the spider? This question interested me. I stepped
up to the web again, and after a few moments’ waiting saw her go down
her web lines to the roll of silken swathing. There seemed to be a
slight movement of surprise at the character of the object; but if she
was greatly disappointed she made little demonstration of the same. She
seized the silken ball within her mandibles, turned upon her path, and
carried it back to her shield, on the upper part of which she fastened
it, somewhat after the manner of a trussed insect set aside for food. I
could not satisfy myself whether she had noticed the escape of her prey
before this return. But evidently she perceived it now. A little while
afterward I found that the swathing cloth had disappeared, and I have
no doubt that the spider took it within her jaws and comforted herself
by feeding upon it; perhaps a poor substitute for the juicy morsel which
she had anticipated, but nevertheless, even with a spider, I suppose, “a
half loaf is better than no bread.”

I observe that the location of the web makes a great difference in
the amount of food obtained by the spider. Those webs which have a
favorable position for the flight of insects, in the neighborhood of the
honeysuckle blossoms of my manse yard, for example, or in positions
on the ampelopis vines easily approached by insects, have an abundant

PROCURING FOOD AND FEEDING. 259

supply of food. Others, less favorably situated, are seen feeding less
rarely. In this matter of location the spider is very much dependent
upon chance. The force or endurance of a current of wind

Location during the first aeronautic flight, or the particular obstruction
Controls : 3 me
Food upon which the balloon may be arrested, will be circumstances

determining the future habitat of the Orbweaver.

More frequently the range of life action is determined by the po-
sition in which the maternal cocoon is suspended, the natural tendency
of spiderlings after egress being to distribute themselves in the imme-
diate vicinity of their birth. But Orbweavers do crawl about from point
to point and shift the site of their snares. I have known one to change its
position by passing along one or two intervening city fences into an ad-
joining yard. The course and extent of these migrations are determined
by the position and continuity of the foliage. But so strong is the seden-
tary habit of Orbweavers that they will suffer a great amount of priva-
tion before leaving the neighborhood, or indeed the immediate site of their
snares. If for any reason this should happen to be poorly stocked with
the creatures’ natural food, their chance for growth and life is poor indeed;
and I have no doubt that sometimes they perish from starvation.

In certain positions it is doubtless true that the excess of life goes to
supply the lack of life nutrition. In other words, spiders are cannibals,

and prey upon each other. The cocoons formed by female Orb-

eae weayers usually send forth large colonies of younglings. As soon
on Eac ;
Bhoe as they set up housekeeping for themselves they begin to prey

upon each other and upon all other sorts of araneads. The
strong, or skillful, or fortunate devour the weaker, less cunning, and the
unlucky. <A few only survive; the great majority must go to give nourish-
ment to the few and secure the perpetuation of the species. Undoubtedly,
in certain sites, this redundancy of life through maternal fecundity is an
important, even an essential, factor in the food supply of spiders.

One who has observed the habit of spiders to spin their webs across
cowpaths, footpaths, and the various trails leading through meadows, pas-
ture lands, and woodlands, must have had occasion to reflect
upon the uncertainty of spider possessions, and perhaps have
‘felt a touch of pity for the industrious creatures whose pains-
taking work is so continually broken down by passing animals and men.
It is certainly true that great loss is thus caused, and that spiders are con-
tinually subject to the destruction of their snares by all manner of passing
creatures; yet there is some compensation for this destruction.

I have often noticed that, as I walked back and forth over the fields,
the grasshoppers, crickets, and other insects were stirred up by my move-
ments, leaped or flew to this side or to that, and in their alarm and
haste numbers of them struck the snares of the near by spiders, were at
once entangled, and became the prey of the waiting proprietors. ‘Thus it

Beating
up Game

260 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

comes about that the very means of destruction to one proprietor becomes
a means for furnishing abundant supphes to another; and doubtless that
which at one time serves to destroy, at another time brings food to the
larder of the same spider. There are not many animals that enjoy a like
distinction of having human unfriends “beat up” the game for them as
does the hunter spider silently seated at its araneal “ run.”

The ability of spiders to endure prolonged abstinence is very great,
and to this end nature has admirably arranged their constitution. When
the abdomen is opened in dissection a large quantity of adipose
matter comes into view, which supports and separates the dif-
ferent internal organs. This reservoir of fat is a storehouse of
nutriment, which enables spiders to bear very long abstinence. When
they have been deprived of food for a long time, the abdomen becomes
smaller and shriveled up. I have at this writing in my possession one of
our American tarantulas, Eurypelma Hentzii, which has had nothing to
eat for a period of more than seven months.t During that time I have
supplied it freely and continually with water, and it appears to be in en-
tire health, and quite active. On several occasions I have preserved the
same species quite as long without food. Longer periods of abstinence
have been recorded by other observers. Of course, I do not refer to the
period of hibernation, during which no food is required, but to absti-
nence during the seasons when spiders are wont to feed.

When an opportunity is given for feeding, they appear to be able to
make up for lost time by consuming an extraordinary amount of food.

The number of insects which a healthy spider is able to devour

Long
Fasting.

Enor- during a day, without apparent inconvenience, has often been a
mous , cHppria Pp a » 1 oI q a
Heeding great surprise to me. Before reaching maturity, such feeding

rapidly produces a very apparent effect in growth. A half-grown
spider, happening upon a location visited numerously by insects, will ex-
perience astonishing increase within a brief time.

EEL
The manner of feeding among other tribes is not greatly different
from that of Orbweavers. The Lineweavers swathe their captives in the
manner above described, and eat them while they hang back

Compara- downwards upon their snares, revolving the careass and sucking
tive afer! Vous ; ; -

; its juices in the same manner as Orbweavers. In their mode of
Feeding :

Habits, feeding, the Tubeweavers, although Sedentary spiders, quite re-

semble that which prevails among the Tunnelweavers and the
Wandering tribes. That is to say, they simply seize prey with their paws
and fangs, and feed upon them without swathing. Such Tubeweavers as
Agalena noeyia and Tegenaria medicinalis seize the insects as they drop

1 From the latter part of October, 1888, until June 19th, 1889.

PROCURING FOOD AND FEEDING. 261

upon the outspread sheet, or into the sheeted pouch which forms the
trap, and then dragging them to their tubular dens suck the juices.
The Wandering spiders leap upon their prey, falling on them with the
fangs, palps, and united claws of the front pairs of legs. Ordinarily, the
first spring proves successful in capturing the victim, and, if it be not so,
I believe that it is not often repeated.

I have frequently observed Hentz’s tarantula feeding in confinement.
When the spider was disposed to eat, an insect was seized with the fore
legs, palps, and mandibles, which rapidly conveyed it to the mouth. In
this position it was held by the palps, which, as the spider had occasion,
also turned the carcass, aided by the mandibles, the latter organs mean-

Fic. 238. Hentz’s tarantula eating a locust.

while crushing the victim. (See Fig. 238.) During this act Tarantula was
anchored to the rug on which it was wont to sit by several threads at-
tached to the spinnerets. On one occasion, while in the act of eating a
locust, a second locust approached near enough to be seized. It was struck
upon the ground, where it was held down until the tarantula, moving slowly
around, overspun and swathed it, evidently reserving it for future use.

I may say here that my experience in keeping other large spiders is
that there is quite as much danger from overfeeding as underfeeding. I
, have found the best success by giving a generous supply of liv-
Fee te food during the summer and early autumn, and withholding

food almost entirely during the remainder of the year. I was
particular, however, to keep a vessel continually supplied with fresh water
within the box. Spiders require water quite as much as other animals,
and failure to keep them supplied will be fatal to health and life.

262 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

I have sometimes succeeded in tempting tarantulas to suck the juice
of a bit of raw beef, but the only food that can be relied upon is living
insects; and these spiders appear to be able to lay up within the four or five
months of summer enough nourishment, in connection with a free supply
of water, to last them during the entire year. These Mygalidz do not be-
come torpid in winter time, but remain active throughout the entire sea-
son, provided they are kept in a room heated to a moderate temperature.
If exposed to a severe cold they are soon benumbed, but quickly recover
when again brought into a warm atmosphere.

Ve

Although spiders can long survive without food it is absolutely neces-
sary, as far as my experience extends, that they should be continually sup-
plied with water. I have frequently received species of various
Need of . . 1° . : 5 :
Water. tribes which had been shipped through the post office and were
taken out of their packages apparently in the last stages of life.
These I have often succeeded in restoring by applying them to water—
placing them in such a position that their mouth organs would be near or
over a drop of the liquid. In a longer or shorter time, according to the
degree of exhaustion, but also, I think, varying with the peculiar consti-
tution of the species, many of these would be restored and become as active
as ever.

This is a common experience with those who have kept spiders in
artificial conditions for the sake of observation and experimentation. Mr.
Campbell says of the common English house spider, Tegenaria guyonii,
that the habits of the females of this species, spending as they do an ap-
parently sedentary life in dry places, render it difficult to see how they can
obtain water except -during their occasional excursions. Yet the frequent
supply of water or a damp atmosphere is necessary for spiders. He had
kept a Tegenaria guyonii for more than twenty-seven months without any
liquid except that which she derived from insects. In one case a spider
that he was keeping was found lying helpless at the bottom of the bottle
with her legs drawn close to her body. He immediately filled a tube with
water and dropped some on her back and in front of her. She quickly
balanced herself, and, wetting the last joints of her palps, placed them to

her maxille. This she did five times and then advanced and

‘lowered her whole body so that the maxillee were dipped in the
water, Thus she remained, apparently motionless, for a few seconds,
when she raised herself to her normal position, and repeated the draught
after an interval of a few minutes. Shortly afterwards she mounted to
her usual roost at the shoulder of the bottle, with her abdomen consider-
ably distended. !

Drinking

1. Maule Campbell, Jour. Linn. Soc. Zool., X VI., page 537.

PROCURING FOOD AND FEEDING. 263

This mode of drinking as described by Mr. Campbell accurately ex-
presses the common method as I have observed it. In the case of large
spiders that have long been kept from water, such, for example, as Hentz’s
tarantula, the spider will sometimes rush to the water, greedily drop the
maxille and mouth organs into it, the body being partly sustained in
the meantime by the outspread legs. Sometimes the mouth will be lifted
up for a little while, and then again sunk into the water.

Many sedentary spiders, and indeed numbers of other tribes, must ob-
tain a considerable supply of water during the process of cleansing them-
selves. The little drops of dew and rain which gather upon the hairs of
the legs are brushed or squeezed into the mouth when the limbs are drawn
through the mandibles in the process of toilet making, as described in
Vol. II. of this work.

Cambridge observes that drought as well as excess of wet, but more
especially the former, and unseasonable weather of all kinds have a strong
effect in reducing the number of spiders. Some species found in marshy
places are so susceptible to injury, from lack of moisture, that they cannot
be carried alive in a box for more than an hour or two, unless a small por-
tion of damp moss be placed with them. Others, on the contrary, appear to
thrive best on the most arid spots, and in the hottest sun. As a rule, how-
ever, spiders are thirsty souls, constantly requiring water to drink.!

I have received one authentic report of spiders drinking milk. It was
sent me by Mrs. Mary Treat, to whom it was communicated by one of her
lady correspondents, Mrs. J. B. Harrison. The species referred
to was not identified, but the statement made is that the spider
spun a thread from the side of a box down to a milk pan, and
then deliberately and carefully descended inside the vessel until it came to
the milk, which it then sucked. This was observed in several cases. One
cannot help wondering whether the spider’s taste was sufficiently keen to
distinguish between the milk and its ordinary drink. Probably not. The
same lady speaks of a spider whose snare was on a pump in the yard, and
which every night spun a delicate line just across the spout, and from this
position procured drinking water.

Does the spider eat its web? is a question which has often been asked,
and variously answered by both, scientific and non scientific observers. In
point of fact, the Orbweaver does eat its web. It is its invari-
able habit to gather together the particles of its broken snare,
when it clears away the wreckage to make a new web, and ball
it underneath its jaws with its feet and palps. It then takes it into its
mouth and apparently sucks from it all the viscid material and all the
other nutritious matter—dealing with it, so far as I can observe, very much
in the same way that it does with a fly.

Drinking
Milk.

Eating
Its Web.

264 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

after the morning is well advanced, or after the snare has been broken by
the struggles of a large insect. The spider runs out upon her radial lines,
and with great rapidity cuts here and there the supporting threads, gath-
ering with a quick motion of her feet the various parts underneath her
body and balling them around the mouth. Thence she runs back to the
hub, whence she approaches another part of the web, as she moves clip-
ping the segments and rolling the parts together with her feet. Her ac-
tion is facilitated by the fact that when the supporting radii are cut the
interradials collapse, and, by reason of the viscidity of the beads, mass
together in a lump. This the spider seizes, condenses by a deft and rapid
action of her feet, adds it to the little ball already gathered, then runs
along a line which she is always careful to preserve, to a main foundation
line leading to her shelter or nest, and settling herself imbibes the juices
of her morsel at her leisure.
An English observer records a note which indicates that certain tube-
weaving spiders consume their snares in winter time. A species of Aga-
lena or Tegenaria was kept during the summer abundantly fed,
oe. its energy and excessive nutrition being largely consumed in in-
Rie °F creasing its web, adding layer to layer, one upon another, in
texture almost as close as tissue paper. When the winter came
and flies disappeared, the observer expected his pet to hibernate or become
torpid. On the contrary, however, it seemed to be as active as ever in mid-
winter. It was then noticed that certain curious holes appeared in the
web, which looked as if it had been cut away with some sharp instrument,
and it kept on going and going, until altogether six or seven superficial
inches of this paper like web had been devoured. The spider did not
thrive on this food, and became very thin. It lived, however, until the
following summer, and once more grew fat on abundance of flies.1

We

The capture of food is always more or less disastrous to the snare of
the Orbweaver, as may be easily seen by a study of the various figures rep-
resenting that action. The insects themselves in their struggles thoroughly
twist up the whole viscid section upon which they are caught, and thus
throw it into a confused tangle of merged, crossed, and diverg-

Wear and ing lines, which extend in every direction. If the insect is a
Tear of very larg tl ount of breakage is much greater. So
Snares, Very large one, the amount o akag greater,

also when the spider runs from her den or hub to seize the insect,
her own action in swathing her prey increases the confusion of the lines.
Frequently she is compelled to cut out the radii and portions of the spiral
space in order to accomplish her capture; and after the insect 1s swathed
a further damage frequently occurs by the act of the spider in cutting out

‘Gilbert R. Redgrave, “Science Gossip,” 1872, page 140.

PROCURING FOOD AND FEEDING.

and transporting the mum-
mied insect. If the day
happens to be a very good
day, viewed from the spi-
der’s standpoint, or a bad
one from that of the flies;
if the net site happens to
be one where insects are nu-
merous, the web will pre-
sent a very forlorn appear-
ance even early in the day,
and by the time evening has
come it will be but a tat-
tered remnant of the beau-
tiful object which caught
the morning dew and glis-
tened in the first sunbeams.

Fig. 239 is a sketch of
a portion of web of Epeira
strix, from which a freshly
captured insect had been
taken. The lines are drawn
very accurately from nature.

In the act of captur-
ing an insect it becomes
necessary for the spider to

Fic. 239. Section of Epeira’s orb after an insect has been captured.

piece together the parts of the web which are separated either by the
breakage of the insect’s struggles or the intentional cutting of the spider

herself. This mending is done with great deftness and skill. The
broken parts are held together by one or more of the feet, usually
the hind feet. The claws on one side of the body grasp

“ sett ate one portion of the armature, while those on the other
roken ;
grasp the opposite broken part. At the same time a
Weer 2 ee 3 | .
thread is thrown out from the spinnerets, is attached to
I ° ° . .
w the margins of the fracture, and the rent is pieced together in a
R manner almost impossible to describe, and indeed to observe at all,
Fic. 240. so rapidly is it accomplished.
Piece of = ee i a : f - t :
broken Fig. 240 is a piece of a broken radius spliced by Epeira strix.
bee R, represents the radius; L, L, lines which were run along either
splice¢ ; 4 ; ‘ ; :
byEpei- side thereof; and W, a zigzag cross line by which the three straight
ra strix.

lines were warped together. At other times the angular points of

the fracture on either side are simply held together by one or more lines,

as the case requires, thus taking the place of the sundered radii and lost

spirals by which the segments had been held together.

266 AMERICAN SPIDERS AND THEIR SPINNINGWORK. .

It frequently occurs that the insects entangled upon a snare are never
used by the spider; although a most voracious creature, her ap-
Unused petite is necessarily limited, and, at all events, she becomes some-

ea what dainty as her appetite is satisfied, and will not trouble her-
Insects, ‘self with insects of a minor sort. Indeed, many large spiders,

except when very hungry, pay no attention to the small insects

strung upon their webs.
It is surprising how many of these will be arrested in the course of the
day. I have counted as many as two hundred and thirty-six insects, great
and small, hanging upon various parts of the web of Epeira

AMos- gclopetaria, after the proprietor had abandoned the day’s work
quito : ; E
Tae and retired to her nest to await the evening meal. One day,

while crossing the long bridge over Deal Lake, Asbury Park, I
stopped to count the number of insects upon a web spun just beneath the
bridge, and noticed that thirty-six mosquitoes had been entangled. Cer-
tainly this was a goodly amount of service for one spider to render a most
unappreciative and ungrateful humanity.

A friend has recently been deeply interested in the problem whether
dragon flies, or, as they are sometimes called, mosquito hawks, might not be
reared in sufficient numbers along the seashore to keep in check the immense
number of mosquitoes that sometimes make life at our watering places very
unsatisfactory to guests. There is no telling what artificial propagation
may accomplish in this direction, and, at all events, all experiments in
natural science are worthy of consideration until they are demonstrated
to be impracticable. But I venture to suggest that the most effective nat-
ural checks upon the increase of insect pests are their natural enemies,
the spiders. If men would abate the unreasonable prejudice which they
have against this most friendly and helpful animal, they probably would
suffer less from the raids of that piping and piercing pest, the American
mosquito.

The spider is doubtless Nature’s chief check against the undue increase
of insects. Despised Arachne is entitled by her services to occupy the chief

place among invertebrate philanthropists. She is, I might al-
Nature's most say, absolutely harmless to mankind. With the exception
Check to i : é 6c G al Me) S ino 1 1
ee of an occasional alleged “spider bite” issuing in suffering or

death, and delivered by the traditional and indefinite “ black
spider,” I know of no evil that can be charged against her. True, as long
ago the wise Proverbialist said, “The spider taketh hold with hands, and
is in king’s palaces.”?! She builds her cobwebs in our homes, but there
is no harm in that. If one will take the pains to study the cobwebs, they
will be found beautiful structures, and, at all events, the housewife can
brush them away without encouraging hatred for the harmless creature

1 Holy Scripture, Proverbs xxx. 28.

PROCURING FOOD AND FEEDING. 267

that makes them. For, be it considered, the spider only comes into our
homes because mosquitoes and other insects also come! She comes, not
seeking to harm us, but to help us, and therefore, for the sake of her mo-
tive, if she be not welcome, let her, at least, be thought of kindly.

The number of insects of all sorts and sizes destroyed by spiders sim-
ply passes calculation. If one will walk out on a dewy morning, with
his eyes open for spider webs, he will be surprised to find how many there
are, and how various, too, the forms of spinningwork that meet him. All
over this new plowed field he will find them fresh spun; in yonder meadow,
also, hanging by myriads upon myriads on the grasses. Along that hedge
row they are nested, and have woven their dainty snares, and built their
nests on the feathery ferns. In the branches of these shrubs and on the
foliage of yonder trees are other hosts.

If one will push back the foliage, he will see yet others, spiders of
the Wandering group, that stalk their prey as do the wild beasts of the

forest, crouching on trunk and branches and lurking among the

Arachne leaves. If one turns to the earth, other myriads are seen, whose
the Phil- : :
Aarne homes are on the ground, or who build slight webs close to the

pist. surface. These have laid the axe at the very root of the tree,
and are destroying the insects ere they rise from the surface to
visit our homes,

All these unnumbered multitudes of spiders are engaged, during every
moment of their existence, in waging relentless war upon the insect world.
When one considers how many spiders there are, and that they all thus
feed upon their natural food, the insects, he may form some just conception
of how needful they are to mankind. I do not hesitate to say that, unless
Nature should provide some equivalent in the way of check upon insects,
man could not dwell in many inhabited parts of the world were it not for
the friendly service of spiders.

CRAP TER xv i

EFFECTS AND USES OF SPIDER POISON.

Wuat are the effects of spider venom? Nothing connected with the
life history of spiders has given rise to greater diversity of opinion than
this question. The well nigh universal belief is that all spiders
are very poisonous and their bite apt to be serious and even
fatal to human beings. It is this, doubtless, which maintains
the most unjust popular dread of and hostility to these useful animals.
On the other hand, naturalists have been generally inclined to an opin-
ion quite the reverse of the popular one, and have held spiders as harm-
less to man.

Current
Opinions.

Ie

Let us first inquire what light anatomy can throw upon the subject.
More than two hundred years ago Leeuwenhoek gave a substantially cor-
rect description of the fang of a spider, pointing out the small aperture
through which the liquid poison is emitted.
Since that time the poison apparatus has

been frequently described, and any

Poe one with a microscope can easily
ions o

satisfy himself of the facts. What-
Anatomy.

ever may be the effect of the secre-
tion from the poison glands of spiders, it is
certain that the organs and armature secret-
ing and conveying the venom are formida-
ble enough to suggest the idea of injury to
Fic, 241. View of the falces (fx) and fangs creatures affected thereby. The fangs of Ar-
of Argiope cophinaria, from camera lu- : iathngraty ane el sa Seana DAdneen
cida drawing. The teeth ononesideare glope cophinaria are shown in Fig. 241, where
shown in outline, and the opening (o)in they are enlarged about fifteen times. The
the fang is shown. 15. a : :

mandibles from which the drawing was made

were taken from a nearly adult female. The falx, fx, was about two mil-
limetres long and one millimetre wide. ‘The fang itself was about one
millimetre in length. When examined under the microscope it showed
very clearly the matrix in which the poison gland had been placed, as
seen in the outline drawing (camera lucida) at Fig. 242, gm. One also
sees the canal, cn, which contained the duct, and the little aperture at the
extremity, 0, from which the secretion of the gland issued.
(268)

EFFECTS AND USES OF SPIDER POISON. 269

The gland itself was well observed in a dissection made from Epeira
domiciliorum, and represented at Fig. 243, multiplied about twenty-five times.
The sac is covered with muscular fibre, as shown in the drawing, and yet
more magnified in the camera lucida sketch of a portion of the sac
at Fig. 244. This muscular provision
implies a formidable arrangement for
expressing the contents of the gland
through the duct and its canal out of
the opening in the fang, o

Still another view is given at Fig.
245, the poison apparatus of Epeira di-
ademata. The sac or poison gland, g, i
inclosed in its coating of striated mus-
cles; the duct, d, about the length of the
gland, enters the falx and fang, f, and
the outlet is shown at 0, which appears }
to be along a little shallow groove in the jy, 249, much magnified outline of the falx
outer surface-of the inside face of the nd fang of Argiope cophinaria. g.m., matrix

mm : - of the poison gland; cn, canal which contains
fangs. The outlet (0) is shown again at the auct leading from the gland; 0, opening
x, magnified about thirty mimes, CRG: eee e eee cake ke Ye ae
muscular fibres coil spirally and very
regularly around the bag. The aperture is not only an oyal slit, but the
side towards the point is doubly Dees thus facilitating the emission and
direction of the venom.!

As the discharge of the poison is not dependent upon the mechanical
action of erecting the fang, as in the case of poisonous snakes, it is not
improbable that the spider has the power of withholding the poison at
will. As the emission of the venom depends on the compression of the
muscles by the poison sac, and this compression is within the volition

Fic. 243. View of the muscular system inclosing the poison gland of Epeira domiciliorum.

Camera lucida sketch. 25.
of the spider, we may well suppose that the animal often strikes without
feeling the necessity of injecting poison into the wound, but destroys its
J o ’
prey simply by piercing. That this arrangement is general among the
tribes of spiders appears by a similar examination of any other indi-
vidual.

1 From “Science Gossip,” December, 1867, page > 270, oe Henry Davis.

270 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Fig. 246 shows the poison sac, gland, and one of the fangs of the
Mason spider (Nemesia cementaria) as dissected by Blanchard.! The ver-
tical articulation of the fangs, or movement up and down, which char-
acterizes this tribe of spiders,
may be noted in the cut. Fig.
247 represents the formidable
mandibles of the large My-
gale, popularly known as the
“tarantula,” drawn twice the
size of nature. The outlets

for the poison from the fangs
oer Sen coat are here very manifest. .They
magnified, of a see. are situated near the point of
oie a ee re the inner surface, and are of
of Epeira domicilioe the shape represented in the
na figure. On one side of the
falx is a formidable row of ten teeth. The other side is protected by a
picket of closely placed stiff red bristles. It might be expected that such
a formidable armature would certainly inflict a grievous hurt, whatever
may be the case concerning the feebler armature of our ordinary familiar
spider fauna.

Another illustration of these organs is given at Fig. 248, which repre-
sents the fang and falx of an immature Drassus, multiplied about twelve
times, taken from a camera lucida drawing made by the late Mr. Richard
Beck.2, The manner in which the falces and fangs are related to the mouth
organs is shown at Fig. 249, which is a view from
beneath of the cephalothorax of Epeira quadrata.
The lp is seen at the tip of the sternum, which
lies just under the maxille, which organs in turn
are situated just beneath the falx.

The moults of spiders form admirable specimens
in which to examine microscopically the external
character of the fang. They not only show the
opening far more distinctly than the entire organ
taken from the animal, but they present the fangs
in a most favorable position for examination.

In view of the above results, we are free to say

A

: ORM pease A sais : pane | AOS acl and fang (f) of Epeira diadema-
that as far as the testimony of anatomy goes, itis 4, x the point of fang yet

plain that spiders of all tribes are abundantly — more enlarged, to show the ex-

= ~ : oO a ternal opening, 0. (After Davis.)
provided with an armature for dealing an injurious

wound to those whom they strike. One can hardly suppose that such a
gland as I have described, with such an attachment, is intended to secrete
any other substance than one which provides for the defense or nourish-
ment of its possessor.

1 Cuvier, Regn. Anim. Arachnides. 2 “Science Gossip,” 1866, page 202.
: 5) 5

EFFECTS AND USES OF SPIDER POISON. po i |

i.

From the indications of anatomy we turn to the testimony of natural-
ists and other observers of the effects of spider venom. First in order of
value, for their extent and thoroughness, are the experiments of Mr. Black-
wall,!_ an abstract of which I present. The experi-
menter induced a female Epeira diademata to bite him
on the inside of the left hand, near the base
of the fore finger. It continued to force its
fangs deeper into the flesh, during a period
of many seconds, and at last quitted its hold volunta-
rily, when a little blood issued from the wound. Though
the spider was in a state of great excitement from pre-
vious irritation, Mr. Blackwall did not experience more Suis uo
inconvenience from its bite than from a puncture made quct, and fang of Neme-
near it at the same time with a fine needle. The ef- ea ass
fects of both injuries appeared to be very similar.

Again, a highly exasperated female Diademata was allowed to seize
him on the inner side of the left fore arm near the carpus. It continued

for more than a minute to bury its fangs deeper into the flesh,
Effect of and, on quitting voluntarily, a little blood flowed from the wound-
hii ed part, near which a puncture was made simultaneously with
a fine needle. The effects of this and the preceding experiment
were alike. In both cases the air was sultry and the temperature as high as
seventy-five degrees. These two wounds were inflicted in the month of July.

In the latter part of August, a powerful
and much irritated female Epeira quadrata bit
Mr. Blackwall on the inner side of the left
fore arm near the carpus. It retained its hold
for the space of five minutes, occasionally forc-
ing its fangs deeper into the flesh, and, on quit-
ting it voluntarily, blood issued freely from the
punctures. The effects of this bite did not dif-
fer materially from those of a wound made at
the same time with a needle of average size,
the intensity and duration of pain being very
similar in both instances.

During. the same month spiders of various

Evidence
of Effects.

Fic. 247, The mandibles of Hentz’s E a :
Tarantula. X 2. (From nature.) Species were induced, under the influence of ex-
The bristles and teeth on the inte- =U ent 5 : . -

, 4A os ve) mS va) Tee y y
Site cuiide ciflis Gace aecnieee cited feelings, to seize a piece of clean window

andthe openinginthefangsthrough glass with their fangs, when a transparent fluid,
which the venom exudes. : > ae .
which escaped from the small aperture near their

extremity, was deposited upon it. The application of this fluid to the tongue
did not produce any sensible effect upon that organ.

1 Linn. Trans., Vol. XXI., pages 31-37.

ae AMERICAN SPIDERS AND THEIR SPINNINGWORK.

In order to compare the effects of spider venom with that of hymen-
opterous insects, Mr. Blackwall touched to his tongue the poison emitted
under like circumstances with the above from the sting of the common
wasp (Vespa vulgaris), the hive bee (Apis melifi-
ca), and the humble bee (Bombus terrestris). A
powerfully acrid, pungent taste was the immediate
consequence of applying the insect poison to the
tongue.

A contrast equally remarkable was evinced
when these insect fluids were transmitted into the
recent wound, ‘That secreted by the in-
sects caused inflammation, accompanied
by acute pain, effects which, if pro-
duced at all by that secreted by the spiders, were
scarcely appreciable.

Baron Walckenaer also experimented upon his own person, allowing
himself to be bitten by the largest species of spiders around Paris without

consequent swelling or reddening. The small punctures made by
Walek- the spider’s fangs gave him no other sensation than would have
enaer’s qo tae: ‘s . ;
Witness, been produced by a pin or a needle thrust into the finger. It
is his judgment that the venom of a spider has not as great
an effect upon man as that of a wasp, bee, bed bug, flea, or even smaller
insects, ! :

Rey. Pickard-Cambridge often tested the absence of venom in some of
the strongest British species.27 Dugés made experiments upon himself with
the largest spiders, such as Segestria and 'Tegenaria,
without producing any physical pain or wound that
could not readily be dissipated. M. Eugene Simon re-
cords that he was struck in his finger by the fangs of
Lycosa tarentula, which affected him after the fashion
of the prick of two needles. The pain was lively, the
blood flowed, but the little wound healed without any i
special ill effects. A correspondent of “ Science Gos- LES
Sip * says that his son was bitten in his closed hand ee ee eee
by a spider, which left two small blood stains. His guaarata, viewed from
wife was bitten, but there was simply a slight swelling. pate Cee
Another correspondent writes that a boy was bitten at
Cape Colony by a large spider, which is called a tarantula, so badly as to
make his finger bleed, but no further effect followed.

Mr. George B. Lownes, a gentleman living in the suburbs of Phila-
delphia, informed me that on one occasion, while walking through a lane,

Inocula-
tion Test.

Fic. 248. A falx and{fang (f) of
Drassus. (After Beck.)

1 Aptéres, Vol. II., page 423. 2 Spiders of Dorset, Vol. I., Introduction, page xxv.
’ Histoire Naturelle des Araignees, page 27.
4G. B., Science Gossip, September, 1868, page 231.

EFFECTS AND USES OF SPIDER POISON.

bo
=~]
oo

he stopped to pick up a flat stone under which a ground spider (probably
Lycosa scutulata) was nested in a little cave along with her cocoon. The
spider sprang upon his finger, making a puncture like. the prick of a
pin. The wound bled, but had no other inconvenient effect.
My own personal experience with spider bites has been very limited,

as I never but once could succeed in teasing my captives to bite me.

While roughly handling a large Epeira insularis, August 29th,
The Au- J] was struck by her in the ball of the thumb. The fangs left
piaaaial two slight punctures about one-eighth inch apart. At the mouth
perience.

of each puncture on the skin was a little drop of transparent
colorless liquid, evidently venom, which had been extruded from the poison
gland. I waited a little space to allow this to enter the system, and then
applied the liquid to the tip of the tongue. It had an acrid taste, leaying
a remainder in the mouth something lke the astringency of alum. Not
the slightest inconvenience resulted from this wound. No irritation or
swelling of any sort followed, and I was conscious of no pain except the
very slight sensation produced by the original incision, which was no greater
than that of the prick of a dull pin point.

Til,

We turn now to some of the evidence that spiders do inflict a serious
wound. Mr. J. M. Meek, of Waiwera, New Zealand, sent the following
narrative of the effects of the bite of the katipo, or native spi-

Venom- der,! which appears to be a species of Latrodectus: “On the

2 ia morning of the 24th ult., at three o’clock, my son (a man of
oa thirty-one years of age) was awakened from his sleep by the

Zealand, bite of one of those poisonous insects, and came into our bed-
room about an hour afterwards, and exclaimed to his mother
‘and myself, ‘I am bitten by one of those spiders that the natives have
so often spoken to me about, and am full of pain. See, here it is, in the
bottom of the candlestick.’ I looked at the insect, whose body was about
the size of an ordinary pea, and in color nearly approaching to black.
His mother, on looking at his back, saw the puncture the spider had made,
and immediately commenced sucking the wound. I proceeded to the hotel,
and obtained the services of Dr. Mohnbeer, when, on my return with him
to my house, my son was suffering the most excruciating pain in the groin,
the virus apparently working its way in that direction. After an applica-
tion of ammonia by the doctor, the pain shifted from the groin and worked
its Way up the spine, affecting the arms and chest during the remainder of
the day and lasting till the following morning, my son moaning with pain
the whole time.
“On Tuesday the pain became intense, the virus working its way into

' Popular Science Gossip, 1877, page 46.

274 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

his legs, causing the veins to swell very much. We applied turnip poul-
tice to the wound, and when this was taken off a quantity of black fluid
came from the sore. During the afternoon the
pain in the legs and big toes still continued.
Dr. Mohnbeer prescribed a liniment, which, after
rubbing well into the legs, caused a black, inky
colored fluid to emit itself through the pores of
the skin in large drops, from which time my
son began to improve, and has continued im-
proving ever since, but suffers much from weak-
ness. From the time he was bitten on Mon-
day till the Friday following he lost exactly
twelve pounds in flesh. I forgot to state that
when he was first bitten I gave him small
doses of brandy, at intervals during the first
\ two days, which seemed to have the effect of
\ greatly relieving the pain.

i NY “T am informed by Te Hemera, native chief
Fic. 250. Latrodectus mactans, adult here, and also by Sy 7

female. Twice natural size.* other natives, that \ \

many fatal cases among their ranks have taken \ |

place by the bite of the katipo; they also be- \
lieve the sufferer is sure to die if they cannot \ i
find the spider; but, on the contrary, if they find :
it and burn it in the fire, the patient gets well in, ; Fr,
three days. If they cannot find the insect, they ff
set fire to the house and burn buildings, effects, y ;
and everything else. In this case the spider was %
found, and Dr. Mohnbeer has it pre- aL,
served in spirits in his surgery. I :
write this to caution persons to look eS
well to their bedclothes before retiring to rest, / Fis. \
as I have witnessed persons suffering from the 7 Ney
bite of snakes and other reptiles in Australia, f
but never saw any one in such agony as my son dpe i
during the time the poison was taking effect.” 4

Notwithstanding this very clear and appar- |

\

ceca

Native
Notions.

ently trustworthy account and the examples

which follow, M. Lucas, a well known natural- |
ist, gives a testimce Thich is exact he re- f

ist, Blves a testimony W hich 1S €X actly the Te Fig. 251. Latrodectus mactans, male.
verse concerning the yenomous effects of the Twice natural size.

.

1 For this cut and the two next following I am indebted to the courtesy of the Secre-
tary of the United States Department of Agriculture.

EFFECTS AND USES OF

very same spider.

SPIDER

POISON. Zid

He states that he had studied the habits of Latrodec-

tus in Algeria, where it is frequently found, and that he never observed

Lucas
Denies.

that its bite was venomous, although he himself had been bitten
several times without any bad effect.1

Can it be that the very

state of mind in which the naturalist approaches the inquiry
neutralizes the poison by nullifying the effects of an excited imagination ?
In the entomological journal known as “Insect Life,’ issued by the

United States Department of Agriculture,

2

there is

an excellent article

giving the evidence for and against the possibility of a fatal bite from

our common spiders.
authenticated are given of
Latrodectus mactans, as
One of them resulted fatal

The symptoms of the
of the victims were negroes.

from Mr. F. W.

New ber of cases from
Zealand j
Edtipo O22 variety of
and describes a
practice, which, however,

He considers that the symp
himself make it evident
fully affected by a narcot
being absorbed into circu
brain, and nervous system
tent, almost amounting to
was treated with spirits of
wound, and with ammonia
bined with brandy in con

Mr. Wright adds that
quainted with these spi
sidered their bite very dan

Fic. 252. Varied markings

of the abdomen. b,c, d,
e, f, g, upper side of abdo-
men; h, under side of the
specimen marked g; e, f,
g,h are enlarged two, c
and d three times, b four
times the original.

In this article two cases which appear to be well

the effects of the bite of
found in North Carolina.
ly, and the other seriously.
bite are fully detailed. Both
The same article quotes
Wright,? who gives a num-
hearsay of fatal bites by

spider in New Zealand,
serious case in his own
did not result in death.

toms of the case treated by
that the man was power-
ic and acid poison, which
lation affected the heart,
to a very considerable ex-
fatal syncope. The man
ammonia, applied to the
and water, afterward com-
siderable doses internally.
the Maories well
ders, and have always con-
gerous. The tufts of sedge

are ac-

upon the sea beach are the favorite haunts of the red spotted variety, and
the natives avoid sleeping in such places. Half a stone’s throw inland,
however, they do not fear the “ Katipo,” as they call the aranead. This
statement appears to me to throw discredit upon the entire testimony of
the natives, for it is not possible to believe that the venomous character
of the spider can be affected by a simple removal from the sedgy growth
along the seashore to the herbage half a stone’s throw inland.

Mr. Gosse* records the effect produced upon one of his servants who

1 Annals Entomological Society of France, 1848, page 8.
2 Insect: Life, Vol. I., No. 7, pages 204-11.

3 Transactions of the New Zealand Institute, 1869.

4 P. H. Gosse: Naturalist’s Sojourn in Jamaica, page 241.

276 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

was bitten by one of the large, beautiful Nephilas who spin their huge
orbwebs in the forests of Jamaica. Coming through the woods at early
dawn his face came into collision with one of the strong webs. He stopped
to brush it off, and immediately felt some large insect run down his body,
which presently bit him on his great toe. The pain was less severe than
that following the sting of a wasp, or even the puncture of a Tabanus;
but the man described it as having three distinct paroxysms—if one may
use such a term for so small a matter. The pain was not of long duration.
Here, as in so many other cases, the record fails positively to show that
the wound was really inflicted by a spider, but that may be inferred.

An English gentleman records that while removing some old boxes
he felt a sharp nip in the hand between the fore finger and thumb, and
found a large spider fastened on his hand, which at first he could not
push off, as his fangs were fastened in the skin.
After killing the spider he found two small holes,
one twenty-fourth of an inch apart, filled with
blood. , There was a tingling sensation in the part
for eighteen hours afterward, with a tenderness in
the wound.!

It must be confessed that the experiments of
naturalists, as well as their observations, are un-
favorable to the popular belief in the dangerous
character of the spider’s stroke, except in the case
of the very large species, such as our American
tarantula. I can only say for myself, that having
handled thousands of living spiders, taking them
up with my fingers, and permitting them to crawl

* on hands or face, I have never experienced the
Fic. 253. The Saltigrade spider, : 6 0
Phidippus morsitans (Walck.), Slightest inconvenience, and have only been con-
ens OTS sciously bitten two or three times. Other than this,
if I have been pricked by the fangs, the wound has been so insignificant
as entirely to escape notice.

Yet the belief in the venomous, if not fatal, character of the spider's
stroke is so deeply rooted in the popular mind that it would be almost

impossible to eradicate it. The question arises, is not this

The Pop- general belief worthy of credence? If it were unsupported by
ular No- ¢ . . a Sik aq .
ee facts, I certainly should not hesitate to answer, no! ‘There is so

much ignorance, amounting even to absurdity, as to the danger-
ous character of many insects and other inferior animals, and ignorance
has so often shaded into superstition, that one is justified in holding even
a widespread popular opinion of no value until the contrary is demon-
strated. However, the problem is much confused by what appear to be

‘Science Gossip, page 165, 1868.

EFFECTS AND USES OF SPIDER POISON.

bo
~1
~J

authentic facts concerning wounds inflicted from time to time by certain
spiders. I have met many cases recorded in public prints, in magazines,
and personal letters. It is true that in most cases the testimony can
hardly be regarded as reliable. It amounts, usually, to this: That some

one was bitten by an insect, the result being either serious or
Indefinite fatal; that a “black spider” was seen somewhere near the in-
Testi- sees :
ie dividual, or near the couch or bed or seat upon which the

individual rested; that the said black spider (it is always a
“black spider,” with no further description) was immediately killed, and
therefore no specimen of the individual could be obtained. The indefinite
character of such testimony at once excludes it as evidence.

But cases somewhat better authenticated are also reported, several of
which appear to be worthy of credence. In these examples the same
“black spider” figures. But something more definite appears after a little
cross questioning; and it is important to note that in most of such cases
the testimony centres upon two spiders. One is a well known and widely
distributed Lineweaver, Latrodectus mactans, Walck. (the L. verecundum
of Hentz), and the other a large black Saltigrade spider which is proba-
bly Phidippus morsitans (Walck.).1. In most cases Latrodectus is the
offending party. Concerning this species there is a very general concensus
of popular feeling that it is extremely poisonous, and this feeling is found
not only among the colored people and others of the United States and the
West India Islands, but in communities in the old world where the genus
has representatives. The testimony above quoted concerning this aranead
certainly seems to justify the popular belief; yet the well known naturalist,
M. Lucas, as we have seen, was bitten by Latrodectus without the least
discomfort! (See Appendix for additional facts.)

EY.

Separate from the question as to the effect of spider venom upon the
human organization, is the question, what is its effect upon the natural
enemies and prey of the spider? One writer? says that five
or six flies which he fed to an Orbweaver, were trussed up suc-
cessively after having been apparently killed. After the lapse
of fifteen or thirty minutes, these began to revive, and before the hour
was completed, most of them had extricated themselves and got away. The
flies which recovered were the last ones thrown into the web.

Another observer? describes a conflict between a lineweaving spider
and a species of Epeira, in which the latter was wounded by the former,
the fangs being sunk into the leg, where the biter hung on like a bull dog.
From this moment, Epeira, though much larger, made no attempt to

Effects on
Insects.

The Attus audax and A. sexpunctatus of Hentz.
? Edward Sutton, “Science Gossip,” 1868, page 45. *“Science Gossip,” 1876, page 254.

278 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

retaliate upon its puny assailant, but commenced to pull with all its force
to liberate the imprisoned limb. This was accomplished after a few sec-
onds, when it hurried to its corner and began to work at the
Volun- wounded limb with its palpi, falces, and labium. At first he had
pat eal the impression that it was trying to suck the poison from the
" wound, but was surprised to see the spider pull the wounded
limb out of its socket and cast it away. On picking up the discarded leg,
a small globule of what seemed to be poison was seen glistening on the
place where the spider had fastened. This case of voluntary amputation
may have been caused by consciousness of the effect of the poison, but
just as likely by the hurt of the puncture and crushing alone.
Mr. Blackwall directed his attention to the effects of the poison of spi-
ders upon their own order. The following examples will show the unvary-
ing result of his investigations. A female Epeira diademata, in
Spider 4 violent struggle with a female Ccelotes saxatilus, pierced her

Venom : ; : :
Saas abdomen in the medial line of the dorsal region, about one-
Spiders. third of its length from the spinnerets. The wounded spider

did not exhibit any marked symptoms of distress, and speedily
resumed its accustomed habits. Two female Diadematas were engaged in
a severe contest, when one of them was seized by the fangs of her antag-
onist near the middle of the right side of the abdomen. A brown fluid
flowed from the punctures and soon coagulated. But the spider appeared
to be only slightly and very briefly affected by the injury. Another female
Diademata in a highly excited state bit itself near the middle of the fe-
mur of the left anterior leg. A transparent fluid flowed copiously from
the wounded part. Coagulation, however, quickly ensued, after which the
spider manifested no unfavorable symptom whatever.

A male Tegenaria civilis, in a violent struggle with a female of the
same species, deeply inserted his fangs near the middle of the dorsal region
of her abdomen, and retained his hold for several seconds.
Tegenaria From the punctures thus made a brown fluid issued copiously,
and . : E ele ;
1 cokat and in a few minutes coagulated. ‘The injured spider appeared
to suffer very little from the severe wounds it had received, as
it speedily constructed a small web in a phial in which it was confined, and
continued for more than a year to feed freely on the flies introduced to it.
A female Ciniflo atrox was bitten by an exasperated female Lycosa
agretica near the middle of the cephalothorax. The Lycosa retained its
hold for many seconds, and, on quitting it voluntarily, a transparent fluid
flowed from the punctures and coagulated. The wounded spider, appar-
ently regardless of the injury it had received, spun a web with which it
long continued to ensnare its victims. It thus appeared that the injuries
inflicted by spiders, in a number of genera and species, seem to exercise
no greater degree of influence upon other spiders than upon the human
species.

—_~

EFFECTS AND USES OF SPIDER POISON. 279

Mr. Blackwall then directed his attention to the effects of spider wounds
upon insects. His observations were made upon a number of genera of
spiders in their assaults upon such insects as wasps, bees, flies,
and grasshoppers. The result of these observations, which are
recorded in considerable number, is that all these insects sur-
vived after the infliction of the spider’s stroke for a period of time, in
some cases, as high as three days.

The experiments did not present any facts which appear to sanction
the opinion that insects are deprived of life much more quickly when
pierced by the fangs of spiders than when lacerated mechanically to an
equal extent by other means, regard being had in both cases to the vitality
of the part injured—a circumstance upon which the suddenness of death
largely depends. It is true that the catastrophe is greatly accelerated if
spiders maintain a protracted hold of their victims. But this result is
attributable to the extraction of their fluids, which are transmitted, by oft
repeated acts of deglutition, into the stomach.

Mr. Cambridge does not hesitate to say that the bite of a spider is
undoubtedly poisonous when inflicted upon its prey.t And he supposes
that at least one effect of the bite in most cases is to benumb or par-

alyze the insect, which, if not at once devoured, remains in a

Effects on
Insects.

Cam- state of insensibility, and is available as fresh food for some
bridge’s

ee hours and perhaps for several days. I do not know upon
Opinion.

what grounds this distinguished arachnologist bases this opinion,
as he gives no facts bearing upon the matter, and qualifies his opinion by
the word “probably.” Perhaps he has reasoned from the analogy of the
effect of a wasp’s sting upon a spider, which is precisely that which he
supposes to result to the victim of the spider’s bite. But analogy is not
argument, and while it may guide us to a safe conclusion, cannot be
received as a sufficient demonstration in a matter of this sort.

For myself, I may say that I have never seen a single case that would
justify Mr. Cambridge’s conclusion. It is undoubtedly difficult to make a
decisive observation, because in the case of Sedentary spiders, the habit of
swathing the prey in a thick shroud of white silk prevents one from ob-
serving whether the stroke of the spider’s fangs has produced any special
effect. This swathing is done so rapidly, and the limbs and wings of an
insect are so effectually wrapped up, that it needs no suggestion of par-
alyzing venom to account for the creature’s utter immobility. Moreover,
I have often seen insects struggling within their enswathment a_ little
while after they had been captured.

Nor is it the unvarying custom of Sedentary spiders to strike their
victims when they capture them. My observations convince me that the
stroke is perhaps more frequently omitted than given, the insect being

' Spiders of Dorset, Introduction, page xxy.

280 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

at once seized by the fore feet as it struggles in the web, swung around
towards the spinnerets, and wrapped up. It is only in the case of partic-

ularly large and formidable insects that the stroke is adminis-
Prey Not tered, and that after they have been partially disarmed by en-
Be swathment. In fact, I believe that Orbweavers, at least, are quite

chary about coming into such close quarters with large insects as
would permit the use of fangs. It is true, as I have fully illustrated, that
spiders do hang an enswathed victim to a portion of their snares that they
may feed upon it at their leisure; but even when immediately fed upon,
as is ordinarily the case, the same enswathment is practiced.

If we turn to the Wandering group of spiders, who stalk their prey, it
is doubtless true that when one springs upon its victim it often strikes it
with its fangs. But this is certainly not the universal practice, for I have
often observed insects simply seized by the feet and at once carried around
to the mouth and eaten without any more ceremony. This is commonly
the case with the large Mygalide from our Southwestern States kept by
me in artificial conditions. Grasshoppers fed to them, for example, are
generally struck down or seized with the fore feet without any application
of the fangs. Perhaps the superior vigor of the spider in this case renders
such action entirely unnecessary.

On the whole view of the subject I must say that I am in doubt as to
what special use the poison gland and apparatus can be to the spider in
ordinary cases, and am inclined to think that it is a sort of re-
serve weapon for special exigencies, and is sparingly used. It
appears to be unnecessary for ordinary purposes of capturing
food, especially with the Sedentary groups, but is apparently of greater im-
portance to the Wandering groups, who stalk their prey afield. Yet, even
in such cases, it would seem that the puncture of the fangs without any
poisonous injection is sufficient to fulfill every requirement for sustaining
and defending life.

Nevertheless, the fact remains that the spider is furnished with a poi-
son gland and apparatus somewhat resembling that of venomous serpents,

and I have too much confidence in the wise economy of force

A Reserve
Weapon.

Influence and material in nature, to suppose that so perfect an organ
of Physi- | ; : : ; sede
cal Con. Could be without some useful function in the life economy of

dition, the aranead. Reasoning from analogy of other venomous ani-

mals, serpents for example, it is probably true that much of the
effect of spider venom depends upon the condition of the spider itself as
to degree of irritation, etc., at the time when the stroke is given. On the
other hand, the physical condition of the person bitten also largely deter-
mines the effect of the bite. That which is harmless to one individual
we know is often injurious or fatal to another; and that which at one
period of life may produce serious results, at another time is compara-
tively harmless, It is therefore probably true that there are a few of our

EFFECTS AND USES OF SPIDER POISON. 281

indigenous spiders, as Latrodectus mactans and Phidippus morsitans, which
at certain times may inflict an injury upon certain individuals which may
be serious and even fatal. But in the great majority of cases, there is no
more, and indeed is less, reason to apprehend danger from a stroke or
bite of a spider than from the sting of a bee or probe of a mosquito,

In the case of the immense creatures (Mygalidz) known as tarantulas,
the matter, of course, is different. It would be strange, indeed, if such large
animals, with so formidable fangs and such a considerable sup-
ply of venom in the poison glands, should not be able to inflict
a serious wound. The cases which have been reported to me of
injury resulting from the stroke of these large spiders I consider sufficient
to establish this fact, and to warrant the general feeling that they are ani-
mals to be handled with great care. Yet even concerning them I must say
that I have never experienced much difficulty in capturing them, and, as a
rule, I believe they are more inclined to run away from man than to
attack him. Nevertheless, I have well authenticated instances of our south-
western Mygalide springing upon individuals, and even upon horses, when
specially irritated.

It is a common amusement (I have been informed) among the Texas
cowboys to set two Tarantulas to fighting. They surround the combatants
in a ring, after the fashion of frequenters of the cockpit, and freely bet
their money on one or the other. I have never heard of any injury
suffered by the managers of these aranead gladiatorial duels; and the
reports would seem to indicate that the big fellows are of rather a slug-
gish temperament.

The Ta-
rantula.

V.

It would be quite impossible, and indeed undesirable in a work of this
character, to enter at length upon the strange superstitions which have
grown up around belief in the fatal character of spider yenom.
The prejudice is a very ancient one. Diodorus Siculus records
that there borders upon the country of the Acridophagi a large
tract of land, rich in fair pastures, but desert and uninhabited. Afore-
time the region was inhabited, but there fell an immoderate rain, which
bred a vast host of spiders and scorpions. Whoever was bitten or stung
by these creatures immediately fell dead. The whole nation arose and at-
tempted to destroy these implacable enemies of their country, which so
rapidly increased that they threatened to depopulate the land. In point
of fact, they did this, for the inhabitants were unsuccessful in their war-
fare, and were forced to fly to another place. !

The supposed effects of the Italian tarantula are well known, and

Supersti-
tions.

' Diodorus Siculus, Book III., chapter 2. This wonderful story may also be found recorded
in Strabo’s Geography, Book XVL., chapter 6, section 13.

282 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

travelers in Italy, for a small sum, may see the “tarantula dance” executed
in the very best style, either with or without the original accessory of a spi-
der’s bite. The superstition is doubtless a very ancient one, prob-

Italian ably handed down from early Roman times. A species of Lycosa,
Tarantula |: : : :
Dance, Which takes its name from Tarentum, near which it was sup-

posed especially to abound, is the spider to which tradition as-
scribes the peculiar effects to be described. The modern scientific name
is Lycosa tarentula. When one is bitten by this spider, so the story goes,
at first the pain is scarcely felt; but a few hours after come on a violent
sickness, difficulty of breathing, fainting, and sometimes trembling. Then he
is seized with a sort of insanity. He weeps, he dances, he trembles, laughs,
cries, skips about, breaks forth into grotesque and unnatural gestures, as-
sumes the most extravagant postures, and, if he be not duly assisted and
relieved, after a few days of torment, will sometimes expire. If he sur-
vive, at the return of the season in which he was bitten, his madness
returns.

Some relief is found by divers antidotes, but the great specific is
music. At the sound of music the victim begins the peculiar movements
which are known as the “tarantula dance,’ and continues them while the
music continues, or until he breaks into a profuse perspiration which
forces out the venom. ‘Thereupon he sinks into a natural sleep from
which he awakes weakened, but recovered. Such in substance is the story
generally told, believed, and until comparatively modern times unquestioned,
which has found its way into the works of many travelers and natural-
ists of the earlier sort. It may be worth while to print an example of
these stories. Here is what one old writer has to say :—

“ Alexander Alexandrinus proceedeth farther, affirming that he beheld
one wounded by this Spider, to dance and leape about incessantly, and the
Musitians (finding themselves wearied) gave over playing: where-
upon, the poore offended dancer, hauing vtterly lost all his forces,
‘fell downe on the ground, as if he had bene dead. The Musi-
tians no sooner began to playe againe, but hee returned to himselfe, and
mounting vp vpon his feet, danced againe as lustily as formerly hee had
done, and so continued dancing still, til hee found the harme asswaged,
and himselfe entirely recovered. Heerunto he addeth, that when it hath
happened, that a man hath not beene thorowly cured by Musique in this
manner; within some short while after, hearing the sound of Instru-
ments, hee hath recouered footing againe, and bene enforced to hold on
dancing, and never to ceasse, till his perfect and absolute healing, which
(questionlesse) is admirable in nature.’’!

Goldsmith, who seems to have been well informed on this point, does

An An-
cient Tale

: Quoted from “ Treasurie of Ancient and Modern Times,” age 395 in Mr. Frank Cowan’s
o b]
“Curious Facts in the History of Insects.”

EFFECTS AND USES OF SPIDER POISON. 283

not hesitate to declare that the whole matter of the tarantula poison is
an imposition of the peasants upon travelers who happen to pass through
that part of the country, and who proffer then a trifle for suf-
fering themselves to be “bitten by the tarantula.” Whenever
the peasants find a tourist willing to try the experiment they
readily offer themselves. They are sure to counterfeit the whole train of
symptoms which music is supposed to move.!

It is not to be wondered at that notions such as these were formerly
fixed in the minds of common people, when we remember that it is but
a comparatively short period since learned men and physicians
were under the dominion of kindred errors as to the deadly
effects of spiders. Dr. James, in his Medical Dictionary, thinks
it worth while to give a number of examples of this sort. He tells seri-
ously of a woman who was possessed with a cruel passion for destroying
spiders by burning them in the flame of a candle, but who was cured by
a remedy quite as remarkable as the disease. One night while the perse-
cutor was destroying a large black spider it burst with a great crack, and
the animal fluids were thrown into her eyes and upon her lips. There-
upon she flung away her candle and cried for help, fancying herself killed
with the poison.

In the night the woman’s lips swelled excessively, and one of her eyes
was much inflamed. Her gums and tongue were affected, and a continual
vomiting attended. For several days she suffered the greatest pain, but
a cure was eventually effected with a preparation of plantain leaves and
cobwebs applied to the eyes, and taken inwardly two or three times a
day.2 It is a pity that people in this age of vaunted science and intelli-
gence, and who are not far removed from the folly and cruelty of this
woman, could not like her at least fall under the sway of a kindred fear,
and thus be moved to spare the unfortunate creatures whom they slay.

The same medical authority records that several monks in a monastery
in Florence are said to have died from the effects of drinking wine out of
a vessel in which there was afterwards found a drowned spider. One per-
haps might be persuaded that in those “good old days” even monks may
have been found who “died from the effects of drinking wine.” But modern
judgment would probably decide the aforesaid story of the spider’s fatal
offices a case of “post quod” rather than “ propter quod.”

These curious examples of intellectual bondage and credulity among
learned and unlearned alike might be greatly multiplied, and no doubt
would be interesting. But they belong to the natural history of man rather
than of the spider. Let us hope that the emancipation of our race from
all errors concerning spiders may soon be complete.

An Im-
position.

Credulous
Doctors.

1“ Goldsmith’s Animated Nature,’ Philadelphia edition, 1795, Vol. [V., page 153.
2A Medical Dictionary, by R. James, M. D., Lond., 1743, Vol. L., “Araneus.”

Citar a tik, Xv.

NESTING HABITS AND PROTECTIVE ARCHITECTURE OF
ORBWEAVERS.

THE spinningwork of spiders may be classified generally as, first, the
Snare, spun for the capture of prey; second, the Enswathment, by which
insects are disarmed and prepared for food; third, the Gossamer,
Forms of ysed for purposes of aqueous or aerial locomotion; fourth, the
Spinning- , : hie. : i 2
Eiteetily Cocoon, spun for the propagation and protection of the species ;
and, fifth, the Nest, which is a domicile more or less elaborate
and permanent within and under which the aranead dwells for protection
against the exigencies of weather and the assaults of enemies. It is not
implied by this classification
that a difference in quality
marks the material used in
spinning the above forms,
although to some extent
this is true. In point of
fact the silk used in all
modes of work is substan-
tially the same, and the dif-
erence in results is chiefly
one of quantity, condition,
color, and manner of appli-
sation. The present chap-
ter will describe that form
of industry which secures

for the orbweaving species

Fic. 254. Nest of Insular spider in clustered leaves of blackberry.

a domicile or temporary re-
treat, which is popularly known as a den, tent, or nest. This domicile is
usually wrought of clear spinningwork, or some adaptation of foliage.
One who studies these nests of rolled leaves and silken tubes must
often have suggested to him the habits and spinningwork of many larve
of true insects, particularly the Lepidoptera. It would almost
seem that one were marking a survival of manners which might
justly characterize the immature period of a race, while the race itself has

Analogy.

swept on to maturity. Thus, it is not in the function of spinning alone
that spiders raise a suggestion of the larve of insects.
Be
(284)

NESTING HABITS AND PROTECTIVE ARCHITECTURE. 285

ip

Among the Orbweavers the leaf rolling habit is perhaps most decided
in the Insular spider. She invariably domiciles upon shrubs, bushes, and
bushy trees, and commonly chooses a site within five to eight feet
Spectacle of the ground. Her tent is located always
ere above and gener ally to one side of her snare,
and is a series of leaves drawn together and
tied as at Fig. 254, or a sin gle leaf rolled up and tied
as at Fig. 255. The form of nest shown at Fig. 254
may perhaps be character ized as the cluster-leaf nest.
The leaves have been pulled down at the free ends and
fastened together by cross threads drawn over the ex-
ternal surfaces at the mar gins. The concavity within
which the spider dwells is frequently lined more or
less thickly with silken sheeting, which is heaviest
at the summit of the dome, against which the apex of
the abdomen rests, appar ently secured thereto by a
ray of threads adhering to the spinnerets.

The cluster-leaf nest sometimes takes the form
of Fig. 256. This was made in a clump of weeds and
tall grass, whose stalks, leaves, and blossoms
re ee were so woven to gether as to form the helmet

shaped or “ Lib erty Cap” domicile here
figured. The lower and open part of the tent was
quite delicately spun of lines that united and held
in place the graceful foli age of the grasses. Within
the crown of this dainty nest the spider was en-
sconced, holding by the fore feet to the taut trap-
line which joined the snare at the hub.

Another nest (Fig. 255) may be characterized as the
rolled-leaf nest. It is a large leaf folded over and

edges by overlaid lines. In

fastened at the
the example giv en (Fig. 255) the leaf was
between four and five inches long; the lower
and wider end opened toward the snare. About
two-thirds of the distance Pica Seactaie within the tent was a cur-
tain (Fig. 257) stretching from the floor to the roof
along one side of the den. The curtain was three-fourths of one inch
high, and one inch wide. Against this curtain the spider had pushed
the apical part of the abdomen. She was preying, when found, upon a
hornet (Vespa maculata), a very good proof of her vigor.

It sometimes happens that the single leaf within which the spider is
nested will be stayed by lashings which unite it to an adjoining leaf,

Rolled
Leaf Nest

Fic. 255. Folded leaf nest of

Fic. 256.

AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Nest of the Insular spider, woven with grasses and leaves. The spider’s
foot is shown outthrust from the nest and grasping the trapline.

NESTING HABITS AND PROTECTIVE ARCHITECTURE. 287

as in Fig. 258. Indeed, constant regard is had in the nest architecture
to the stability of the leafy domicile. Stay lines of various
lengths and thickness are thrown out to adjoining objects until
the nest hangs firmly poised, and is thus thoroughly inter-
woven with the spinningwork system of the occupant.

A third form of nest may be designated the woven leaf nest. It is
shown at Fig. 259, where it is seen to be a close textured silken bell,
woven between the needle like leaves of a pine tree. The mouth
opens downward and toward the snare. This silken tent does
not appear to be woven as closely as that often spun by the
Furrow Spider, but affords good protection to the inmate, and shows her
ability to deftly adapt her spinningwork to her environment.

These three forms of nest, tent, or den will be found to indicate, with
more or less accuracy, the spinningwork of Orbweavers, and, to some ex-
tent, of all the Sedentary spiders, as applied to arboreal nest architecture.
The terms cluster-leaf nest, rolled-leaf nest, and woven-leaf nest may there-
fore be used in the above sense, although without attempting to establish
anything like a rigid classification.

To these may be added a fourth type, the woven nest, which is well
illustrated by the close textured tubular den spun by Epeira strix and
Epeira sclopetaria against exposed parts of human habitations.
This form of nest is sometimes cylindrical, as with the nests
woven by Strix and Sclopetaria. This is composed of a close
textured sheet of spinningwork rolled as in Fig. 260, and stayed by guy
lines attached to various parts of the surrounding surfaces. Often the
nest is quite egg shaped. The spider inhabits this tube, having her face
toward the opening, and holding as usual to her trapline. Sometimes the
nest is simply a square patch of thick white silk stretched across an angle
or corner, open in the direction of the snare, and either open or closed at
the other end. Many nests of this sort have been seen on the verandah
of a gentleman’s cottage at Niantic, Connecticut, spun by Epeira patagiata
and E. sclopetaria. During the day the spiders keep closely to cover, and,
as the afternoon declines, creep out and weave their snares. They have a
weird look as they swing to and fro against the darkening sky.

Again, the woven nest is bell shaped, and open as with the tent of
Epeira domiciliorum (Fig. 261) when she chooses a similar site. The lower
part of this nest is spun of open linework, and is supported
by silken guys hung upon thick foundation lines or directly
attached to the surrounding surfaces. The upper part is closely
woven, and thus affords protection to the spider who rests within, and
particularly to the soft abdomen, which is the most vulnerable and_ least
defensible portion of the body, and which, as it occupies the topmost part
of the tent, is, of course, most protected from assaults of raiding Hymen-
optera.

Stability
of Nest.

Woven
Leaf Nest

W oven
Nest.

Domicile
Spider.

88 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Fic. 257.

Fic. 258.

Fic. 259.

Fig. 260. Fic. 261.

Fig, 257. The curtain or silken lining of the upper part of nest. 1G. 258. Nest lashed to an adjoin-
ing leaf. (Epeira insularis.) Fic. 259. Woven leaf nest of Insularis. Fic. 260. Tubular nest of
Epeira strix. I'1G, 261. Bell shaped nest of Epeira domiciliorum.

NESTING HABITS AND PROTECTIVE ARCHITECTURE. 289

a.

As a rule, the various groups of Orbweavers differ from each other and
agree within themselves in characteristic nest forms. The form prevailing
in each family is substantially the same; each species seems to
adhere quite steadily to one characteristic form; but there are
some marked variations in the habit of certain species, as in
the Insular spider, whose nest architecture we have seen is not
constant in form among the individuals of that
species. Indeed, the variation extends without a
doubt to the habits of the same individual under
different circumstances. This opens a most inter-
esting feature in the story of spider industry, which
may as well be kept in mind as we proceed with
the description of these nesting habits. It will be Fis. 262. Nest of Strix within
obyious that some of the variations are adaptations faa
to changed environment. Some of the most decided of these variations have
been observed in the nest architecture of Epeira strix. I observed two of
this species domiciled in the beautiful hedgerows of a New England meadow,
within nests of several rolled leaves, which had an inside lining quite like
that which is made by Insularis. Both nests were below the orb, one ten
inches below. The second example had for her nest a very bright red
rolled leaf with a tube inside of it, which made a strikingly pretty object.

The ordinary nest of Strix when domiciled in the open field or wood
is a rolled leaf. A single leaf is taken, the edge pulled up, drawn under,

and fastened by adhesive threads into a rude cylinder, within

Varia- which the spider hides during the daytime. (Fig. 262.) A
tions an : : a p : Sd
Meant: thread connection with the foundation lines of the snare is
tions. sometimes maintained; but rarely with the centre of the orb by
a taut trapline, as is the habit of the Insular spider. For this

reason I have often been greatly puzzled, and not infrequently foiled, in
searching for Strix in the neighborhood of her orb, which one comes at
last to recognize on sight with tolerable accuracy.
This severing or concealing of her trail threads is
undoubtedly a protection against raiding natural-
ists; but I cannot imagine any security which it
gives against natural enemies. This cylindrical nest
will often be spun within any convenient cavity, as,
Fic. 263. Nest of Strix within for example, a bit of curled birch bark, Fig. 263, a
urea specimen found on an island in St. Lawrence River.

A second form of the nest of Strix varies from the rolled leaf nest in
having the edges of the two adjacent leaves bent towards each other and
lashed together on the exterior at the juncture by silken cords, and on the
interior by adhesive tissue web. An oval opening is left at the united

Architec-
tural Va-
riations.

290 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

points of the leaves, through which the connecting line passes to the snare.
The spider domiciles within the leafy cavern thus formed.

Again, the spider avails herself of small holes in wood or stone, open-
ings in fences, the interspaces between curled bark on the trunk of old
trees, or some lke cavity, which she appropriates as a nesting place.
A slight lining will generally be found upon the concave surface. I have
noticed that in such cases the snare is sometimes diverted from its normal
shape in order to give a convenient approach thereto from the den. One
such example was found spun between a side of. the Peace Fountain in
Fairmount Park (Philadelphia) and a stone wall adjoining. In order to
pitch her tent within a hole in the rock, the spider diverted one of the
radii from the plane of the orb and extended it backward to the hole. The
spirals which passed over this radius thus made an elbow, which was
nearly a right angle, and gave the orb an odd, broken appearance. The
radius, of course, served as a bridge line by which Strix passed from her
den to her snare.

Another variation, or rather series of variations, was noted upon the
side of Brush Mountain at Bellwood, Pennsylvania. Several young pine
trees had been cut away and tossed from the mountain to a
bank of the Juniata River below. The foliage had withered and
fallen from the boughs, whose branches stretched out dry and
bare, and among them a colony of young Furrow spiders had pitched their
tents and spread their snares. One specimen happened to spin her web
near the axil of several goodly sized branches, which were formed into a
natural shelter by the inverted position of the bough. The spider had
recognized this vantage, and made her nest at the point of juncture, or
rather took shelter there, for there was little artificial nesting beyond a
faint tissue spread over the bark at the point where she sat.

A second specimen had lodged at a point near the tip of a small
branch, whose delicate, dry twigs gave no sufficient shelter, and, besides,
were directed upward. Accordingly, a silken tube, funnel shaped, was spun
between the twigs, within which young Strix nested. (Fig. 264.)

A third spider, lodged in a similar site, had made a silken sack for a tent,
whose mouth had apparently originally opened directly toward the snare.
But a Saltigrade spider had fastened a parasitic tubular nest upon one
side of this sack, and accordingly the mouth was found closed and the
door shifted to the opposite side, as though to avoid interference with a
troublesome neighbor. A fourth individual had woven a silken cover or
screen, behind which she lodged. <A fifth had pitched her tent upon a stray
leaf, beneath which a similar cover, a small rectangular piece of silk canvas
(suggestive of the military bivouac or “dog tent”), was stretched by lines
attached to the sides and corners, and fastened to the leaf surfaces and
surroundings. Between this sheet and leaf the spider was ensconced, hav-
ing the usual bridge line connection with the orb. (ig. 265.)

Shelter
Tent.

NESTING HABITS AND PROTECTIVE ARCHITECTURE. 291

Two of the above colony had established nests in tufts of a parasitic
moss fastened upon dead limbs. One of these was very pretty and ingen-
ious. The moss grew in a bunch about the size of a hickory

nut; this was pierced at the top, and the filaments
pushed aside sufficiently to allow an interior cavity
‘large enough to house a spider. An oval door or
opening was formed near the top by bending and binding
back the fibres of the plant. A secure and tasteful retreat
was thus obtained at the only really available spot in the
vicinity of the snare. (Fig. 266.)

When the Furrow spider weaves her orb upon the ex-
posed surfaces of human habitations, as the cornices of porch- yye, 264. Funnel
es, outhouses, etc., her nest takes a form quite different from shaped nest of
any above described. A tube of stiff, silken fibre is spun against ae
the surface, to which it is lashed at all sides. This cylinder is
about an inch long and half an inch thick, and at the end
toward the orb has a circular opening about a quarter of an
inch in diameter. (See Fig. 260.) The stiff texture of this nest appears
to be necessary to make the walls self supporting, inasmuch as there are
no supports like the twigs and _ leaves
found at hand in arboreal sites. Moreover,
the open position of the domicile exposes
the spider very freely to the assaults of
the mud daubers who frequent such |lo-
calities, to birds, and other enemies, so
that a canvas is needed of tougher text-
ure than that required in sheltered sites.
Nevertheless, it may be remarked that Strix will often
spin a quite close tube even within a rolled leaf of
two or three thicknesses.

In this summary of the nest architecture of the
Furrow spider it is manifest that while there is a gen-
eral regard to protection of the spider’s person, there

is a modification over quite a wide degree of

Tent in
the Moss

Tubular
Nest,

Fic. 265. Shelter tent of Epeira strix.

ae variation in the form of the protective nest.

en , : ae

ai Further, that this modification appears to be Fi. 266. Tent in the
: 7 Reertiugse all cscics - SS latte . moss. E. strix.

tation, leguiated, more or less, by the accidental en-

vironment of the domicile, and in such wise as to show no small
degree of intelligence in adapting the ordinary spinning habit to various
circumstances, and to economizing labor and material.

ges

One of the most interesting sights in the way of spinning industry
which it has been my privilege to see was observed upon a rocky hillside

292 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

in the neighborhood of Niantic Bay, Connecticut. The field had formerly
been a wooded slope, but all the timber had been cut away, and in its

stead an undergrowth of sumac, huckleberry, and laurel well
A Fair nigh covered the surface. The characteristic stone fences of New

ider . c
eee England marked the margins of the slope, along which clumps
ent. of ferns, golden rod, raspberry vines, and various other wild

plants were thickly aligned. Standing upen the crest of the
hill, one could see in the <distance the shimmering waters of the bay
melting into the ocean beyond, covered with the white sails of passing
ships. The permanent abodes and summer habitations of human beings
were scattered along the crescent lines of the beach. The river wound in
sinuous course at the foot of the hill, and emptied into the bay a mile or
two beyond.

The scene was a beautiful setting for a picture that warmed the heart
of an arachnologist. For all over these bushes that covered the rocky
slope was encamped an innumerable host of spiders of various species. It
has never been my privilege to see so many and such fine examples of the
order established within so limited a space. The largest and most beau-
tiful of our indigenous fauna were there represented in vast numbers.
Argiope cophinaria hung in the centre of her white shield, which with its
zigzag cords above and below glistened in the sunlight and marked dis-
tinctly the habitation of its proprietor. The black and yellow of the im-
mensely distended abdomen (for the time of ovipositing was near) and the
mingled black and brown of the outstretched legs showed in striking con-
trast against the pure white silken shield.

Here and there one noted the orbs of our other species of Argiope (A.
argyraspis), whose web scarcely differs from her congener, but whose abdo-
men of glittering silver, crossed with lines of black and yellow, at once
mark her as peculiar and exceeding in beauty among the tribes of
Arachne. Here a delicate snare of the Hunchback spider, Epeira gib-
berosa, hung among the laurels, the bright green of the aranead herself,
as she swung beneath the hub of her snare, scarcely distinguished against
the background of the leaves over which it was extended.

If one reached out a hand to this side or that, he could touch the
beautiful orbs of two of our most persistent nest building species; but the

spiders themselves were not in sight, and their great round
Tent , snares seemed deserted. They hung to thick threads of yellow
a silk, constituting the upper foundation lne, thicker than an or-

dinary pack thread, of a glossy yellow color, and stretched some-
times three feet, four feet, six feet, eight feet from point to point in the
midst of the open spaces between bush and bush. Where are the occu-
pants of these empty webs? What destroyer has been abroad that so
many of them should stand deserted at this evening hour?

Lay your hand upon this trapline, fastened to the centre of the orb,

NESTING HABITS

AND PROTECTIVE ARCHITECTURE.

Ad
yy NG
aR R

Ae
7

ea Met

Various Nests of the Shamrock Spider.

294 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

holding every radius taut, though slightly bagging at the hub. Carry
the finger outward to this clump of bushes. What is this? A nest! The
leaves have been spun together deftly until they make a beautiful cap
shaped or helmet shaped habitation, within which, if you will take the
pains to stoop a little, you may see the goodly proportions and the fair
colors of the Insular or the Shamrock spider. These nests are built on
every side, and vary in their forms according to the character of the
plant of whose leaves they have been constructed.

The closing days of August have already begun to tint some of the
bushes. These sumacs have assumed their party colors of red and crim-
son and brown, so that our aranead dwells within a_ habita-
tion of divers hues like the tabernacle in which ancient Israel
worshiped. Of course, the spider had no part in the selection
of these varied colors for her tent, and has no share in the enjoyment
of the discoverer who notes the pretty effect it has on her domicile.
Nevertheless, it adds to the pleasure of the scene, and helps to impress the
observer with a sense of the fitness of all the surroundings not only, but
of these industrious creatures in the midst of their surroundings.

I had never thought it possible that by any combination of favoring
circumstances so many of these handsome spiders could have been _pre-
served in so limited a space. But here everything appears to
have united to protect them from their natural enemies. These
bushes are just the sites in which spiders love to spin. This
slope, with its sunny outlook towards the east and south, has protected
from winter chill the eggs within cocoons, and warmed them into life
when springtime came. With them have come also swarms of the insects
which form their natural food. The place, too, is a lonely one as far
as man is concerned; for, besides the farmer’s occasional visits, only now
and then a straggler, or a lover of fields like myself, happens along. A
cow or two may sometimes feed here and pick up the bits of pasture that
grow between clumps of bushes and outcropping boulders of granite. Here,
too, come, in the summer season, the women and children to gather huckle-
berries. But the very vision of the many spider webs, and particularly of
the great Argiope swinging at the centre of her hub, is enough to cause
them to shy away and leave unplucked the tempting clusters of berries
that hang around the dreaded snare.

Other than these, few visitors come to the spot; and thus, largely de-
livered from destructive enemies, warmed and cheered into life by the
favoring slope, with abundant provision for spinning sites that give good
and easy access to the low flying insects which supply Arachne’s larder,
these creatures live and feed and grow and prosecute their loves, their
wars, their maternal duties and cares, and die amidst the glowing foliage
of autumn, having fulfilled as happy a destiny as one could reasonably
hope for a child of the spider world,

Tinted
Nests.

A Spider
Paradise.

NESTING HABITS AND PROTECTIVE ARCHITECTURE. 295

In the neighborhood of Philadelphia the Shamrock spider is somewhat
rare, but here her huge orbicular snare is hung on every bush.

Sham- Without passing the limits of a single field I could collect hun-
es dreds of specimens of females, whose large, rounded abdomens
show that they are approaching the crisis period of motherhood.

During the entire day, with rare exception, these araneads keep them-
selves closely to their nests, leaving them only in the late evening hours
to station themselves at the centre of their orbs for the more convenient
trapping of prey. The nests are in most respects well suited as a domi-
cile for the occupants. They vary in style and proportion according to
the character of the plants upon which they are spun. Often they consist
of a single leaf, in which case the edges of the leaf will be brought together
and fastened close to the stem. The lobes of the leaf also, as far as prac-
ticable, will be joined in the same manner, but with a wider interval be-
tween the tips, the interspace being spanned by threads or by a thin tissue
of spinningwork.

The laurel is a strong, tough leaf, yet even that will be rolled and sewed
together by this spider’s art. (Fig. 267.) Sometimes, as though to save the
effort required for the bending of such stiff material, several
laurel leaves will be adjusted in a manner somewhat peculiar.
One leaf will be selected as the roof, and without being curled
will be fastened across the edges of two other leaves, which have been so
disposed that they stand with their flat surfaces almost upright. Thus
both roof and sides are flat, as though they had been built of inelastic
boards, and within this cubical refuge the spider fixes her home. On the
sumac plant, whose leaves are lanceolate and very pliable, a number of
leaves are chosen, and these are overlapped and the tips bent downward
until they form a wigwam, within which the spider dwells. (Fig. 268.)
Its blossoms also (Fig. 269) are pressed and spun into nests.

Here, again, in this natural fernery, which straggles along the borders
of the stone fence, one has a good opportunity to select nests that are
strikingly beautiful in form. The delicate tips of the ferns,
sometimes one spray, sometimes more, are drawn together, over-
laid and interlashed, until a domicile is constructed that might
attract even the Queen of the Fairies to fix her palace therein. (Figs.
270, 271.) Hard by, a neighbor Trifolium is ensconced beneath a bower
of rich brown blackberry leaves. (Fig. 272.) Thus, it will be observed that
the spiders have wrought upon their material as practical architects, adapt-
ing methods and accommodating plans to the quality of their material.

The nest of the Insular spider differs very little from her congener
Among these bushes scattered over the rocky slope she pitches her tent
and makes her home side by side with the Shamrock spider. Perhaps, if
I were asked to name a distinction, I would say that Insularis is rather
more fond of an open wooded location than Trifolium, and is somewhat

Nests in
Laurel.

Fern
Nests.

296 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

more inclined to select a loftier site for her habitation. For example,
let us climb these bars into the adjoining woodland and walk along the
wagon trail, which is absolutely embowered by the young over-

eae of hanging trees. We find on all sides large, round webs, swung
nsular : ;

: to long foundation lines that stretch from the lower branches of
Spider. 8

the trees to the ground, or to the low undergrowth. Long trap-
lines extend upward to a leafy cell, within which one can see the orange
and yellow colors of Insularis, as she crouches, with legs drawn up
around her face, against the upholstered end of her chamber. The great
leaf of the young hickory, or the long, palm shaped leaf of the oak,
are often chosen by this spider, and they make a roomy dwelling place.

On a closing day of August one sees hanging near by the nest of the
female Insularis another curled leaf, not quite so artistic and complete,
perhaps, but showing the outward signs of a spider habitation. Turning
back the tip he sees a male Insularis who has come a-courting,
and he has pitched his tent as near that of his lady love as
circumstances seem to allow. He is not the only lover on the premises,
however, for on the opposite side of my lady’s bower is another courtier ;
and just below, swinging to some straggling ratlins stretched against the
stem, a third attendant is found. These are the days of mating, with all
their joys and sorrows, their successes, and their perils. Yes, perils I must
say, for twice to-day, at least, I have seen the unfortunate gallant rolled
up within silken swathing, dangling at the jaws of his lady love, who thus
proved how greatly she liked him, after the shocking fashion of the canni-
bal islanders.

Let us pluck one of these Trifolium nests, that we may examine its in-
terior. This requires a little care, for the tips and other parts of the leaves
are so stayed by numerous lines, radiating to this side and to that, flaring
downward, and attached to the upper foundation cable of the snare as well
as to adjoining foliage, that, if one is not careful to chp the threads all
around the leaf, it will be torn as he draws it away from the stem. The
nest, of course, is always open downward, never upward, always facing the
centre of the orb, so that the trapline can pass directly out of the nest
to the hub. No obstruction, therefore, is permitted at the door of the
tent, or, if one so please to phrase it, at the mouth of the den. But the
opposite end is always closed, usually by a thick curtain of silk which en-
tirely shields the abdomen, and makes a comfortable resting place for that
part of the body. All around the sides of this end of the chamber one
sees, especially if the nest has been occupied several days, little white
patches of thickened silk, which show where the spinnerets of the spi-
der have attached the dragline which it is the invariable habit of the
species to use as an anchorage whenever it moves. These little white
spots, scattered all around the inner surface of the cell, and showing with-
in the lighter silken lining of the leaf, have a very pretty effect, and one

Courting.

NESTING HABITS AND PROTECTIVE ARCHITECTURE. 297

might think at the first glance that they had been thus distributed with
esthetic intent. They are, however, simply the result of accident, caused
by the restless movements of the spider around and around her room, and
by the habit just alluded to. Out of the front door stretches the trapline,
to which the fore claws of the spider are clasped; and towards the back
part of the room, fastened to the spinnerets and probably clasped occa-
sionally by the hind feet, there is another line which anchors the spider
to her nest. Thus, both fore and aft, this truly domestic creature has
strong attachments to her home.

In order to test the ability of Insularis to adapt her nesting habits to
change of plant environment, I selected several that had made nests in

several leaves of oak and in clustered leaves of sumac. These
Adapta- [| transferred to some coniferous trees (spruce) standing upon a
tions of jawn. The spiders proved themsely tent t et th
Nesting (@¥2 piders prove ves competent to meet the
Sanit. emergency. Their first movement

was to station themselves beneath
the branches of the pine, and in the course
of time they chose themselves a site at the :s
points where several twigs united. It was ¥
impossible, of course, to treat the situa-
tion after the fashion to which they were
bred among the clumps of huckleberry and
sumac bushes, or in the grove of young
oaks. The needle like leaves of the pine
would permit of no such treatment, but it
was not long before the upholstering art of
the spider had overcome the difficulty, lashed pre. 273. adapted Nest of Insular Spider.
the prickly leaves into some respectable sem-
blance of smoothness, and covered them all over with silken tapestry.
Finally, a hemispherical nest was placed within the joints, partly pro-
tected on three sides by the twigs, and at the exposed points spun of such
close tissues that it formed ample protection. In this particular the plh-
ability of the spider’s architectural instinct was fully demonstrated.

I have repeated the experiment many times, and always found that
these two nest making species when transferred from one plant to another,
no matter how different the foliage may be, as in the above cases, are able
completely to adapt themselves to the new circumstances and spin a habit-
able home. (Fig. 273.)

In the Domicile spider the habit of leaf tenting is not quite so firmly
fixed as in the above species. She often builds a leaf nest which does
not differ from those of her congeners already described, but I
have frequently found her without any such domicile. In Wood-
land Cemetery (Philadelphia) are great numbers of this species,
who find a favorite web site in the interspaces of a barbed iron fence. Very

Domicile
Spider.

298 ‘AMERICAN SPIDERS AND THEIR SPINNINGWORK.

many dried leaves are seen in late summer, pierced by and clinging to the
barbs, and within these the spiders establish a congenial but not very
artistic domicile. (Fig. 274.) Others have a rude nest of rubbish at one
side, under the sheltered parts of the fence. From these dens several trap-
lines, in an irregular series, frequently stretch to the orb centre. Like In-
sularis she also spins a bell shaped tent when a suitable arboreal shelter
is not convenient to her site. Indeed, her habit in this respect appears
to form (if one might so say) a connecting link between the confirmed
leaf nesting behavior of Insularis,
whom I have never seen without a
leaf nest, and the habit of those spe-
cies that persistently occupy snares and
have no tented retreat.

I have always found Epeira trivit-
tata upon a vertical web, with a
meshed hub and the usual charac-
teristics of Epeira strix and that group of Orbweavers. I do not remember
to have seen her dwelling in a nest of a very perfect character,
but she makes a simple shelter at the side of her orb, in which
she spends part of her time. One female (Massachusetts) was
seen hanging in a sprig of golden rod at one side of her snare, having
several lines extending therefrom to the web. (Fig. 275.) Another was
resting, with her back upward, in a little nest in the leaves of an adjoining
golden rod plant. A series of slight irregular lines connected the hub with
the stem of the bush on which the orb was spun.
Trivittata! is closely related to Domiciliorum in gen-
eral structure and habit. This spider is distributed
throughout the larger part of the United States, its
locality having been determined from New England
to Wisconsin, and from Florida to Texas and Cali-
fornia.

A quite persistent nest maker is Epeira verte-
brata,? a spider which is naturally grouped with the
last named. I have received numerous specimens from

the Pacific coast, and from cocoons sent me by Mrs. Rosa Smith

FIG. 274. Nest of Domicile spider in dried leaf.

Epeira
trivittata.

Fic. 275. Shelter nest of
Epeira trivittata.

een Eigenmann (San Diego) have raised a number of specimens upon
a 1 ‘ 1 ¢ rs r Leta a 5 ‘ TAd
ae vines In my manse yard. These all made nests of rolled leaves,

but they are evidently not as persistent and artistic nest builders

ee
as Trifolium and Insularis. Early in the afternoon they would make snares,
and usually wait at the hub for prey, instead of watching from their den.

‘KK. arabesca, Walck., Nat. Hist. Aptéres, Vol. II., page 74. E. trivittata, Keyserling
Sitzungsberichte der Isis, 1863.

* McCook, “ Descriptive Notes of New American Species of Orbweaying Spiders.” Pro-
ceed. Acad. Nat. Sci., Philadelphia, 1868, page 196.

NESTING HABITS AND PROTECTIVE ARCHITECTURE. 299

The nesting habits of all the Angulata group of Epeira known to me
are like those of the Insular and Shamrock spiders. I have always found
Epeira bicentennaria and E. sylvatica within rolled leaf nests

The Bt precisely resembling those heretofore described and figured. This
= ee group is distributed over the entire continent, and may be dis-

tinguished by two conical processes, more or less prominent, one
on each side of the anterior part of the abdomen. The Diadem spider,
the well known Epeira diademata of Europe, heads the group, and may
have been an importation in the vast trains of human emigrants who
have sought our shores. The far western Epeira gemma, and Epeira
cinerea well scattered over the Northeast, belong to the same group. All
have probably the same nesting habits, and are closely related structurally.
The brief descriptions of the nests of Epeira diademata, quadrata,
apoclisa, and other European and exotic species made by Blackwall,
Menge, and Walckenaer, for example, permit us to assert their
identity in nesting habit with American species. It will proba-
bly be found that this characteristic is cosmopolitan, and that
all nest making species of Orbweavers throughout the world have sub-
stantially the same architectural methods within affiliated groups, and
that their tents, dens, domiciles, or nests closely resemble each other, the
variations depending largely upon the nesting site and the material avail-
able for manipulation and underspinning.

Unity of
Habit.

Ly.

It is difficult to observe all the steps in the construction of a leaf
nest, inasmuch as the process is not continuous from beginning to com-
pletion, but is gradual and accumulative. There is certainly a
How difference in this respect; some species, like Insularis, having a
Nests are ; Ge : :
Built. stronger disposition to provide a well protected nest from the
outstart of any settlement in a new site. But many spiders con-
tent themselves with a comparatively rude shelter at first, and, as occasion
or disposition may prompt, proceed to add to their domicile.
At one time the leaf or leaves will be drawn closer together; at an-
other, the roof will be overspun with fresh silk; again, the supporting
lines will be strengthened, and the silken approaches extended,
ae or the outlying warp receive additional woof, so closing up the
Gradua], Walls of the tent. Thus the nest is likely to be perfect in pro-
portion to the time that the occupant has been upon the prem-
ises. In the intervals of trapping, eating, and snare spinning, the aranead
architect occupies herself in adding to her house and perfecting its ap-
pointments.
Nevertheless, one may have opportunities for seeing the spider’s archi-
tectural methods, and by piecing together various observations can know
the entire process. I have been favored with several views of the various

300 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

stages of the work, and therefore proceed to record my observations. A
typical example of methods was given by a female Domicile spider.
The first foundation line of her orb was already stretched when
I began the observation. She passed over this once or twice,
and then, without waiting to spin an orbweb, near one of the
extremities began preparing a nesting place from two leaves of the honey-
suckle vine upon which she was located. When the work commenced
the leaves presented the appearance of Fig. 276. The first steps consisted
in stringing a number of lines (L L) between the inner surfaces of the
two leaves, at the upper part thereof. This work was done rather
slowly, the spider striding across from one leaf to the other until a little
maze of lines was thus formed between the inner surfaces. Any pressure
upon these lines, in the way of tightening or
shortening them, tended to approximate the tops
of the leaves. The next step consisted in at-
taching a line (A, B) to the edge of one of the
leaves near the tip. Striding across to the other
leaf, dragging out the line after her, the spider
threw the legs on one side of her body around
the outer surface of the leaf, then attached the
line and began slowly to shorten it.
This movement, of course, drew the
tips of the two leaves towards each
other. The edges of the leaves on the oppo-
site sides were treated in the same manner.
Thus, by fixing a line to one leaf and pulling
i the opposite leaf towards this point, and then
Fic. 276. Process of nest making; attaching thereto the other extremity of the
eee ee line, the leaves were approximated, as indi-
tips after lines A, B, etc., are cated by the dotted lines X X, and the prepar-
ea atory stages of a nest accomplished. When
the nest was completed it presented the appearance of Fig. 277.

The spider stayed in this nest for several days without making any
marked additions to it, which was due, perhaps, to the fact that heavy
rains were falling most of the time. After this work of nest construc-
tion was over, she dropped from the projecting stem of the leaves by a
dragline, threw out a swinging basket, and issued a thread from her spin-
nerets, apparently with a view to seeking a foundation. This thread at-
tached itself to the vine at an opposite point about a foot distant, but for
some reason was in a little while loosened and floated away before the
spider crossed over and strengthened it. At this point I was compelled to
cease observation.

First
Stages.

Joining
Edges.

A half grown Insular spider colonized upon an arbor afforded another
opportunity to note the first stages in nest building. After she had been

NESTING HABITS AND PROTECTIVE ARCHITECTURE. 301

placed upon the vines, she spent a considerable length of time in wan-
dering back and forward over the leaves, climbing upward all the while,
never downward, which may be said to be a common habit of

Begin- spiders under such circumstances. Finally, she reached a spot
ning a é
et well to the top of the vine covered arbor, which seemed to suit

her. Several leaves, closely clustered together, drooped over in
such a way as to form a natural shelter, and underneath these the spider
began arranging her tent. She passed backward and forward under the
surfaces of the several leaves in the cluster, stretching lines from one to
the other in the manner already described. Her motions seemed to be
really aimless. She appeared to be guided by no special principle in ex-
tending any single thread, and it was difficult to observe what bearing her
work might have upon the end manifestly in view. After a long time
spent in this kind of spinning, a confused mass
of lines was left upon the upper part of the in-
ner surfaces of the clustered leaves.

In the meantime, however, the process had
evidently drawn the leaves somewhat together, at /7
least had compacted them into a closer cluster, // /
holding one against the other so tightly that Lit
they were not separated by the currents of wind. {
The spider then placed the end of her body, the \//
abdomen, against this maze of threads. The de-
tails of her behavior thereafter were not accu-
rately marked, but the substance of her method
appeared to be as follows: she pushed against
the lines with her abdomen, moving the spin-
nerets back and forward at the same time, until
a slight concavity was formed, and the mass be- F's. 277. Last stages of nest
gan to assume the shape of an inverted bowl. aa
The same movements that produced this effect, by pulling upon and tight-
ening the weft, drew the leaves still more closely together, and forced them
into the shape of the clustered leaf nest represented at Fig. 254.

From this shelter the spider departed, and proceeded to spin her orbic-
ular snare, carrying her trapline into her den, from which she awaited,
as usual, the trapping of her prey. In the course of time, had
the spider not been disturbed, the mass of crossed lines would
have been reduced to a texture of close white silk, and the whole
would haye been moulded into a dome like tent as a lining to the inner
surface of the leaves. Further on, the margins of this lining would have
been stretched out towards the tips of the leaves, the edges of the leaves
would have been agglutinated or sewed in the manner above described,
and thus the nest would have been completed.

An interesting illustration of the method of sewing was given by a

Uphol-
stery.

302 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

large Epeira insularis, whose nest I had opened by breaking the threads
near the lower margin. ‘The inmate reached her claws over the upper
edge of the leaf, pulled it downward toward the lower edge, and, while
holding the two edges together, elevated the spinnerets, and threw out a
ray of threads, which immediately adhered to and cemented them together.
The process is not really a “sewing,” as it is popularly called, at least in
the sense that the leaf is perforated and the thread drawn through the
holes. That word, however, is the best that we have, and, perhaps, suffi-
ciently characterizes this behavior.

The fastenings are evidently made in part, at times, from without, as
the threads show application to the outer surface of the leaf. This spin-
ningwork is well shown at Figs. 254 and 255, in which cases the
spider has crawled over the outside of the leaves, swinging her
abdomen alternately from one side to the other, touching the
spinners to the surface at each movement. Again, the nest presents the ap-
pearance of having been sewed from within in the same manner. In such
cases the spider evidently applies the liquid silk to the tangent or ap-
proached edges of the leaf, which, when released from the pressure of the
spider’s claw, spring back and stretch out the thread, leaving an open seam
across which the lines run. Sometimes this seam is subsequently entirely
closed. The character of the sewing of this and other Orbweavers is shown
at Fig. 255, into which the threads have been drawn very accurately from
the natural specimen. The sewing habit obtains among the nest makers of
all tribes, and the mechanical methods are in all quite identical with those
of the Orbweavers as above described.

Passing now from the spiders whose snares are full orbed, we find the
nest making habit existing, with some modifications, among the smaller

group that weave a sectoral orb. Of these the most numerously
Zilla : represented in species is the genus Zilla; her nest is sometimes
Nest of ; ;
ent simply a rude den of netted lines, so arranged as to leave a
concavity in the centre of the mass sufficient to shelter the spi-
der. The young Zillas quite invariably weave such a shelter tent when
they first set up housekeeping. (See Fig. 1388, Chapter VIII.)

Among the adults of the genus the dome shaped silken tent, such as
has already been described (Fig. 261), is very common. ‘This tent is swung
in various positions, according to the location of the spider, and
may or may not have a screen of tented leaves. At other times,
as I have often seen with Zilla x-notata, in New England, the
shelter is spun underneath leaves, and occasionally the leaves are used as
a protection, without a very decided woven tent. On the whole, my obser-
vations of the habit of Zilla show that it is not strongly inclined to avail
itself of the protection of leaves in the manner of Epeira trifolium and
others of that group. However, it occupies its home, and uses its trap-
line in the manner of the nest making Epeiroids.

Mode of
Sewing.

Domed
Tent.

9

NESTING HABITS AND PROTECTIVE ARCHITECTURE. 303

Closely related to Zilla in the character of its snare is Epeira thaddeus,
but in this species the nest making habit appears to be more strongly de-
veloped. It may often be found nestéd in the angle of a door
Nest of or window, or other like situation,
Epeira
Se Pe the outhouses of farms and
rural buildings. Here it spins a
white silken tube of close texture, which is
generally a quite exact cylinder. In this
respect it differs from the nests of Zilla and
Epeira triaranea, which are almost habitually
in the shape of an inverted bowl or dome.
The cylindrical tent of Thaddeus varies in
length from three-fourths of an inch to one
and one-quarter inch, the latter being the
length of the nest represented at Fig. 278.
The cylinder is stayed by a series of lines
attached to it at various parts and stretched
to numerous points in the surrounding sur-
face, thus holding it intact. Within the cylinder Thaddeus sits holding
her trapline, through which all agitation upon her sectoral orb is com-
municated,

She has learned, however, the value of screening her cylindrical tent
beneath a shelter of clustered leaves, as at Fig. 280. In this case the leaves
are agglutinated by threads spun upon the inside or sewed upon the out-
side, precisely as in the case of the Insular and Shamrock spiders.

I have found this cylindrical nest spun within the needle like leaves
of the pine tree, and the manner in which it was stayed, and preserved in
sufficiently rigid attitude for the practical uses of its occupant, was a good
example of the ingenuity of this species. (Fig. 279.) Im the above ex-
amples the nest is visible by the observer, but at other times it is wholly

Fic. 278. Cylindrical nest of Epeira thad-
deus, spun in the angle of a door.

screened from view, being spun beneath and within the concave surfaces
of two attached leaves whose edges have
been sewed together, and the entire shelter
stayed by means of lines stretched to ad-
joining leaves and the common stem. If
the stay threads be cut and the leaf turned
back,
side as represented at Fig. 280.

FIG. 279. Cylindrical nest of Thaddeus in Again the eylindrical tent of Thaddeus
pine leaves. in

the cylindrical nest will be seen in-

will be woven underneath a cluster of sev-
eral leaves (Fig. 281), which overarch it like a rounded roof, making a
pretty and effective shelter. Beneath this dome the silken cylinder may
be seen projecting, the external end stayed by lines fastened to adjoining
leaves, and the trapline stretched out taut to the centre, or the sectoral

304 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

snare hung among the foliage underneath. One would certainly think
that a spider thus domiciled has secured for herself the highest attainable
security and comfort within the compass of aranead nidification. At other
times her den will be found within the point of a single leaf, which has
been curled over and sewed together.

Tt will thus be seen that the nesting habit of Thaddeus is closely re-
lated to that of the group represented by Insularis and Trifolium, the
principal difference being, that in the last named species the silken part
of the structure seems to be rather the lining, while in the former the
silken tent is quite distinct and the leaf shelter appears to be rather a
secondary matter. At all events, no matter how complete may be the
security afforded by the clustered leaves
or rolled leaves, the cylindrical tent of
Thaddeus may nearly always be found
entire, and in a well secured retreat.

In the case of Triaranea the use of
the leaf in nidification is extremely
rare. Such, at least, is the
result of my own observa-
tions, although I should not
be at all surprised to find that in
other geographical provinces the spider
may be found to resort to the aid of
leaves and other material quite as free-
ly as some of her cogeners. Neverthe-
less, it is probable that the maze of
netted lines within which she swings
her bell shaped tent answers all the
Fic. 280. Nest of Epeira thaddeus within leaves. purposes of a leafy protection, and

The tube is shown uncovered atthe upper right 949 long as her home is protected by
meg eS es such an environment she will be less
likely to resort to the additional protection of leaves.

Be that as it may, her home is a silken dome, swung within a mass of
netted lines supported upon the foliage of trees, or stayed upon the sur-
rounding surfaces of her nest site. It is open downward toward the orb,
to which the home is connected by the ordinary trapline. ‘The mass ex-
tends well below the mouth of the tent, and a little free space is usually
left between the maze and the orb. Sometimes the tent is decidedly bell
shaped, widest at the mouth, and is much larger than the occupant herself,
as at Fig. 282. Again, I have seen a tubular passage way or vestibule ex-
tending from the mouth of the nest entirely through the length of the
maze, thus affording a sheltered passage for the spider along her trapline,
well nigh to the point of approach to the orb at its hub. (See Chapter
VIIL, Figs. 123, 182.) It often happens that Triaranea selects a site that

Nest of
Triaranea

NESTING HABITS AND PROTECTIVE ARCHITECTURE.

305

enables her to dispense with much of her shelter.
Niantic Bay (Connecticut) and Cape Ann (Massachusetts) many of this

species are domiciled. They spin
their nest upward against the
boulders built into the wall, and
avail themselves of the little cay-
ities and rugosities therein, Thus
sheltered above and from within
they need less protection, and ac-
cordingly their silken tents are
generally very scant and = rudi-

mentary. .
Closely related to Triaranea in
the character of her nidification
is the Labyrinth spider,

Laby- = one of the most inter-
rinth : f ee
Suafor's esting of our indige-
Nest. nous fauna. Labyrin-
thea weaves a_ silken

dome, hung within a maze of
crossed lines, precisely like that of
Triaranea. I have marked a dif-
ference in the character of the
trapline, which seems to consist
of a number of threads more
commonly than in the case of

In stone walls along

AX
Wi

Fic. 281. Cylindrical nest of Epeira thaddeus woven
beneath a tent of clustered leaves.

Triaranea.

s

Fic. 282. The bell shaped silken
nest of Epeira triaranea. m,
the retitelarian mass; T, trap-
line.

There is one feature,

however, which seems to be peculiar to this species.

Within the midst of her maze will almost al-
ways be found a dry leaf; and underneath this
the spider rests, sometimes without much inter-
posed spinningwork, but at other times within
the ordinary silken dome. (See Chapter VIII.
Fig. 114.) The leaf may frequently fall within
her retitelarian snare, and probably is not, as a
rule, brought there by the action of the spider,
although I cannot affirm this. But it is certain
that, the leaf being within her maze, she does
draw it to some central place and cluster the
netted lines around it as a central point, and
then establishes herself beneath the leaf, against
which, in the course of time, she proceeds to abut
the summit of her silken dome. (Fig. 283.) She

has thus secured additional protection from assaults made from above.

306 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

In some cases the concavities of the leaf are utilized, and the spider,
creeping within them, finds an additional shelter, and makes such con-
cavities the site for the location of her silken dome.
(Figs. 284, 285.) Labyrinthea is able to avail her-
self of other roofing material than a leaf,
for I have more than once found her snare
in the pine forests of New Jersey, having
in the centre of the maze a mass of miscellaneous
material, such as fine sawdust, or the castings of
moth larvee, or drifted rubbish of various sorts, which
had probably fallen upon the tangle of crossed lines,
and had been gathered by the occupant into a mass,
which, being agglutinated
by the viscid threads, was
finally shaped into a solid
shelter, beneath which the
spider rested and eventu-
| ally constructed her silken

Fic. 283. Leaf roofed dome of dome.
the Labyrinth spider.

Leafy
Roof.

Labyrinthea is a most
persistent dweller within her domicile. I think
the female rarely leaves the confines of her web,
limiting her life to living within her tent, spin-
ning her orb and trapping flies upon it, and wan-
dering back and forward in various duties of house-
keeping and house repairing through her retite-
larian maze. She may make excursions into ad-
joining foliage and surroundings, as some other
Orbweavers do; but, if so, I have never been able
to find her abroad. She even spins her cocoons
within the limits of her netted snare, and there gig. ogg.

Leafy canopy of Laby-
her young are hatched and frequently occupy the ‘thea, hung within the maze.

site for a while after egress, and subsist upon the microscopic insects that

are entangled upon the lines.
The nesting habits of the Hunchback Epeira (Epeira
gibberosa) have already been referred to (Chapter IX.,
page 154, Fig. 145) in connection with the mak-

Gibbero- ers of horizontal orbs. The nest is simply a
sa’s Ham-
hammock or net of crossed lines, commonly
mock a
Nosh. stretched between the edges of a leaf, which
ALS ot iearbemer eo are pulled up so as to make a slight concay-
leaf. o, trapline. : ; . d ' =
ity. Beneath this spinningwork the spider suspends her-

self, back downward, after the fashion of the Theridioids and the spinners
of horizontal orbwebs. Her face is outward toward her snare, and the feet

NESTING HABITS AND PROTECTIVE ARCHITECTURE. 307

clasp the trapline leading thereto. The occupant is sheltered beneath and
on both sides by the leafy walls, and, as her hammock shelters from at-
tacks coming from above, she may be regarded as well protected. A front
view of Gibberosa’s nest is given at Fig. 286, and a side view at Fig. 287;
the nest is shown even more plainly at Fig. 145.

V.

The various forms of nest architecture described above may be said to

é have developed around the instinct of protection. In other words,

Nesting the spinningwork of spiders used for domiciles is protective indus-

try. It may be well, with this in view, to make a summary of the

nesting habits of Orbweavers as above described, and _ briefly
compare them with those of other tribes of the order.

It may be said, at the outset, that the portion of the body which is
most assailable by enemies and least defensible by the spider is that which
is invariably especially protected. That
part is the soft abdomen. Around this
the tube, tent, or screen, or whatever

characteristic defense is provided, will

tective.

Fic. 286. Hammock nest of Gibberosa on a leaf. Fic. 287. Nest of Gibberosa ; side view.

certainly be spun. It is this part that parasitic enemies assail; it is
this which forms the juicy bit coveted by birds, frogs, lizards, and other
arachnophagous animals. The legs and even the face will therefore be
thrust out of the entrance of the nest or be left partially unprotected,
while the abdomen is entirely screened. One cannot suppose that this
coincidence is accidental. Evidently the animal is conscious that the ab-
domen is the portion of its body which most requires protection, and has
directed its industry to that end.

The following are some of the varied forms of protective industry:
1. Spiders protect themselves by leafy tents, that is to say, tents, coverings,
or screens made of bits of a leaf, of a whole leaf, or of several
leaves united. The Labyrinth spider, for example, appropriates
a dry leaf that may drop into her snare, or which she secures
for that purpose. It is placed in the midst of her labyrinth of crossed
lines, frequently with the concavity downwards. Underneath this she
stations herself, pressing the abdomen upward against the leaf. Insularis
and others of the group represented by her protective industry make a

Leafy
Tents.

308 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

more artistic use of the leaf. Several leaves will at times be drawn to-
gether, being united by the edges and tips so as to give a bell shaped
tent; sometimes one leaf alone is used, the edge being folded over like
a grocer’s cornucopia; sometimes sprays of grasses and blossoms are
united with a leaf or two, making a very pretty effect. The concavity
of these structures is silk lined, and within it the spider sits, her abdomen
forced inward and generally rested against a silken cushion or sheet. The
face looks towards the snare, and the spider’s feet grasp a trapline which
is joined thereto.

2. Again, protective industry takes the form of silken tents. These
are woven inside of leafy tents, as in the case of the Insular and Sham-
rock spiders, or under a leaf or other objects, as with the Laby-
rinth spider. Some species make tents of pure silk. The Domi-
cile spider sometimes spins a bell shaped tent, opening down-
ward, the apex of which is fixed within the angle of a house or against
the trunk of a tree or leaf. This dome is quite large; from one to one
and a half inch in length and breadth at the mouth. Indeed, it may be
stated generally that the size of the dwelling corresponds with the size
of the aranead inhabiting it. There is not much waste of spinning energy.
There is little room for obtrusive enemies to enter into the door and share
with the lawful inhabitant the unoccupied space. This applies only to
silk nests, as the leaf ones are often very roomy. It is noticeable that spi-
ders which make use of curled leaves for domiciles can, when circum-
stances require, dispense with these leaves and provide themselves with
silken tents or tubes as their sole defense.

Epeira thaddeus makes her tent against, or under, or even within a
curled leaf, or within the needle like leaves of the pine. It is ordinarily
cylindrical, instead of bell shaped. Others, again, as the Furrow spider,
make a close cylinder or tube a little longer than their own length, with
a small opening at one end looking towards the orb.

3. Another phase is represented by such spiders as Labyrinthea and
Triaranea, in whose webs the protective industry appears to have reached

its most complex development. In the case of the Labyrinth
Threefold spider there is, first, the leafy roof or screen; there is, next, the

Silken
Tents.

Protect- ; ;
ae little tent or tube spun against the leaf, whose mouth opens down-
dustry. ward toward the orbweb; and then, encompassing the whole, is

the maze or labyrinth of crossed lines, which forms in itself a
very complete protection against raiding insects. The same form of in-
dustry substantially characterizes Epeira triaranea, except that this spider
never provides for her silken tent a leafy roof or covering of miscellaneous
material.

4, Protective industry assumes the form of wings, or aprons, or fenders
of crossed lines thrown out upon the flanks of the snare. The retitelarian
maze by which the Labyrinth spider and Triaranea protect themselves may,

NESTING HABITS AND PROTECTIVE ARCHITECTURE. 309

in part, be seen upon the webs of our two large indigenous species of
Argiope. On either side of the orb these spiders are in the habit of
throwing out wings of crossed lines, which extend, as a rule, be-
neath the lower margin of the hub upon which the spider ordi-
narily hangs, thus securing industrial protection from every di-
rection except from below, which point is guarded by the defensive organs
and armor. In point of fact, Argiope thus encloses herself within a rude
tent of straggling lines. These lines ward off assailants, or check or en-
tangle them, and give warning of danger in time to escape. Their purpose
is manifestly protective, since they are apparently too open to serve for
catching prey, and otherwise do not seem adapted to that end. The Or-
chard spider, Argyroepeira hortorum, resorts to the same mode of protec-
tion, but, inasmuch as she makes a horizontal web and hangs upon the
under part thereof, the protective apron is thrown beneath the orb, and
thus secures the aranead against the approach of enemies from the ex-
posed quarter.

5. The central shield of thick spinningwork, which is found beneath
the Banded and the Basket Argiope, may also be regarded as protective;
and it is probable that the thick scalloped and pointed ribbon decorations
characteristic of the Banded Argiope and also of Uloborus, serve some pro-
tective purpose besides the strengthening of the net. At least, it is the
habit of the spider to place herself behind these screens, which thus pro-
tect her from the exposed point, the shrubbery and other objects against
which the snare is fastened being the protection from the other side.

6. Another protective use of simple lines may be seen in the case of
the Hunchback orbweaver, Epeira gibberosa, who makes a hammock tent,
swung between leaves. She spins a series of straight lines quite thickly
between the edges of a leaf, or several leaves, and hangs underneath them,
communicating with her snare by the usual taut trapline. She is thus
protected beneath and on all sides by her leafy site, and above by her
hammock.

7. In addition, and generally, it may be said that almost all the orb-
weaving families will avail themselves of any chance cavity or projection
for temporary shelter or as a permanent site. Therein they hide them-
selves, either with or without additional protection of spinningwork, and
remain until appetite prompts them to spin their snares and place them-
selves upon them to procure food. In some cases, as with the Furrow
spider, such a shelter is habitually preferred; a hole or depression, or eyen
more frequently a dry curled leaf or bit of bark, being chosen.

In point of fact, spiders appear to live continually in dread of enemies,
and their whole life is spent in a defensive industrial warfare for the pro-
tection of their persons, or in offensive war upon those insects which fur-
nish them their natural food. In the former case they are habitually in
hiding; in the latter, in ambush.

Protect-
ive Wings

310 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

VI.

The subject of nesting architecture could hardly be considered com-
plete without a glance at the curious habit of nest parasitism, as it may
(somewhat loosely) be termed. The facts in my possession are
not numerous, but are enough to indicate that more, and more
interesting ones, may await future observers. Saltigrade spiders
are very much in the habit of attaching the silken cell in which they live
to the nest of Orbweavers, and, indeed, I may say, of other tribes. One
may find a little Saltigrade snugly ensconced, as in Fig. 288, on the silken
dome of Epeira, with the mouth of the cell opening almost next door to
the exit of her host’s house. It seems strange, at first thought, that the
two would pass to and fro without molesting and destroying one another ;
but they manage to do this.

Again, I have often found underneath a bit of loose bark, or a flat
stone, the tubular nest of Epeira strix, surrounded on all sides and even
overlaid by the cells of various Saltigrade species,
in some of which the mother would be found
dwelling with her young. Here, again, the wonder
is that the colonists dwelt together in unity.

It is not an unusual thing to find the little
7 silken cell of Clubiona and various Drassids spun
Fic, 988. Parasitic nest of Sal. Underneath some portion of curled leaf or leaves,

tigrade spider upon nest of which are used by the Insular or Shamrock spiders
Epeira strix. : :

for nests. Indeed, these ubiquitous Tubeweavers
feel free to attach their cells to any object, in almost any site,
without the slightest regard to the equity of squatter sovereignty.
Observations of this kind are so frequent that I have fancied that
during the hours of rest within the domicile the predatory nature
of araneads may be in abeyance, and that there may be a mutual under-
standing—a sort of modus vivendi—that in such cases the ordinary canni-
balism of their kind is to be suspended.

Vinson gives an interesting account of the manner in which the little
Linyphie of the African islands whose fauna he has described, take up
their dwellings upon the huge snares and extended foundation lines of
large Orbweavers, mostly of the genus Nephila. Here they remain quite
at home, and apparently undisturbed by their gigantic hostess, and sup-
port themselves by picking up the small insects ensnared in their neigh-
borhood, and which are too minute to satisfy the appetite of the proprietor
of the snare.t This appears to be quite a fixed habit among the smaller
species of Africa. A similar phenomenon I have often observed among
our American fauna, and shall allude to it in a following chapter (Vol. IT.),
upon the Babyhood of Spiders. The little ones of a recently escaped

Nest Par-
asitism.

Squatter
Sover-
eignty.

' Aranéides des Iles de la Réunion, ete., page xix.

NESTING HABITS AND PROTECTIVE ARCHITECTURE. oie

brood will occupy the abandoned snare of an adult Orbweaver, and, clear-
ing out the space between the radii, spin their own minute orbs. I have
seen a brood of young Epeira patagiata attempt this sort of squatting
upon the premises of an adult Zilla x-notata, very much to their own dis-
comfort. For, although the little fellows succeeded in getting positions for
their minute orbs, the original proprietor, by skillful management, was
able to dislodge and one after another devour them, until she had eaten
up nearly all her guests.

Moreover, among certain species of the Retitelarie, the habit has be-
come fixed of invading the snares of other species for the purpose of
destroying the occupants. Argyrodes trigonum, for example, will
invade the nest of the Labyrinth spider, whose maze forms an
admirable retreat, and therein will establish herself. Another
species of Argyrodes, which I have described as A. piratica, was sent to me
from California, and is said by Mrs. Rosa Smith Eigenmann to be an
habitual depredator upon the premises of the Orbweavers of San Diego.
The little creature will fearlessly invade the snare; attack, destroy, and de-
vour her huge opponent. The particulars of this habit I reserve for the
chapter (Vol. II.) upon the Enemies of Spiders.

The abandoned nest of Orbweavers is often occupied by Tubeweaving
spiders. Agalena ncevia especially finds it a pleasant retreat, and makes
it the centre of her broad, sheeted snare. So also I have found the
rolled leaf nest of a young Epeiroid occupied by a Saltigrade. I have
no evidence, however, that any of these spiders deliberately dislodges the
owner in order thus to take possession. Nor have I ever seen one Orb-
weaver make a raid upon the premises of a congener for a like purpose.

Mrs. Treat records! a case which looks very much lke nest parasitism.
An interesting Lycosid, Dolomedes scriptus, appeared to take a special fancy
for the nest of a female Shamrock spider. For more than two weeks,
while the Dolomede was carrying her cocoon, her favorite resting place was
on the top of the Orbweaver’s tent, and often, when the latter left her
domicile to seek prey upon her orb, as is her custom, Dolomede would
stealthily slip inside. But she always seemed to know when ‘Trifolium
was about to return, and would quickly emerge and take her place on the
outside. The only wonder to me, in this case, is that the Lycosid, which
is a large and powerful spider, abundantly able to cope with and destroy
Trifolium, did not at once make a meal of the Orbweayver whose home
she coveted, and, after the fashion of human creatures, take possession of
the premises from which she had dislodged the rightful occupant.

On the whole, I am inclined to think, although the facts are cer-
tainly inadequate to form a just conclusion of any sort, that cases of
proper nest parasitism are rare. That is to say, it is not often that one

Piratical
Invaders.

1“My Garden Pets,” page 24.
4 £

ol? AMERICAN SPIDERS AND THEIR SPINNINGWORK.

spider will deliberately appropriate a part of the nest of another, or dis-
lodge another in order to possess the whole place.
The fact is that the construction of a nest is not a very difficult mat-
ter. Orbweavers, at least, are apt to change their position when in any-
wise made uncomfortable, and build a new home. Material costs
Facile nothing, for leaves are plenty and free as fuel in an Adiron-
nest dacks forest; and, as to tapestry and other hangings for her
Making. ‘acks forest; o tapestry e ging e
abode, she possesses an unfailing manufactory within her own
person, and at her own command. Moreover, there is a wholesome fear
of results which, in the absence of any moral sentiment, is apt to restrain
a covetous aranead from assaulting a spider who is ensconced within her
own castle, and has the advantage of being on the defensive; for, even in
spider world it is easier to defend a fort from an assailant than to attack
it upon scaling ladders.

Omar rTrER XV IIT.

NEST MAKING: ITS ORIGIN AND USE: DEVELOPMENT IN
VARIOUS TRIBES.

1

A stupy of the modes of construction described in the preceding chap-
ter suggests the thought that the habit of nest making may have origi-
nated among the Orbweavers in an accidental way. The tendency is natural

and universal, among spiders of all kinds, to shelter themselves
Origin of underneath arboreal or other surfaces. They know instinctively
Nest . ;
Méiking that they are exposed to enemies. The under surfaces of leaves, or
Habit, the little domes formed by clusters of drooping leaves, are most

common and natural shelters for spiders when living on arboreal
sites. With such creatures, that subsist by means of the spinning habit,
and constantly protect themselves by fastening draglines to the surfaces
over which they move, and thus never venture any distance without leay-
ing an attachment behind them, and a thread by which they can return,
it would be the most natural thing conceivable to attach themselves in
like manner by outspun threads to surfaces beneath which they had thus
sought shelter.

In the restless movements of the body back and forth, numerous attach-
ments would be made, and so a rude silken shelter would easily result;
and it would inevitably follow, without premeditation or purpose of the
spider, that the leaves, by the very action of the threads, would be held
together, and in the course of time drawn closer together into the various
nest shapes which we see. These forms might thus be made without any
fixed purpose or definite movement of intelligence. That it is often so I
am well satisfied. That the more perfect habit could have originated in
this seemingly accidental way, and have become fixed in the course of
time by heredity, appears not an unreasonable theory.

At all events, it is certain that in the selection and adjustment of mate-
rial in the nidification of Orbweavers, one does not see such a deliberate

and intelligent purpose as is found, for example, among some of

aia the Lycosids. The turret spider, Lycosa arenicola Scudder, de-
gen li ; see Sat

: iberat ‘ks and selects the s straw and _ sticks of
Pr berately seeks and selects the bits of straw and sticks out

which she rears her little tower so like an old fashioned log
cabin chimney. (Fig. 289.) There is here a deliberate choice and bring-
ing of material to the nest site.
(313)

314 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

The same aranead, when building on the seashore, will show intelligent
adaptation in the use of the material at hand. I have often found her
burrow, when dug within the sand, with a course or two of small quartz
pebbles laid around the rim, upon which, as a sort of foundation, the usual
chimney or turret of straws would be raised.

If one will thrust a twig down the burrow, which goes straight down-
ward six, eight, or ten inches, and will dig away the sand on either side,
he will see the delicate silken lining of the burrow clinging to the twig,
as shown at Fig. 290. It is a delicate fabric, with whose strands the
grains of sand are interblend-
ed. But it serves, in part, to
keep the tube intact.

Lycosa carolinensis con-
structs from the needle like
leaves of the white pine (as
in the cut Fig. 291), or from
other available material, by
bending and _ pasting, domi-
ciles which more closely re-
semble birds’ nests than any-
thing that I have met in ara-
nead architecture. These are
pasted together by a process
not unlike a rude sort of
basket weaving. In this case,
also, one must assume a delib-
erate and intelligent action on
the part of the spider.

The selection of the pine
needles as they lie scattered
over the field;
bringing them to
the nest site; ar-
ranging them in the little fasciculee or bundles which may be seen in the
cut (Fig. 291); the bending of these into place to form the basket like
vestibule or dome above the burrow—all these actions, not to speak of
others, imply a process of selection and adaptation more or less deliberate
and intelligent. 1

On the contrary, in studying the nests of Orbweavers and noting their
manner of constructing them, one cannot escape the conviction that chance
has had quite as much to do as design in the outcome of some of the
beautiful forms illustrated in the foregoing chapter. It is in the act of

A Basket

Fic. 289. The Turret spider’s nest. The earth is represented
cut away, to show the burrow. W eaver.

1The nest of Carolinensis from which the figure has been drawn was contributed to
>
my collection by Mrs. Treat, and was made by a New England spider.

NEST MAKING: ITS ORIGIN AND USE. 315

sewing together the leaves, after the nest site is selected and the prepara-
tory stages wrought out, that one sees most evident marks of intention on
the part of the architect. There can be no doubt that here is
manifest the deliberate purpose to effectually enclose the dwelling
and secure it from intrusion of enemies and inconvenience of
weather changes.

Design in
Sewing.

i

If now we come to compare the protective industry of Orbweavers with
that of other tribes of spiders, even those which most widely differ from
them in structure and
general life habit, we
shall find less essential
difference than might

have been an-
Compar- ticipated. The
ative é
Studies. germinal form,

or prevailing
type of protective archi-
tecture, for all tribes, is
the tube or some modifi-
cation thereof. The en-
tire tribe of Tubitelarie,
for example, domicile
within tubes which do
not differ in essential par-
ticulars from that which
is woven by the orbweay-
ing Furrow spider and
others of kindred habit, Fic. 290. Upper figure: Turret spider’s tower built on a pebble founda-

: tion. Lower figure: inside lining exposed by digging out the sand.

or by Epeira thaddeus.
Indeed, the open dome shaped tent of Epeira domiciliorum and other spi-
ders is only a modification of the architectural type. The little tube of the
Drassids (Fig. 292), and numerous species of Tubitelariz that construct kin-
dred domiciles, scarcely differs in any regard from the tube of the Epeiroid
Thaddeus and Furrow spiders. In the case of the Speckled Agalena, whose
funnel shaped web is known to all familiars of our fields, the tubular part
thereof is really the spider’s domicile, and the broad sheet outstretched
upon leaves, grass, or surrounding surface of its site may be re-
garded as a portion of the snare. The same spider protects her-
self, as is the case with many Orbweavers, by a maze of straight
lines spun above the separating sheet, and which also serves in part to
sustain it, and acts besides as a snare to arrest prey.

If, again, we take such an example as the Medicinal spider, Tegenaria

Tube-
weavers.

316 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

medicinalis (or Durhami), whose web is so frequently found in cellars and
shaded outhouses, the same fact meets us. There we see the thick sheet,
not spread out broadly as in the case of Agalena, but rather pouched ; thus
forming a good receptacle for dropping insects, who are apt to roll easily
into the little round open-
ing at the apex of the
snare. Above this open-
ing is spun a short tubu-
lar tower, which also is
prolonged a little way be-
neath the opening. With-
in this peculiar structure
the spider protects herself,
precisely as in the case of
the Orbweavers above de-
scribed. (See Fig. 221,

Fic. 291. The nest of Lycosa carolinensis, built from the needle Chapter XTV,)
like leaves of a pine tree.

If we pass next to the
Saltigrades we find the same fact. The jumping spiders, whose bright
forms and animated movements are familiar around our houses and

; yards, spin for their domicile thick white silken tubes, which
ae differ very little in form and structure from those of the orb-

weaving Furrow spider or the tubeweaving Drassid, Disdera, or
Segestria. (Fig. 293.)

The Lineweavers, although such close neighbors to the Orbweavers in
structure, and having remarkable points of approach in certain features of
the snare, are somewhat defective in points of architectural resemblance as
far as the nesting tube is concerned. But they have some striking repre-
sentatives of the prevailing type. There
is, for example, the little lineweaving
Theridium zelotypum which I have
often observed along the trails in Adirondack for-
ests, living in a little tent whose roof was the
gathered leaves of a young pine tree, and whose
interior was a silken tube or bell shaped dome
quite resembling the nest of the Insular spider.
Within this tent the mother Theridium domiciles,
and with her dwell a number of her young. (See
Fig. 294.)

When the habits of American Lineweavers
shall be studied more carefully, it will probably be found that Zelotypum
is not alone in the matter of nidification. At least, we know that among
the European Theridioids there are some species who almost equal the
Epeiroids in the perfection of their nests. Theridium neryosum is one

Line-
weavers.

Fic. 292. Tubular nest of Drassus.

NEST MAKING: ITS ORIGIN AND USE. 317

of these; in the midst of her pyramidal snare of interlacing lines, or, at
other times, sheltered underneath a growing leaf, she prepares a_ perfect

little nesting tent, which is fastened by silken cords into a dome
Huropean like frame. The tent is lined with white silk, and is covered
area with small dead leaves or flowers, or the stamens of larger flow-

ers, or anything which has presented itself. It is decorated with
the wings or other parts of insects, among which
the beautiful wing cases of the nut weevil are often
found. This tent is not used for a domicile alone,
but as a receptacle for the cocoon.

Theridium riparium builds a nest which Black-
wall thus concisely describes: She fabricates a
slender, conical tube of silk, of a very slight
texture, measuring from one and a half to two and a half inches in
length, and about one-half inch in diameter at its lower extremity. It
is closed above, open below, thickly covered externally with bits of indu-
rated earth, small stones, and withered leaves and flowers, which are in-
corporated with it, and is suspended perpendicularly, by lines attached to
its sides and apex, in the irregular snare constructed by this species. In
the upper part of this triangular domicile the female spins several glob-
ular cocoons of yellowish white silk, of a slight texture, whose mean
diameter is about one-eighth of an inch, in each of which she deposits
from twenty to sixty small spherical eggs, of a pale, yellowish white color,
not agglutinated together. The young remain with the mother for a long
period after quitting the cocoons, and are provided by her with food,
which consists chiefly of ants.?

In point of fact, this English Lineweaver possesses the faculty of nest
' building to as remarkable a degree as any
known spider. I therefore insert at length
a series of interesting observations recorded
by Mr. Edward H. Robertson, of Brixton,
England. ?

tiparium has a great antipathy to strong
light, and usually completes her nest under
the shade of overhanging banks,
seldom making her appearance
during the day, and becoming act-
ive as darkness creeps on. The nest is a
tube varying in length from one to two and a half inches, closed above,
but open at the lower end, the diameter at the mouth being about one-half

Fic. 293. The tubular nest of a
Saltigrade spider, in a rolled leaf.

Material
Used.

Fic. 294. Nest of Theridium zelotypum.

1 Staveley, British Spiders, page 145.

* Blackwall, “ Researches in Zoology,” page 356. Also, Spiders of Great Britain, Introduc-
tion, page 9.

* “Science Gossip,” January, 1868, page 12 sq.

318 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

inch. The materials of which it is composed externally are small particles
of hardened earthy pebbles, twigs, withered leaves, etc., rather slightly at-
tached by threads. This tube is lined with silk, forming a comfortable
home. However irregular in appearance the nest may
be externally, the interior is always smooth.

Mr. Robertson examined sixty or seventy nests, and
kept a dozen of them under glass cases for closer ob-
servation. Most of the nests were suspended under the
leaves of raspberry and gooseberry bushes and like situ-
ations at a distance of from two to four inches from
the earth; in a few instances they were suspended in
the angles of old walls. When built above the soil the
pebbles alone seemed to be used. When built near a
wall particles of mortar were taken. In the latter case,
the nests were the most regular in form. When with-
ered leaves were near, these and small twigs were used,
Fic. 295. Nestof Theria- 2nd the nests formed of such materials were the - least

oe of symmetrical. It is thus manifest that the mechan-
ical finish of the domicile depends largely upon the
building material available.

In order to test the capabilities of these little architects, the observer
supplied those which were in confinement with small twigs cut in lengths

of about one-eighth inch, mixing with them larger pieces. He
Artificial was surprised to find that the smallest pieces were not often
Supplies ; : c
Ted. selected, and apparently the most unsuitable pieces were fre-

quently chosen by the little architect. Figs. 298 and 299 are
examples of nests formed by these twigs. The upper parts, above the
marked line in the cuts, were built before they were transferred to cases.
Fig. 298 was constructed in the course of three weeks. Fig. 299 was built
by a wonderfully industrious mother of two large families, who subse-
quently made a neat little residence of particles of chalk.

While the eggs remain unhatched, the nest seldom exceeds one inch in
length. No sooner, however, does the mother find that she has to accom-
modate a large family than she is_ seized
with a building impulse, and may be seen
to descend suddenly to the earth.
She then takes a seemingly pur-
poseless scramble over the material
beneath her nest. Passing by much _ build-
ing material apparently well fitted for her FIG. 296.

purpose, without any attempt at examination, Nests in their earliest stages.
(Theridium riparium.)

Mode of
Building.

she fixes upon a twig or other object which
often appears disproportionate to her size and strength. ‘To this she attaches
a line, and quickly scrambles back again, dragging the twig after her.

NEST MAKING: ITS ORIGIN AND USE. 319

This dragline she fastens to one of those which connect with the mouth
of her nest, and which just serve to suspend the object. Returning, an-
other thread is attached, and the piece is suspended midway between earth
and nest. A third trip serves to fix the substance at the mouth of her
domicile, to be afterward
more neatly arranged.
Several objects are thus
frequently suspended at
one time, giving the nest
a rather unfinished ap-
pearance, as represented
in the figures.

Nests built in the
open air are almost im-
pervious to light, while
those built in confine-
ment admit the light
through the various in-
terstices left by angular
pieces of the building
material. The little crea- Fic. 298. Nest made of materials artificially supplied; the lower part
ture seems unable to rem- of sticks. (Theridium riparium.) Fi, 299. Nest with dead leaves,
edy this, doubilesa joes twigs, etc., intermingled with pellets of earth. (Theridium riparium.)
cause the natural site affords her better opportunity for the selection of
material adapted to her wants.

The objects used are invariably built into the inner surfaces only ; and
Mr. Robertson scarcely ever observed one of the busy little workmen on
the exterior of its house, excepting when forming a slight covering of silk
on the upper part, which is sometimes done,

The snare of the spider is spun downward from the mouth of her

tubular nest. The lines are the ordinary intersecting threads of
eae her species, which are so disposed that they enclose an inverted

funnel shaped space, the mouth of the nest representing the
point of the funnel.

From some unknown cause these spiders sometimes left their homes
Se with their broods, built on the inside of a
Fe Si SUN branch irregular structures, one of which is
figured. (Fig. 300.)

Riparium’s nest is not simply a domicile for
Fic. 300. A rudimentary refuge, or ex- Br : ‘
perimental nest. (Theridium ripa- the proprietor, but is a nursery and home in

Bay) which to rear the young. The mother spins
several nearly spherical cocoons of yellowish white silk, the diameter of
each being about one-eighth of an inch, within which are contained
from thirty to sixty eggs. When the young are hatched, they remain

Fic. 298. Fic. 299.

ae
ile 4: a

320 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

with the mothers until they gain a considerable size—a period of several
weeks. The first, and probably the second, moult take place within the
nest, the third occurs after the spider has commenced life on
Domicile its own account. Although so numerous, the juvenile Ripariums
and . ) eee
Nursery. 2 Mr. Robertson’s artificial nests appeared to be on very good
terms, seldom engaging in any quarrels—not so frequently, he
thought, as the same number of boys in a school would have done. The
mother Theridium exhibits wonderful affection for her eggs and young.

The food of the spider is principally ants, and many deserted nests
were literally full of the remains of these insects. House flies, when
trapped upon the snares, are held very tenaciously by the viscid
globules which, Mr. Robertson asserts, are dispersed over the in-
tersecting lines. It is most interesting to watch the proceedings of the
juveniles when the mother is endeavoring to catch a fly. Hearing or
seeing a disturbance, a young spider cautiously descends a line, followed
at a distance by another and another. These approach the victim, evi-
dently as anxious to assist the mother as children are to use their little
fingers when they see others busy. The fly struggles in its toils, and
away scamper the young spiders as fast as tiny legs can carry them, re-
peating this process until they can make a meal off the fly. When an
insect is captured it is usually enswathed and drawn up within the nest
to be devoured.

These examples would seem to indicate that among our American The-
ridioids we may expect to find the nesting habit much more strongly de-
veloped than has heretofore been supposed. At all events, it is seen that
this tribe has in some of its representatives fair rivals of the Orbweavers
in the perfection of the nesting habit. The difference in the use, in the
case of Theridium, appears to be that the nests of Orbweayers are habit-
ually the dwelling places of their builders, while those of Lineweavers
are not so much permanent dwelling places as retreats for the cocooning
season. However, the Orbweaver’s nest is also occasionally used to house
her cocoon.

One may find rude examples of the nesting habit in the genus Liny-
phia. There is no more common or more interesting snare along the

skirts of our American woods, especially in the Middle and At-
Nesting antic States, than that of Linyphia marginata. This consists of
Snares of - 5 : ' 3
Mineohia o dome of open meshwork which is stretched in the midst of a

maze of crossed lines. It looks not unlike a miniature umbrella
minus a handle and hung by innumerable cords to the foliage. (Fig. 157.)
Within this structure the spider has her abode, hanging inverted, close to
the ceiling, ready to dash through the flimsy fabric and seize the unfor-
tunate victims that drop down upon the roof through the labyrinth above.

Linyphia communis spins a nest precisely like the above in structure,
but differing from it in that the concavity of the dome is invariably

Food.

bo

NEST MAKING: ITS ORIGIN AND USE. 3

Fic. 301. Fie. 303.

Fic. 301. The silk lined burrow or nest of the American Trapdoor spider, Cteniza californica. The
earth is cut away, giving a vertical exposure of the tube and its lining. Fic. 302. A colony
of Purseweb spiders’ nests on a palmetto trunk. Fic. 308. Purseweb spider’s tube; soil removed
to show underground burrow.

322 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

turned upwards instead of downwards. (See Fig. 156, Chapter IX.) The
spider rests, as in the case of her congener, beneath her tent, and waits
for the prey that, striking upon and arrested by the labyrinth of crossed
lines stretched above, drop into the inverted silken bowl, beneath which
the watchful aranead hangs. Thus among the Linyphia, also, the Line-
weavers have fair representatives of that nest making habit which we
have regarded as germinal and
typical of the nesting architect-
ure of all the tribes.
Among the Territelariz the
tube making habit has a very
high development, par-
Terri- ticularly in the genera
telarian : ten:
Tbe. Nemesia, Cteniza, and
Atypus. All these spi-
ders make tubular burrows be-
neath the surface of the ground,
which are lined with a_ thick
sheeting of silk that really con-
stitutes a tube within a tunnel.
(Fig. 301.) The genus -Atypus
carries this tube above the sur-
face, attaching it, in the case of
Abbot’s Atypus,! to the surface
of trees (Figs. 302, 303), while
Atypus piceus fastens her tube
to the surface of weeds and grass
into which or along which it is
carried. Thus we find that in
this large and interesting tribe
_ the tube is also made the archi-
Fic. 304. The tubular, funnel shaped nest of Cyrtauchenius

elongatus. Elevated above the ground, and suspended to tectural type of the domicile.
grasses. The earth is opened to show a section view of The nest of Cyrtauchenius

the subterranean tube. (After Moggridge.)

elongatus, as described by M.
Eugene Simon, closely resembles that of Agalena ncevia in the character of
the tube alone; but this tube is enclosed within a deep cylindrical burrow,
and is prolonged upward for about three inches above the surface of the
ground, and enlarged into a funnel shape, so that it becomes from two to
three inches across at the orifice. (Fig. 304.) This aerial portion is snow
white, and at once attracts the eye, even from a considerable distance; the
nests, rising up amid sparse grass, which serves to support but not conceal
them, present the appearance of scattered white fungi. Cyrtauchenius

a Ld:

aT

‘ Atypus Abboti Walck.

NEST MAKING: ITS ORIGIN AND USE. 323

belongs to the Territelarize, and appears to be nearly related to Atypus
and Nemesia. Mr. Moggridge classifies its nest among those of the Trap-
door spiders, characterizing it as the funnel shaped nest.1
Among the Citigrades we find a resemblance in general habit to the
Tunnelweayers. The burrowing habit is quite identical, and the tube
making habit, although not so high-
ly specialized, nevertheless exists. It
is chiefly displayed, how-
ever, In spinning a tubu-
lar lining to the little tower
prolonged above the burrow, as in
the case of the interesting nest of
the turret spider,? Fig. 289, or the
silk lined, dome shaped vestibule of
the Tiger spider,? composed of moss
or various scraps of miscellaneous
material, which is wrought into an
entrance to the sloping burrow that
extends beneath the surface of the ground. (Fig. 305.) The silk lined
tower of the turret spider may be said to resemble very closely the tubu- _
lar nest of such Orbweavers as Epeira domiciliorum and E. thaddeus,
when they build within the leaves of a pine tree or weave their tent in
like situations. The silk lined vestibule of the Tiger spider is not unlike
the leafy nest constructed by the Shamrock spider and others of the group
to which she belongs. (Compare Fig. 259, Chapter XVII., with Fig. 305.)
Coming finally to the Laterigrades we find here the nest making habit
less developed than in any other tribe of the order. These araneads stalk
their prey afield; use no sort of spinningwork for their
capture; and, as far as I know, make no fixed domicile
of spinningwork for their permanent abode. I
have, however, found Laterigrades, as Philo-
dromus and Misumena, dwelling with their co-
coons beneath tubular structures of delicate texture, which
Be ee as served both as a cover to the spider and her cocoon. In
of Lycosa tigrina. s, form and spinningwork these differed in no essential par-
ease ticular from the tubes of Drassids and Epeira and the
is indicated beneath; cocooning tents of Orbweavers. This, I believe, is a
i anichneo pema common habit, particularly with the mother Laterigrade
at the cocooning period. So far, then, as she may be
said to possess in any degree the instinct of nest building, she displays
a tendency to adopt the typical form, and screens herself within a tube.

Citi-
grades.

Fic. 305. Vestibule of Lycosa tigrina (McCook).

Lateri-
grades.

' Moggridge: Harvesting Ants and Trapdoor Spiders, page 183, pl. 13.
* Tarentula arenicola Scudder. * Tarentula tigrina McCook.

324 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

As a result of the above comparative study of the nesting industry of
the spider fauna, we may conclude that there is one germinal or typical
form of nest among all the tribes, which form is the tube.
Around this common and rudimentary form the greatly varied
and widely divergent nests of spiders, whether known as dom-
iciles, dens, tents, tunnels, or caves, may be grouped in series of more or
less modified forms.

It may be allowable to say, using the language of accommodation, that
all these variations have been developed in these various species around
this typical and germinal form; but the statement cannot be said to rest
upon any demonstration of actual facts, and
must stand simply as a convenient and appro-
priate formula for expressing certain relations.
It is, however, a sufficiently interesting discov-
ery that, amidst so many forms which at first
sight appear to be widely different, one is able
to trace with striking and manifest clearness a
common plan.

As-one considers them, he is conscious of
something like the feelings with which he wan-
ders through the studio of an artist of fecund
and versatile genius. Variety of invention and
detail in execution are certainly manifest; but
everywhere, also, are apparent to the critical
student traces of a single mind, whose dominant
characteristics inevitably assert themselves in its
products. The details vary; the Author’s style
E is one. Perhaps this unity of plan is not to be
Fic. 307. Partly covered and sanded wondered at, when we reflect that the physio-

oe EE a logical characteristics of spiders in all tribes and
species are not widely different, and hence the functions might be expected
to find very similar expressions, at least in certain fundamental points.

One Typi-
cal Form.

SS ‘
= ‘fae SUNTAN | \
sa S- ao
eee 5 NN

———

a5

ses

=

JUL

In comparing the detailed studies of the manner in which the various
tribes of spiders construct the typical tubular nest, one reaches the con-
clusion that there is little or no difference in the processes as
pursued by individuals. When Epeira constructs a tubular den,
Manufac- || _ . =
ane she proceeds in her work in precisely the same way as Agalena
Method, When laying out the tubular part of her snare, or as Abbot's
Atypus, the Purseweb spider, when constructing the long tube
within which she spends her life. So, also, the Basket Argiope, when
spreading the thickening shield which forms the centre of her orb, has
the same method as the Speckled tubeweaver or the Medicinal spider when

Uniform

NEST MAKING: ITS ORIGIN AND USE. ya)

spreading out the carpet like structure or the pouched bag which form
respectively the snares of those species.

I have described at length the method in a paper upon the habits of
the Purseweb spider,' and it will fairly represent the action of all other
species making similar dwelling places. The characteristic tube
of the Purseweb spider is spun against the trunk of a tree, ex-
tending several inches above the surface of the ground and
about an equal distance beneath it. (Fig. 303.) The first stage in con-
structing this tube is to stretch a series of lines about two inches from the
surface of the ground to various points on the surface of the tree, until a
circular or nearly circular row is formed, extending from the tree to the

Method
of Atypus

Se ee

—

SS

ANS!

Fie. 308. Fic. 309. Fie. 310.

Fic. 308. The frame of original lines stretched against a stock. Fic. 309. The frame partly covered over;
the spider is seen within putting on the weft. Fic. 310. The completed tube, with a small cross tube
woven at the base.

ground. This forms a frame of straight lines, which is the foundation
of the tube. (Fig. 308.) The spider now passes within this structure, and,
clinging to the threads with her feet, moves her abdomen simultaneously
backward and forward and up and down, meanwhile issuing from the
spinnerets thickened lines, which adhere to the framework. In_ other
words, the framework constitutes the warp, and the lines issued there-
after the woof of her texture. (Fig. 309.) As the threads are drawn out
from the spinnerets they are beaten down upon the frame lines by the

1 Proceedings Academy Natural Sciences, Philadelphia, 1888, pages 208-18. “The Nest-
ing Habits of the American Purseweb Spider.”

326 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

spinnerets, not interwoven with them. When a sufficient number has been
laid upon the original frame, by the repeated spinning and beating action
of the spider, the whole presents the appearance of a thickened sheet
wrought into the form of a tube. (Fig. 310.) .

I have observed the overspinning of an- under-
ground burrow by a Purseweb in a glass jar. The
same method was followed, except that the frame lines
were spun against the concavity of the
burrow and the inner surface of the glass.
The spider then proceeded to thicken
over the frame by spinning against it lt-
tle ribbons of silk and beating them down
with her long spinnerets. When hang-
ing head downward, with claws clasping
the frame lines, and spinning upward
against the roof of her burrow (Fig. 312),
she presented to the observer a rather
odd appearance. No doubt this is the

Zk Ri mode by which the spider silklines the
Bg EE IES, underground part of her tubular snare
Fic. 311. Purseweb spider’s nest. View below which extends beneath the sand some-

paar en 2 ane te annan ” times as far as above the surface, and is
either single, or branched, after the man-
ner represented in Fig. 311. (See also Fig. 303.)

The same method of spinning is used by our American tarantula, Ku-
rypelma hentzii, in weaving the rug upon which it often loves to stay

when in artificial confinement. In the act of spinning, the

4 pS} le Dy

The Ta- jong posterior spinnerets are curved upward and forward (which
rantula’s
Rue is, indeed, an habitual position with this tribe), and from the

spinning tubes along the exterior part of the spinneret are given
out numerous fine threads. , an
These are pressed to the ground \ Mi WW
by the downward motion of Yee
the spinnerets. The abdomen

is then lifted up, and by this q
; . Y
action the threads are drawn j
Yj

out. Again the downward mo- yy
5 aoe : 4,
tion is repeated, and simulta- i
Y

neously the end of the abdo- Wy YA

men to whic .° spinnerets
rela une spinnerets Fic. 312. Purseweb spider working the weft on an
are attached receives a lateral eriersronndceanes

motion that causes the threads to be spread over the surface of the
ground. At the same time the animal slowly moves its whole body

around, as upon a pivot, thus dispersing the silk over a circular patch of

NEST MAKING: ITS ORIGIN AND USE. 327

surface about equal in diameter to twice the length of its body, or to
the spread of its legs.!

Thus the thick texture of the sheeted web is produced by the act of
beating downward with the long spinnerets, repeated motions of which up
and down make little loops, which thicken over the surface and are beaten
down and then smoothed over by the spinnerets. (Fig. 313.) It will be
seen that this action does not differ from that of all other spiders while
engaged upon similar spinningwork.

The spinning habit is not greatly developed among the Lycosids, al-
though that group of spiders furnishes some interesting examples of nest
making. Nevertheless, in the work of making the cocoon, in
which its spinning industry is most conspicuous, we find Lycosa
dropping into the common method of fabrication. I haye ob-
served and described the mode of spinning a cocoon,
which is as follows:
A circular cushion
of beautiful white
silk about three-
fourths of an inch
in diameter is the
piece out of which |
the round egg bag
of Lycosa is made.
In spinning this
the spider’s feet
clasp the circum- Le oe Se ea
ference of the co- i a ea
coon, and the body Fic. 313. Tarantula putting the weft upon her rug. (Eurypelma Hentzii.)
of the animal is slowly revolved. The abdomen is lifted up, thus drawing
out short loops of silk from the extended spinnerets, which, when the
abdomen is dropped again, contract and leave a flossy curl of silk at the
point of attachment. The abdomen is also swayed back and forward, the
filaments from the spinnerets following the motion as the spider turns,
and thus an even thickness of silk is laid upon the eggs.”

I have seen Saltigrades engage inthe same act of spinning their co-
coon and silken cylindrical nest, and the words used for describing the
above might be almost exactly applied to the behavior of the Attoid. The
details of these methods of cocoon making will be reserved for the proper
chapter in the second volume of this work. But, in the meanwhile, this
reference to the method falls into the purpose of present thought.

Among
Lycosids.

18ee my notes on the Age and Habits of the American Tarantula, Proceed. Acad. Nat.
Sci., 1887, page 377.

2See my note on “ How Lycosa Fabricates her Round Cocoon,” Proceed. Acad. Nat.
Sci. Phila., 1884, page 138,

328 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

If we turn to the Tubeweavers we find a varied and interesting field
of spinning industry in the making of snares, nests, and cocoons. In all
of these it may be confidently said that the methods, as far as known,
are substantially the same as those described as prevail-
ing in other tribes. A few illustrations show this fact.
The interesting and well known water spider
of Europe, Argyroneta aquatica, weaves in
water a bell shaped tent (Fig. 314), within
which she dwells, deposits her egg sac, and
rears her young. The following observation indicates
Sey Gare shaped that even in this seemingly unnatural element the

the water sider, under Same general method characterizes the spider’s weay-
water. ing. Fig. 315 represents a patch of spinningwork
made by this water spider upon a glass within which she was confined,
and drawn by Mr. Underhill! On examining the central part of this
patch, it appeared, both to the naked eye and to the microscope, like
a piece of thg spider’s cocoon. Certain broad threads at the edge of the

patch at once explained the method by which this close and

Methods
of Tube-
weavers.

eae even texture was obtained. They are represented by Fig. 315, ¢,
Spider as they appeared under the microscope. They seem to have been

produced, as in the cases above described, by the spider erecting
or placing, parallel to one another, a series of spinning tubes, which emitted
separate and parallel threads, instead of lines directed towards one point.
These bands Mr. Underhill supposed
to be the product of the anterior ny
spinnerets, while the other two i
threads, a and B, are emitted by the
posterior and middle spinnerets.
When Agalena ncevia wishes to
extend the borders of her sheet
like snare, she proceeds
Agalena’s.
Method. 1 the same way, carry-
ing first various lines be-
yond the margin to the desired dis-
tance, which lines are stretched
across the foliage or other surface
that forms the nest site. When
the desired number of these lines

B

F a Fig. 315. Highly magnified piece of the Water spider's
has been laid down the Ar ube- web. a,a, BB, the single original or warp lines; ¢, ¢, ¢,
)

é ‘ ing the weft.
weaver moves backward and for- the banded filaments forming the we

ward over them, spinning out all the while a stream of silk, at the same
time moving her long spinnerets up and down from the surface of the

“Science Gossip,” 1875, page 134.

NEST MAKING: ITS ORIGIN AND USE. 329

frame, by this vertical movement drawing out the thread and beating it
back again, thus thickening the weft upon the lines. In this manner a
sheet of thin texture is rapidly formed, and this, in the course of time, is
thickened by a repetition of the same mode of spinning. This is exactly ©
the method, as I have heretofore shown, pursued by Argiope cophinaria
in thickening her shield. (See Chapter VI. and illustrations.) It is the
manner in which the dome hke tents of all the Epeiroid spiders are con-
structed. When the method of procedure has been ascertained in one
spider, the arachnologist may be assured that he has the key to the
methods practiced among all the tribes.}

ive

The tube making faculty appears to be, as far as secondary causes are
concerned, the natural result of the instinct of self protection. It is, per-
haps, most natural that the lower animals should seek to protect
Origin of themselves within barriers formed by their body secretions, as is
Tube- .
ae the case among the larve of many insects. The restless move-
Habit, ments of the body, characteristic of these creatures, conjoined
with the instinct to cover themselyes up, to protect themselves
from unfavorable weather changes and from the approach of enemies,
may be a sufficient natural explanation of the origin of the tube making
habit.

Thus, the silk moth larva, while secreting silk from the glands which
open on the upper lip, moves backward and forward, continually distribu-
ting its secretions, and at the same time, by the motion of its body, limits
them to the borders of the space around which it moves. In the same
way the social caterpillars have learned to shut themselves within their
well known tent, which presents so largely the appearance of a designed
structure, but which, in its origin at least, may have been quite as much
the result of accident, the silken secretion simply hardening around the
limits of the space through which the restless creatures move, and which
by their motions they keep free from threads.

In like manner the larva of the ant, at the moment when nature brings
upon it the sense of the great change from its larval to its pupal state,

moves backward and forward within a narrow space, secreting its

care delicate silk, which by its movements is pushed away from di-
makin aes ;
Sana rect contact with its body, and hardens into the little case or

pouch in which itself at last is encompassed. Thus we may

suppose that, in an entirely natural way, the Supreme Overforce, while

‘It took many years of observation, numberless experiments by day and throughout

many nights of careful watching among the various species, to reach this conclusion. But I

am so confident that I have fully demonstrated it, that I have no hesitation in declaring

the general principle here announced. I have little doubt that subsequent studies of other
species in all the tribes will verify the generalization.

330

Fic. 316.

FiG. 317.

Fic. 316. The rolled leaf nest of a Tortricid moth larva, made among ferns.
leaf nest of the Shamrock spider, made among ferns.

AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Fia. 317.

A rolled

NEST MAKING: ITS ORIGIN AND USE. 331

governing all creatures and all their actions, has developed in certain ar-
thropods the habit of spinning tubes or cylinders as a protection to the
body.

Among the spider fauna this habit is particularly prominent. It does
not exist, as with insects, in a larval state, but in the perfect animal, the
only one, with possibly one exception,! of which we have knowl-
edge. The belief has been expressed that both sexes of the Pso-
cidee possess the power of spinning a web which McLachlin affirms is not
distinguishable from that made by spiders.?. This habit, which character-
izes the larvee of insects, is carried forward to the perfect animal among
the Aranez, and, as we have seen, the habit of protecting themselves by
tubular spinningwork, in one form or another, exists among some _ spe-
cies of every tribe of spiders.

One who is conversant with insect architecture cannot but be struck
with the resemblance between the nests of spiders and those made by the
larvee of certain insects. Brief allusion has already been made to this, but
it may be worth while to call attention more distinctly thereto.

Very often I have met, along the seashore in New Jersey, a species of
leaf roller Tortricid moth, whose species I do not know, that has reminded

me of the nests of Epeira trifolium spun among the ferns, and
Hpeira which is one of the most beautiful examples of the nesting habit
oiee to be found among spiders. The two objects may sometimes be

seen almost side by side, and even the most casual observer
would scarcely fail to note that they must have been constructed upon the
same fundamental principles of architectural instinct. There are, of course,
differences which one may note without very acute perception; but the
resemblances are certainly worthy of consideration, and it is to these that I
have here wished to call attention. (See Figs. 316 and 317.)

The nest of Theridium riparium is constructed on very much the same
principle as that of the larva of the caddis fly, or case worm, a Neurop-

terous insect which is very well known, and whose remarkable

Psocide.

Reute architectural habit has excited the interest of naturalists. Sev-
um an Sa.

eral illustrations of the nests of this insect are given.* The first
the Cad-

dis Fly. Tepresents a case made of bits of moss, and is the work of Lim-

nophilus rhombicus. (Fig. 323.) The second represents the case
worm, found in great abundance by Professor Packard in Labrador, and
which he supposes to be the work of Limnophilus subpunctulatus, the
most abundant species found in Labrador. The case is straight, cylindri-
cal, and built of coarse gravel, and the larva is a thick, cylindrical, whitish
worm. The next figure (Fig. 320) represents the nest of Limnophilus

1 Psocus sexpunctatus. See a note of the author in Proceed. Acad. Nat. Sci. Phila., 1883,
page 278.
* Monograph British Psocidee, Entomological Monthly Magazine, Vol. ITI, 1866-7, page 268.
‘These are copied from Packard’s “Guide to the Study of Insects,” page 617.

332 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

flavicornis, a European species which is often constructed of small shells;
and Fig. 324 illustrates the case or nest of the European Limnophilus pel-
lucidus, which is formed of large pieces of leaves laid flat over each other.

I am not familiar with the larva’s method of putting together these
nests, although I have some very interesting ones in my possession, not
greatly differing in construction from those which are here illustrated.
The principle on which the various particles of material are collected and
placed together to form the perfect cover made by the little worm cannot
differ greatly, judging from architecture alone, from those which regulate

Fic. 319.

Fic. 318.*
Nests of Theridium (Fig. 318), and the Bag worm (Fig. 319).

the behavior of Theridium riparium when she builds the nests described
upon the preceding pages. (Fig. 318.)
A like reflection is suggested by the work of the well known bag worm,
or basket worm, Theridopterix ephemereformis. (Fig. 319.) This is the
caterpillar of a species of moth, sometimes known as the house
ene builder moth (Oiketici). The insects are also called Canephore,
um an i
basket carriers, and the Germans call them Sacktriiger, or
Bag es :
Worm, ‘sack bearer. The baskets of the above species are among the
most familiar objects in this geographical district, and may be
seen hanging in multitudes to the limbs of trees after the leaves have
fallen in autumn. I have been greatly interested in studying the whole
srocess by which these interesting objects are made, and have described it
d d
elsewhere.”

‘The part above the horizontal line on the left of the figure was made of pellets of
clay in natural site; that below of material artificially supplied. “Science Gossip,” January,
1868, page 12, sq.

? In my “Tenants of an Old Farm,” Chapter XIX., “ Housekeeping in a Basket.”

NEST MAKING: ITS ORIGIN AND USE. 333

The material which is fastened upon the internal silken sack consists
of particles of the food plant upon which the caterpillar is reared. These
are the stems and other rejected portions of the plant, left when feeding,
and which hang to the silken bag on the outside. They are sometimes so
thickly placed that the silken sack is entirely covered, as at Fig. 325,
which is a specimen from the Southern States in my collection of insect
architecture.

One might extend these comparisons much further and find that the
striking resemblances between the protective architecture of spiders and
that of the larvee of insects might be carried to the very lowest
forms of life. Prof. Joseph Leidy, in his monumental work
upon the Rhizopods,! has presented numerous forms of these
creatures, that he so far down in the scale of animated being, which at
once call to mind the habits of the caddis fly larva and the larva of the
house builder moth. Fig. 326 represents the Rhizopod, Difflugia urceolata,
a common form found in ditches in the neighborhood of Philadelphia.
Ordinarily the shell of this Difflugia strikingly resembles the ancient
Roman amphora. The body of the shell varies from a globular shape to
a more or less ovoid form; the principal extremity or fundus is more ob-
tusely rounded, or more or less acute; and sometimes it is rounded and
more or less acuminate. The shell is composed, as is generally the case
in other species of the genus, of colorless angular particles of quartz sand,
mostly of larger ones scattered with more or less irregularity, while the
intervals are occupied with smaller ones. Frequently larger stones occupy
the larger shell; but, passing this, they gradually become smaller, approach-
ing the edge of the rim or reflected lip.?

Another Rhizopod which suggests at once the architecture of the bag
worm is represented at Fig. 327. Difflugia acuminata is one of the most
common forms of Rhizopods, and is very generally distributed. Not un-
frequently, as in the figure, the shell is composed of colorless, chitinoid
membrane incorporated with quartz sand, alone or with this and intermin-
gled diatoms. In this the grains of sand are usually closely placed in jux-
taposition at and near the mouth of the shell, but are elsewhere scattered
and separated by wide intervals. In some cases the shell is more or less
covered with large diatoms, which are generally adherent in the length,
and diverge upward beyond the boundary of the shell.*

Not only do we find these striking resemblances in the external archi-
tecture of these widely separated creatures, but apparently we find the
same purposes originating the architecture. The house builder moth larva
constructs her thatched domicile in order to cover over its soft body;

Rhizo-
pods.

'“Fresh Water Rhizopods of North America,’ Washington, 1879.

* Op. cit., page 107, and pl. 14, Fig. 3.
* Leidy, Idem, page 111, pl. 13, Fig. 21.

AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Wy Ae , x
ji, Wah

rat
v7;
Mui? Z

Fic, 324.

Fig, 321.

] Fic. 326.
A COMPARATIVE VIEW OF THE NESTING ARMOR OF RuIzOPODS, CADDIS FLIES, AND BAG WORMS.

Fia. 320. Case of Caddis (Limnophilus flavicornis), made of minute shells. Fig. 321. Case of gravel,

made by the larva (Fic. 322) of a Caddis fly. Fic. 323. Case of Caddis worm (Limnophilus rhom-
bicus), made of moss. Fie. 324. Case of Caddis (Limnophilus pellucidus), made of pieces of
leaves. Fic. 325. The basket or thatched bag of the Bag worm (Theridopterix). Fig. 326. Shell
of a Rhizopod, Difflugia urceolata (variety amphora), built up of quartz sand. 100 diameters.
(After Leidy.) Fic. 327. Shell of Rhizopod, Difflugia acuminata, composed of quartz sand and
diatoms. 200 diameters. (After Leidy.)

NEST MAKING: ITS ORIGIN AND USE. 335

the caddis fly builds over her body her tiled tube of shells or pebbles, or
covers it with thatched moss, for the same purpose. The animated body of
sarcode known as a Rhizopod evidently is moved by the desire
Common {9 preserve its protoplasmic structure, when it gathers diatoms
Architec- 114 pits of sand from which to rear around itself its beautiful
tural Aim ; 2 : :
architectural armor or encasing wall. The nest making spider,
Epeira trifolium or Theridium riparium, is manifestly moved by the same
disposition to shelter the soft abdomen, which is the most assailable and
vulnerable part of her body.
From the lowest form of Rhizopod, through these more highly organ-
ized insects and arachnids, we may ascend to man, who occupies the sum-
mit of the zoological pyramid, the crown and king of creation,
Man's and note the same outcome of life. In the great cathedrals
saa which he rears to the Almighty, or in the humble cottages
cture. : a , ; : : >
which he builds, alike in stone wall, in tiled or shingled or
thatched roof, we may see the methods of his humbler fellows of the
creature world, only carried out upon a loftier scale and with a nobler
purpose.
Thus, in the nesting architecture of living things, the naturalist may
see, as on so many other fields of observation, the harmony which _per-
vades creation.

“From harmony, from heavenly harmony,
This universal frame began :
From harmony to harmony,
Through all the compass of the notes it ran,
The diapason closing full on Man.”

What is the meaning of this harmony? By what dominating Force,
through what natural laws has it been accomplished and is it main-
tained? These are problems which have occupied the thoughts
of students of nature, and upon which they have honestly and
earnestly divided. We may indulge the hope that when the
realm of life has been sufficiently explored, from the larger knowledge of
facts there may issue, in this matter also, substantial harmony.

By whatever theory one may account for these facts, certainly the facts
themselves show that an unexpected degree of harmony pervades all the
home building industry of the smaller creatures that inhabit the globe in
common with more highly organized animals. The traces everywhere ap-
pear of one common origin, or (as many would prefer to express it) of one
Originating Mind, whose Will, the source of all natural forces, is expressed
in the infinite variety of forms and methods which these natural forces are
working and have wrought through all the ages of time.

Universal
Harmon

COEIBACE Wy XOX:

THE GENESIS OF SNARES.

Ir now remains to trace the relations which exist between the various
forms of spinningwork treated in detail or alluded to in this volume.
In attempting this I am well aware that great difficulties he
Spinning- in the path, and am not unmindful of the fact that one is in-
work Re- |. : : ; a
linens. clined in such a task to give greater or less play to imagination.
Moreover, the limited knowledge of the spinning habits of our
spider fauna hinders me from tracing the connecting links that would
perhaps show intimate relations between industries which now seem widely
separated. Nevertheless, one cannot well resist the effort.
In considering the natural relationships of snares it is at least conven-
ient to proceed from the standpoint of a gradual evolution or development
of the spinning habit. In justice to my own belief, it 1s proper
A Hypo- to state that such a course is entirely hypothetical. As far as I

eee have been able to grasp the subject and reach conclusions there-
point. from, there appears to be no ground, either in the habit of ex-

isting fauna or in the records of geologic ages, to justify the as-
sertion that any one tribe of spiders has been the parental stock out of
which the others have proceeded, or that any one form of spinningwork
has been the germinal form from which all the varied aranead industries
have had a natural and gradual growth.

Nevertheless, in that scientific use of the imagination which is a most
advantageous and often a necessary factor in exhibiting the relations of
things, it is proper for one to so far take advantage of current beliefs as
to express certain relationships, which very clearly and beautifully ap-
pear, as though they had originated through diverging or interblending
lines from one common source. Doubtless many of my readers, certainly
most of my scientific friends, will think that my tentative standpoint ex-
presses the real state of things; and if the truth rests with them I shall
be glad to thus help them make it appear.

If,

As the starting point of our first comparative view I take the Trapline.
The simplest use of the thread or combination of threads thus denomi-
nated may be seen in the habits of such a spider as Epeira strix. This
aranead, like the majority of her congeners, forsakes her web during the

(336)

THE GENESIS OF SNARES. 337

day and seeks some near by retreat. This may be a curled leaf, the shelter
of a projecting bit of bark, a recess in the rocks, or other like refuge, in

which she is measurably protected from her enemies. As she
Genesis abandons the centre or hub of her orb, upon which she has
of a 5 : ; i
frapline. been hanging during the night and early morning, she leaves

behind her the precautionary thread which is habitually drawn
out after spiders when they move, and which I have called the dragline.

This thread is carried from the hub to the point of retreat. It can
nearly always be traced by a careful examination of the orb, and by
means of it the practiced spider hunter can frequently trace this
most secretive species to her snare. This is not universally the
case, however, as I
have sometimes been foiled
in attempting to find Epeira
strix by her dragline. How-
ever, the custom prevails, and,
with less secretive species, the
line can more readily be used
as a trail to the spider’s re-
treat. I do not know that
this line serves any other
purpose than a sort of gang-
way by which the spider
leaves her web and_ returns
to it when the evening shades
begin to fall. Nevertheless,
one may recognize in it, per-
haps, the germ of the trap-
line.

With other species, such as
Epeira trifolium and Epeira
insularis, the trapline is more
sharply differentiated from the snare itself, and is specialized in its uses.
It is a line connected by more or less deltated branches with the
retreat of the spider in her leafy or silken tent. This is habit-
ually a single line in the species just named. The end by which
it is connected with the hub of the orb diverges into several branches,}
forming a delta or triangular pyramid, the basal lines of which seize
the hub at several points. The opposite extremity enters the nest and
is held by one or more of the spider’s feet (Fig. 328); usually one
of the front legs is extended and grasps the line with the claw. In
this manner the trapline is held very taut. The branching portions draw

Fic. 328. A nest of Epeira trifo- 1
lium, showing the trapline at \ /
the nest terminus.

Trail and
Telegraph

‘See the various figures in Chapter X VII. illustrating this point.

338 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

up the various lines of the snare, so that all the radii, particularly, are
held in a tense condition.

This tension of the trapline and radial lines makes the whole web an
efficient telegraphic instrument for conveying to the spider in her den or
domicile any vibration caused by insects entangled upon the snare. When
by such telegraphy the capture of an insect is communicated to the sen-
sitive feet of the spider, she immediately rushes along her trapline to the
hub, and from that point to her prey. Thus, in the typical Orbweaver’s
snare, the trapline serves the two purposes—first, of communicating to
the proprietor the presence of entangled insects; and, second, of affording
a gangway to the net and back again to the tent. In short, the incidental
dragline appropriated to the uses of a gangway, in Epeira strix, is here
specialized into a trail and a telegraph.

As far as I can positively affirm, no other than these two purposes
are served by the trapline in these species. However, it is the habit of
spiders who thus use this specialized instru-
ment to frequently pull upon it, increasing the

tension by drawing it towards them-

i selves and then letting it go again,
ae reP" making a series of rapid jerks. I

have never been able to observe that
this motion had any purpose or effect to in-
crease the entanglement of an insect, and have
always regarded it simply as a means of deter-
mining the presence, weight, and energy of the
Ear opear eben et a victim, and thus estimating the degree of cau-
at her hub, to show the radiiclus- tion necessary in approaching it. If the insect
Op et wee be quiescent, as often occurs, the pulling and
sudden relaxing of the trapline is quite sure to set it in motion again.

It might, perhaps, be observed in this connection that even when the
spider is hanging on guard at the centre of her orb, she spins a series of
deltated lines, the apex of which is grasped by several claws of
‘the legs, and the opposite ends of which are attached to the
radii in such a way as to cause a direct communication between all parts
of the orb and the sensitive feet within which these lines are thus con-
verged. Examples of this are especially observable in the various species
of Acrosoma. Fig. 829 shows the manner in which Acrosoma rugosa, when
hanging upon the open hub of her snare, thus gathers converging radii
into her claws. <A like habit in the cases of Acrosoma mitrata and spinea
is illustrated by Figs. 112 and 113, page 127. In the same manner that
the trapline is jerked by nest building Epeiras, in order to tighten it and
test the presence of insects, this series of footlines is also frequently jerked,
and apparently for the same purpose.

While I cannot record observations which justify. me in asserting that

Footlines

THE GENESIS OF SNARES. 339

this use of the trapline, or the similar use of the footlines, aids in entang-
ling insects, I can very well believe that it may frequently contribute more
or less to this result. This may be done either by the mechanical momen-
tum of the lines which are swung around the insect by the sudden tighten-
ing and releasing thereof; or by exciting the insect and causing it to move
its wings and legs, thus entangling it more and more within the viscid
spirals.

A young Epeira domiciliorum well illustrated the general tendency in
this direction when under special compulsion of circumstances in the cap-

__. ture of prey. When observed, her web had been badly damaged
Utilizing }y insects. At the sides all the spiral lines had disappeared,
Web ¥s :

Brag and a few patched radii alone remained. On the upper part of
ments. the orb were a few spirals. A segment remained in tolerable
condition on the lower part of the
snare, but it also was greatly damaged by the
‘fracture of some of the radii. The spider had
spun a number of lines from the hub to the spin-
ning space, and these, with the remaining radii,
were gathered together in all the fore feet and
pulled very taut. The upper part of the web was
also tightened, but to a less extent, by the action
of the two hind feet. But on the sides the web
appeared to hang loose, and, taking a side view of
it (Fig. 330), one could readily see how the whole
action of the spider was bent upon keeping the
valuable portion of the web in a taut condition,
ready for service, while the other parts were left
to take care of themselves. This spider had lit-
tle more space available for the capture of prey 6. 980. Epeira domiciliorum,
= . 3 trapping with a fractured snare.
than a Triangle spider with a complete web. I
have no doubt that, had I waited to see an insect strike the sector thus
controlled by the fore feet, I should have seen this Orbweaver let go the
clustered traplines held in her claws precisely as the Ray and Triangle
spiders habitually release their single traplines.

Another example was afforded by the snare of a full grown Stellate
spider (Epeira stellata), which by some rare ill fortune had lost the entire
central part of the orb. Yet the animal was not discouraged, but
held her place at the hub with her legs doubled up in the manner
usual to the species, and holding quite taut her little remainder
of a web out on the margin, together with the connecting radii that had
survived the wear and tear. Here, again, a few sectors quite disconnected
from the hub were doing duty for trapping insects, as is habitually the
case with the Ray spider. (See Fig. 331.) (Compare Fig. 331 with Fig.
187, page 196.)

Epeira
stellata.

340 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

In certain species the trapline consists of several threads, as, for exam-
ple, in Epeira labyrinthea. In other species, where a single trapline is
the rule, the same habit will be sometimes observed, as, for ex-
ample, in the case of Zilla, whose trapline becomes a strangely
complicated series of threads. (See Chapter VIII, Fig. 118.)
Labyrinthea connects the central portion of her orb with the silken dome
or leafy shelter within her maze of intersecting lines, by a series of straight
lines sometimes quite numerous. These make a little bridgeway between
the tent and the orb. When the spider is within the tent the feet are
reached beyond the borders and grasp at various points these lines.
Sometimes the lines are twisted into a strong and single thread, either ac-

cidentally or by the voluntary
action of the spider.
When one takes a_ side

view of the orb (see Fig. 116,

page 138) he almost invaria-’

; bly finds the centre

| ae Be drawn inward and
| upward towards the
spider’s retreat, thus causing
all the radial lines to bow
inward or toward one anoth-

fren er. In this position the snare
ee

a ey ay in its general outline has a

al striking resemblance to that

of a Ray spider when it has

been bowed by its proprie-

| tor in the manner described

Fic. 331. The Stellate spider trapping with the scant and illustrated at Fig. 190,

remnants of a snare. 5 5

page 196. Enpeira triaranea

has the same habit of bowing her web upward and inward towards her

den, and, indeed, such is the case with some other species; necessarily,

more or less of this bowing of the orb must result from the habit of

holding the trapline taut. But in the case of Labyrinthea the bowed

condition of the web is more striking, I think, than in any other spe-

cies with whose spinningwork I am acquainted, and is so noticeable that
the most casual observer may see it.

We come now to the use of the trapline as it is even more highly

specialized in the habit of the Triangle spider. Here the line serves not

only the purposes common to the species already described, but

Multiplex
Traplines.

Hypt- becomes a real instrument in the spider’s hands for springing
Ote8 her net. Such Orbweavers as Epeira strix and Epeira trifolium
Trapline. :

when they are drawing their traplines taut, necessarily leave a
little slack line between the point of seizure by the fore claws and the

THE GENESIS OF SNARES. 341

point at which the inward end of the line is fastened to the tent or stays.
But this loop is only incidental, and serves no special purpose (as far as
we know) in securing the entanglement of prey. But with the Triangle
spider the coil is a prominent and special feature of the net. It is always
found between the hind legs and the third pair of legs, and when the
snare is sprung, as already described, this coil instantly straightens out,
permitting the whole net to shoot forward, and the forward motion sends
every line around the entangled victim and adds to the degree of its en-
tanglement.

When we consider the Ray spider’s habit we find the trapline here
even more highly specialized. It has, first, the uses common to the typical

Orbweaver, that is to say, it serves for telegraphy and _transi-
Ray tion. Second, it acts as a regular trap, inasmuch as it has a
Spider’s Fae ; ; ; ;
TE DEOS. prominent coil of slack line ready to be sprung at any time.

But, further, it unites all the separate sectors of the orb into one
common system, thus serving not only to spring a single net, as in the case
of Hyptiotes, but a series of united nets of the same sort.

Moreover, this spider possesses the habit of moving its trapline from
point to point, instead of keeping it fixed as in the case of the Triangle
spider—certainly a remarkable adaptation. Further, by a simple but ingen-
ious system of “locking” the web, that is, twisting the axis of the sey-
eral rays around the extremity of the trapline, the spider causes the trap-
line to hold her whole snare in workable position while she resorts to
any part thereof to seize her prey. ‘Thus, also, as the daily wear and tear
in capturing food destroys in succession various parts of the web, the
trapline holds together and intact the remaining parts, even though quite
opposite to each other.

We have thus traced the natural history of this important and useful
member of the Orbweaver’s web, from a simple dragline by which the an-
imal escapes from and returns to her snare, through an interesting series
of variations, to this quite specialized and complex use which marks the
trapping habit of Theridiosoma gemmosum.

Thus, as a dragline it serves, first, the cautionary use of escape from
danger by swinging to an anchorage; second, it affords a trail for retreat
to the place of departure; third, it serves to telegraph agitation
of the snare to the proprietor; fourth, it holds the snare taut,
and thus maintains its efficiency; fifth, it acts as the spring line of a
genuine trap; and, sixth, it binds and locks together the united or the dis-
severed parts of a snare, which at the same time it also springs separately
or together as need requires. Of course, I do not pretend to intimate that
there has been anything like a development of the use of the trapline in
the sense that there is any traceable genetic connection between the various
adaptations here pointed out. So far as I know, and, perhaps, as far as
can be known, every species preserves its own habit quite independent of

Summary

342 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

any relation to other species of its tribe. Yet it is certainly interesting
to observe the varieties of use to which this implement has been placed,
and to observe that a seemingly rudimentary implement and incidental
service in one species, as Epeira strix or Epiblemum scenicum, become in
another and widely separated species a special instrument and a complex
and permanent habit.

Of

In the foregoing section we have traced the connection between the
primitive dragline and the traplines by which snares are operated, and
_ have noted the relations or points of resemblance
Genesis of a: : Ree ces .
poner between the various forms of trapline among Orb-
‘weavers, from the simplest to the most complex.
We may now attempt a lke service for the entire sys-
tem of trapping spinningwork known as
the snare. In this undertaking I propose
to go beyond the field of orbwebs, and
take into the view the characteristic snares
of all the aranead tribes.
Let us suppose, again, that the original form of spinningwork was the
single line which has been alluded to as the dragline, and whose relation-
ship we have just traced into the various forms of snares made
The Origi-})y Orbweavers. If now we venture further to suppose that the
nal Spin- : i : pee : + i
: spider always possessed the habit which is strongly apparent in
ningwork : , i Oo. :
such tribes as the Lineweavers and Orbweavers, of moving rest-
lessly to and fro between twigs and leaves, spinning out a single thread,

Fic. 332. The original spinning thread—
the dragline, a.

——

Fic. 333. The meshed snare of Theridium, thickened at the top, and supported by
silken trestles.

and making anchorages and attachments as it moves (Fig. 332)

arrive at the form of snare characteristic of Lineweavers.
These straggling lines, crossed at all angles, would soon, and without

we easily

)

THE GENESIS OF SNARES. 348

any apparent purpose of the spider, drop into a maze of interlacing single
threads, which would present in crude form the typical snare of such

genera as Theridium, Pholcus, Ero, Neriene, and others of the
Therid- Retitelarie. That web is, in point of fact, just such a snare as

ium’s :
Becsniad I have seen other spiders make, notably the Orbweavers, by such
Snare. Purposeless moving back and forward as I have mentioned,

To be sure, the snares of Theridium and Pholcus, as we now see
them, have a little more finished character than that of the crude cobweb

1 \
rh a \\\\

RU Be

\ I lige, 2a i

Yi Z
Y SS
Poy A
he. =— .
fx \ 2
Cry = — ‘=

WE,

ail

Fie. 334. The sheeted web of Linyphia costata.

described, but the difference is not very great, and it therefore implies a
rigid persistence in habit throughout an immense period of time.

We take another step in the development of web making, confining
ourselves still to the tribe of Lineweavers. I have already described, in
the chapter on Engineering Skill, the manner in which Theridium tends

344 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

to thicken that portion of her snare in which she hangs back downward.
This is a most natural action, resulting from several facts. First, as she
passes from her resting point to the various parts of her snare in which
insects are entangled, she spins out an anchorage for the dragline, by
which she is sure to connect herself to this roosting spot.

Again, when she returns with her prey, she swings her abdomen around
several times, before finally settling for her banquet, and at each time she
ejects a similar jet of silk and unites the thickened spots by a little thread.
(See Fig. 59, page 61.) Still further, in her restless movements back
and forward over her web, around this central roost, she throws out sim-
ilar anchorages and lines. Thus, this spot and its vicinity in a little
while become much thicker than the surrounding portions of the snare.

AIS SEU

SSSA
PSSS

Fia. 335. Linyphia’s snare among the morning glories.

Here, now, we have the germ of the typical snare of the genus Liny-
phia. In point of fact, it consists, as I have already shown (Chap-
ter [X.), of a sheet like bit of spinningwork, whose fibres are

aheeed very open, or, as one might otherwise express it, of a netted
erid- eG fein tt Rie 5 ee ae 3 tas
cog sheet of spinningwork, whose meshes are very close. Our origi-

Linyphia, 28! snare of irregularly crossed lines has thus advanced a step

toward a meshed sheet like snare. In many species of the genus
Linyphia the snare is simply a netted sheet, more or less horizontal, having
outgoing straight lines, which support it above and below. It thus very

THE GENESIS OF SNARES. 345

nearly approaches, in the habitual form of its snare, that form which, as
I have shown, incidentally results from the long use of Theridium’s web
of intersecting lines.
The step is not a large one by which we may conceive the snare just
described to be transformed into that of the dome shaped web of Linyphia
marginata, or the bowl shaped web of Linyphia communis. It

apea only needs, in the former case, a little more downward pressure
serie e upon the cords at the edges, and in the latter a little more

pressure upon the marginal cords upward, to complete the proc-
ess. (Fig. 335.) We may now pass from Lineweavers to Tubeweavers. A
glance at the snare of Agalena novia, for example, as represented in
Fig. 215, page 217, and Fig. 336, will show how close is the resemblance
between it and the snares of Linyphia already described. Agalena has a
sheeted web of open spinningwork, or of close, irregular meshwork, as one
may choose to put it, whose weft becomes
much thickened in course of time by fre-
quent overlaying. It also has the crossed
lines extending upward, for the most part,
but often downward also, representing the
original rude intersecting lnes of our sup-
posed primitive snare. This retitelarian fea-
ture of the web is a most important factor
in the daily capture of prey, by signaling
their presence to the waiting proprietor ;
by arresting and trapping them so that they
fall upon the sheeted premises beneath; and
by actually entangling them.

‘Tis modehiealyoreanized, of allc thie (> 6, Sieeted wel aud tube of Agalens
r . 3 ncevia, woven on a hedge.
Tubeweaving species has therefore substan-
tially a Lineweaver’s snare. To this structure is added the tube, which,
in point of fact, is not the snare, but the nesting place. I have already
shown, in the chapter on Nesting Habits (Chapter XVII.), the manner in
which this feature of the snare may have been gradually developed by
the natural action of the spider. In point of fact, the tube is the typical
nest of all species, and is naturally formed by the movements of the spider
within a limited space, spinning out as it moves the silken material which
it secretes.
Theridium, and still more habitually and definitely Linyphia, will form

a little tube like structure by the mere gravity of the body as it hangs

upon its snare in this manner: The eight legs reach upward,
From forming what may be called the sectional outline of a tube cut
rien es horizontally. The weight of the spider, aided by the violent agi-
pete ght ¢ e spider, y the g

tation of its snare when struck by an insect, pulls down these
eight points in such a way that a little conical or dome like tent is formed

346 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

just above the spider’s feet. This is illustrated at Fig. 157, page 167.
The same effect is produced by the stay lines which are attached above,
and which often draw up parts of the surface, as at Fig. 537, into little
domes. We might almost think of these as the germinal form of the
tube as it is seen in the Lineweaving species. But still more distinctly
we may see the habit naturally engrafted upon such an interesting species
as Theridium zelotypum or Theridium riparium, whose beautiful nesting
habits are described in Chapter XVIII. In these species the inside lining
of the nest of gathered sticks and rubbish is a distinct tube, which is
sometimes prolonged beyond the mouth of its den.

Indeed, whenever a Theridioid spider takes its place beneath a leaf or

f > P

oe a , lly .

a oi, he,
ie AB vl

T WAwmttcds
i », MeL fy 41
Oy dt (Sf PN (. Wit
Ms e.
Gi i 1s yi
ay, 4
¢ ihi./

Up Wry. aft

ih

\
4 tw rn o>
a a bi I ) La, Leg y
fou CA My ap pz AY ws, A i
© we hi ity, 0 a \"\ on Ns ti us \ i.
P WAIE\\> " 4 ia /A\\¥
\; Ie 7 | Ue AUR\\ a NOYES
\ I) ey , Ne AM PAA TNEY i
, Mai ait Ui NOTA. :
PON ea (Ce aN as
eg oy ul oa
Y wifi =}

yp
i NEN

ith ;
U0 PMI Ly

“ BY ; Corn

Mon,
Q oP

Fig. 337. Snare of Linyphia costata, showing tent like elevations.

other shelter, as it often does, especially under stress of continued bad
weather, it is sure to spin above and around its abdomen a little
conical mass of lines, which, by the pressure upwards of the an-
imal, is compacted or beaten into a concave form. If the weather
continue unfavorable, or the spider is undisturbed for a considerable length
of time, this little rudimentary tube will gradually make encroachments
upon the leafy shelter, and will be prolonged outward and downward.
Now, when the sun comes out and invites anew to web spinning, it is in-
evitable that the snare will be spun just beneath or close in the neighbor-
hood of this tube like shelter. Thus it becomes easy to explain the ap-
pearance of a tubemaking habit, not only in Lineweavers, but in Orbweavers

Growth of
a Tube.

THE GENESIS OF SNARES. 347

and Tubeweavers. The same is true of the Saltigrades, who persistently
live in tubes; of the Laterigrades, who occasionaly form them; and of the
Citigrades and Tunnelweavers, who make silk lined
tubular burrows in the ground.

Among the causes that would lead directly from a
simple lineweaving to a tubeweaving habit are the ma-
ternal function and instinct. The mother seeks retire-

ment when the time of ovipositing draws near.
Influence Beneath some ledge, or leaf, or stone, or twig,
of Mater- :
nite or other convenient shelter, she takes refuge,

and there remains until the last act of ma-
ternal care. The very continuance in one place would
naturally lead to the formation of a rudimentary nest
in the manner just explained. The mother’s prompt-
ings to protect her progeny by overspinning the eggs
would lead almost inevitably, in many cases, to her- 5, 565 qnecocooning nest
self sharing the provided shelter, or extending or of a Laterigrade spider,
adapting it for her own benefit. seme iataea

How natural is such a step appears from the fact that such spiders as
the Laterigrades, that never (or but rarely) use any sort of snare or shelter,
resort to a tubular cell for the protection of their eggs
and young, and dwell within it themselves during the

hatching season. (Fig. 338.) So, also, Ly-
Lateri- cosids, which habitually wander in the open
as ae in pursuit of prey, when the time for co-
Lycosids. Cooning comes make a burrow or nest in

the ground or beneath a rock, which they
silk line and use as a domicile. Thus, also, Dolo-
medes, which is persistently nestless and webless in
ordinary habits, is drawn by maternal instincts to spin
among the leaves, or in like situation, one of the
most complete nests that can be found in the whole
range of aranead spinningwork.

Having thus pursued the line of analogy from
the Lineweaving to the Tubeweaving species, we may

return upon our course for a moment to
Analogy trace the analogies between the Lineweaving
Between and Orbweaving species. Already, in a pre-
et ceding chapter (Chapter VII.), I have fully
and Orb- illustrated the peculiar habit of certain Orb-
weavers. Weavers to combine with their typical or-

bicular snare the typical retitelarian snare
of the Lineweavers. Conspicuous examples of this are Epeira labyrin-
thea, Epeira triaranea, and most of the species belonging to the genus

Fic. 339. The cocooning nest
of Dolomedes sexpunctatus.

348 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Zilla. In point of fact, the Lineweaving habit seems to drop into the
spinningwork of all the Orbweavers with more or less facility. Such a
genus as Argiope is able to swing out
from either side of its orb a snare
which, considered separately, is entire-
ly characteristic of the Lineweavers.
(Chapter VI., Fig. 96.) It will proba-
bly be sufficient in this connection to
refer the reader to the figures and
facts contained in Chapter VIII. (See
Figs. 115 and 123.)
An interesting illustration of this
commingling of typical habits was
once observed upon a bare,
Coopera- qead branch of a bush.
yeas Within the branching limbs
= keeping. 2 Labyrinth spider had es-
FIG. 340. Coiperative housekeeping between Epeira tablished her peculiar snare.
labyrinthea and Linyphia communis. :

The delicate orb swung
at one side, and a maze of crossed lines containing the nest-
ing tube was woven above the orb. Close by a female
Linyphia communis had spun her snare, which consists of
a bowl of loose sheeted spinningwork and a maze of reti-
telarian lines hung above it. Now, it so happened that ¢&
these two neighbors wrought their snares so
close to each other that they really interblend-
ed. The cross lines of Labyrinthea and the
cross lines of Linyphia were so interwoven that Fie. 341. The tubular den of Epeira
it was impossible fer me to determine the “"*°0°%s “tin Sevedical,
boundary line between the two webs, or
to say at what point the work of the one
ended and the other began. (Fig. 340.) It
was a case of cooperative housekeeping,
something like that which I have already
illustrated in the case of two Labyrinth
spiders (see Fig. 120, page 135), the differ-
ence being that in this case the codpera-
tion was between species of different tribes,
instead of the same species. Nothing could
better illustrate the community of habit,

Fig. 342. The curled thread of Dictyna on its in the particular of spinning retitelarian
supporting radiating lines. (After Emerton.) :

snares, than such a juxtaposition as this.
af . . .

We have already seen how the tube is used habitually by certain

species of Orbweavers, as, for example, Epeira strix, Epeira triaranea, Laby-

7

THE GENESIS OF SNARES. 349

rinthea, and Thaddeus (Fig. 341), and, indeed, by all the nest making
species, such as the Furrow, Insular, and Shamrock spiders. This feature
of their spinningwork is readily ac-
counted for, and appears most closely
to connect that tribe with the other
tribes of the spinning fauna. It is,
however, far more difficult
to explain the origin of
such a remarkable habit as
the construction of an orbicular snare
of that geometric character with which
the reader is now familiar. We ap-
proach it, however, from the direction
of the Tubeweaving genera, as Dic-
tyna and Clubiona. The fact has ~ ,
heretofore been alluded to, that they
are provided with special organs, the
cribellum and calamistrum, for the
exudation and preparation of a floc-
culent thread out of which their trap-
ping lines are spun. These threads
are placed upon lines composed of or-
dinary spinningwork, which usually
diverge with more or less regularity from some common point. The manner
of placing them is well illus-
trated by Fig. 342, where the
curled thread is seen spread
along its supporting lines, and
passed from one line to anoth-
er, and so back and _ forth
throughout the snare.

This would seem to be a
most natural movement. It is
precisely the one which, as we
have explained (see Fig. 95,

Chapter VI.), is. re-
Dictyna’s sorted to by Argiope
Curled ab ite :
Spiral cophinaria and Argi-
Thread. Ope argyraspis when

they form the zigzag

Fig. 344. Orb like snare of Dictyna philoteichus, woven band which adorns and charac-
ree h terizes their round web. It is

naturally produced by the striding movement of a spider between two
lines, swinging her abdomen backward and forward as she moves. In

Origin of
Orbwebs.

Fic. 343. The snare of the Wall loving Dictyna,
woven on a Philadelphia city wall.

350 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

some cases, as In the web of a species of Dictyna which abounds in Phila-
delphia and vicinity, and everywhere spins upon our walls and fences, this
peculiar snare takes upon it, in a rude way, the outlines (Fig. 348) and even
in greater detail the general form of an orb,-as may be seen by consulting
Fig. 344. In other words, this wall loving spider starts from its little tubu-
lar nesting place and drags its lines out to surrounding adjacent points.
Between these lines it then extends its flocculent thread, carrying it down-
ward to the circumference and backwards again towards the centre, and
so back and forth, until, as we have said, the rude outline of an orbweb
is formed.
Now, it is of interest to know that among the Orbweavers we have two
well defined families who are provided with the calamistrum and cribellum,
and spin the same kind of a thread as that just described.
Orb- Hyptiotes, or the Triangle spider, makes a web whose four di-

weaver’s . : : eet : : :
Curlea Vers!2g lines, with their interlacing flocculent spiral, might very
Spirals. Well be represented by a section taken from the web of Clubiona

or Dictyna. We are not able to trace a close relation between
these two families, along any structural lines (apart from the cribellum
and calamistrum), but the relation between their spinningwork is very ap-
parent.

Yet, further, we have among the Orbweavers the family Uloborine,
whose species construct an exact orbicular snare, in every essential respect
resembling the snare of such Orbweavers as the Orchard spider (Argyro-
epeira hortorum) or the Extended spider (Tetragnatha extensa), except
that the spirals have the teased or flocculent characteristic of Clubiona,
instead of the viscid beaded armature common with Orbweaving species.
Thus our sectoral snare of Hyptiotes with its flocculent spiral lines has
become a complete orb; or, in other words, the circular sector appears as
a full circle, retaining its flocculent interradials.

It is interesting here to note, that while the Triangle spider, on the
one hand, is connected with the Tubeweayvers by this peculiar flocculent

thread, and, on the other hand with the species that spin full
The Ray orbs by the same characteristic thread, it is connected with the
Spider’s : : } ; ; ;
Tink. Orbitelariz at another point by the interesting species known as

the Ray spider. That is to say, the Ray spider has the viscid
armature common to the Epeiroids, and its snare is arranged in orbicular
form, like that of Uloborus and other Orbweavers. But, strangely, the
various sectors of the circle are so combined that they can be managed
wholly or in part in the same peculiar manner which characterizes the
Triangle spider. That is to say, the trapline is held with a coil of slack
thread above the two hind feet, and the various sectors of the circular
webs are snapped off separately or unitedly by the same spring movement
that marks Hyptiotes, and which is fully described in Chapters XII. and
STL,

THE GENESIS OF SNARES. ool

In considering the relations which the snares of Orbweavers bear to
those of other tribes, one cannot overlook the important characteristic
which has been considered under the chapter relating to the
viscid armature. That is to say, the characteristic snare of the
Orbitelariz consists of a series of straight lines covered with
viscid beads, and disposed in the form of spiral concentrics, or spiral
loops upon radiating lines lacking this viscid quality.

Is there any trace of this remarkable characteristic in the spinningwork
of the other tribes? We have seen that the webs of Uloborus and Hypti-
otes are destitute of this peculiar armature, substituting therefor the floccu-
lent thread which has been heretofore described. We have also noted that
in this particular the spinningwork of the Orbweavers finds its homologue
in the snares of certain Tubeweavers, as, for example, Dictyna and Amau-
robius. Concerning Dictyna, it may be stated that so careful
and distinguished an observer as Bertkau, for example, offers the
opinion that this genus is provided with certain glands which secrete vis-
cid material that must be intermingled with the flocculent spinningwork
which forms the cross lines of the typical snare. Undoubtedly the amount
of viscid material must be very small; nevertheless, it is an interesting fact
that the organs for producing it should be found among the Tubeweaving
genera armed with the calamistrum. ‘That the same organs exist in Ulo-
borus and Hyptiotes, the Orbweaving genera provided with calamistrum
and cribellum, I take for granted.

As to the snare of Amaurobius, I think that no one who has ever ex-
amined it will hesitate to say that it is provided by the spider which spins

it with a considerable amount of viscid material. The way in
Sticky which it sticks to one’s fingers, and the entire characteristics of

Viscid
Lines.

Dictyna.

ps the thread when examined carefully, go to establish this point.
robius, -. have not examined the genus by dissection, and cannot, there-

fore, speak from anatomical observation, but have no doubt at
all that Amaurobius will be found possessed, in a yet more decided degree
than the genera just noticed, with organs for the secretion of viscid ma-
terial.
One other fact remains to be noted, and I confess that I speak of it
with considerable hesitation. On one occasion, while studying the snare of
a species of Theridium which I took to be T. differens, I was
Are — surprised to find it distinctly marked with viscid globules. (Fig.
Therid- 345.) They were of an irregular character, but were manifestly
ium’s Sc i
Threads Similar to those which form upon the snares of Orbweavers.
Viscia? Thinking that I might have been deceived by a little twist in
the line forming natural nodules, I examined carefully and often,
with the same conclusion, that. the lines were beaded as with the webs of
Orbweavers. I have never met with a similar case, and scarcely know
what to think of this. Could it have been an abnormal act on the part

352 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

of the spider forming the snare, resulting from some morbid physiological
condition? Could it be that an Orbweaver had straggled upon the web of
this Lineweaving species, and left some traces of her presence by emitting
her peculiar viscid beads which, forming upon the retitelarian meshes, left
the traces of the stranger’s presence? Could I have been mistaken ?

I should not have ventured even to mention this experience had I not
noticed the statement made by Mr. Edward H. Robertson,! that the snare
of Theridium nervosum in England is characterized by a similar armature.
He states positively that house flies when trapped upon the snares of
this species are held very tenaciously by the viscid globules which are dis-

;~ persed over the intersecting lines. I do
M | not remember to have noticed this feature
| attributed to any Lineweaving
|

i Therid- snecies by any other observer.
ium ner-
NTL!

Fe That it must be a rare phenom-
_ vosum.
MN HI enon is manifest from this fact;
ip: fet | but may it not be that a more careful
(ii?) examination, with this point distinctly in

i
| character ?

| At all events, it is proper to say that

‘IS (| DY NI aoa view, will show results of a more decided
\
b

|
| | there remains the possibility that one of
ies f the most striking industrial characteristics

SS
ee,

| | of the Orbweaving spiders may have been
| | | bestowed in some degree upon the tribe of
ail Lineweavers whose species are most closely
related to the Orbitelariz, both in struct-
v of Uhatidiumn difersss chewing - ure and economy. Thus im ihis partic:
viscid beads. ular, also, we are able to trace, though it
must be confessed in a not very decided manner, an analogy between
Orbweavers and at least two of the other tribes of Arane, viz., Tube-

weavers and Lineweavers.

Tit.

In the preceding section I have shown how one may rise to the complex

orbweb from the simplest form of snare—a few lines. It will perhaps

equally illustrate the general harmony of habit which I have

Another frequently pointed out, and the danger of fixing any arbitrary
Starting _. ; : ews

Point, point from which development has progressed, if I show that one

may reach the same terminus from a very different starting point,

viz., the tubular snare. Indeed, my first conclusions settled upon this as

the most natural point of departure, since (as I have heretofore shown) the

1 “Science Gossip,” January, 1868, page 12.

THE GENESIS OF SNARES. aoa

tube is probably the most rudimentary form of nest. Moreover, the Tube-
weavers are quite generally thought by systematic arachnologists to include
the species that rank lowest in organization. Their characteristic web
might, therefore, with considerable confidence be assigned the lowest place
in an order of industrial development.

Our alignment of facts from this point will necessarily require the use
of the same material, only shifting the relative positions. But in the
movements one may catch new views of the factors concerned, their
values and relations. Let us, then, start with some form of
tube as the typical snare and retreat of the spider in its most
rudimentary phase of life. At one end of the tribe of Tubeweavers we
find the most lowly organized families, such as Gnaphosa, who limit them-
selves to simple tubes with the few lines which are necessary to fix them
to their surroundings. At the other extreme we find the highly organ-
ized and interesting spider, Agalena noevia, whose tube has developed from
its outer extremity into a widespreading sheet or pouch. ‘This, again
(which is another manifestation of spinning habit), is supported by out-
going straight lines, which intersect each other at various points.

If now we pass from the Tubeweavers to the Lineweavers, we observe

that the sheeted snare, which forms so important a part of Aga-

Tube- lena’s web, appears as the sole snare of certain species of Liny-
weavers |. ; : ; cA
to Line. Phila as, for example, Linyphia costata, whose web is a simple

weavers, letted sheet with lines above and below to support it. In other
words, it is the snare of Agalena minus the tube.

Again, in the same genus of the Lineweavers, we observe that the inter-
secting lines, which are but a subordinate feature in the snare of Agalena,
are a prominent feature in such species as Linyphia communis and Liny-
phia marginata, which, however, also retain, but in a less developed form,
the sheeted portion of the snare. This part assumes the form of a bowl
in the one case, or of a dome in the other. The meshes of the spinning-
work lack the closeness of texture commonly observed in Agalena ncevia
or the closely related Tegenaria medicinalis.

Once more, in the same tribe of Lineweavers, we find that the inter-
secting lines of Agalena’s snare appear in the genus Theridium, where they
are developed into a well organized mass of netted intersecting lines, form-
ing a formidable snare for the capture of insects. The position of the
spider within this web is entirely like that of Linyphia, and is wholly dif-
ferent from that of Agalena.

It must be observed, however, that even in the case of Theridium the
intersecting lines have a strong tendency to approximate each other at the
central point where the spider rests, until, as in the case of Theridium
tepidariorum and Pholeus phalangioides, the spinningwork approaches
closely that of Linyphia’s dome, and more remotely the sheeted spinning-
work of Agalena.

304 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Thus we see that it is possible to trace a close resemblance and apparent
relation between the spinningwork of the Tubeweavers as represented by
Agalena and the principal genera of the great tribe of Lineweavers.

Let us start again, but from another standpoint, in the tribe of the
Tubitelarize. The Clubionide represent a very important and interesting
group, many of whose genera are characterized, as we have learned, by
the special spinning organs known as the cribellum and calamistrum.
Let us take, for example, the genus Dictyna, a species which I have here-
tofore described as the Wall loving Dictyna (D. philoteichus). It is very
common in the city and suburbs of Philadelphia. Its interesting snare is
spun everywhere upon fences and walls, in the angles of outbuildings and
upon leaves of vines and various plants. The central point is a little tube
woven against the site in which the snare is pitched. From this outgoing
lines proceed, diverging as they go, somewhat after the manner of the radii
in an Orbweaver’s web. Between these lines is spun a flocculent thread,
consisting of minute filaments which have been teased by the calamistrum.
This curled thread is laid in between the radii quite after the fashion of
the zigzag ribbon characteristic of the orb of Argiope. That is to say, it

crosses diagonally from one diverging line to another, as repre-
Dictyna’s sented in the Fig. 344. It is the habit of Dictyna to overlay
Orb like . . eae :
Web. one snare with another until the strata of spinningwork, if I

may so call them, are laid several deep. I have often observed
them upon the walls and fences in Philadelphia thus spun out from the
central tube in all directions, until they present so strikingly the appear-
ance of a lace collar that the most casual observer at once notes the resem-
blance. I think one cannot fail to see in the form of this snare a sugges-
tion of the round web of the Orbweaver, with its radiating lines diverging
from the centre.

From this pecular snare of a representative genus of the Tubeweavers
we may be easily led, by the analogy of spinningwork, to a family that
confessedly hes on the very margin of the Orbweaving genera,
namely the Uloborine. In the genus Hyptiotes the Triangle spi-
der has a snare consisting of four diverging lines, or a single
sector of an Orbweaver’s web. Now, we are compelled to observe that the
threads by which these diverging lines are united is precisely of the char-
acter of that used by Dictyna in uniting her diverging lines, and this
thread is spun out by precisely the same kind of spinning organs—the cri-
bellum and the calamistrum. We have thus established a striking relation
on this side of the cireuit between the Tubeweavers and the Orbweavers,
as on the other side we showed a relation between the '’ubeweavers and
the Lineweavers.

The progress of these analogies may be further traced. Hyptiotes
shows but a single sector of a circle, whose radiating lines are united by
the teased thread characteristic of the tubemaking Ciniflonide; but we

The Ulo-

borine.

THE GENESIS OF SNARES. 355

find in the same family another species, Uloborus, whose snare is a com-
plete circle, with lines radiating from the centre all around to the circum-

ference, precisely in the manner of Argiope and Epeira. These
Curled ines, however, instead of being united by viscid concentrics, are
Saag united by a spiral thread precisely like that used by Hyptiotes and

Dictyna. Here we see the flocculent thread upon radiating lines
which appears in a genus of the Tubitelariz, planted upon the radiating
lines of a full orbed web. In other words, Dictyna may be said to have
given to Hyptiotes a fraction of her habit, which Hyptiotes has deyvel-
oped into her fixed and characteristic snare, and in turn has handed on
to Uloborus, which has multiplied the circular sector of Hyptiotes into a
complete orb, while retaining the characteristic interradials of the Tube-
weaving Dictyna.

But we are enabled to trace another resemblance and another variation
in the habit. The most interesting spinningwork of the Ray spider,

Theridiosoma gemmosum, may be said to be constructed funda-
ero mentally upon the plan of Hyptiotes. But that plan has been

enlarged by multiplying the number of sectors. In this respect,
it approaches the spinningwork of Dictyna, as represented at Fig. 344.
But these several sectors or rays have been so united that they form,
under certain aspects, an orbicular web. This web, by means of the trap-
line and the special habit possessed by the spider, can be bowed until it
assumes the form of the dome shaped web of the Lineweaving Linyphia.

Here appears a remarkable variation. While the fundamental character
of the Ray spider’s web unites it most closely to Hyptiotes, and thus back-
ward to Dictyna; the interradial lines show marked divergence in the di-
rection of the Orbweavers. They are covered with viscid beads, precisely
like the webs of the Epeiroids. Thus we are led from the Tubeweavers,
by way of the genus Dictyna, along the line of the Triangle spider, Ulo-
borus, and the Ray spider, to the great tribe of Orbitelarize, whose habits
and industry we have especially considered in this volume.

We can now connect these two wings of habit, which from the one ex-
treme of the Tubitelaria have departed towards the Lineweavers, and from
the other extreme towards the Orbweavers. Let us go back for a moment
to the intersecting lines which support the sheeted snare of Agalena.
These, as we have seen, appear in the genus Theridium and allied genera

as a well developed web of interlacing lines, massed in a laby-

Agalena yinthean snare. It is but a step from this spinningwork across
and The- the border into that portion of the web of Epeira labyrinthea
ridium. :

which is known as the labyrinth or maze. This, in every respect,

is a Retitelarian snare. If we were to sever the orb of the Labyrinth

spider from its composite web, we should find the residuum in no respect
differing from that of the typical web of Theridium tepidariorum.

Nor is Epeira labyrinthea alone in the possession of this characteristic

356 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

lineweaving adjunct to its web. We have seen it in the case of Argiope,
though not so strongly developed and not universally possessed by the in-

dividuals of that genus. We have seen it more decidedly and
Epeira permanently fixed upon Epeira triaranea and Epeira thaddeus.
and The- ‘ ; ; ;
HERAT But, to a greater or less extent, 1t may be said that the lineweay-

ing habit belongs to the Orbweavers, though by way of associa-
tion with and subordination to their typical orbicular snare.

It may further be worth noting, in this connection, that not -all the
Epeiroids make use of a round snare. There is a wide difference between
the mere sector of an orb made by Hyptiotes and the web made
by Epeira triaranea or Epeira labyrinthea, and which I have
denominated a sectoral orb. Yet the last named snares are only
larger sectors of circles, like that of Nephila, for example. By turning to
the description of the manner in which the interradials of Nephila are
woyen in, it will be seen that it substantially resembles that used by Hyp-
tiotes and, indeed, by Dictyna, when placing in its spirals of flocculent
thread. In other words, the sectoral orb is made by a series of loops
passing over the sector of a circle larger or smaller, as the case may be.

Moreover, a very considerable group of the Orbweavers spin horizontal
orbs; and it is interesting to observe that Uloborus, which is related to
Orbweavers generally by its round web, and to the Tubeweavers
through Hyptiotes and Dictyna by their nonviscid armature of
flocculent spirals, spins a horizontal web like that group of the
Epeirine to which the Orchard and the Hunchback spiders belong.

Thus it has been shown that one may pass by natural gradations,
through forms more or less distinctly marked, from the simpler and seem-
ingly more primitive spinningwork, to the various orbicular snares,
which may be considered the most complex of all known webs.
These relationships are often very striking, and, on the whole,
beautifully indicate the industrial unity of the entire order Aranez.

Nevertheless, no one better knows than the student of spider habits how
vast are the intervals which, at many points, have no more substantial
bridge than that which imagination or analogy may supply. When arach-
nologists shall have more thoroughly wrought out the natural history of

spiders, some of these interspaces may be united or more nearly
Unity of approached. Perhaps some species have disappeared whose spin-
Industrial ~ ‘ : ir a oe : :
Habit. ningwork might have furnished missing industrial links. Never-

theless, the veritable facts of science can go no further than to
show the points and degree of approach, and exhibit the general har-
mony, one might almost venture to say the germinal unity, of industrial
habit which marks the children of Arachne.

Sectoral
Orbs.

Horizon-
tal Orbs.

The Con-
clusion.

THE END.

mwP PED Xx.

WHILE revising the index for this volume I received a note from Pro-
fessor Thorell, calling my attention to a paper by Dr. Carl Apstein upon
the spinning organs of spiders,! and particularly to a point (referred to in
Chapter XIX.) on which we had had some correspondence. The paper
had escaped my notice, having but recently reached the library of our
Academy of Natural Sciences. Had I seen this valuable and interesting
paper a few months sooner, it would have enabled me to revise and in
some places correct matters which appear in certain chapters of my book.
As, however, my sheets are printed, and the type distributed, it is only
permitted me to make use of an Appendix Note to call attention to what
I deem very important.

Nore A.—On THE SPINNING ORGANS.

(Cuaprer IT.)

Dr. Apstein, in the paper above alluded to, has wrought out with great
pains the scheme of study which years ago I had proposed to myself, as
I have already intimated in my preface. He has observed with care, and
presented in his plates, the exterior spinning organs of various species
from the several tribes. He has also made studies and drawings of the
internal spinning organs. It is most interesting to note both the agree-
ments and the differences as thus indicated. I venture to present fac-
similes of several figures, one giving the spinning organs in situ of Epeira
diademata, which the reader may compare with my own partially diagram-
atic figure of Argiope cophinaria, page 39, Fig. 30. I also give some re-
productions of the spinning spools, which Apstein has been able to locate
in their connections with the various glands. This identity has heretofore
been very much in doubt.

Dr. Apstein believes that the material, which forms the viscid beads
upon the snares of Orbweavers and some of the Lineweavers, is secreted by
the Aggregate glands. He thinks that the Tubuliform glands secrete the
cocooning stuff, or the threads which envelop the eggs. The curled threads

*Bau und Function der Spinndriisen der Araneida. Von Carl Apstein. Archiy fiir
Naturgeschichte, 1889, pages 29-74, Plates IIL, IV., V.
(357)

358 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

characteristic of Uloborus, Hyptiotes, and Dictyna are secreted by what he
ealls the Cribellum gland. The Lobate glands prepare the threads by
which the insect is swathed previous to being eaten. Possibly, however,
several glands take part in furnishing the swathing bands. The Pyriform
glands secrete the spinningwork which forms the snare proper, or the
seizing tissue, together with the dragline and trapline. I would venture to
add to this the suggestion that the same glands must also secrete the fila-
ments which form the ballooning thread and floating strands known as
gossamer. The function of the Aciniform glands and Ampullate glands,
according to Dr. Apstein, is not known. (See Figs. 348-354.)

348 350

349
346

347

Fic. 346. Spinning spool of Epeira diademata pyriform gland. X 188. Fig. 347. Longitudinal section of
a spool of the aggregate gland. 188. Fic. 348. Spinning spool of the glandula aciniformis. X 188.
Fic. 349. Longitudinal section of a spool of the ampullate gland. 188. Fic. 350. Longitudinal sec-
tion of spool of glandula tubuliformis. » 188. (After Apstein.) Fic. 351. An aciniform gland. X 30.
Fic. 352. A pyriform gland. 105. Fig. 353. Longitudinal section of pyriform gland. X 105. Fic.
354. The spinning glands of Epeira diademata in natural site. 9. (After Apstein.) ac, aciniform
glands; p, pyriform glands; am, ampullate glands; ag, aggregate glands; t, tubeformed or tubular
glands (glandule tubuliformes.)

Note B.—SEcRETION oF Viscip BEADS.

Dr. Apstein is inclined to think that the foundation thread is created
from the ‘ Aciniform gland.” As soon as the foundation is stretched the
spools of the Glandule Aggregate (the Aggregate or Treeform Glands) are
pressed on it, and leave on it a little drop of viscid secretion. The three
spools stand close together on the superior spinneret—that is to say, their
mouths lay close together. If now the two superior spinnerets be pressed
to the foundation thread, the six spools of the two sorts will embrace it,

APPENDIX. 359

and the secreted drops can unite and thus surround the thread upon all
sides. In order that the minute drops remain, it is necessary that the
foundation thread be dry when the Aggregate gland places its secretion
upon it. As the foundation thread is very strong, it will dry more quickly
if it consist of numerous fine threads instead of a single strand. For this
reason Apstein believes that the Aciniform gland secretes the foundation
thread. In the same way one can believe that the Pyriform gland forms
these threads. ‘The foundation thread is more elastic than the dry threads
composing the snare itself. As the last named are formed from the Pyri-
form glands, there seems to remain only the Aciniform gland for the secre-
tion of the foundation thread.

Notre C.—Viscip THREADS OF LINEWEAVERS SNARES.
(CHapterR XIX., Pace 351.)

The viscid drops form, in masses close together, a large glutinous spot,
upon which small insects adhere. With Epeiroids the spirals of the snare
are formed of this thread. Among the Retitelariz Dr. Apstein found these
threads on the large, loose meshed web above the habitation of the spider.
If an insect flies into this roof formed web it sticks to it. By its efforts to
escape the loose threads are broken, and the animal falls into the home
web, where it is seized by the spider. In no other web did he observe these
threads, and no other spider possesses these glands. 1

The bearing of these facts upon the relations between the spinning-
work of Orbweavers and Lineweavers is manifest. Dr. Apstein confirms,
both from the standpoint of histology and field observation, the statements
concerning the viscid character of the web of Theridium, which I have
made with so great reserve. (See page 351.) He thus immensely strength-
ens the plausibility of supposing an easy passage from the spinningwork of
Lineweavers to that of Orbweavers, or in the reverse direction. Had these
observations reached my hand in the summertime, I should certainly have
made a thorough examination of the snares of Linyphia and Theridium.
At this date the matter is impossible, and must go over for another year.

Notre D.—THE SwatHiInc THREAD FOR INSECTs.

The Lobate or Lobeformed glands? occur only in Theridium steatoda
and some others of the above mentioned Retitelaria. They have, there-
fore, only a limited extension, less so than the Aggregate glands. The
swathing threads are produced by the Lobeformed glands, as the spider has,
in her great lumen, always a large quantity of this material in reserve.

1 Apstein, op. cit., page 63.
* Lappenformige. These appear to be the Bulbous or Tuberose glands of Meckel, figured
Chapter II., page 44.

360 AMERICAN SPIDERS AND THEIR SPINNINGWORK.

Besides, this spinning material can flow off through a wide spool and pro-
duce the necessary spinningwork for throwing on the animals. Pholcus
has a large gland and a wide spool. Apstein believes that this gland
serves to throw threads on the animals in the web, and keep them there.1

Nore E.—MEeEpIcINAL PROPERTY OF SPIDER WEBS.

(PaGcE 95.)

Dr. James, in his Medical Dictionary, introduces his article Araneus?
with this statemént: “ Both Spider and the Web are used in Medicine.
The Spider is said to avert the Paroxism of Fevers if it be applied to the
Pulse of the Wrist, or Temples, but is peculiarly recommended for a
Quartan, being inclosed in the Shell of a Hazle-nut. The Web astringes
and conglutinates, and is therefore vulnerary, retains Bleeding and prevents
any Inflamations.”

Note F.—EFFreEcts oF SPIDER POISON.
(PaGE 281.)

Dr. James, in his Dictionary, quotes from the works of Harvy the fol-
lowing sentence, which shows that the distinguished discoverer of the cir-
culation of the blood was a fearless experimenter and an earnest searcher
after Truth: “ Having for Trial’s sake pricked my hand with a Needle I
after rubbed the point of the same Needle with the Tooth of the spider,
and perforated the Skin therewith in another part of my Hand, but could
distinguish no Difference in the Sense of the Punctures. However there
was one remarkable enough in the Skin, for in the Envenomed Puncture
the same was soon raised up into a Tubercle looking red with Heat, and
Inflamations rising up as it were to shake off the inflicted.”

Doleshall shut up small birds with Mygale javanica and M. suma-
trensis, both large and strong spiders, and the birds died in a few sec-
onds after being bitten. One of the spiders was left for ten days with-
out food, and then was made to bite another bird, which was injured, but
in six hours recovered. The same author was bitten in the finger by a
Jumping spider. The pain was severe for a few minutes, and was fol-
lowed by lameness of the finger, and gradually of the hand and arm, which
soon went away entirely.®

Bertkau allowed spiders to bite his hand. On the ends of the fingers
the skin was too thick to be penetrated, but between the fingers they easily
pricked it. The bite swelled and smarted for a quarter of an hour, and
then itched for some time, and for a day after itched whenever rubbed, as
mosquito bites will do.- He also experimented on flies, which died in a

1 Apstein, op cit. Med. Dict., Vol. I., London, 1748.
® Quoted by Emerton, “Structure and Habits,” page 34.

APPENDIX. 361

few minutes after being bitten. Of course, however, experiments of this
kind are greatly invalidated by the fact that it cannot be determined
whether the death of the insects resulted from poison, or from the mu-
tilation produced by the entrance of so formidable a weapon as a spider’s
fangs.

Dr. Alfred Dugés gives an account of a little girl patient who had
been bitten by one of those enormous spiders, quite common in Guanajuato,
Mexico, which Mr. Leon Becker has named Metriopelma breyeri. The
wound presented an oblong, tumefied border, about three lines high, of a
livid violaceous color, filled with a serosity which he was not able to ex-
amine. The centre of the tumor was concave, and filled with red pus.
Kight days after the accident there was little pain, but no general symp-
toms. Dr. Dugés was not able to follow up the case, but thinks that if
there had been any serious consequences of the bite the child would have
been brought back to him for further treatment.

1“Tnsect Life,” Vol. II., No. 2, 1889, page 47.

INDEX OF

DD «

Abdomen, anatomy of, 22; general descrip-
tion of, 25; manner of protecting, 288 ;
section view of organs, 27.

Acrosoma, characteristic snares, 55; compared
with Orchard spider, 153 ; influence of cli-
mate upon, 164; length of legs, 24; rib-
boned brace, 57; webs of, 64.

Acrosoma mitrata, 126, 127.

Acrosoma rugosa, foundation web, 73; snare
of, 125, 126; Acrosoma rugosa, 338 ; man-

ner of trapping flies, 254.
Acrosoma spinea, 126; position at hub, 127.
Adaptation, in laying foundation lines, 73;
after mutilation, 78; in spinning spirals,
82,83; labor saving, 85; to force of winds,

209, 216, 217; of orbweb for its ends, 247 ;
in nesting habits of Epeira strix, 289, 290;

of nesting habit, 297.

Aeronautic habits, swinging basket, 68, 69.

Affinities, 204.

Agalena labyrinthea, 45.

Agalena noevia, 28, 28, 220, 221, 227,
345, 353.

“Aevricultural Ants of Texas,
164, 168.

Air currents, in making foundation lines, 62,
64, 74.

Alternate apposition of radii, 75, 228.

Amaurobius, sticky web of, 351, 352; see Ap-
pendix.

260, 315,

”

author’s work,

Analogies, in spinningwork of Orbweayers
and Lineweavers, 170.

Anatomy of spiders, see Chapters I., II.

Anchors, of stone, for orbwebs, 213, 214.

Angulata group, nesting habits, 299.

Anthropomorphism, 210.

Apstine, Dr. Carl, see Appendix.

Arachne, Greek myth of, 15.

Arachnida, origin of the word, 15.

Architecture, 284; see Nesting habits.

Argiope, ribboned decorations, 57.

argentata, character of orb, 108.

argenteola, 108.

Argiope

Argiope

(3

VOERUMT

Argiope argyraspis, 59, 87,95; decorations on
web, 107; suspended to snare, 55; view of
abdomen, 22.

Argiope cophinaria, 90; character of orb, 108;
description of snare, Chapter VIIL., 96,
229; as a bird catcher, 234; curious in-
cident while feeding, 256; distribution,
96; loses a captured bee, 258; protective
wings of, 309; sheeted hub, 55, 56; silk
glands, 40; snare, figure of, 52; spinning
spigots, 38; spinning spools, 37; swathing
insects, 250.

Argiope fasciata Hentz, see Argiope argy-
raspis.

Argiope riparia, see Argiope cophinaria.

Argyroneta aquatica, nest of, 328.

Argyroepeira hortorum, 77, 91, 92; beautiful
colors, 151; favorite sites, 152; position at
hub, 152; protective apron, 152; orb char-
acteristics, 153.

Armature of orbwebs, 78, Chapter V.

Attoidee, 19.

Attoids compared with Lycosids, 20.

Atypus Abboti, nests of, 325.

Ausserer, 16, 28.

99
oo 2 .

3ag worm,

| Ballooning, see Aeronautic habits.

Banks, Sir J., 77.

3asilica spider, see Epeira basilica.

Beads, viscid, 80; on spirals, acid character

of, 95, 96; adhesiveness of, 94; appearance
to eye, 88; formation of, 88, 89; dissolved
by rain, 91, 92; effect of sun and air on,
94; natural formation of, 90, 91; prey on
webs, 93, 94; size and shape, 87; value in
capturing prey, 86; on Tubeweavers’
snares; 351; on Theridium’s snare, 352;
see Appendix.

3ee, honey, escaping from spider’s swathing,

| 258.

Bertkau, Dr. Philip, 18, 21, 178.

| Bible reference to spider, 26.

62)

INDEX.

363

Blackwall, 26, 28, 49, 56, 61, 63, 75, 76, 85, 93,
129, 231, 249, 279, 317; classification of
spiders, 17; experiments with poison of
spiders, 271.

Bowing the snare, 198.

Bridge lines, 342.

Bridges, of spider silk, 63, 64, 65;
Stilt spider, 157, 158.

Bridge suspension of Theridium, 224.

Bucholz, Dr. Reinhold, anatomy of spinning
organs, 35, 40; see Chapter IT.

Bucholz and Landois, 42; see Chapter II.

snare of

Caddis flies, various nests of, 333, 334.

Capturing insects, 206.

Calamistrum, 26, 177, 186, 351;
186.

Cambridge, Rey. O. Pickard—Cambridge, 19,
23, 27, 28, 62, 174, 195, 204, 263, 272, 279.

Campbell, Mr. F. Maule, 143, 262.

Cannibalism, 259.

Capturing insects, by Labyrinthea, 152.

Cephalothorax described, 21.

Central space, economy of, 56.

Chandler, Mr. Horace P., photograph
Epeira’s nest, 110.

Ciniflo atrox, 278.

Citigrades, 16, 20, 347.

Classification, general divisions, 17.

Claws, used in hanging to snare, 55.

Cleaver, Mr. P., 243.

Climate, limiting distribution, 163.

Cocoon, influence of position, 259; egg bag
of Lycosa, 327; of Theridium neryosum
and T. riparium, 317; nests of Misumena
and Philodromus, 323; tent of Attus, 327;
tent of Water spider, 328.

Cocooning, 347; boxes for observing, 29;
Argiope cophinaria, 39.

Coil of slack line, 189.

Collecting, implements for, 31; manner of,
28, 29,

Color, 26; brilliancy of certain spiders, 20;
of Nephila’s threads, 147; of Tetragnatha
extensa, 156; of Orchard spider, 151,
Tetragnatha, 155.

Composite snares, 130.

Construction of leaf nests,

Codperative housekeeping, 135, 348.

Counterpoise, 210.

Courtship of Epeira labyrinthea, 132.

Cribellum, 178, 351.

Cteniza californica, see Trapdoor spider, 19.

Currents of air, use in beginning a snare, 62.

Cyclosa caudata, 87, 128.

of Hyptiotes,

of

299.

of |

|

of |

Cyclosa bifurea, 128.
Cylindrical glands, 42.

Cyrtauchenius elongatus, 322

OL4.
Darting threads, 45.
Darwin, 234.

Decoration, ribbon cords, 57; ribbons of Ulo-

borus, 175, 176; on orb of sr aap 107;
flossy, on Gasteracantha’s web, 125.

De Laet, 233.

Development of Labyrinth spider’s web, 134;
of habit in Triaranea, 141, 142, 162, 247.

Dews, effect of, on webs, 231, 232.

Diagram of spinning organs, 39.

Dictyna, 354; curled thread of, 348;
of, 349.

Dictyna philoteichus, webs of, 348.

Diptera, indifference to a spider, 257.

Direction, sense of, 248.

Distribution, 109, 182; vertical,
spider, 116; effect on Epeira strix,

Dolomedes scriptus, 311.

Dolomedes sexpunctatus, nest of, 347.

Dolomedes captures a spider, 236.

Domed orbs, 150, 164.

Domicile spider, see Epeira domiciliorum.

Dragline, 60, 61, 342.

Drassus ater, spinning spools, 49.

Drassus, falx and fang of, 272; nest of, 316.

Drinking, 262.

Duct, of silk glands, 42
naria, 49.

Dysdera, 223.

Dysdera bicolor, 222.

snares

of Domicile
ee

length of, in Tege-

Edwards, Rey. Dr. Jonathan, observation of

spiders, 68.

Eigenmann, Mrs. Rosa Smith, 120, 122, 125,
142, 211, 298.

Emerton, J. H., 59, 86, 106, 129, 178, 186.

Enemies of spiders, 132.

se ta ee of spiders,
XIII., 342, 3

Environment, ‘edactins
sites, 68; influence on food,
tribution, 163; power to resist,

Epeira, figure of face, 21; floating the
water, 161; the most common species, 110;
orbs of, frequent, 56; water, 64.

Epeira apoclisa, 93, 299.

Epeira basilica, its discovery, 164;
snare, 165; figure of the spider, 165;
architecture of snare, 166; manner of
building the dome, 168; 169 ;
web relations with Orchard spider, 168.

208, Chapter

web
dis-

selecting
259; on
163.
on

in

orbs over

form of

cocoons,

364

Epeira benjamina, see Epeira domiciliorum.

Epeira bicentenaria, 122.

Epeira bifurca, see Cyclosa.

Epeira cinerea, 121.

Epeira cornuta, resemblance to Epeira strix,
1GUL

Epeira diademata, 94, 231, 299; effects of
bite, 271; poison apparatus of, 269, 270;
silk glands, 41; spinning glands, 38; spin-
ning organs, 48, 49.

Epeira displicata, 121.

Epeira domiciliorum, 78, 79, 255, 339; distri-
bution, 116; nest of, 288.

Epeira gemma, 15, 121.

Epeira gibberosa, snare and nest of, 154;
distribution, 154.

Epeira hortorum, see Argyroepeira.

Epeira insularis, anatomy, 22; figure of foot,
25; its coloring and distribution, 118; its
bite, 273; identical with Marmorea, 77;
measurements of webs, 230; nest and orb,
117; nest and trapline, 337.

Kpeira labyrinthea, Chapter VIII, 130; de-
scription of snare and tent, 130, 131, 132;
geographical distribution, 136; joint house-
keeping, 185; the orb described, 133, 225,
226; nest of, 305, 306, 340, 348, 355, 356.

Kpeira marmorea, identical with Insularis, 77.

Epeira patagiata, 116.

Epeira quadrata, 299;
272.

Epeira sclopetaria, 75,
bution, 115.

Epeira stellata, 122, 339, 340.

Epeira strix, 218, 229, 255, 340; distribution,
110, 111; its habits, 112; favorite loca-
tions, 114; nest of, 288; snare twisted by
captive, 265; various forms of nest, 289-
291.

Epeira sylvatica, 122.

Epeira thaddeus, 348; tubular nest of, 303,
304, 305.

Epeira triaranea, 166, 340; favorite sites, 136;
snare and tent, 137; variation in nest,
138; orientation of sector, 138; snares of
young, 139; variation in trapline, 139;

mouth organs of, 270,

229; habits and distri-

measurements of web, 140; retitelarian
maze, 140; affinities, 141; tubeweaving

tendency, 141; looped spirals in orb, 141;
distribution, 142; orientation of centre,
141; coloring, 118; habit and spinning-
work, 119; nest of, 305.

trifolium, 3840; fern nest of, 320;
swinging nest of, 216; various nests of,
293; an encampment of, 294.

EKpeira

Epeira trivittata, 117; nesting habit, 298.

Epeira umbratica, 215.

Epeira vertebrata, 74, 120, 248, 252; nesting
habit, 298.

Epeira vulgaris, see Epeira sclopetaria.

Epeiroids, distinguished from Theridioids, 20;
general characteristics, 19.

Epiblemum scenicum, 19, 342.

Eurypelma, 16.

Eurypelma hentzii, 260; weaving, 326, 327.

Evolution, 151, 166, 170, 171; see Chapter
XIX.

Eyes, basis of classification, 17; Orbweavers
and Lineweavers, 21; use for specific dis-
tinction, 21.

Face, characteristics, 20.

Fecundity of female contributes to perpetu-
ity, 259.

Feeding habits, 86, 191, 192; of Hyptiotes,
capturing insects, 187; of Labyrinthea, 132.

Feet, anatomy, 28, 24; commanding the
snare, 113, 114; threads carried in, 75.

Fern nests, 295.

Fighting tarantulas, 281.

Fish, captured by a spider, 236.

Fitch, Dr. Asa, 240.

Flies, mode of capture by spiders, 254; small
diptera banqueting with spider, 256.

Floating, habit of Tetragnatha and Epeira, 161.

Flocculent spirals, 186, 187; thread of Hyp-
tiotes, 186.

Flossy tufts on webs, 124.

Food, manner of capturing, 114; regulating
web sites, 144; small vertebrates, 246, 248,
249; enswathing captured insects, 280,
251, 252; food carried to the den, 251,
253; trussing captives for future use, 254,
255; subordination of instincts, 256; flies
banquet with the spider, 257; special in-
cidents and disappointments, 258; loca-
tion controls, 259; cannibalism, 259; long
fasting, 260; comparative feeding habits,
260; Tarantula’s mode of feeding, 261;
drinking, 262; eating the web, 263; the
habit beneficial to man, 267.

Fossil spiders, 172.

Foundation lines, 60, 61, 71, 72,
double, 73; of Orchard spider,
by means of air currents, 62,
preserved, 66; strength of, 231.

Frame lines, 60; see above.

Fraternity, among spiders, 185; in a Scotch
colony of Zillas, 144.

Free zone, 56, 58.

219, 230;
152, 153;

65; long

INDEX.

365

Gabb, William, 109. |

Gasteracantha, 122; description of orb, 123;
limited by climate, 163.

Gasteracantha bourbonica, 124.

Gault, Edwin S., 206.

Genesis of snares, Chapter XIX., 336.

Geographical distribution, world wideness of
Epeira patagiata, 116; of Labyrinthea,
136; of Tetragnatha extensa and Epeira
diademata, 162; of various Epeire, 163.

Geometrical arrangements of webs, 208.

Gibberosa, Epeira, hammock nest of, 307.

Glands, silk, 40.

Gnaphosa variegata, 19.

Goldsmith, Dr. Oliver, 282.

Gossamer threads used for sails, 161.

Gosse, P. H., 275.

Grout, Rey. Mr., 146.

Guidon, flossy, 86.

Habitat, 292.

Hahn, 173.

Hairs, color of, 26.

Harmony, universal, in nature, 335.

Heineken, Dr., 78.

Hentz, Prof. Nicholas M., 57, 59, 110, 118,
119; 151, 172, 173; -238.

Hopper, Mr. J. W., 242.

Horizontal orbs, 53, 150, 356; Basilica’s web,
169.

Hub, centre of orb, 54; open, 55; flossy gui-
don, 74; orbs with open, 126; of Orchard
spider, 152; position of spider at, 86, 112;
position of Acrosoma at, 127; position of
Tetragnatha at, 156; meshed, of Laby-
rinthea, 133; sheeted, 55.

Hulse, Dr., 61.

Hunt, Mr. Benjamin H., 101. |

Hymenoptera, 19.

Hyptiotes, 350, 354; the Triangle spider, 177;
systematic place, 180 ; description of snares
and habits, Chapter XI.; compared with
Theridiosoma, 204; trapline, 340.

Hyptiotes paradoxus, 181.

Industry, nesting, protective, 307.

Industrial habit, unity of, 356.

Insects, manner of entanglement, 248; effect
of poison on, 277.

Instinct, in beginning an orb, 62; in young
spiders, 70; variation in number of radii,
77; subordination of, 255.

Insular spider, see Epeira insularis; nests of,
284, 285, 286, 287, 295, 296; mode of mak-
ing a nest, 301.

Intelligence, 69, 71, 212, 216, 218, 227,
2533 in use of swinging basket, 68.

Intellect of spiders, 228.

Inverted posture of spiders, 112, 113.

248,

Jaws of Tetragnatha, 155.
Jerking snare, 249.

Katipo, a New Zealand spider, 273.
Keyserling, Count E., 17, 136, 178, 195, 207.
Kirby and Spence, 56, 71, 86.

Knott, Hon. Proctor, 244, 245.

Koch, Dr. Louis, 107, 108, 196, 204.

Labyrinth spider, 130; see Epeira labyrinthea.
Landois, Dr. Leonard, 35, 40; see Chapter IT.
Larvie, tube making, 329.

Laterigrades, 16, 347; nests of, 323.

Latreille, 15, 16.

Latrodectus mactans, 274.

Laurel, used for nests, 295.

Leeuenhoek, 231, 268.

Legs, anatomy of, 24; antennal use of, 69;
effect of mutilation, 78; fourth leg in Acro-
soma, 127; not used as a measure, 76; use
in spinning spirals, 80, 81; voluntarily am-
putated, 278.

Leidy, Prof. Joseph, 240, 245, 333.

Lepidoptera, larval spinningwork suggesting
spiders, 284.

Lineweayers, 19, 20, 21, 353; derivation of
word, 17; swathing captives, 260; nests of,
316.

Linyphia, 353; site of webs, 206; parasitic
habits of, 310, 311; nest and snares of, 320.

Linyphia communis, 167, 320, 344, 348; bowl
shaped web, 166.

Linyphia costata, 167; sheeted web of, 348;
snare of, 346.

Linyphia marginata, 19, 28, 157, 345.

Lister, 28, 62.

Loops, spiral and corner, 80.

Looped spirals, 140.

Lownes, George B., 272.

Lucas, 274, 277.

Lycosa, manner of weaving, 327.

agretica, 278.

arenicola, 19, 314; see Turret spider.

Lycosa

Lycosa

Lycosa carolinensis, 314.

Lycosa scutulata, figure of, 20; effect of bite,
273.

Lycosa tigrina, nest of, 323.

Lycosidse, 19; physical powers of, 235; high
organization of, 20; nidification of, 313,

314.

566

INDEX.

generative organs,
of Argiope cophi-

Male, palpal organs, 25 ;
28; rudimentary web
naria, 106.

Mandibles described, 22.

Manufacturing methods, uniformity of,

Marx, George, M. D., 120, 168, 169.

Maternity, influence on habit, 347.

Mathematics, 73; imperfection of orbwebs,
79; irregularity of radii, 76; order of spin-
ning radii, 77; orientation of lines, 75 ;
polygonal and triangular forms in snares,
61.

McCook, Commander Rhoderick Sheldon, 222.

McLeay, 17.

Meade, R. H., 27, 38; anatomy of spiders, 44.

Mechanical advantage, order of radii, 76;
notched zone, 77.

Mechanical skill, distributing force of winds,
ete., 74; strength of webs, 229, Chapter
XIV.; use of lines, 169, 170.

Meckel, Heinrich, anatomy of

gans, 40; see Chapter IT.

Medicinal property of beads, 95.

Mending snares, 179, 265.

Menge, 28, 111.

Mentalism, 78, 82, 84, 85, 86, 93.

Meshed hub of Epeira, 54.

Meta, 171.

Meta menardi, 128.

Meta merianee, 129, 214.

Meta seementata, 56.

Migration, by means of air lines, 62.

Milk, spider drinking, 263.

Mimiery, 155, 182.

Misumena, cocoon nest of,

Misumena rosea, 17.

Mitchell, Prof. Ormsby, 232.

Mogeridge, 323.

Mosely, 233.

Mosquito captured on snares, 248, 266.

Moulting, 24.

Moults, good specimens for observing
fangs, 270.

Mouse captured by a spider, 242, 248, 244.

Mouth organs, 22.

324.

spinning or-

999
323 .

poison

Muscles inclosing
50.

Muscular vigor and rigidity, 193, 194.

Mutilation, effects of, 78.

Mygalide, 280, 281.

silk glands and spinnerets,

Natural sites of snares, 114, 119, 120, 157, 158.
Natural habitat and distribution, 207.
Navigating, by Tetragnatha, 159.

Nemesia cementaria, poison apparatus, 271.

of |

Nephila, 49, 95, 96, 233; the bite of, 276;
snares of, 310.

Nephila plumipes, description of female, 147 ;
snare of, 147; golden strands, 147; form
of web, 147; Wilder, 147, 148; distribution,
146.

Nephila wilderi, see Nephila plumipes.

Nests of spiders, manner of preserving, 31;
making, 134, 173, 225; Chapter X VII.
Nesting habits, Chapter X VII., 284; cluster
leaf nest, 284, 286; folded leaf, 285, 288;
silken tubes, 288, 289; various adaptations
of, 290; favorite sites for, 292; nests of
Trifolium in various plants, 293; fern

‘nests, 295; plant habitat modifying nest
and habit, 297; of Domicile spider, 298;
Epeira vittata and Epeira vertebrata, 298 ;
of the Angulata group of Epeira, 299;
how nests are built, 300; beginning a
nest, 301; mode of sewing, 302; nests of
Zilla, 302; of Thaddeus, 308, 304, 305;
Triaranea, 3805; Labyrinthea, 134, 306;
Gibberosa, 307; silken tents, 808; protect-
ive uses of, 309; parasitic nests, 310, 311.

Nest making, origin of, 313; intelligent selec-
tion in, 313; Turret spider’s nest, 314,
315; nest of Lycosids, Saltigrades, Dras-
sids, 316; of European Theridioids, 317;
of Theridium riparium, 318, 319; of Trap-

and Atypus, 321, 322; of Ly-

323; uniform manufacturing

method in, 324; one typical form, 324;

method of Atypus, 325; method of Taran-
tula, of Argyroneta, 328; origin of
tubeweaving, 329; spider nests compared
with nests of other animals, 332, 333.

Nesting sites, 173.

Niantic, 292.

Night habits, 67,

Ninni, 215.

Notched zone, 55, 56; bracing the radii,
of Orehard spider, 153.

door spiders
cosa tigrina,

Syl S

112.

oe
ee

Oeflinger, 35.

Orbweb, divisions of, 54.

Orchard spider, see Argyroepeira hortorum.
Orton; Prof Ji, 234:

OT

Ovaries, 27.
Packard, Prof. Asa 8., 331.
Pairing, 132.

99

23, 24.

Palpi, anatomy,
Parasitic nest, 310.
Parona, Prof. Corrado, 214, 216.
Pavesi, Prof., 213.

INDEX.

ise)
or)
~I

Peckham, George W. and Elizabeth G., 109,
173.

Perception, accuracy of, 248.

Perty, 17.

Phidippus morsitans, the bite of, 276.

Philodromus, nest of, 3238, 347.

Phillyra riparia, see Uloborus.

Pholceus phalangioides, 228, 353.

Physical power of spiders, 229.

Pliny, 241.

Poison of spiders, 32; effects and uses of,
Chapter XVI.; poison fangs of Argiope, |
268, 269; gland of Epeira, 269, 270; gland
and falx of Nemesia, 270, 271; of Epeir
diademata, 270; of Hentz’s Tarantula, 270,
271; effects of, 271; bite of Epeira, 272;
inoculation with, 272; comparative harm-
lessness, 273; venomous effects, 274; by
Latrodectus, 275; of Nephila, 275; of Sal-
tigrades, 276; popular notions, 277; effects

on insects and spiders, 278; a reserve
weapon, 280; superstitious notions con-
cerning, 281, 282; Argiope cophinaria,

fangs and falces, 268; position of poi-
son gland of, 269; Epeira domiciliorum,
poison gland of, 269; gland poison, 269,
270; muscles surrounding poison gland,
269.

Prey, capture of, 67, 86, 234.

Protective architecture, 284, see Nesting.

Protective environment of Labyrinthea’s nest,
132.

Protective industry, 3808; Argiope’s shield,
99; Argiope’s wings or fenders, 104; apron
of Orchard spider, 152.

Protection of person, protective use of fore
legs, 69.

Protection, of snares by ribbons, 57.

Psocidee, 331.

Pulmonary sacs, 27.

Purseweb spider, 325; see Atypus abboti.

Pyriform glands, 40, 41.

Radii, bent in the notched zone, 134; order

of spinning, 75; number of, 85; single or
double, 76; spinning the first, 74; varia-
tion in number, 139, 140.

Rain, dissolving spinningwork, 102; effect of,
on webs, 92.

Ray, John, 61. |

Ray spider, Chapter XII., 195; see Theridio-
soma.

Reasoning powers of spiders, 227.

Rennie, 76, 86.

Reproduction, organs of, 27; of limbs, 78.

Retitelarize, 16, 17, 20, 342;
ers.

Rhizopods, shells of, 333, 334.

Ribbon decorations, 125; temporary in Epe-
ira, 116; possible origin of, 117.

Robertson, Edward H., 352; describes nests
of Theridium riparium, 317.

Rolled leaf nests, 285.

Romanes, 77, 78.

Rudimentary snares, 229.

see Lineweay-

Sailing, habit of Tetragnatha, 159.

Saltigrades, 19, 347; nest of, 316; manner of
spinning, 327.

Scaffolding, spiral, 79; removed after use, 86.

Seaffold foundations, Nephila’s peculiar form,
147.

Schaffenberger, 231.

Scudder, 8. H., 19.

Sectoral orbs, 130.

Sedentary spiders, 15.

Segestria senoculata, -50.

Sewing, 285; design of, 315; by Epeira thad-
deus, 303; manner of, 302.

Shamrock spider, see Epeira triaranea.

Shield, central shield of Argiope, 97; use of,
99.

Shooting threads, 45, 63.

Silk, liquid, of spiders, 39; used for sailing,
160.

Simon, M. Eugene, 107,

Site of snares dependent on foundation line,
66, 181.

Sloane, Sir Hans, 233.

Snake, enmity between spider and, 241; en-
snared by spider, 237, 238.

Snare, as a tool for trapping, 247; wear and
tear of, 264.

Spigots, spinning, 36, 46, 48; see Appendix.

Spines, tarsal, used in spinning, 81.

Spinnerets, 34; anterior, 37; middle, 36; pos-
terior, 85; used to clamp spiral string, 81,
82.
Spinning, Argiope’s
shield, 99, 100.
Spinning glands, of Epeira, 39, 48; of Aga-
lena labyrinthea, 45; of Tegenaria domes-
tica, 45; see Appendix.

Spinning organs, anatomy of, Chapter IL,
34; muscles regulating, 51.

ory

a(s.

method of spinning

Spinning spools, development of, 50; see Ap-
pendix.

Spinningwork, analogies, 170; classification
of, 284.

Spiral threads of Dictyna, 355.

INDEX.

Spirals, art of spinning, 80; character of
notched, 80; deltated by rain, 92; of floc-
culent thread, 177; scaffolding for, 79;
mode of spinning with Triangle spider,
184; rapidly spun, 86; variation in num-
ber, 139; viscid material on, 90.

Spring, Prof. Edward A., 235.

Springing the snare, 202.

Snare, control of, by feet, 114.

Solomon, reference to spider, 26.

Spools, spinning, 37, 38, 46; see Appendix.

Staveley, E. F., 317. ~

Stilt spider, see Tetragnatha grallator.

Stings of insects compared with spider poi-
son, 272.

Superstitions concerning spider venom, 281.

Suspension bridges, 62.

Swathing, manner of, 191, 249, 250,

Symmetry, not essential, 208.

203.

Tailed spider, 128; see Cyclosa caudata.
Tarantula, 16, 271, 326; dance, 282.
Tegenaria, 45.

Tegenaria civilis, 278.

Tegenaria domestica, 49.

Tegenaria guyonil, 262.

Tegenaria medicinalis, 95, 316, 353; captures
a snake, 238; its web and cocoon, 239;
strength of its web, 240 ; seizing insects, 261.

Telegraphy, 337, 338.

Tents, nesting, 291; made of leaf, 308.

Terby, M. F., 63.

Tetragnatha, 154; position on web, 155;
webs over water, 64.

Tetragnatha elongata, see Tetragnatha gral-
lator.

Tetragnatha extensa, is it imported from
Europe, 155; distribution, 155; jaws and
mouth parts, 155; colors, 155; position on
hub, 156.

Tetragnatha grallator, 157, 206; favorite posi-
tions, 158; walking on the water, 159;
navigating the water, 160; silken sails of,
161; distribution, 162.

Tetragnatha vermiformis navigating the wa-
ter, 160.

Territelarize, figure of, 16; nests of, 323, sqq.

Theridioids, spinningwork, with
Orbweavers, 166.

Theridiosoma gemmosum, see Theridiogsoma
radiosum.

Theridiosoma, 340, 341, 350.

Theridium, 205, 223, 353, 355; trestle snare
of, 342.

Theridium differens, 224, 351.

relations

Theridium neryosum, 316, 352.

Theridium tepidariorum, 3842; captures a
snake, 240, 241, 245; figure of, 20; face of,
21; globular snares of, 225.

Theridium riparium, 19; nest of, Blackwall’s
study, 317; full description of nests, 318, 319.

Theridium zelotypum, 317, 346.

Theridiosoma radiosum, the
Chapter XII.

Theridiopterix, 332.

Thompson, Charles H., 109.

Thorell, Prof. Tamarlan, M.D., 16, 18, 25, 77,
146, 171, 181, 192, 196, 215; answer to
Bertkau, 18; arrangement of spiders, 15;
general classification, 17; on instincts, 19.

Tools, snares of spiders, 247.

Tortricid moth, nest of larva, 320.

Trail of silk, 337.

Trapdoor spider, 19; nests of, 321, 323, 324.

Trapline, Labyrinth spider, 1384; and slack
line, 201; variation in form with Zilla,
144, 145, evolution of, Chapter XIX.; sim-
plest form of, 336; as a trail and tele-
graph, 337; multiplex traplines, 340; Ray
spider’s, 341; Epeira trifolium, trapline
and nest, 337.

Trapping insects, 144; by means of foot lines,
113; by Hyptiotes, 190; by Ray spider,
201; with fractured snare, 339.

Treat, Mrs. Mary, 122, 181, 182, 218, 263.

Trestles, by Theridium, 223.

Treviranus, 28.

Triangle form of orb frame,

Triangle spider, Chapter XI., 180; see Hyp-
tiotes cavatus.

Tube, the germinal form of nests, 315; as
germinal form of nest, 346.

Tube making habit, 346.

Tubeweavers, 19, 23, 345, 353; manner of feed-
ing, 260; nests of, 315.

Tubeweaving, origin of habit, 329; among
Orbweavers, 141.

Tubitelariz, 16; see Tubeweavers.

Tubular bridges, 222.

Tunnelweavers, 347.

Turret spider, 19, 314.

Trussing captives, 254.

Ray spider,

72

ae

Uloborus, 350, 354; flossy braces, 58; spin-
ningwork of, Chapter X., 172.

Uloborus plumipes, character of snares, 174;
web measurements, 175; ribbon decora-
tions, 175, 176; a genuine Orbweaver, 177 ;
position beneath her orb, 179; distribu-
tion, 172.

INDEX.

Uloborus mammeatus, 172.

Uloborus walckenaerius, 173, 178.
Underhill, H. M., 27, 45, 47, 48, 49, 50, 328.
Uniformity in type of nests, 524.

Unity of nesting habit in Epeira, 299.
Upholstery, spider, 301.

369

Water necessary to spiders, 261, 262.

| Wear and tear of web, 203.

Weather, effect on Labyrinthea’s snare, 132.

Weaving, common methods of, 325, sqq.; by
larvee, 329; by Psocidee, 331.

Westring, Nicolas, 23, 24.

| Wilder, Prof. Burt G., M.D., 146, 180, 184,

Variations in habits of Epeira sclopetaria, |
115; in spinning orb plane, 150; in snare |
of Triaranea, 139; in traplines of Zilla,
145; in traplines of Epeira, 146.

Venom, see Poison.

Vertical snares, 52.

Vinson, Dr. Auguste, 95, 124, 233, 310.

Viscid beads, 177, 2085.

Viscid lines on Tubeweaver’s snares, 351; on |
Theridium’s, 352; on Linyphia’s, see Ap- |
pendix. |

Walckenaer, M. le Baron, 23, 107, 108, 110,
126, 157, 272.

Walking, anchored by dragline, 60; over
leaves, 70.

Wallace, Alfred Russell, 235.

Wandering spiders, tribes composing them, 16.

Warburton, Mr. Cecil, 56.

Water spiders, 160, 328.

190, 234.
Wind, effects of, on webs, 209.
Wings, protective, of Argiope’s web, 104, 105.
Wood, Rev. J. G., 212.
Wounds, by spiders, effect of, 278.
Wright, Mr. F. W., 275.

Young spiders, 140, 230; habit of sailing the
water, 160; Labyrinthea, 132; snares of
Triaranea, 138; webs of Zilla, 144; varied
orbs of, 151.

Zigzag ribbon of Argiope, 97, 102.

| Zilla, 171; looped spirals of, 140; nests of,

302.

Zilla atrica, 144.

Zilla callophylla, 144.

Zilla x-notata, snare of, 142, 143; Scotch col-
ony, 143, traplines of, 144, 211.

| Zone, notched, 56, 58; free, 58.

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