Table of Contents

PREFACE.

The object of this book is to give a plain account of the best known habits of spiders, and as much of their anatomy and classification as is necessary to understand these habits. The portion on the spinning and flying habits is copied chiefly from Blackwall and Menge; that on the trap-door spiders from Moggridge; and the habits of Nephila and Hyptiotes, from Wilder. The observations of these authors have been repeated as far as possible, and some changes and additions made to their accounts of them. The numerous stories of deadly poison, supernatural wisdom, and enormous size and strength of spiders, have been omitted as doubtful. Several cuts from the papers of Professor Wilder have been repeated by favor of the author and publishers. Most of the figures are, however, new, and engraved by photography from my own drawings.

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LIST OF ILLUSTRATIONS.

PAGE
1.	Under Side of Epeira Vulgaris	13
2.	Foot of Epeira Vulgaris	14
3.	Foot of Attus Mystaceus	15
4.	Upper Side of Epeira Vulgaris	18
5.	Section of Epeira Vulgaris	20
6.	Mygale Hentzii	24
7.	Dysdera Interrita and Eyes	26
8.	Drassus	26
9.	Agalena Nævia	27
10.	Lycosa and Eyes	28
11.	Salticus and Eyes	29
12.	Thomisus and Eyes	30
13.	Theridion	31
14.	Mandibles of Epeira Vulgaris. Front View	33
15.	Claw of Mandible	33
16.	Spinnerets of Epeira Vulgaris	39
17.	Single Spinning Tube	40
18.	Spinning-Glands	40
19.	Spinneret of Prosthesima	41
20.	Spinneret of Agalena with some of the hairs removed	41
21.	End of Thread	42
22.	Trap-door Nests. Copied from Moggridge	47
23.	Nest of Dolomedes	52
24.	Web of Agalena	55
25.	Web of Linyphia Marmorata	57
26.	Web of Linyphia Communis	59
27.	Pholcus swinging	61
28.	Round Web of Epeira Vulgaris	62
29.	Web of Zilla	65
30.	Web of Nephila Plumipes. From Wilder	66
31.	Part of Web of Nephila, to show the smooth threads. From Wilder	67
32.	Epeira Spinea	69
33.	Spinnerets of Amaurobius	72
34.	Calamistrum of Amaurobius	73
35.	Dictyna spinning Curled Web	73
36.	Part of Web of Amaurobius	74
37.	Part of Web of Dictyna, showing regular arrangement of threads	75
38.	Unfinished Web of Triangle Spider. From Wilder	76
39.	Finished Web of Triangle Spider, and Spider holding the Web.
	From Wilder	78
40.	Young Lycosa flying	81
41.	Flying Spider with a Thread attached to the Ground	84
42.	Large Attus flying by a Brush of Threads	85
43.	Male and Female Nephila Plumipes. From Wilder,
	in Proceedings Boston Society Natural History	78
44,45.	Heads of Males of Several Species of Erigone	88, 89
46.	Palpal Organ of Mygale	89
47.	Palpal Organ of Epeira	90
48.	Palpal Organ of Theridion	91
49.	Epigynum of Epeira Riparia	92
50.	Epigynum of Theridion	93
51.	Epigynum of Theridion	94
52.	Copulation of Lycosa	95
53.	Copulation of Linyphia	96
54.	Copulation of Agalena	96
55.	Copulation of Epeira Riparia	97
56.	Drassus laying Eggs	99
57.	Lycosa carrying Cocoon attached to her Spinnerets	100
58.	Attus Mystaceus laying Eggs	101
59.	Epeira Strix making Cocoon	101
60.	Epeira Strix laying Eggs	102
61.	Cocoon of Argyrodes hanging by a Stem	103
62.	Cocoon of Epeira Riparia. From Wilder	103
63.	Eggs during Segmentation	106
64.	Eggs further Advanced	108
65.	Young Epeira Riparia after First Moult	109
66.	Moulting of Nephila Plumipes. From Wilder
	in Proceedings American Association	111
67.	Nephila Plumipes just after Moulting. From Wilder	111

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THE STRUCTURE AND HABITS
OF SPIDERS.

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CHAPTER I.
ANATOMY AND CLASSIFICATION.

The spiders form a small and distinct group of animals, related to the scorpions, the daddy-long-legs, and the mites, and less closely to the insects and crabs. They are distinguished by the more complete separation of the body into two parts; by their two-jointed mandibles, discharging a poisonous secretion at the tip; and by their spinning-organs, and habits of making cobwebs and silk cocoons for their eggs.

The common round-web spider, Epeira vulgaris of Hentz, will serve as well as any species to show the anatomy of spiders in general. Fig. 1 shows the under side of this spider; Fig. 4, the upper side; and Fig. 5, an imaginary section through the body, to show the arrangement of the internal organs. To begin with Fig. 1: the body is seen to be divided into two parts, connected only by the narrow joint, A, just behind the last pair of legs. The front half of the body, called the thorax, contains the stomach, the central part of the nervous system, and the large muscles which work the legs and jaws. The hinder half, the abdomen, contains the intestine, the breathing-organs, the principal circulating-vessels, the organs of reproduction, and the spinning-organs. Connected with the thorax are six pairs of limbs, four pairs of legs, B B B B, a pair of palpi, C, and a pair of mandibles, D.

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LEGS.

The legs are used chiefly for running, jumping, and climbing; but the front pair serve often as feelers, being held up before the body while the spider walks steadily enough on the other six. One or both of the hinder legs are used to guide the thread in spinning; the spider at the same time walking or climbing about with the other six or seven. The legs are seven-jointed; and on the terminal joint are three claws, Fig. 2, A, B, C, and various hair and spines. In many spiders a brush of hairs takes the place of the middle claw, as in the jumping spiders, Fig. 3. Spiders with these brushes on their feet can walk up a steep surface, or under a horizontal one, better than those who have three claws. The legs of most spiders have among the hairs movable spines, which, when the spider is running about, extend outward at a right angle with the leg, and, when it is resting, are closed down against the skin.

PALPI.

In front of the legs are the palpi, Fig. 1, C, C,—a smaller pair of limbs, with six joints and only one claw or none. They are used as feelers, and for handling food, and, in the males, carry the curious palpal organs, which will be described farther on. The basal joints, Fig. 1, E, of the palpi are flattened out, and serve as chewing-organs, called “maxillæ.”

Mr. Mason has lately described, in the Transactions of the Entomological Society of London, a large spider which has teeth on the inside of the palpi, which, when the spider is angry, are rubbed against teeth on the mandibles, producing a noise.

MANDIBLES.

The front pair of limbs, the mandibles, Fig. 1, D, are two-jointed. The basal joint is usually short and stout, and furnished on the inner side with teeth and hairs. The terminal joint is a small and sharp claw, which can be closed against the basal joint when not in use.

ABDOMEN.

On the under side of the abdomen, just behind the last pair of legs, are two hard, smooth patches, which cover the front pair of breathing-organs, the openings to which are two little slits at Fig. 1, H. Between these is the opening of the reproductive organs, and, in female spiders, the epigynum, Fig. 1, J,—an apparatus for holding the reproductive cells of the male.

Fig. 1Fig. 1