Ever since those mythic times when Arachne contended with Minerva for supremacy in needlework, and was changed, for her pains, into a spider, our little spinners have been famous (Spider= ^m\z) for their matchless achievements in thread. And still their industrious art is plied everywhere around us ; in our chambers, in our windows, in our cellars, in our walls, in our gardens, in waste and desert places, and even under water. But you shall hear what Professor Owen says on the degree and mode in which Spiders exercise their singular secreting faculty, which " varies considerably in the different species. Some, as the Clubionce, line with silk a conical or cylindrical retreat, formed, perhaps, of a coiled-up leaf, and having an outlet at both extremities, from one of which may issue threads to entrap their prey. Others, as the Segestrice, fabricate a silken burrow of five or six inches in length, in the cleft of an old wall. The Mygale cemetaria lines a subterraneous burrow with the same substance, and manufactures a close-fitting trap-door of cemented earth, lined with silk and so attached to the entry of the burrow as to fall down and cover it by its own weight, and which the inmate can keep close shut by means of strong attached threads.

" The arrangement of Spiders by Mr. Walckenaer into families, characterised by their habits, places the principal varieties of their webs in a very concise point of view.

" The Cursores, Saltatores, and Laterigradw make no webs : the first catch their prey by swift pursuit ; the second spring upon their prey by insidious and agileleaps ; the third run, crab-like, sideways or backwards, and occasionally throw out adhesive threads to entrap their prey. The Latebricolce lijde in burrows and fissures, which they line with a web. The Tubicolce inclose themselves in a silken tube, strengthened externally by leaves or other foreign substances. The XiditeJce weave a nest, whence issue threads to entrap their prey. The Filitelcp, are remarkable for the long threads of silk which they spread about in the places where they prowl in quest of prey. The Lapitelce spin great webs of a close texture, like hammocks, and wait for the insects that may be entangled therein. The Orbitelce spread abroad webs of a regular and open texture, either circular or spiral, and remain in the middle or on one side, in readiness to spring upon an entangled insect. The RetiteliP spin webs of an open mesh-work, and of an irregular form, and remain in the middle or on one side, to seize their prey. Lastly, the Aquitelce spread their silken filaments under water, to entrap aquatic insects.

" The silken secretion of Spiders is not applied only to the formation of a warm and comfortable dwelling for themselves, or of a trap for their prey ; it is often employed to master the struggles of a resisting insect, which is bound round by an extemporary filament, spun for the occasion, as by a strong cord. It forms the aeronautic filament of the young migratory brood. It serves to attach the moulting Hydrachna to an aquatic plant by the anterior part of the body, when it struggles to withdraw itself from its exuvium. Lastlv, a softer and more silken kind of web is prepared for the purpose of receiving the eggs, and to serve as a nest for the young." *

The silk with which these various fabrics are constructed is a thick, viscous, transparent liquid, much like a solution of gum arabic, which hardens quickly on exposure to the air, but can meanwhile be drawn out into thread. So far, it agrees with the silk of the silkworm * Owen, "Comp. Anat." (Ed. 2), 458. p 2 and other caterpillars ; but the apparatus by which it is secreted, and that by which it is spun, are both far more complex and elaborate than those of the latter. Generally speaking, there are three pairs of spinnerets, or external organs, through which the threads are produced ; but in some few cases there are only two pairs," and in others, as the Garden Spiders (Epeira), the hindmost pair seem to be united into a single spinneret. These are always situated at the hinder extremity of the body, and I will show them to you presently. First, however, I will describe the internal apparatus ; the source of the threads.

The glands which secrete the gummy fluid are placed in the midst of the abdominal viscera ; and, in some instances— as in the female of Epeira fasciata, a species which makes a remarkably large web— they occupy about a quarter of the whole bulk of the abdomen. About five different kinds of these glands mav be distinguished, though they are not all present in every species. The Epeircr, however, present them all.

In this genus there are :— 1. Small, pear-shaped bags, associated in groups of hundreds, and leading off by short tubes, which are interlaced in a screw-like manner, and open in all of the spinnerets. 2. Six long twisted tubes, which gradually enlarge into as many pouches, and then are each protracted into a very long duct, which forms a double loop. 3. Three pairs of glandular tubes, similar to the preceding, but which open externally through short ducts. 4. Two groups of much-branched sacs, whose long ducts run to the upper pair of spinnerets. 5. Two slightly-branched blind tubes, which terminate by two short ducts in the middle pair of spinnerets, f

It is not very easy to examine the spinnerets with a

"There is a fourth pair in Mr. Blackwall's family of the Cinifloridce, situate iu front of the ordinary anterior pair." (Meade.)

T See a valuable account, by Mr. E. H. Meade, of the secreting glands in Spiders, and of the distinct functions of the various kinds of these organs, read at the British Association, Sept. 25, 1S58.

microscope, so as to make out their structure. If we confine the Spider in a glass cell, it is so restless that the least shock or change of position will cause it to move to and fro ; and, besides, when it does become quiescent, the spinnerets are closed in towards each other, so that we cannot see their extremities. By selecting a specimen, however, recently killed, such as this Clubiona, we may discern sufficient to enable us to comprehend their construction.

Looking, then, at the abdomen from beneath, we see the three pairs of spinnerets clustered together close to the extremity. The pair most forward are shaped somewhat like barrels, whose free ends bend over toward each other. They are covered with stiff black hairs, and just within the margin of what may be called the head of the barrel (for it is cut off horizontally, with a sharp rioi), there is a circle of very close-set, stiff, whitish bristles, which arch inwards. The whole flat surface of the " head," within this circle of bristles, is beset with very minute horny tubes, standing erect, which are the outlets of the silk-ducts that belong to this pair.

Behind this first pair are seen the middle pair, almost concealed, however, from their shortness and smallness, and from the approximation of the first and third pairs. We can discern that thev are more teat-like than the preceding, terminating in a minute wart, which is prolonged into a horny tube. The whole teat is set with similar tubes, which are larger and longer than those of the first pair. Finally, the third pair resemble palpi, for each consists of two lengthened joints, and are bluntly pointed. The spinning tubes in these are limited, as it appears to me, to one or two at the extreme end of each spinneret, the whole surface besides being covered with the ordinary long bristles. Strictly speaking, however,, they are three-jointed, for all the spinnerets spring from wart-like sockets, which may be considered as basal joints ; and as the circlet of bristles in the first pair doubtless indicates a short joint, sunken as it were within the preceding, this pair is likewise three-jointed ; the middle pair appears to be but two-jointed.

The minute horny tubes are themselves composed of two joints, the basal one thick, the terminal one veryslender, and perforated with a very minute orifice, through which the gum oozes at the will of the animal as an equally attenuated thread. On our Clubiona, the number of tubes in all the spinnerets is about three hundred; but in the Garden Spider (Epeird) they exceed a thousand.

This remarkable multiplicity of the strands with which the apparently simple and certainly slender thread of the Spider is composed, has attracted the attention of those philosophers w rho seek to discover the reasons of the phenomena they see in nature. The explanation was first suggested, I believe, by Mr. Itennie,* but it has been amplified with much force by Professor Jones, in the following words :—

" A very obvious reflection will here naturally suggest itself in connexion with this beautiful machinery ; why, in the case of the Spider, it has been found necessary to provide a rope of such complex structure, when in so many Insects a simple, undivided thread, drawn from the orifice of a single tube, like the thread of the silkworm, for instance, was sufficient for all required purposes. And here, as in every other case, it will be found on consideration, that a complicated apparatus has been substituted for a simple one only to meet the requirements of strict necessity. The slow-moving caterpillar, as it leisurely produces its silken cord, gives time enough for the fluid ©f which it is formed to harden by degrees into a tenacious filament, as it is allowed to issue by instalments from the end of the labial pipe ; but the habits of the Spider require a very different mode of proceeding, as its line must * " Insect Architecture," 337.

be instantly converted from a fluid into a strong rope, or it would be of no use for the purposes it is intended to fulfil. Let a fly, for example, become entangled in the meshes of a Spider's web; no time is to be lost ; the struggling victim, by every effort to escape, is tearing the meshes that entangle it, and would soon succeed in breaking loose did not its lurking destroyer at once rush out to complete the capture and save its net, spun with so much labour, from ruin. With the rapidity of thought, it darts upon its prey, and before the eye of the spectator can comprehend the manoeuvre, the poor fly is swathed in silken bands, until it is as incapable of moving as an Egyptian mummy. To allow the Spider to perform such a feat as this, its thread must evidently be instantaneously placed at its disposal, which would have been impossible had it been a single cord, but being subdivided into numerous filaments, so attenuated as we have seen them to be, there is no time lost in the drying; from being fluid they are at once converted into a solid rope, ready for immediate service." *

IS o doubt you have often admired the exquisite regularity of those Spiders' webs which are called geometric; that of our abundant Garden Spider, for instance. You have observed the cables which stretch from wall to wall, or from bush to bush, in various directions, to form the scaffolding, on which the net is afterwards to be woven ; then you have marked the straight lines, like the spokes of a wheel, that radiate from the centre to various points of these outwork cables, and finally the spiral thread that circles agaiu and again round the radii, till an exquisite net of many meshes is formed.

But possibly you are not aware that these lines are formed of two quite distinct sorts of silk. It has been shown that the cables and radii are perfectly unadhesive, while the concentric or spiral circles are extremely viscid. * " Nat. Hist, of Anim.," ii. 339.

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