I was one day in an omnibus, in the corner of which sat a butcher. Presently a man got in, whose blue gingham coat indicated the same trade. He seated himself opposite the other, and the two were soon in conversation. *'Do you know Jackson?" says A. "No," savs B: " where does he slaughter?" The reply gave me a new idea; he evidently considered that "slaughtering" was the only occupation worthy of a man, and therefore the only one worthy of man's thought. Spiders are just the same. If an Epeira met a Clubiona, probably the first interchange of civilities would be something like— "Where do you slaughter?"

" No one," says Professor Rymer Jones, " who looks at the armature of a Spider's jaws can mistake the intention with which this terrible apparatus was planned. 'Murder ' is engraved legibly on every piece that enters into its composition." But surely the Professor is rather severe. I do not think this paragraph was written on an autumn morning, when the flies had driven him out of bed prematurely early, by incessantly alighting on his nose ; nor on coming home from a summer evening's walk through the marsh, where clouds of singing and stinging gnats had been the only objects of cognisance to sight, hearing, and feeling. If so, he would have been ready to pronounce " killing no murder," and have blessed the slaughtering Spiders as pursuing a most praiseworthy and useful occupation. Circumstances change opinions.

We will not, then, touch the moral question; but just look at this apparatus from the head of one of our common Spiders (Clubiona atrox), a long-legged and swift species, that builds a compact cloth-like web in our out-houses, with a gallery open at each end for retreat in danger. The specimen is a part of the slough or cast skin, which you may always find in the neighbourhood of such a web ; -and it is particularly suitable for examination, because it is sloughed in the most perfect condition ; every part, the fangs, the palps, the legs, with all their joints, the corneae of the eyes, the entire skin with every hair,— all are here, and all in their places, with a cleanness and translucency which it would require much skill in dissection to obtain, if we captured a living Spider for our purpose.

There are in front of the head two stout brown organs, which are the representatives of the antennae in insects;; though very much modified both in form and function. They are here the effective weapons of attack. Each consists of two joints : the basal one, which forms the most conspicuous portion of the organ, and the terminal one, which is the fang. The former is a thick hollow case, somewhat cylindrical, but flattened sidewise, formed of stiff chitine, covered with minute transverse ridges on its whole surface, like the marks left on the sand by the rippling wavelets, and studded with stout coarse black hair. Its extremity is cut off obliquely, and forms a furrow, the edges of which are beset with polished conical points, resembling teeth.

To the upper end of this furrowed case is fixed by a hinge-joint the fang, which is a curved claw-like organ, formed of hard chitine, and consisting of two parts, a swollen oval base, which is highly polished, and a more slender tip, the surface of which has a silky lustre, from being covered with very fine and close-set longitudinal grooves. This whole organ falls into the furrow of the basal joint, when not in use, exactly as the blade of a clasp-knife shuts into the haft ; but, when the animal is excited, either to defend itself or to attack its prey, the fang becomes stiffly erected.

By turning the object on its axis, and examining the extreme tip of the fang, we see that it is not brought to a fine point, but that it has the appearance of having been cut off slant-wise just at the tip ; and that it is tubular. Now this is a provision for the speedy infliction of death upon the victim ; for both the fang and the thick basal joint are permeated by slender membranous tube, which is the poison duct, and which terminates at the open extremity of the former, while at the other end it communicates with a lengthened oval sac, where the venom is secreted. This, of course, we do not see here, for it is not sloughed with the exuvise, but retained in the interior of the body ; but in life it is a sac, extending into the cephalo-thorax,—as that part of the body which carries the legs is called,—and covered with spiral folds produced by the arrangement of the fibres of its contractile tissue.

When the Spider attacks a fly, it plunges into its victim the two fangs, the action of which is downwards, and not, like that of the jaws of insects, from right to left. At the same instant a drop of poison is secreted in each gland, which, oozing through the duct, escapes from the perforated end of the fang into the wound, and rapidly produces death. The fangs are then clasped down, carrying the prey, which they power- FANG OP SPIDER. fully press against the toothed j.1 1 1 or p the j 1 stout edges basal piece, by which means the nutritive fluids of the prey are pressed out, and taken into the mouth, the dried and empty skin being rejected. The poison is of an acid nature, as experiments performed with irritated spiders prove; litmus paper pierced by them becoming red as far round the perforations as the emitted fluid spreads.

In the slough, the upper surface of the cephalo-thorax is always detached as a thin plate, convex outwardly, concave inwardly. As it is upon the front portion of this division of the body that the eyes are situate, the slough displays these with great clearness and beauty beneath the microscope. Here you may see them. The whole slough

from its thinness is semi-pellucid, but the eyes transmit the light with brilliance, not, however, as if they were simple round holes, because you can discern very manifestly a hemispherical glassy coat, by which it is refracted.

It is, however, when we examine the forehead of a living Or recently killed spider, that we see the eyes to advantage. In this example of the same species (Clubiona atrox), you see them, like polished globes of diamond, sunk into the solid skin of the head. Their form is unimpeachably perfect, and the reflection of light from their surface most brilliant.

EYES OF SPIDEB.

The arrangement of these lustrous eyes is worthy of attention. They are generally eight in number in Spiders ; but their relative position varies so much, as to afford good characters by which naturalists have grouped them in genera. In the Clubiona which we have been examining, they are placed in two nearly straight transverse rows on the forehead ; but, as this surface is convex, it follows that the axis of every' eye points in a different direction from that of its fellows. In Epeira, on the other hand, represented by our Great Garden Spider, so commonly

seen in the centre of its perpendicular web, on shrubs and in corners of our gardens, the four middle eyes form a square, and the two lateral ones on each side are placed in contact with each other.

It is interesting to remark that their arrangement is not arbitrary, but is ancillary to the varying instincts and wants of the different kinds. On this subject I will quote to you what Professor Owen says :—"The position of the four median ones is the most constant ; they generally indicate a square or trapezium, and may be compared with the median ocelli in hexapod insects. The two, or the two pairs of lateral ocelli may be compared with the compound eyes of insects ; the anterior of these has usually a downward aspect, whilst the posterior looks backwards; the variety in the arrangement of the ocelli of Spiders always bears a constant relation to the general ronformation and habits of the species. Dujrs has observed that those Spiders which hide in tubes, or lurk in obscure retreats, either underground or in the holes or fissures of walls or rocks, from which they only emerge to seize a passing prey, have their eyes aggregated in a close group in the middle of the forehead, as in the Bird-spider, the Clotho, &c. The Spiders which inhabit short tubes, terminated by a large web exposed to the open air, have the eyes separated, and more spread upon the front of the cephalo-thorax. Those Spiders which rest in the centre of a free web, and along which they frequently traverse, have the eyes supported on slight prominences which permit a greater divergence of their axes : this structure is well marked in the genus Thomisa, the species of which lie in ambuscade in flowers. Lastly, the spiders called Errantes, or wanderers, have their eyes still more scattered, the lateral ones being placed at the margins of the cephalo-thorax." *

The shining hemisphere (or nearly a sphere) is in each * " Comp. Anat." (Ed. 2), 451.

case covered with a thick cornea, a continuation of the skin, perfectly transparent, and throwing off its outer coats successively in the process of moulting, like that of the rest of the body. The centre of its inner surface is deeply excavated for the reception of a crystalline lens, which is globular in form, and which rests behind on the front surface of a hemispherical vitreous body, without sinking into it. The space between this body and the sides of the lens forms a ring-like channel which is filled with an aqueous humour, and into this projects a circular process of the thick pigment-coat, which corresponds to the choroid, thus defining the pupil of the eye, and at the same time confining the lens to its proper situation. The margin of this pigment-ring may be considered as an iris, and is of various colours, as red, green, or brown, in those species which are active by daylight, while it is black at the back of the eye. The nocturnal species have no dark pigments, but are furnished with a curtain (tapetum), which reflects a brilliant metallic lustre, and makes the eves of these Spiders glare in the twilight, like those of cats.

It will be interesting to compare with this range cf eyes, the same organs in a kindred animal, the common Harvestman (Phalanghnn cornutum). Here in the centre of the cephalo-thorax rises a short pillar, which is crowned with two rows of conical points, with polished black tips. On each side of the pillar is a large black eye, hemispherical in form and brilliantly glossy, exactly resembling, indeed, those which we have just examined. There are, however, only this single pair which thus look out laterally, exactly like the eyes of Birds. There is, indeed, a speck on each side of the thorax, considerably removed from the eye-pillar, just above the origin of the first pair of legs, which has been mistaken for an eye ; 'but it is truly a spiracle, or breathing-hole.

There are many other points of interest about this Harvestman, such as the conical spines which stud the head, p body, and limbs ; the multitude of small bead-like joints into which the foot (tarsus) is divided : and in particular the hammer-like form of the modified antenme, which bend abruptly downwards, and have pincer-tips. These are highly curious, and you may examine them at your leisure ; but for the present we will return to our Spiders.

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