Under a high power the structure of the investing hairs is very interesting ; for they are seen to be flat filaments of the yellow chitine, very much dilated at their bases, and set side by side in regular whorls, the bottom edges of which form the rings of which the tongue is composed. The tip is probably a sensitive organ of taste, for it terminates in a minute globose pulpy body, whose surface is beset with tiny curved points. Thus I have pointed out to you, in this Bee, all the parts which enter into the

JAWS OF BEE.

mouth of the Beetle, except the maxillary palpi; and these, very small indeed, but quite distinct, you may see on the outer edge of the maxillw, just below the point where their outline begins to swell into its graceful curve.

The cylindrical tongue is capable of considerable ex-

tension and contraction at the will of the animal ; being sometimes pushed far out of the mouth, and at others quite concealed within its sheath. " The manner," observes Mr. Newport, "in which the honey is obtained, when the organ is plunged into it at the bottom of a flower, is by lapping, or a constant succession of short and quick extensions and contractions of the organ, which occasion the fluid to accumulate upon it, and to ascend along its upper surface, until it reaches the orifice of the tube formed by the approximation of the maxillce above, and of the labial palpi, and this part of the ligula below."

"Well might Swammerdam, when describing this exquisite structure, humbly exclaim :—" I cannot refrain from confessing, to the glory of the immense and incomprehensible Architect, that I have but imperfectly described and represented this small organ ; for, to represent it to the life in its full perfection, as truly most perfect it is, far exceeds the utmost efforts of human knowledge."

Here you may see the implement with which the Bug performs its much-dreaded operation of blood-sucking ; for though this is not the head of the Bed-bug, but of one of the winged species that are found so abundantly on plants, and which I have just obtained by beating the hedge at the bottom of my garden, yet the structure of the mouth is so exactly alike in all the members of this immense family, that one example will serve for all others.

From the front of the head, which, owing to the manner in which this part is carried, is the lower part, proceeds a fine thread, about four times as long as the head itself, passing along between the fore legs, ' close to the body beneath the breast. It is, however, at the pleasure of the animal, capable of being brought up so as to point directly forward, and even projected in front of the head, and in the same plane as the body ; a fact which once came under my own observation. I found a Plant-bug (Pentatoma) which had plunged this thread-like sucker of his into the body of a caterpillar, and was walking •about with his prey, as if it were of no weight at all, •carrying it at the end of his sucker, which was held straight out from the head, and a little elevated. He fiercely refused to allow the poor victim to be taken away, being doubtless engaged in sucking its vital juices, just as the bed-abomination victimises the unfortunates who have to sleep at some village inn.

Well, we put this head with its sucker between the plates of the compressorium, upon the microscope-stage. The thread is an organ composed of four lengthened slender joints, beset with scattered bristles, and terminating in a point on which are placed a number of exceedingly minute radiating warts, probably the seat of some sensation ; perhaps taste. This jointed organ is the under-lip ; it is slit all down one surface, so that it forms an imperfect tube, or furrow, within which lies the real weapon, a wire of far greater tenuity, which by pressure I can force out of its sheath. It is so slender that its average diameter is not more than TttV otn °^ an inch, and it ends in the most acute point ; yet this is not a single body, but consists of four distinct wires, lying within one another, and representing the maxilke and the mandibles. These can be separated by the insect, and will sometimes open when under examination ; but no instrument that I can apply to them is sufficiently delicate to effect their separation at my pleasure. Just at the very tip, however, under this high power, we can see, by the semi-transparency of the amber-coloured chitine of which the organ

composed, that there is another tip a little shorter, and, as it were, contained within the other. This inner point is cut along its edges into saw-teeth pointing backward. Such exquisite mechanism is bestowed upon the structure, and such elaborate contrivance is displayed for the comfort of an obscure and offensive insect, by Him Who has not disdained to exercise His skill and wisdom in its creation !

You know the stout flies which are denominated Horseflies or Whame-flies (Tabanus), which are so numerous in the latter part of summer, flying around horses, and men too, if we intrude upon their domains. They are continually alighting on the objects of their attentions, and, though driven away, returning with annoying pertinacity to the attack. You may always recognise them by the brilliant metallic hues—reds, yellows, andgreens— with which their large eyes are painted, often in stripes or bands. These are voracious blood-suckers ; and, as might be supposed from their propensities, they are well furnished with lancets for their surgery. Here you may see their case of instruments, which are so effective, that Reaumur tells us that, having compelled one to disgorge the blood it had swallowed, the quantity appeared to him greater than the whole body of the insect could have been supposed capable of containing.

All the parts here are formed of the common ambercoloured chitine, brilliantlv clear and translucent. The upper lip forms a sort of straight sheath, in which all the other parts are lodged when not in use. The mandibles are narrow lancets, of which one edge near the tip is beset with reverted saw-teeth, and the opposite edge with exceedingly sharp points standing out at right angles ; while the surface is roughened with lozenge shaped knobs set in regular rows. Below these are the maxilla', which are the principal cutting instruments ; these are shaped like a carving-knife with a broad blade, strengthened at the basal part of the back by a thick ridge, but brought to a double edge near the tip. The back-edge is perfectly fine and smooth, so that the highest powers of the microscope can only just define its outline, while the other edge is notched into teeth so delicate that twelve of them are L cut in the length of a ten-thousandth part of an inch; and yet they are quite regular and symmetrical in length, height, and form ! I know of no structure of the kind which equals this. These teeth are continued throughout the inner edge of the blade from the tip to the base, and are about eight hundred in number ; though the length of the entire blade is only such that upwards of a hundred and fifty of them, if laid end to end, would not reach to the extent of an inch !

The office of these wonderful instruments is doubtless to cut and enlarge the wound within, and thus promote the flow of blood. The whole apparatus is plunged into the flesh of the victim—horse or man; then the maxillce expand, cutting as they go, and doubtless working to and fro as well as laterally, so as to saw the minuter bloodvessels. At the same time the mandibles, with their saw-teeth on one side, and pricking points on the other, work in like manner, but seem to have a wider range. Finally, there is an exceedingly delicate piece beneath all, which seems to represent the labium or under lip.

In the active and cunning little Flea, that makes his attacks upon us beneath the shelter of the blankets and under cover of night, the piercing and cutting blades are very minute, and have a peculiar armature. They remind me (only in miniature of course) of those formidable flat weapons w rhich w^e often see in museums, the rostrums of the huge Saw-fishes (Pristis) ; a great plate of bone covered with grey skin, and set along each side with a row of serried teeth. Here the blades are similar in form, being long, straight, narrow plates of transparent chitine, set, along each edge, with a double row of glassy points, which project from the surface, and are then hooked backwards. These are the mandibles, and they closely fold together, inclosing another narrower blade, the upper lip, which has its two edges studded with similar points, but in a single row.

insects: their mouths.

general, as we have seen, the maxillce are the specially armed weapons ; the mandibles acting a secondary part, often serving as mere sheaths in those insects which pierce other animals Avith the mouth. But in this case the mandibles are the favoured parts, the maxillce being developed into broad leaf-shaped convex sheaths, inclosing the mandibles.

There are, however, two cutting blades besides ; the labial palpi, which have their upper edge thick, divided into four distinct joints, and set with bristles, thus retaining the proper character of palpi ; while their under edge is thinned away to a fine keen blade, in which there is no sign of jointing. Then there are the maxillary palpi, of which the joints are furnished at their tips with tiny projecting warts, doubtless the seats of a delicate sense, and hollowed into a double series of chambers, which are filled with a dark-coloured fluid.

All this is very interesting to behold, and is calculated to exalt our ideas of the wonderful and inexhaustible resources of Omnipotence, as well as to humble us, when we reflect how little we certainly understand even of what we see. But, common as the Flea is, it is not a matter of course that you will be able to repeat these observations with the first specimen you put on the stage of your microscope. Several favourable conditions must combine in order to insure a successful examination. You should choose a female Flea, partly because of her greater size, and partly because the predatory weapons, in all these piercing and sucking insects, are better developed in the females,—true Amazons. Then you will find it needful to amputate the head, in order to get rid of the front legs, the thick thighs of which else impede your sight of the mouth, being projected on each side of it. And this is a delicate operation; it must be performed on a plate of glass, under a lens, with one of those dissecting needles whose points are ground to a l 2 cutting-edge. Next, having severed the head, you must place it in a drop of water, between the plates of your compressorium, the graduated pressure of which, by means of the screw, will cause the organs of the mouth to open and expand separately. Finally, you must have a good instrument, and a high power : less than 600 diameters will not avail to bring out distinctly the toothing of the mandibles and labrum ; and even then you will need delicate manipulation and a practised eye. But the object is worthy of the care bestowed upon it.

Once more. Let us submit to examination the complex case of instruments wherewith the Gnat performs her unwelcome yet skilful surgery. I say " her," because among the Gnats also, as I have just intimated, it is the females only who possess skill in the art of bleeding ; the males being innocent of any share in it, and being indeed unprovided with the needful implements.

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