up in the air, make a short gyration, and descend, with a sudden dart, at his very feet.

‘ The time of the appearance of the perfect fly varies according as the season has been warm and dry or cold and damp. In the course of the four years that I watched for them, their first appearance varied from the eighth of August to the fifth of September, and their disappearance from the fifth to the thirtieth of September. The jDrocess of transformation from the larva, to the fly continued, in the entire community of them, from twenty-one to twenty-five

days.’

The pupa of this insect is shown at Fig. h. Fig. a represents a magnified profile view of the head of the perfect insect, and hig. cl is the front view of the mouth.

We now come to the second division of the Cephalota, namely the 'Brachocera, or Short-horned Diptera. They are divided into smaller groups, or Stirpes, as Mr. Westwood calls them. The first of them is the ISTotacantha, or Thornbacks, in which the antennas are apparently composed of only three joints (of which the last is seen, when examined by a I lens, to be articulated), and the proboscis seldom contains I more than two lancets. The pupa is enclosed in the skin of the larva, which, however, retains its previous shape instead of being formed into an oval cocoon, as is the case with the common flies and bluebottles. We can only take one example of this group, the Forked Chameleon Fly {Stratiomys furcata), which is represented on Woodcut LXXI. Fig. 3. In this genus the proboscis is very short, and the basal joint of the antennae is much longer than the second. The third joint is I apparently very long, but the microscope shows that it is ^ composed of several joints fused together, as may be seen by i reference to Fig. h. ^ Most of the insects belonging to this family are beautifully ^ coloured, and many of them n shine u 2 with metallic tints, mostly

tending to purple. The present species is rather variable in colouring, whence one of the three species derives the name of Chameleon. It always, however, has a velvet-black body, on which are a number of bold yellow patches, arranged as shown in the illustration. The legs also are yellow. There are three species all very much alike in colouring, and almost identical

LX XI

Asilus orabronifonnifl. 2. Asilna germaniciis. 3. Stratiomys fiircata. tenax. a. Aeilus crabronifonnis, tarsus. b. Stratiomys furcata, antenna, 4, EristalU tenax, antenna. c. Eristalis

their life history. The larva of this insect is an oddin looking creature, long, slender, and worm-like, with its segments very strongly marked, and gradually diminishing iu towards the tail, which is furnished with a star of diameter hairs. As is the case with the larva of the Gnat, that radiating breathes through the end of the tad, of the Chameleon-fly suspended with its head downwai ds and its the larva remaining tail at the surface. The life history of the Common star-tipped

Chameleon-fly (^Stratiomys Chameleon) has been so tersely and

fully given by Mr. F. Walker in his ‘Insecta Britannica,’ that

I cannot do better than transfer his account to these pages : — ‘ These flies feed on the honey of flowers, and appear in the

spring and in the siunmer on aquatic plants : their flight in ; hot weather is very rapid, but short, and they quickly return to

the spot whence they took wing. The larvae are aquatic, and j the metamorphosis of Stratiomys Chameleon has been often

observed. ‘Its eggs from white become green, and then change to

orange-green ; they are arranged like tiles on a roof, one laid

partly over another, on the underside of the leaves of Alisma

plantago, the water plantain. The larva often remains

suspended by its radiated anus at the surface of the water,

with its head downwards. Its ganglions are so near each other

as to appear like a string of beads. When it is disposed to

sink to the bottom or to descend, by bending the sides of its

tail, so as to form a concavity, it includes in them a bubble of

air, in brilliancy resembling silver or pearl, and then sinks

with it by its own weight : when it would return to the surface

it is by means of this bubble. If it moves upon the surface or

horizontally, it bends its body alternately to the right and

left, contracting itself into the form of the letter S, and then

extending itself again into a straight line : by these alternate i movements it makes its way slowly in the water. It has much

resemblance to some of the Polypi vaginati. The last joint of

the pupa retains the exact form of the larva-body, is extremely ^ long, and terminates in an orifice to receive the air, which is ^ surrounded by a circle of about thirty diverging rays, conbi sisting of beautifully feathered hairs or plumes.

‘ The feathery hairs are so prepared as to repel the water, \s and thus to suspend the animal by its tail at the surface, and tl preserve a constant access of air. When it has occasion to K sink, it turns these hairs in and shuts the orifice, carrying down V. with it an air-bubble that shines like quicksilver, and, as is IS conjectured, enables it again to become buoyant when it V wants to breathe. The dorsal vessel (series of hearts, or artery) > IS attenuated at both ends. The ovaries of the fly are agglof merate, and the egg-tubes form two t bundles, in which the

branches are not discernible.’

The last-mentioned fact is a very curious one, as all will admit who have dissected insects. I have dissected a vast number of insects, representing every order, and nearly every \ important group in entomology, but I never dissected a | Stratiomys, and never saw the remarkable structure which | j\Ir. Walker mentions. {

When the larva is about to undergo its change to the pupal [ form, tbe larval skin hardens, without much alteration of its f shape, and within this cover the pupa becomes developed. ■ Being much smaller than the larva, the pupa only occupies a | portion of the larval skin, so that a. large space is left, render- I , ing the pupa and its case much lighter than water, and j enabling it to float at liberty on the surface. 1 I

We now come to the next group, or Stirps, of the Cephalote Diptera. They are called Tanystoma, or Long-mouthed Flies, ^ 1 in consec[uence of the construction of the mouth, which is generally very prominent, and is furnished with a lancet-like labrum and tongue. The larvae are very worm-like, without feet, and having the head hard and scaly. They live underground, and there pass through their transformations, as we shall see in our short history of the following insect. i

On Plate XX. Fig. 1 is represented the Great Breeze Flt, Cleg {Tabanus hovinus), one of the largest of our » Gad Fly, or Dipterous insects. Its colour is rather variable, but its general | effect is brown, sometimes deepening into dark-brown and yellow, | triangular marks down the centre. It has very with chestnut much the aspect of a large bee, and its wheeling flight and hum serve to strengthen the similitude. The mouth is loud most formidable lancets, and the insect, at least the armed with Breeze Fly, can employ them with terrible effect. The female skin of cattle is no defence against the lancets of the tough and the very hum of one of these insects is able Breeze Fly, to set a whole herd of cattle scampering off in every direction. are not exempt from the attacks of the

Even human beings Breeze Fly, as I can aver from much experience. Some yeai^ a week or two in the New loiest, an ago I was spending it without alloy, had it not been for the would have enjoyed almost drove me out of the Forest. They Breeze Flies, which me at a wonderful distance, and, with a loud, seemed to detect

fierce hum, as if sounding the charge, they would dart at me, and in a moment hury their lancets in the skin. So fierce were their assaults that they even pierced a stout coat of Scotch tweed and a flannel shirt, and, in spite of these protections, drew blood from my arms. For the first few days I was so persecuted by these insects that I hardly dared venture into the Forest, and was seriously considering whether I should not be obliged to go home again.

Their favourite point of attack was just behind the ear. There was no hope of resisting them, for they did not wait to settle, as reasonable flies might be expected to do, but drove straight at me with extended beaks, and buried their lancetarmed beak so deeply that each prick felt as if a stout needle had been run sharply into me. On returning to my lodging, after a few hoiu's in the Forest, I have had the whole space beliind my ears filled with clotted blood, my neck filled also with blood, my collar glued to my neck, and long tracks of blood running down my body and arms. The hands were served in just the same way, and, if I had not worn leather gauntleted gloves, and tied them at the wrists, I should scarcely have been able to move a finger.

At last I discovered a plan which enabled me to enjoy comparative immunity from these and other insect pests. Before starting into the Forest, I dipped a little sponge in paraffin and rubbed it well over my hands, face, and neck. I also put some of the liquid into the gloves, and took a little bottle with me, so that I might renew it as soon as the odour began to decrease in strength. Thus armed, I went into the Forest, and, hearing in the distance the well-known trumpetcharge of the Breeze Fly, determined to await its onset without flinching.

The creature drove fiercely at my face until it was within a toot or eighteen inches from me, when it came within the vapour of the parafiin, and darted off like an arrow. Two or three times it tried the assault, and as often had to check itself, until at last it flew off in disgust and did not return. After this glorious repulse of the enemy I never troubled myself about the flies, but used to amuse myself by hearinothem in the distance, and then seeing them dart away, utterly discomfited with the novel odour. Of course, the smell of the

paraffin was not very agreeable to my own nostrils, but of the two evils it was infinitely the lesser, and I was only too glad to F accept it.

On the frontispiece. Fig. 9, is a coloured portrait of the Humble-bee Fly {Bomhylius medius), as it appears while on the wing.

This insect is an example of the Bombylidse, a family in which the body is short and thick, with the wings extended horizontally on either side of the body. The proboscis is very long, and the thorax very convex. All the Bombylidae fly with wonderful rapidity, and in many of their habits resemble the Humming-Bird Moth, which has already been described. Like that insect, the fly has a way of suddenly appearing as if by magic, and then disappearing as rapidly, its darting flight being as invisible as the track of a bullet through the air. Like the Humming-bird Moth, it feeds while on the wing, balancing itself at some little distance from a flower, plunging the end of its long proboscis into the nectary, and sucking out the sweet juices.

Page 107 of 117