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them. 17. Do you often become weary ? 18. I become weary when I have nothing to do. 19. How do you amuse yourself when you are in the country? 20. We walk in the morning, and work the remainder of the day.

EXERCISE 70 (Vol. I., page 334).

1. Ne vous trompez-vous pas ? 2. Je ne me trompe pas. 3. Le banquier ne se trompe-t-il pas ? 4. Il ne se trompe pas, mais son commis se trompe certainement. 5. Ne vous trompe-t-il pas ? 6. Il ne me trompe pas, il ne trompe personne. 7. N'avez-vous pas tort de

tromper votre père ? 8. Je n'ai pas l'intention de le tromper. 9. Le marchand ne se trompe-t-il pas ? 10. Il se trompe dans le mémoire qu'il écrit. 11. Aimez-vous la ville ou la campagne? 12. Je préfère la ville, je m'ennuie bientôt à la campagne. 13. Cet enfant ne vous ennuie-t-il pas par ses questions ? 14. Cette longue his. toire ne vous ennuie-t-elle pas ? 15. Elle ne m'ennuie pas, elle m'amuse. 16. Vous amusez-vous quand vous êtes à la campagne ? 17. Je m'y amuse, j'apprends le français et l'italien. 18. Ne vous ennuyez-vous pas chez votre oncle ? 19. Je ne m'y ennuie jamais. 20. M. votre frère se trompe-t-il souvent? 21. Tout le monde se trompe quelquefois. 22. Sa conversation vous ennuie-t-elle ? 23. Au contraire, elle nous amuse. 24. Reçoit-on des nouvelles de M. votre frère ? 25. On n'entend pas parler de lui. 26. Malle. votre sœur se porte-t-elle bien ? 27. Non, Monsieur, elle est malade.

EXERCISE 71 (Vol. I., page 342).

1. Can you do without ink? 2. We can do without it, we have nothing to write. 3. Do you use your pen? 4. I am not using it, do you want it? 5. Will you not draw near the fire? 6. I am much obliged to you, I am not cold. 7. Why do those young ladies go from the window? 8. They leave it because it is too cold there. 9. Do not those children apply to you? 10. They apply to me and to my brother. 11. At what hour do you awake in the morning? 12. I awake generally at a quarter before six. 13. Do you rise as soon as you awake? 14. I rise as soon as I awake. 15. What books do 16. I use mine and yours. 17. Do you not use your 18. I use them also. 19. Are the pens which you use good? 20. Why does your friend draw back from the fire? 21. He draws back because he is too warm. 22. Why does your servant draw near it? 23. He draws near to warm himself. 24. Are you becoming weary of being here? 25. I am not weary of it.

you use ? brother's ?

EXERCISE 72 (Vol. I., page 342).

1. Voulez-vous me prêter votre canif? 2. Je ne puis m'en passer, j'en ai besoin pour tailler ma plume. 3. Voulez-vous vous servir de mon livre ? 4. J'ai besoin de m'en servir, voulez-vous me le prêter ? 5. De quel couteau M. votre frère se sert-il ? 6. Il se sert du couteau de mon père et de la fourchette de mon frère. 7. Ne voulez-vous pas vous approcher du feu? 8. Nous vous sommes bien obligés, nous avons chaud. 9. Cette demoiselle a-t-elle assez chaud? 10. Elle a très-froid. 11. Dites-lui de s'approcher du feu? 12. Pourquoi vous Aloignez-vous du feu ? 13. Nous avons trop chaud. 14. M. votre frère s'éloigne-t-il de la fenêtre ? 15. Il s'éloigne de la fenêtre parcequ'il a froid. 16. À qui ce monsieur s'adresse-t-il ? 17. Il s'adresse à moi et à mon frère. 18. Pourquoi ne s'adresse-t-il pas à mei? 19. Parce

qu'il a honte de vous parler. 20. Vous éveillez-vous de bonne

heure, tous les matins ? 21. Je m'éveille de bonne heure, quand je me couche de bonne heure. 22. Pourquoi vous endormez-vous? 23. Je m'endors parceque je suis fatigué. 24. Avez-vous peur de vous approcher de votre père ? 25. Je n'ai pas peur de m'approcher de

27. Nous ne pouvons

lui. 26. Pouvez-vous vous passer de nous ? nous passer de vous, mais nous pouvons nous passer de votre frère. 28. Avez-vous besoin du cheval de mon frère ? 29. Non, Monsieur, nous pouvons nous en passer. 30. Avez-vous l'intention de vous passer d'argent ? 31. Vous savez très-bien que nous ne pouvons nous en passer. 32. M. votre frère s'ennuie-t-il ici? 33. Il ne s'ennuie pas ici. 34. Approchez-vous du feu, mon enfant.

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In many of its properties this element resembles chlorine, but its affinities are not so strong, since it can be displaced from its combinations by that gas. It owes its name to the severe manner in which it affects the respiratory organs. Bpwuos is the Greek for "stench." It never occurs free in nature, but is found combined with magnesium in sea-water, especially in that of the Dead Sea. The peculiar smell of sea-weed is due to its presence. Berthier discovered it in a silver ore from Mexico, but it is invariably obtained from the "mother liquor" of the sea.

Preparation. A quantity of sea-water is reduced by evaporation; the crystallisable salts, sodium chloride, etc., "crystallise out;" into the "bittern" which thus remains a stream of

chlorine is passed. The chlorine seizes the magnesium, and sets free the bromine, which gives a reddish-yellow colour to the liquid. The bittern is now shaken with ether, which dissolves the bromine and floats on the surface; it is decanted into a glass vessel; a little caustic potash being added, potassium bromide is made. This process is frequently repeated, the same ether being used. The potassium bromide which is thus prepared is mixed with black oxide of manganese and sulphuric acid in a retort; The reaction is thus heat being applied, bromine distils over. expressed

2BrK + 2H,SO, + MnO, = 2Br + K,SO、 + MnSO ̧ + 2H2O. It will be noticed that this process is identical with that of liberating chlorine from common salt.

Properties.-Bromine is a liquid of a deep red colour, having a density of 2.966. It boils at 47° Cent., and evaporates at all temperatures. Its vapour is a dense red. If swallowed, it operates as a powerful irritating poison. It bleaches more feebly than chlorine, but will not support the combustion of a taper. It combines with many metals forming "bromides."

Hydrobromic Acid (symbol, HBr; combining weight, 81; density, 40.5).-This compound cannot be made like hydrochloric acid from the combination of hydrogen and bromine in the sun-light, but the elements will combine if passed through a red-hot porcelain tube. It may also be obtained by decomposing the bromide of phosphorus by water. Thus

PBr, 4H,0 = H,PO, + 5BrH.

The experiment is performed by a tube bent as in Fig. 44. In the bend P pieces of phosphorus are placed, separated from In the bend B is each other by fragments of moistened glass. On placed a little bromine, and the tube closed by a cork. applying a gentle heat at B, the bromine vapours pass into P, where the bromide of phosphorus is formed and is decomposed by the water on the glass. The hydrobromic acid thus produced passes out from T. It is a colourless gas, and can be liquefied under strong pressure. Its action on metallic oxides is analogous to that of hydrochloric acid, forming a bromide of the metal and water.

COMPOUNDS OF BROMINE WITH OXYGEN.

Hypobromous Acid (Symbol, HBrO).—An aqueous solution of this acid can be obtained by agitating bromine water with the oxide of mercury. In distilling the solution, care must be taken not to raise the temperature above 30° Cent., lest the hypobromous acid should be decomposed into bromic acid and free bromine. The aqueous solution of the acid is light yellow, has a sweetish taste, and is a powerful bleaching agent.

Bromic Acid (symbol, HBrO3) is formed when chlorine is Thuspassed into bromine water.

Br+3H,0 + 5C1 = 5HCl + HBrO,. With bases this acid forms "bromates," which salts are decomposed by heat in the same way as chlorates. Bromine forms with hydrogen an oily detonating liquid, which resembles the chloride of nitrogen.

IODINE.

SYMBOL, I-COMBINING WEIGHT, 127— DENSITY, 127. Iodine is found in the sea in really less quantities than bromine, but it is obtained with more ease, for the sea-weeds, etc., store it in their tissues. When these are burnt, the ash, which is called kelp, is broken into small fragments, digested with boiling water, and the solution thus formed is evaporated down until a film forms on its surface, when it is set aside to crystallise. Sodium sulphates and carbonates and potassium chloride separate. The mother liquor is treated with one-eighth of its bulk of sulphuric acid, and after it has stood to allow the precipitates to fall, and some of the sulphates to crystallise out, the clear liquid is mixed with manganese dioxide, and introduced into a leaden retort. Upon the application of heat, iodine passes into the receivers and condenses. The reaction is

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Iodine gives off vapour at all temperatures, and must therefore be kept in a bottle with a glass stopper, as the vapours attack cork. The skin and organic bodies are stained by it yellow. This stain, however, passes away so soon as the iodine evaporates. It is slightly soluble in water, this liquid being capable of holding of its weight in solution. It is freely dissolved in alcohol and ether, and a minute piece of iodine imparts a rich colour to bisulphide of carbon; but the chief liquid employed for its solution is the solution of a soluble iodide, such as potassium iodide.

The most delicate test for iodine is the intense blue colour it imparts to starch. However, to effect this, the iodine must be in an uncombined state. Chlorine water or nitric acid will always liberate

of three atoms of caustic soda, and one atom of sodium iodate. Nitric iodide, which is generally supposed to be the ter-iodide of nitrogen (NI,), is an interesting compound, from the readiness with which it explodes. Place a little iodine in a capsule, and pour upon it sufficient ammonia to cover it well. Allow this to digest for half an hour; then pour off the supernatant liquid, and place the brown substance upon pieces of blotting paper-a little on each paper; leave them to dry, if by a fire, at some distance from it. When dry, a shake of the paper is sufficient to determine the decomposition with explosion.

Fig. 4.

iodine from its combinations, and therefore, if the presence of an iodide be suspected, add one or other of these agents to the solution, and then the starch paste. One part of iodine, dissolved in a million parts of water, will be made apparent by this test. Hydriodic Acid (symbol, HI; combining weight, 128; density, 64). This acid is best prepared in a manner similar to that by which hydrobromic acid was procured-namely, by acting on phosphoric iodide with water, thus

PI, 3H,0: = H.PO,+3HI.

However, it may be made directly by heating iodine in an atmosphere of hydrogen; or a solution of this acid may be easily prepared by suspending iodine in water, and transmitting a current of sulphuretted hydrogen gas until the brown colour disappears. Sulphur is deposited, and hydriodic acid formed, which goes into solution in the water. If this solution be exposed to the air in sunlight, it gradually absorbs oxygen, the hydrogen of the acid forming with it water, and the liberated iodine renders the liquid brown. Iodides are formed by replacing the hydrogen of the above acid by the metal, according to its atomicity. When iodides are heated, the iodine goes off, and an oxide of the metal is formed. Of course, in the case of the noble metals (Au, Ag, Pt, and Hg), the metal remains. The elements, chlorine and bromine, when acting on iodides, have the power to remove the iodine, and insert themselves in its place. Oxides of Iodine.-This element has a greater affinity for oxygen than either of the preceding halogens; but of its oxides, the only two which have been studied are iodic acid and periodic acid. Iodic acid, or hydric-iodate (symbol, HIO,), corresponds closely to chloric acid. It is prepared by the action of strong nitric acid on iodine. When the iodine has nearly disappeared, the liquid upon cooling gives crystals of iodic acid.

Iodine is noted in the medical world for its great powers of absorption. Glandular swellings may be removed by it which have resisted every other means. It is used for this purpose in a solution, which is made as above described. Its action is greatly accelerated if a few grains of potassium iodide be taken internally each day.

FLUORINE.

SYMBOL, F-ATOMIC WEIGHT, 19.

Hitherto no attempt to isolate this element has been successful. Its affinities are so powerful, and its action on the human frame so violent, that little is known of it. Its only compound which occurs in any abundance, is Derbyshire spar, calcium fluoride (CaF2). Many minerals contain this salt in small quantities. It is detected in teeth, and even in the blood of animals. Fluorine is not known to combine with oxygen, nitrogen, sulphur, or the other halogens.

Hydrofluoric Acid (symbol, HF; combining weight, 20; density, 10).-To prepare this acid, Derbyshire or fluor spar is reduced to a powder, introduced into a leaden or platinum retort (Fig. 45), and then mixed with sulphuric acid. Upon the application of heat, this reaction ensues

=

H,SO. CaF, CaSO, + 2HF. The bent part of the tube in Fig. 45 is immersed in a freezing mixture, and here the hydrofluoric acid condenses into a colourless liquid.

It is an energetic acid, and has the power of converting metallic oxides into water and metallic fluorides. Of all chemical

substances, its effect on the skin is the most painful. It will produce a sore which exhibits but small inclination to heal. Its most characteristic property is its power to etch on glass. It effects this, because with silica-one of the constituents of glass-it forms a gaseous product (Si F.), hydrofluosilicic acid: thus

SiO,+4HF= 2H,O+SiF..

To exhibit its effects, a glass plate is covered with bees'-wax, upon which fluorine has no action, and any design traced with a sharp point in the wax. This is exposed to the vapour of hydrofluoric acid, and the parts of the glass exposed are etched; the glass is "frosted" by the vapour; but if the solution

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When iodine is dissolved in caustic potash or soda, the result is a mixture of iodide and iodate of potassium or sodium. The iodate being much the most difficult to dissolve, may easily be separated from the iodide. Or if, in the course of the process, chlorine gas be passed, then no iodide is formed; thus- of the acid, which is sold in gutta-percha bottles, be poured on

I + 6KHO + 5C1 = KIO,+5KCI + 3H,O.

Fig. 45.

When iodates are heated, they behave like chlorates, giving off oxygen.

Iodic acid is at once decomposed by sulphurous acid. This provides a test for the presence of sulphur in any combustion. Soak a piece of paper in a mixture of potassium iodate and starch-paste, then expose it to the fumes; if any sulphurous acid be present, the paper becomes blue. Morphia possesses a like power, and hence by this test the presence of this powerful poison may be detected.

Periodic Acid, or Hydric-periodate (HIO,).-This acid can only be obtained in combination. Sodium per-iodate (NaIO,) may be prepared by passing chlorine through a solution

glass, the glass is eaten away. Any photographic artist will at once appreciate this fact to enable him to remove the frosting from the back of the glass stereoscopic slides, and thus it will be possible to take "prints" from them.

The halogens form the best defined of natural groups of elements. Their atomic weights are almost in arithmetical progression.

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COMPARATIVE ANATOMY.-XI.

INSECTA-CLASSIFICATION.

ENTOMOLOGY, or the study of insects, has always been a favourite branch of natural history. The great beauty, both of form and colouring, to be found in many of the species of this class has always commended it to the attention of all who have any bent towards such studies. Probably the hues of the gorgeously-tinted butterfly, or the elegance and graceful activity of the dragon-fly, have been the first incitement to many a youth to the study of living creatures. Besides these, many thousands who have no claim to be called naturalists have found great pleasure in collecting and preserving insects. "A thing of beauty is a joy for ever," and whether the external

of insects, to have expended her most exquisite workmanship in the architecture of their superficies, or the boundary between themselves and the outer world. The character, the capabilities, and the efficiency of insects depend mainly on the framework of their external casing. This external casing is the resisting and supporting structure upon which all the soft parts are built. From this peculiarity of structure it follows that when an insect is dried-when the muscles have withered and its nervous, nutritive, and reproductive organs have shrivelled or decayed-since they are all internal, not only is its beauty left intact, but all the essential features by which its habits and relationships may be determined are undestroyed. Moreover, it is found that when any class has any great peculiarity, any part specially well developed, the modifications of

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HEMIPTERA:-1, CICADA (AN HOMOPTEROUS INSECT); 2, HALYS; 3, HYDROMETRA. DIPTERA:-4, ASILUS CRABRONIFORMIS; 5, ERISTALIS. LEPIDOPTERA:-6, EUCLIDIA MI. HYMENOPTERA:-7, APATHUS; 8, AN ICHNEUMON FLY. COLEOPTERA:-9, CICINDELA; 10, GEOTRUPES. NEUROPTERA:-11, PHRYGANEA. ORTHOPTERA:-12, MANTIS RELIGIOSA.

stamp of excellence called beauty induces men to examine and appreciate the other excellences of Nature or not, it is good that the great God should receive the praise of a thousand joyous hearts for this alone. The collection and study of insects is pursued with greater ease than that of any other class. Found everywhere in almost infinite variety, they offer an unlimited field in which every lover of Nature can occupy himself. Their size, ranging as it does between a very few inches in length down to an almost limitless minuteness, enables them to be stored, notwithstanding their great multitude, in a space which is at the command of every one. All these facilities for the collection and study of insects would, however, be nugatory if it were not for the peculiarities of their structure. As we have seen in our last lesson, the great peculiarity and excellence of insects is the perfection of the organs of relation, as they are called. By organs of relation is meant the organs through which the animal acts upon, or is brought into contact with, the outer world, such as organs of sense, locomotion, and prehension; of attack and defence. Hence Nature seems, in the case

VOL. III.

that part furnish the best means of classifying the members of that class into minor divisions. Thus, the gills of fish, the breast-bone of birds, and the intra-uterine connection of mother and offspring in brutes, all of which are peculiar or peculiarly developed structures, are made use of severally to divide fish, birds, and brutes into minor sub-divisions. Hence it follows that though in our insect cabinets we have only the dry and lifeless husks of insects, yet we have in them a means of comparing and classifying insects which probably would not be much increased if the whole of the organs were preserved. These advantages have no doubt largely tended to make the study of entomology popular. A class which can be studied with any degree of completeness without recourse to the difficult process of dissection, is sure to receive attention. A simple lens, or at most a microscope of low power, directed upon the exterior of a set specimen, is quite sufficient to determine not only its place in all existing classifications, but even to furnish all the information on which the reasons for the adoption of the several systems of classification are based. Nevertheless,

55

5. Coleoptera (sheath-winged).-Insects with perfect metamorphosis, biting jaws, free, strongly-developed prothorax, and hard, horny fore-wings (Flytra).

hind wings.

7. Orthoptera (straight-winged).-Insects without or with imperfect metamorphosis, biting jaws, and the first segment of the thorax united to the second segment.

One thing should be noted in this ordinal arrangement which otherwise might perplex the student. The Dragon-fly family, with its nearly allied families of the Ephemerida (May-flies) and the Perlidæ, are transferred from the Neuroptera to the Orthoptera on account of their having a free prothorax. Now the dragon-fly was once considered to be the very type of a neuropterous insect, and it seems probable that Linnæus intended that it should be the type of the order he constituted; nevertheless, it is certain that the dragon-flies and the may-flies show a nearer relationship to the Orthoptera than the rest of the so-called Neuroptera.

though all that has been stated is true, though the museums of Europe contain vast collections gathered from all parts of the earth, though the class itself is so rich in species that in it, if anywhere, we might hope to find a complete series which 6. Neuroptera (net-winged).-Insects with perfect metamorwould throw light on the general principles of classification-phosis, biting jaws, free prothorax, and membranous fore and yet the arrangement of insects into minor groups is by no means placed on a satisfactory footing. The external parts of insects have been examined with a minuteness and described with a care which strikes the uninitiated with wonder. Not only the shape of all the plates composing the rings of the body, and the number and form of the joints of the legs and antennæ, have been made to yield characters for classification, but even the number and shape of the joints of the appendages of the mouth-organs, and the direction and number of the nervures of the wings, together with the shape of the cells which they circumscribe, have been impressed into the service of taxonomy. Yet naturalists are far from agreeing in the arrangement of insects into their larger groups. Some classifiers place all insects under seven groups or orders, and some are not contented with less than double that number. Concerning the more conspicuous and independent insects there seems to be a considerable agreement as to classification, and these are comprised under seven orders. The additional orders of those who make more orders than seven are made of minute and generally parasitic insects. These, owing to the peculiarity of their method of life, constitute what may be called aberrant groups-that is, groups which depart considerably from the ordinary typical forms of insects. This idea of aberrant forms will become clearer when we come to describe the several orders. These aberrant groups of insects have been constituted into new orders, or included under the older and better established orders of the more conspicuous insects, according as each classifier is more prone to dwell on the differences or the resemblances of animal forms.

Without going into the merits of the several systems, we shall adhere to that classification by which all insects are arranged into seven orders, because this system will probably give to the reader a clearer idea of the different groups of insects than the ampler system. We have therefore to distribute the aberrant groups among these seven orders, but in so doing we shall call attention to them, so that the reader may not be perplexed when he refers to other systems of classification.

The class Insecta is well defined by the following characters. They are animals with well-developed jointed limbs, one pair of antennæ or head-feelers, compound eyes, feelerless upper jaws (mandibles), a distinct head, a trisegmented thorax, to which is attached three pairs of legs, and (normally) two pairs of wings, limbless abdomen, and respiration by trachea.

The terms used in this classification will be understood by those who have read the last lesson. The whole definition is necessary, in order to cut off the insects from all the neighbouring classes. Thus they possess jointed limbs in common with centipedes, spiders, and crustaceans, but they are by their character cut off from the worms. Centipedes (Myriapoda) have one pair of antennæ, as insects have, but this peculiarity severs these classes from the spiders, which have no antennæ, and also from the crustaceans, which have two pairs. On the other hand, the absence of limbs on the last division of the body, while it is likewise characteristic of the spiders, completely separates them from the myriapods and crustaceans. The possession of two pairs of wings is peculiar to insects, but still this is not a good distinctive character, because wings are not found in all insects.

Insects as thus defined may be divided into the following orders, to each of which we affix the ordinal definition:

1. Hemiptera (half-winged).-Insects with imperfect metamorphosis, free prothorax, and suctorial mouths.

2. Diptera (two-winged).-Insects with perfect metamorphosis, suctorial mouths, membranous naked fore-wings, and aborted hind-wings.

3. Lepidoptera (scale-winged).-Insects with perfect metamorphosis, suctorial mouthed organs, and membranous fore and hind wings, covered with close-set coloured scales.

4. Hymenoptera (membrane-winged).-Insects with perfect metamorphosis, biting jaws, small ring-shaped prothorax, firmly fastened by its upper part to the succeeding segment, and membranous fore and hind wings, of which the latter are the smaller.

The Hemiptera are so named from the fact that many of them have their fore-wings distinctly divided into two parts; the anterior and outer half being horny, like the wing-cases of a beetle, while the inner and hind half is membranous, like the wing of a bee.

As this peculiarity only belongs to one large division of the order, some naturalists have given to it the name Rhynchota, or beaked insects, on account of the long rostrum or sucking snout which is found in every member of the order.

The order is divided into two tribes, the Homoptera and the Heteroptera. In the Homoptera (like-winged) the wings are of the same consistency throughout. One of the largest and most celebrated of these insects is shown in the illustration. The insect represented is the female. The male is larger, and is furnished underneath with two large plates covering in a musical apparatus, which it plies most vigorously both during the day and night. The writer took this insect in Italy, where it abounds, and has been known since classical times. The ancients called the cicada happy, because it had a dumb wife. The cochineal insect, the aphides-whose periodical presence in vast multitudes on plants is commonly called a blight-the Chinese lantern-fly, and the froghopper, all belong to this sub-order. Lice and bird-lice (Pediculina and Mallophaga) may also be considered to be aberrant families of this suborder, though some have made separate orders for each of them.

The Heteroptera (unlike-winged) have wings such as have been described as giving their name to the Hemiptera. The insect marked 2 in the illustration may be taken as a type of this sub-order. The water-scorpion, the water-boatman, and the hydrometra cach represent families of this sub-order. The last-named is represented in the engraving. It may be seen skating over the surface of every piece of water in summer and autumn.

The Diptera may be divided into the flies proper and two aberrant families. The lowest of these families is well known to us, being represented by the almost ubiquitous flea. The mouth-organs of this insect are very different from the genuine flies, and in the place of wings they have only four scales, which appear to be quite useless. Nevertheless, they appear from their metamorphosis, and for other reasons, to be more nearly allied to the Diptera than to any other order. The Pupipara is the name given to other insects which are also parasitic and wingless. These pass the whole of their larva state in the body of the mother.

The genuine flies may be divided into two great divisions, one of which, the Brachycera (short-horned), have short antennæ composed of three joints, while the palpi are of one or two joints; the other sub-order, named Nemocera (thread-horned), have their whip-like antennæ (sometimes beaded) in many joints, while the maxillary feelers are four or five-jointed. The antennæ also often have fine secondary hairs springing from each joint, which gives them the appearance of a plume. This, in the common gnat, is a very pretty object. The common daddy-longlegs (Tipula) is a good example of this order. Both of the flies in the illustration belong to the Brachycera. The hornet-fly is one of the largest of our British Diptera, and while in flight is very like the insect from which it derives its specific name.

The Lepidoptera have been variously divided into groups.

The sub-order, Macrolepidoptera, includes the day-flying butter- | flies, with knobbed antennæ, the hawk-moths (Sphingidae), the thick-bodied moths (Bombycida), the nocturna, and the loopers (Geometrida); while the other sub-order, Microlepidoptera, comprises the pearl-moths (Pyralida), the bell-moths (Tortricidae), the cloth-moths (Tineina), and the plume-moths (Pterophorida). The moth in the engraving belongs to the Nocturna, and is called Euclidia on account of the pattern of geometrical figures formed by the coloured scales of the wings.

The Hymenoptera are divided into the Aculeate, or stinging; the Entomophagous, or insect-eating; and the Phytophagous, or plant-eating, sub-orders. Some species of the latter suborders can prick, but the Aculeata are those which have a perforated sting leading from a poison-bag. The males of these have thirteen joints, and the females twelve joints, to their antennæ. The abdomen is connected with the thorax by a very thin stalk. The females, or workers, usually feed the larvæ or grubs, which are walled up in cells. The bee, the wasp, and the ant each represent different families of this order.

In the entomophagous Hymenoptera, the females are furnished with an ovipositor, placed between two side-plates, which are usually stretched freely out from the end of the abdomen, and are often of great length. This complex instrument is made use of to insert the eggs deep into the bodies of the larva of other insects, in the abdominal cavity of which the footless larvæ live parasitically, and there change into pupa. Hence the enthusiastic lepidopterist who breeds his moths from caterpillars is often woefully disappointed by having a brood of ichneumon-flies emerge from the chrysalis, whose once living tenant they have entirely consumed. No. 8 in the illustration represents an entomophagous insect. In the phytophagous Hymenoptera, the abdomen is joined to the thorax by its whole width, and not by a stalk. These insects are called saw-flies, because they are furnished with a double saw at the end of the body, with which they saw into wood, and there deposit their young, which, when hatched, are herbivorous. The beatles (Coleoptera) form a well-defined order, with scarcely any other approach to other orders among any of their numerous families; and none of these families can be called aberrant that is, they cannot be said to stray far away from the true beetle type. By some, the Brachelytra-which have short wing-cases (as their name implies), under which their flexible wings are closely doubled up, thus leaving the rings of the hind part of the body exposed to view-are related to the Forficulidæ, an orthopterous order. Certainly there is much external likeness between the devil's coach-horse and an earwig, which two insects represent the two families named, bat this is rather a spurious resemblance than a true affinity. The main divisions of the beetles have been founded on the number of the joints of the foot below the tibia. Thus the Pentamera have five joints to all their feet; the Heteromera have four joints to the feet of the third pair of legs, and five to the others. The Cryptopentamera have apparently four joints to all their feet. This appearance is occasioned by the great reduction in size, or, as it might be called, the abortion of one of the joints of each foot. The Trimera, similarly, have apparently three-jointed feet. Both the beetles in the engraving belong to the Pentamerous division. The Cicindela is a carnivorous beetle, and the Geotrupes is an herbivorous lamellicorn e, the last joints of the antennæ are produced into flat, appressed plates.

The Neuroptera, narrowed by the transference of the dragonflies and the may-flies to the Orthoptera, is divided into the Planipennia-in which the hind-wings are like the fore ones, and not folded-and the Trichoptera, in which the wings are hairy or scaly, and the hind pairs folded. To these divisions, also, must be added the aberrant sub-order, called Strepsiptera (crew-winged). The males of these have curious twisted and aborted organs to represent the fore-wings and widely expanded hind-wings; while the females are wingless, and inhabit the bodies of bees, between the segments of whose abdominal rings they thrust forth their heads.

The Orthoptera, as defined above, comprise not only the genuine Orthoptera represented by the cockroaches, walkinglaves, grasshoppers, and crickets-whose main characteristic is the folding of their broad hind-wings longitudinally, after the manner of a lady's fan-but also the white ants, the earwiza, and dragon-flies, etc., and also two aberrant groups, called

Physopoda and Thysanura. The earwigs (Dermoptera) are distinguished by their short, leathery, unveined elytra or forewings, which cover the membranous hind-wings. These latter are folded when at rest, first in a longitudinal direction, and then doubled up transversely, so as to occupy but little space. When extended, these membranous wings are in shape like the human ear, hence the name ear-wing, and its corruption earwig. The pincers at the end of the body, the uses of which are so little known, furnish another character which is conspicuous to all. Two more aberrant sub-orders, the Corrodentia and Physopoda (bladder-footed), are of little importance. Another, called the Thysanura, is remarkable for having long bristles at the end of the body, which in the Podura are bent under the body, and serve as springs to jerk the insect into the air when it wishes to leap, much after the manner of the toy leaping-frog. These creatures have their bodies covered with scales, which are so small yet so beautifully symmetrical in their markings as to make excellent test objects for the high powers of a microscope.

The tribe to which the white ants belong is called Orthoptera socialia, because they live in communities. Although they belong to quite a different order from the true ants, yet the popular name is justified by the fact that their habits are closely similar to them. It is a singular coincidence that in both the cases of the true and the white ants there are not only males and females in the community, but also neutral wingless forms, which, though themselves sterile, are highly instrumental in presiding over the reproduction and rearing of the young from the other fertile forms, and also in the defence of the nest and community. In the case of the Termites, the neuters are called soldiers, because of their immense jaws, wherewith they attack all intruders. The larvæ and pup are active, and do the work of the community. The female has wings which have only a temporary use. When pregnant, she is placed in a royal apartment, and fed while she increases to an enormous size, preparatory to the production of some 80,000 eggs.

The Praying Mantis is a good example of another family. The cognomen is applied on account of the bent fore-legs of the animal, which are supposed to represent the attitude of prayer. The mantis, however, uses them to inflict painful wounds by the aid of the sharp-pointed tibiæ. This insect is an excellent example of the Gressorial Orthoptera. The salta torial Orthoptera are well known as grasshoppers and cricketa

LESSONS IN ENGLISH.-XXVIII.

THE LATIN ELEMENT.

IN our last lesson (Vol. II., page 409) we finished our inquiry into the influence that the ancient language of the Greeks has exerted on our tongue, and we now pass on to the Latin element in the English language.

That element can by the ordinary student be appreciated and acquired but imperfectly. I will, however, do what I can to aid him. Had I had the direction of his studies from the first, I would have done my best to make him at the beginning master of the Latin language. As it is, I must content myself with offering to his diligent attention the chief Latin roots which enter into the body of our tongue. Possessed of these, together with their signification, he will in general bo at no loss, even without the aid of a dictionary, for the meaning of a word of Latin parentage. Seldom, however, do the words in English which may be traced back to the Latin, come into our tongue directly from the Roman soil. They have generally passed through intermediate countries. From the Latin are formed several modern languages, namely, the French, the Italian, the Portuguese, and the Spanish. These are called the Romance languages, because they are essentially Roman in their origin. Some say they received the name because in them the first romances were written; more probably is it that the fictions so called were denominated from the languages in which they appeared.

It is not immediately from the pure Latin of the Latin classics, such as Livy, Cicero, Virgil, Horace, and Tacitus, that the Romance languages are derived, but rather from these so far as they were found in the vernacular tongue, the spoken language of the population in the great centres of intercourse

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