Chapter XXIV: Part II: Animal Life (17)

There are two galls common on the stems of goldenrod. The more numerous is spherical in form and is made by a fat and prosperous looking little grub which later develops into a fly. But although it is a fly that makes the globular gall in the stem of goldenrod, the spindle-shaped gall often seen on the same stem has quite another story. A little brown and gray mottled moth, about three-fourths of an inch long, lays her egg on the stem of the young goldenrod. The caterpillar, when it hatches, lives inside the stem, which accommodatingly enlarges into an oblong room. The caterpillar feeds upon the substance of the stem until it attains its growth, and then seems to dimly realize something about its future needs. At least it cuts, with its sharp jaws, a little oval door at the upper end of its house and makes an even bevel by widening the opening toward the outside. It then makes a little plug of debris which completely fills the door; but because of the bevel, no intrusive beetle or ant can push it in. Thus the caterpillar changes to a helpless pupa in entire safety; and when the little moth issues from the pupa skin, all it has to do is to push its head against the door, and out it falls, and the recluse is now a creature of the outside world.

Comstock’s Manual.]

Many galls are compound, that is, they are made up of a community of larvæ, each in its own cell. The mossy rose-gall is an instance of this. The galls made by mites and aphids are open either below or above the surface of the leaf; the little conical galls on witch-hazel are examples of these. In fact, each gall has its own particular history, which proves a most interesting story if we seek to read it with our own eyes.

LESSON LXXIX

THE GALL-DWELLERS

_Leading thought_--The galls are protective habitations for the little insects which dwell within them. Each kind of insect makes its own peculiar gall on a certain species of plant, and no one understands just how this is done or why it is so.

_Section of same showing cells._

_Female gallfly laying eggs in oak bud._

Photo by C. J. Triggerson.]

_Method_--Ask the pupils to bring in as many of these galls as possible. Note that some have open doors and some are entirely closed. Cut open a gall and see what sorts of insects are found within it. Place each kind of gall in a tumbler or jar covered with cheesecloth and place where they may be under observation for perhaps several months; note what sort of winged insect comes from each.

_Observations_--1. On what plant or tree did this gall grow? Were there many like it? Did they grow upon the root, stem, leaf, flower, or fruit? If on the leaf, did they grow upon the petiole or the blade?

2. What is the shape of the little house? What is its color? Its size? Is it smooth or wrinkled on the outside? Is it covered with fuzz or with spines?

3. Open the gall; is there an insect within it? If so, where is it and how does it look? What is the appearance of the inside of the gall?

4. Is there a cell for the insect at the very center of the gall, or are there many such cells?

5. Has the house an open door? If so, does the door open above or below? Are there more than one insect in the galls with open doors? What sort of insect makes this kind of house?

6. Do you find any insects besides the original gall-maker within it? If so, what are they doing?

7. Of what use are these houses to their little inmates? How do they protect them from enemies? How do they furnish them with food?

8. Do the gall insects live all their lives within the galls or do they change to winged insects and come out into the world? If so, how do they get out?

9. How many kinds of galls can you find upon oaks? Upon goldenrod? Upon witch-hazel? Upon willow?

_Supplementary reading_--Outdoor Studies, Needham, pages 18 and 37; “Houses of Oak,” in Insect Stories, Kellogg; Manual for the Study of Insects.

* * * * *

_A green little world
With me at its heart!
A house grown by magic,
Of a green stem, a part._

_My walls give me food
And protect me from foes,
I eat at my leisure,
In safety repose._

_My house hath no window,
’Tis dark as the night!
But I make me a door
And batten it tight._

_And when my wings grow
I throw wide my door;
And to my green castle
I return nevermore._

THE GRASSHOPPER

_Teacher’s Story_

Because the grasshopper affords special facilities for the study of insect structure, it has indeed become a burden to the students in the laboratories of American universities. But in nature-study we must not make anything a burden, least of all the grasshopper, which being such a famous jumper as well as flier, does not long voluntarily burden any object.

Since we naturally select the most salient characteristic of a creature to present first to young pupils, we naturally begin this lesson with the peculiarity which makes this insect a “grasshopper.” When any creature has unusually strong hind legs, we may be sure it is a jumper, and the grasshopper shows this peculiarity at first glance. The front legs are short, the middle legs a trifle longer, but the femur of the hind leg is nearly as long as the entire body, and contains many powerful muscles which have the appearance of being braided, because of the way they are attached to the skeleton of the leg; the tibia of the hind leg is long and as stiff as if made of steel. When getting ready to jump the grasshopper lowers the great femur below the level of the closed wings and until the tibia is parallel with it and the entire foot is pressed against the ground. The pair of double spines at the end of the tibia, just back of the foot, are pressed against the ground like a spiked heel, and the whole attitude of the insect is tense. Then, like a steel spring, the long legs straighten and the insect is propelled high into the air and far away. This is a remarkable example of insect dynamics; and since so many species of birds feed upon the grasshopper, its leaping power is much needed to escape them. However, when the grasshopper makes a journey it uses its wings.

As we watch a grasshopper crawling up the side of a vial or tumbler we can examine its feet with a lens. Between and in front of the claws is an oval pad which clings to the glass, not by air pressure as was once supposed, but by means of microscopic hairs, called tenent hairs, which secrete a sticky fluid. Each foot consists of three segments and a claw; when the insect is quiet, the entire foot rests upon the ground; but when climbing on glass, the toe pads are used.

_Adult of red-legged grasshopper_

Comstock’s Manual.]

The grasshopper’s face has a droll expression; would that some caricaturist could analyze it! It is a long face, and the compound eyes placed high upon it, give a look of solemnity. The simple eyes can be made out with a lens. There is one just in front of each big eye, and another, like the naughty little girl’s curl, is “right in the middle of the forehead.” The antennæ are short but alert. The two pairs of palpi connected with the mouth-parts are easily seen, likewise the two pairs of jaws, the notched mandibles looking like a pair of nippers. We can see these jaws much better when the insect is eating, which act is done methodically. First, it begins at one edge of a leaf, which it seizes between the front feet so as to hold it firm; it eats by reaching up and cutting downwards, making an even-edged, long hole on the leaf margin; the hole is made deeper by repeating the process. It sometimes makes a hole in the middle of a leaf and bites in any direction, but it prefers to move the jaws downward. While it is feeding, its palpi tap the leaf continually and its whole attitude is one of deep satisfaction. There is an uprolled expression to the compound eyes which reminds us of the way a child looks over the upper edge of its cup while drinking milk. The grasshopper has a preference for tender herbage, but in time of drouth will eat almost any living plant.

Back of the head is a sun-bonnet-shaped piece, bent down at the sides, forming a cover for the thorax. The grasshopper has excellent wings, as efficient as its legs; the upper pair are merely strong, thick, membranous covers, bending down at the sides so as to protect the under wings; these wing-covers are not meant for flying and are held stiff and straight up in the air, during flight. The true wings, when the grasshopper is at rest, are folded lengthwise like a fan beneath the wing-covers; they are strongly veined and circular in shape, giving much surface for beating the air. The grasshoppers’ flight is usually swift and short; but in years of famine they fly high in the air and for long distances, a fact recorded in the Bible regarding the plague of locusts. When they thus appear in vast hordes, they destroy all the vegetation in the region where they settle.

The wings of grasshoppers vary in color, those of the red-legged species being gray, while those of the Carolina locusts are black with yellow edges. The abdomen is segmented, as in all insects, and along the lower side there are two lengthwise sutures or creases which open and shut bellows-like, when the grasshopper breathes. The spiracles or breathing pores can be seen on each segment, just above this suture.

The grasshopper has its ears well protected; to find them, we must lift the wings in order to see the two large sounding disks, one on each side of the first segment of the abdomen. These are larger and much more like ears than are the little ears in the elbows of the katydids.

The singing of the short-horned grasshoppers is a varied performance, each species doing it in its own way. One species makes a most seductive little note by placing the femur and tibia of the hind legs together, and with the hind feet completely off the ground, the legs are moved up and down with great rapidity, giving off a little purr. The wings in this case, do not lift at all. There are other species that make the sound by rubbing the legs against the wing-covers.

The grasshopper makes its toilet thus: It cleans first the hind feet by rubbing them together and also by reaching back and scrubbing them with the middle feet; the big hind femur it polishes with the bent elbow of the second pair of legs. It cleans the middle feet by nibbling and licking them, bending the head far beneath the body in order to do it. It polishes its eyes and face with the front feet, stopping to lick them clean between whiles, and it has a most comical manner of cleaning its antennæ; this is accomplished by tipping the head sidewise, and bending it down so that the antenna of one side rests upon the floor; it then plants the front foot of that side firmly upon the antenna and pulls it slowly backward between the foot and floor.

The grasshopper has some means of defence as well as of escape; it can give a painful nip with its mandibles; and when seized, it emits copiously from the mouth a brownish liquid which is acrid and ill-smelling. This performance interests children, who are wont to seize the insect by its jumping legs and hold it up, commanding it to “chew tobacco.”

Grasshoppers are insects with incomplete metamorphosis, which merely means that the baby grasshopper, as soon as it emerges from the egg, is similar in form to its parent except that it has a very large head and a funny little body, and that it has no quiet stage during life. When immature, the under wings or true wings have a position outside of the wing-covers and look like little fans.

The short-horned grasshoppers lay their eggs in oval masses protected by a tough overcoat. The ovipositor of the mother grasshopper is a very efficient tool, and with it she makes a deep hole in the ground, or sometimes in fence rails or other decaying wood; after placing her eggs in such a cavity, she covers the hiding place with a gummy substance so that no intruders or robbers may work harm to her progeny. Most species of grasshoppers pass the winter in the egg stage; but sometimes we find in early spring the young ones which hatched in the fall, and they seem as spry as if they had not been frozen stiff.

LESSON LXXX

THE RED-LEGGED
GRASSHOPPER

_Leading thought_--The grasshopper feeds upon grass and other herbage and is especially fitted for living in grassy fields. Its color protects it from being seen by its enemies the birds. If attacked, it escapes by long jumps and by flight. It can make long journeys on the wing.

_Method_--The red-legged grasshopper (_M. femur-rubrum_) has been selected for this lesson because it is the most common of all grasshoppers, though other species may be used as well. The red-legged locust, or grasshopper has, as is indicated by its name, the large femur of the hind legs reddish in color. Place the grasshopper under a tumbler and upon a spray of fresh herbage, and allow the pupils to observe it at leisure. It might be well to keep some of the grasshoppers in a cage similar to that described for crickets. When studying the feet, or other parts of the insect requiring close scrutiny, the grasshopper should be placed in a vial so that it may be passed around and observed with a lens. Give the questions a few at a time, and encourage the pupils to study these insects in the field.

Comstock’s Manual.]

_Observations_--1. Since a grasshopper is such a high jumper, discover if you can how he does this “event.” Which pair of legs is the longest? Which the shortest? How long are the femur and tibia of the hind leg compared with the body. What do you think gives the braided appearance to the surface of the hind femur? What is there peculiar about the hind femur? Note the spines at the end of the tibia just behind the foot.

2. Watch the grasshopper prepare to jump and describe the process. How do you think it manages to throw itself so far? If a man were as good a jumper as a grasshopper in comparison to his size, he could jump 300 feet high or 500 feet in distance. Why do you think the grasshopper needs to jump so far?

3. As the grasshopper climbs up the side of a tumbler or vial, look at its feet through a lens and describe them. How many segments are there? Describe the claws. How does it cling to the glass? Describe the little pad between the claws.

4. Look the grasshopper in the face. Where are the compound eyes situated? Can you see the tiny simple eyes like mere dots? How many are there? Where are they? How long are the antennæ? For what are they used?

5. How does a grasshopper eat? Do the jaws move up and down or sidewise? What does the grasshopper eat? How many pairs of palpi can you see connected with the mouth-parts? How are these used when the insect is eating? When there are many grasshoppers, what happens to the crops?

6. What do you see just back of the grasshopper’s head, when looked at from above?

Comstock’s Manual.]

7. Can the grasshopper fly as well as jump? How many pairs of wings has it? Does it use the first pair of wings to fly with? How does it hold them when flying? Where is the lower or hind pair of wings when the grasshopper is walking? How do they differ in shape from the front wings?

8. Note the abdomen. It is made of many rings or segments. Are these rings continuous around the entire body? Where do their breaks occur? Describe the movement of the abdomen as the insect breathes. Can you see the spiracles or breathing pores? Lift the wings, and find the ear on the first segment of the abdomen.

9. If you seize the grasshopper how does it show that it is offended?

10. How does the grasshopper perform its toilet? Describe how it cleans its antennæ, face and legs.

11. What becomes of the grasshoppers in the winter? Where are the eggs laid? How can you tell a young from a full-grown grasshopper?

12. Do all grasshoppers have antennæ shorter than half the length of their bodies? Do some have antennæ longer than their bodies? Where are the long-horned grasshoppers found? Describe how they resemble the katydids in the way they make music and in the position of their ears.

_Supplementary reading_--Chapters XVI-XVIII in Grasshopper Land, Morley.

THE KATYDID

_Teacher’s Story_

“_I love to hear thine earnest voice
Wherever thou art hid,
Thou testy little dogmatist,
Thou pretty katydid,
Thou mindest me of gentle folks,
Old gentle folks are they,
Thou say’st an undisputed thing
In such a solemn way._”
HOLMES.

Distance, however, lends enchantment to the song of the katydid, for it grates on our nerves as well as on our ears, when at close quarters. The katydid makes his music in a manner similar to that of the cricket but is not, however, so well equipped since he has only one file and only one scraper for playing. As with the meadow grasshoppers and crickets, only the males make the music, the wings of the females being delicate and normally veined at the base. The ears, too, are in the same position as those of the cricket, and may be seen as a black spot in the front elbow. The song is persistent and may last the night long: “Katy did, she didn’t she did.” James Whitcomb Riley says, “The katydid is rasping at the silence,” and the word rasping well describes the note.

The katydids are beautiful insects, with green, finely veined, leaf-like wing-covers under which is a pair of well developed wings, folded like fans; they resemble in form the long-horned grasshoppers. The common northern species (_Cyrtophyllus_) is all green above except for the long, delicate, fawn-colored antennæ and the brownish fiddle of the male, which consists of a flat triangle just back of the thorax where the wing-covers overlap. Sometimes this region is pale brown and sometimes green, and with the unaided eye we can plainly see the strong cross-vein, bearing the file. The green eyes have darker centers and are not so large as the eyes of the grasshopper. The body is green with white lines below on either side. There is a suture the length of the abdomen in which are placed the spiracles. The insect breathes by sidewise expansion and contraction, and the sutures rhythmically open and shut; when they are open, the spiracles can be seen as black dots. The legs are slender and the hind pair, very long. The feet are provided with two little pads, one on each side of the base of the claw. In the grasshopper there is only one pad which is placed between the two hooks of the claw. The female has a green, sickle-shaped ovipositor at the end of the body. With this she lays her flat, oval eggs, slightly over-lapping in a neat row.

The katydids are almost all dwellers in trees and shrubs; although I have often found our common species upon asters and similar high weeds. The leaf-like wings of these insects are, in form and color, so similar to the leaves that they are very completely hidden. The katydid is rarely discovered except by accident; although when one is singing, it may be approached and ferreted out with the aid of a lantern.

The katydid, when feeding, often holds the leaf or the flower firmly with the front feet, while biting it off like a grazing cow, and if it is tough, chews it industriously with the sidewise working jaws. A katydid will often remain quiet a long time with one long antenna directed forward and the other backward, as if on the lookout for news from the front and the rear. But when the katydid “cleans up,” it does a thorough job. It nibbles its front feet, paying special attention to the pads, meanwhile holding the foot to its mandibles with the aid of the palpi. But once washing is not enough; I have seen a katydid go over the same foot a dozen times in succession, beginning always with the hind spurs of the tibia and nibbling along the tarsus to the claws. It cleans its face with its front foot, drawing it downward over the eye and then licking it clean. It cleans its antenna with its mandibles by beginning at the base and drawing it up in a loop as fast as finished. After watching the process of these lengthy ablutions, we must conclude that the katydid is among the most fastidious members of the insect “four hundred.”

_References_--Manual for Study of Insects, Comstock; American Insects, Kellogg; Ways of Six Footed, Comstock; Grasshopper Land, Morley.

Comstock’s Manual.]

LESSON LXXXI

THE KATYDID

_Leading thought_--The katydids resemble the long-horned grasshoppers and the crickets. They live in trees, and the male sings “katy-did” by means of a musical instrument similar to that of the cricket.

_Method_--Place a katydid in a cricket cage in the schoolroom, giving it fresh leaves or flowers each day, and encouraging the pupils to watch it at recess. It may be placed in a vial and passed around, for close observation. In studying this insect, use the lesson on the red-legged grasshopper and also that on the cricket. These lessons will serve to call the attention of the pupils to the differences and resemblances between the katydid and these two allied insects.

Drawing by Ida Baker.]

_THE BLACK CRICKETS_

_Of the insect musicians the cricket is easily the most
popular. Long associated with man, as a companion of the
hearth and the field, his song touches ever the chords of
human experience. Although we, in America, do not have
the house-cricket which English poets praise, yet our
field-crickets have a liking for warm corners, and will, if
encouraged, take up their abode among our hearthstones. The
greatest tribute to the music of the cricket is the wide range
of human emotion which it expresses. “As merry as a cricket”
is a very old saying and is evidence that the cricket’s
fiddling has ever chimed with the gay moods of dancers and
merrymakers. Again, the cricket’s song is made an emblem of
peace; and again we hear that the cricket’s “plaintive cry”
is taken as the harbinger of the sere and dying year. From
happiness to utter loneliness is the gamut covered by this
sympathetic song. Leigh Hunt found him glad and thus addresses
him_:

“_And you, little housekeeper who class
With those who think the candles come too soon,
Loving the fire, and with your tricksome tune
Nick the glad, silent moments as they pass._”
WAYS OF THE SIX-FOOTED.

THE BLACK CRICKET

_Teacher’s Story_

If we wish to become acquainted with these charming little troubadours of the field, we should have a cricket cage with a pair of them within it. They are most companionable, and it is interesting to note how quickly they respond to a musical sound. I had a pair in my room at one time, when I lived very near a cathedral. Almost every time that the bells rang during the night, my cricket would respond with a most vivacious and sympathetic chirping.

The patent leather finish to this cricket’s clothes is of great use; for, although the cricket is an efficient jumper, it is after all, mostly by running between grass blades that it escapes its enemies. If we try to catch one, we realize how slippery it is, and how efficiently it is thus able to slide through the fingers.

a, file b, scraper.]

The haunts of the cricket are usually sunny; it digs a little cave beneath a stone or clod in some field, where it can have the whole benefit of all the sunshine, when it issues from its door. These crickets cannot fly, since they have no wings under their wing-covers, as do the grasshoppers. The hind legs have a strong femur, and a short but strong tibia with downward slanting spines along the hind edge, which undoubtedly help the insect in scrambling through the grass. At the end of the tibia, next to the foot, is a rosette of five spines, the two longer ones slanting to meet the foot; these spines give the insect a firm hold, when making ready for its spring. When walking, the cricket places the whole hind foot flat on the ground, but rests only upon the claw and the segment next to it, of the front pairs of feet. The claws have no pads like those of the katydid or grasshopper; the segment of the tarsus next the claw has long spines on the hind feet and shorter spines on the middle and front feet, thus showing that the feet are not made for climbing, but for scrambling along the ground. When getting ready to jump, the cricket crouches so that the tibia and femur of the hind legs are shut together and almost on the ground. The dynamics of the cricket’s leap are well worth studying.

The cricket’s features are not so easily made out, because the head is polished and black; the eyes are not so polished as the head, and the simple eyes are present but are discerned with difficulty. The antennæ are longer than the body and very active; there is a globular segment where they join the face. I have not discovered that the crickets are so fastidious about keeping generally clean as are some other insects, but they are always cleaning their antennæ: I have seen a cricket play his wing mandolin lustily and at the same time carefully clean his antennæ; he polished these by putting up a foot and bending the antenna down so that his mouth reached it near the base; he then pulled the antenna through his jaws with great deliberation, nibbling it clean to the very end. The lens reveals to us that the flexibility of the antennæ is due to the fact that they are many jointed. The palpi are easily seen, a large pair above and a smaller pair beneath the “chin.” The palpi are used to test food and prove if it be palatable. The crickets are fond of melon or other sweet, juicy fruits, and by putting such food into the cage we can see them bite out pieces with their sidewise working jaws, chewing the toothsome morsel with gusto. They take hold of the substance they are eating with the front feet as if to make sure of it.

Photo by M. V. Slingerland.]

The wing-covers of the cricket are bent down at the sides at right angles, like a box cover. The wing-covers are much shorter than the abdomen and beneath them are vestiges of wings, which are never used. The male has larger wing-covers than the female, and they are veined in a peculiar scroll pattern. This veining seems to be a framework for the purpose of making a sounding board of the wing membrane, by stretching it out as a drum-head is stretched. Near the base of the wing-cover, there is a heavy cross-vein covered with transverse ridges, which is called the file; on the inner edge of the same wing, near the base, is a hardened portion called the scraper. When he makes his cry, the cricket lifts his wing-covers at an angle of forty-five degrees and draws the scraper of the under wing against the file of the overlapping one; lest his musical apparatus become worn out, he can change by putting the other wing-cover above. The wing-covers are excellent sounding boards and they quiver as the note is made, setting the air in vibration, and sending the sound a long distance. The female cricket’s wing-covers are more normal in venation; and she may always be distinguished from her spouse by the long sword-like ovipositor at the end of her body; this she thrusts into the ground when she lays her eggs, thus placing them where they will remain safely protected during the winter. Both sexes have a pair of “tail feathers,” as the children call them, which are known as the cerci (_sing. cerca_) and are fleshy prongs at the end of the abdomen.

There would be no use of the cricket’s playing his mandolin if there were not an appreciative ear to listen to his music. This ear is placed most conveniently in the tibia of the front leg, so that the crickets literally hear with their elbows, as do the katydids and the meadow grasshoppers. The ear is easily seen with the naked eye as a little white, disklike spot.

The chirp of the cricket is, in literature, usually associated with the coming of autumn; but the careful listener may hear it in early summer, although the song is not then so insistent as later in the season. He usually commences singing in the afternoon and keeps it up periodically all night. I have always been an admirer of the manly, dignified methods of this little “minnesinger,” who does not wander abroad to seek his lady love but stands sturdily at his own gate, playing his mandolin the best he is able; he has faith that his sable sweetheart is not far away, and that if she likes his song she will come to him of her own free will. The cricket is ever a lover of warmth and his mandolin gets out of tune soon after the evenings become frosty. He is a jealous musician. When he hears the note of a rival, he at once “bristles up,” lifting his wings at a higher angle and giving off a sharp militant note. If the two rivals come in sight of each other, there is a fierce duel. They rush at each other with wide open jaws, and fight until one is conquered and retreats, often minus an antenna, cerca, or even a leg. The cricket’s note has a wide range of expression. When waiting for his lady love, he keeps up a constant droning; if he hears his rival, the tone is sharp and defiant; but as the object of his affection approaches, the music changes to a seductive whispering, even having in it an uncertain quiver, as if his feelings were too strong for utterance.

_References_--Manual for Study of Insects, p. 115; Insect Musicians; Ways of the Six Footed, Comstock.

LESSON LXXXII

THE BLACK CRICKET

_Leading thought_--The crickets are among the most famous of the insect musicians. They live in the fields under stones and in burrows, and feed upon grass and clover. As with the song birds, the male only makes music; he has his wing-covers developed into a mandolin or violin, which he plays to attract his mate and also for his own pleasure.

_Method_--Make some cricket cages as follows: Take a small flower-pot and plant in it a root of fresh grass or clover. Place over this and press well into the soil a lantern or lamp chimney. Cover the top with mosquito netting. Place the pot in its saucer, so that it may be watered by keeping the saucer filled. Ask the pupils to collect some crickets. In each cage, place a male and one or more females, the latter being readily distinguished by the long ovipositors. Place the cages in a sunny window, where the pupils may observe them at recess, and ask for the following observations. In studying the cricket closely, it may be well to put one in a vial and pass it around. In observing the crickets eat, it is well to give them a piece of sweet apple or melon rind, as they are very fond of pulpy fruits.

_Observations_--1. Is the covering of the cricket shining, like black patent leather, or is it dull? What portions are dull? Of what use do you think it is to the cricket to be so smoothly polished?

2. Where did you find the crickets? When you tried to catch them, how did they act? Did they fly like grasshoppers or did they run and leap?

3. Look carefully at the cricket’s legs. Which is the largest of the three pairs? Of what use are these strong legs? Look carefully at the tibia of the hind leg. Can you see the strong spines at the end, just behind the foot or tarsus? Watch the cricket jump and see if you can discover the use of these spines. How many joints in the tarsus? Has the cricket a pad like the grasshopper’s between its claws? When the cricket walks or jumps does it walk on all the tarsus of each pair of legs?

4. Study the cricket’s head. Can you see the eyes? Describe the antennæ--their color, length, and the way they are used. Watch the cricket clean its antennæ and describe the process. Can you see the little feelers, or palpi, connected with the mouth? How many are there? How does it use these feelers in tasting food before it eats? Watch the cricket eat, and see whether you can tell whether its mouth is made for biting or sucking.

5. Study the wings. Are the wings of the mother cricket the same size and shape as those of her mate? How do they differ? Does the cricket have any wings under these front wings, as the grasshopper does? Note the cricket when he is playing his wing mandolin to attract his mate. How does he make the noise? Can you see the wings vibrate? Ask your teacher to show you a picture of the musical wings of the cricket, or to show you the wings themselves under the microscope, so that you may see how the music is made.

6. Why does the mother cricket need such a long ovipositor? Where does she put her eggs in the fall to keep them safe until spring?

7. Look in the tibia, or elbow, of the front leg for a little white spot. What do you suppose this is? Are there any white spots like it on the other legs? Ask your teacher to tell you what this is.

8. Can you find the homes of the crickets in the fields? Do the black crickets chirp in the day-time or after dark? Do they chirp in cold or windy weather, or only when the sun shines?

_Supplementary Reading_--Grasshopper Land, Morley, Chapter XIX.

_CRICKET SONG._

_Welcome with thy clicking, cricket!
Clicking songs of sober mirth;
Autumn, stripping field and thicket,
Brings thee to my hearth,
Where thy clicking shrills and quickens,
While the mist of twilight thickens._

* * * * *

_No annoy, good-humored cricket,
With thy trills is ever blent;
Spleen of mine, how dost thou trick it
To a calm content?
So, by thicket, hearth, or wicket,
Click thy little lifetime, cricket!_
BAYARD TAYLOR.

THE SNOWY TREE-CRICKET

_Teacher’s Story_

This is a slim, ghost-like cricket. It is pale green, almost white in color, and about three-fourths of an inch long. Its long, slender hind legs show that it is a good jumper. Its long antennæ, living threads, pale gray in color, join the head with amber globe-like segments. The pale eyes have a darker center and the palpi are very long. The male has the wing-covers shaped and veined like those of the black cricket, but they are not so broad and are whitish and very delicate. The wings beneath are wide, for these crickets can fly. The female has a long, sword-like ovipositor.

The snowy tree-cricket, like its relatives, spends much time at its toilet. It whips the front foot over an antenna and brings the base of the latter to the mandibles with the palpi and then cleans it carefully to the very tip. It washes its face with the front foot, always with a downward movement. If the hind foot becomes entangled in anything it first tries to kick it clean, and then drawing it beneath the body, bends the head so as to reach it with the mandibles and nibbles it clean. The middle foot it also thrusts beneath the body, bringing it forward between the front legs for cleaning. But when cleaning its front feet, the snowy tree-cricket puts on airs; it lifts the elbow high and draws the foot through the mouth with a gesture very like that of a young lady with a seal ring on her little finger, holding the ornate member out from its companions as if it were stiff with a consciousness of its own importance.

After C. V. Riley.]

There are two common species of the snowy tree-crickets which can hardly be separated except by specialists or by watching their habits. One is called “the whistler” and lives on low shrubs or grass; it gives a clear, soft, prolonged, unbroken note. The other is called “the fiddler” and lives on shrubs and in trees and vines. Its note is a pianissimo performance of the katydid’s song; it is delightful, rhythmic and sleep-inspiring; it begins in the late afternoon and continues all night until the early, cold hours of the approaching dawn. The vivacity of the music depends upon the temperature, as the notes are given much more rapidly during the hot nights.

“So far as we know, this snowy tree-cricket is the only one of the insect musicians that seems conscious of the fact that he belongs to an orchestra. If you listen on a September evening, you will hear the first player begin; soon another will join, but not in harmony at first. For some time there may be a see-saw of accented and unaccented notes; but after a while the two will be in unison; perhaps not, however, until many more players have joined the concert. When the rhythmical beat is once established it is in as perfect time as if governed by the baton of a Damrosch or a Thomas. The throbbing of the cricket heart of September, it has been fitly named. Sometimes an injudicious player joins the chorus at the wrong beat, but he soon discovers his error and rectifies it. Sometimes, also, late at night, one part of the orchestra in an orchard gets out of time with the majority, and discord may continue for some moments, as if the players were too cold and too sleepy to pay good attention. This delectable concert begins usually in the late afternoons and continues without ceasing until just before dawn the next morning. Many times I have heard the close of the concert; with the “wee sma” hours the rhythmic beat becomes slower; toward dawn there is a falling off in the number of players; the beat is still slower, and the notes are hoarse, as if the fiddlers were tired and cold; finally, when only two or three are left the music stops abruptly.” (_Ways of the Six-Footed_, Comstock.)

The lesson on this cricket may be adapted from that on the black cricket.

THE COCKROACH

_Teacher’s Story_

Cockroaches in our kitchens are undoubtedly an unmitigated nuisance, and yet, as in many other instances, when we come to consider the individual cockroach, we find him an interesting fellow and exceedingly well adapted for living in our kitchens despite us.

In shape, the cockroach is flat, and is thus well adapted to slide beneath utensils and into crevices and corners. Its covering is smooth and polished like patent leather, and this makes it slippery and enables it to get into food without becoming clogged by the adherence of any sticky substance. The antennæ are very long and flexible and can be bent in any direction. They may be placed far forward to touch things which the insect is approaching, or may be placed over the back in order to be out of the way. They are like graceful, living threads, and the cockroach tests its whole environment with their aid. The mouth has two pairs of palpi or feelers, one of which is very long and noticeable; these are kept in constant motion as if to test the appetizing qualities of food. The mouth-parts are provided with jaws for biting and, like all insect jaws, these work sidewise instead of up and down. The eyes are black but not prominent or large, and seem to be merely a part of the sleek, polished head-covering.

Some species of cockroaches have wings, and some do not. Those which have wings, have the upper pair thickened and used for wing-covers. The under pair are thinner and are laid in plaits like a fan. The wing-covers are as polished as the body and quite as successful in shedding dirt.

Photo by M. V. Slingerland.]

The legs are armed with long spines which are very noticeable and might prove to be a disadvantage in accumulating filth; but they are polished also; and too, this insect spends much time at its toilet.

Cockroaches run “like a streak”, children say; so speedily, indeed, do they go that they escape our notice, although we may be looking directly at them. This celerity in vanishing, saves many a cockroach from being crushed by an avenging foot.

When making its toilet, the cockroach draws its long antenna through its jaws as if it were a whiplash, beginning at the base and finishing at the tip. It cleans each leg by beginning near the body and so stroking downward the long spines which seem to shut against the leg. It nibbles its feet clean to the very claws, and scrubs its head vigorously with the front femur.

The cockroach’s eggs are laid in a mass enclosed in a pod-shaped covering, which is waterproof and polished and protects its contents from dampness. When the cockroaches, or the croton bugs, as the small introduced species of cockroach is called, once become established in a house, the only way to get rid of them is to fumigate the kitchen with carbon bisulphide which is a dangerous performance and should be done only by an expert.

LESSON LXXXIII

THE COCKROACH

_Leading thought_--The cockroach is adapted for living in crevices, and although its haunts may be anything but clean, the cockroach keeps itself quite clean. The American species live in fields and woods and under stones and sticks and only occasionally venture into dwellings. The species that infest our kitchens and water-pipes are European.

_Method_--Place a cockroach in a vial with bread, potato or some other food, cork the vial, and pass it around so that the children may observe the prisoner at their leisure.

_Observations_--1. What is the general shape of the cockroach? Why is this an advantage? What is the texture of its covering? Why is this an advantage?

2. Describe the antennæ and the way they are used. Note the two little pairs of feelers at the mouth. If possible, see how they are used when the cockroach is inspecting something to eat. Can you see whether its mouth is fitted for biting, lapping or sucking its food?

3. Note the eyes. Are they as large and prominent as those of the bees or butterflies?

4. Has this cockroach wings? If so, how many and what are they like? Note two little organs at the end of the body. These are the cerci, like those of the crickets.

5. Describe the general appearance of the cockroach’s legs, and tell what you think about its ability as a runner.

6. Note how the cockroach cleans itself and how completely and carefully this act is performed. Have you ever seen cockroach’s eggs? If so, describe them.

7. How can you get rid of cockroaches if they invade your kitchen?

LESSON LXXXIV

HOW TO MAKE AN AQUARIUM

The schoolroom aquarium may be a very simple affair and still be effective. Almost any glass receptacle will do, glass being chosen because of its transparency, so that the life within may be observed. Tumblers, jelly tumblers, fruit jars, butter jars, candy jars and battery jars are all available for aquaria. The tumblers are especially recommended for observing the habits of aquatic insects.

_To make an aquarium_: 1. Place in the jar a layer of sand an inch or more in depth.

2. In this sand plant the water plants which you find growing under water in a pond or stream; the plants most available are Water-weed, Bladderwort, Water Starwort, Watercress, Stoneworts, Frog-spittle or Water-silk.

3. Place on top a layer of small stones or gravel; this is to hold the plants in place.

4. Tip the jar a little and pour in very gently at one side water taken from a pond or stream. Fill the jar to within two or three inches of the top; if it be a jelly tumbler, fill to within an inch of the top.

5. Let it settle.

6. Place it in a window which does not get too direct sunlight. A north window is the best place; if there is no north window to the school room, place it far enough at one side of some other window so that it will not receive too much sunlight.

7. To get living creatures for the aquarium use a dip-net, which is made like a shallow, insect net.

8. Dip deep into the edges of the pond and be sure to bring up some of the leaves and mud, for it is in these that the little water animals live.

9. As fast as dipped up, these should be placed in a pail of water, so that they may be carried to the schoolroom.

10. In introducing the water animals into the aquarium it is well to put but a few in each jar.

_The care of the aquarium_--Care should be taken to preserve the plant life in the aquarium, as the plants are necessary to the life of the animals. They not only supply the food, but they give off oxygen which the animals need for breathing, and they also take up from the water the poisonous carbonic acid gas given off from the bodies of the animals.

1. The aquarium should be kept where there is a free circulation of air.

2. If necessary to cover the aquarium to prevent the insects, like the water boatmen and water beetles, from escaping, tie over it a bit of mosquito netting, or lay upon the top a little square of wire netting used for window screens.

3. The temperature should be kept rather cool; it is better that the water of the aquarium should not be warmer than 50 deg. Fahrenheit, but this is not always possible in the schoolroom.

4. If any insects or animals die in the aquarium they should be removed at once, as the decomposing bodies render the water foul.

5. To feed the animals that live upon other animals take a bit of raw beef, tie a string to it and drop it in, leaving the free end of the string outside of the jar. After it has been in one day, pull it out; for if it remains longer it will make the water foul.

6. As the water evaporates it should be replaced with water from the pond.

_References_--The Fresh Water Aquarium, Eggeling and Ehrenberg; Insect Life, Comstock; The Brook Book, Miller; Nature Study and Life, Hodge; The Home Aquarium, How to Care for It, Eugene Smith.

THE DRAGON-FLIES AND DAMSEL-FLIES

_Teacher’s Story_

A pond without dragon-flies darting above it, or without the exquisitely iridescent damsel-flies clinging to the leaves of its border would be a lonely place indeed. As one watches these beautiful insects, one wonders at the absurd errors which have crept into popular credence about them. Who could be so silly as to believe that they could sew up ears or that they could bring dead snakes to life! The queer names of these insects illustrate the prejudices of the ignorant--devil’s darning needles, snake doctors, snake feeders, etc. Despite all this slander, the dragon-flies remain not only entirely harmless to man, but in reality are his friends and allies in waging war against flies and mosquitoes; they are especially valuable in battling mosquitoes since the nymphs, or young, of the dragon-fly, take the wrigglers in the water, and the adults, on swiftest wings, take the mosquitoes while hovering over ponds laying their eggs.

From Outdoor Studies, Needham.]

The poets have been lavish in their attention to these interesting insects and have paid them delightful tributes. Riley says:

“_Till the dragon fly, in light gauzy armor burnished bright,
Came tilting down the waters in a wild, bewildered flight._”

While Tennyson drew inspiration for one of his most beautiful poems from the two stages of dragon-fly life. But perhaps Lowell in that exquisite poem, “The Fountain of Youth,” gives us the perfect description of these insects:

_In summer-noon flushes
When all the wood hushes,
Blue dragon-flies knitting
To and fro in the sun,
With sidelong jerk flitting,
Sink down on the rushes,
And, motionless sitting,
Hear it bubble and run,
Hear its low inward singing,
With level wings swinging
On green tasselled rushes,
To dream in the sun._

It is while we, ourselves, are dreaming in the sun by the margin of some pond, that these swift children of the air seem but a natural part of the dream. Yet if we waken to note them more closely, we find many things very real to interest us. First, they are truly children of the sun, and if some cloud throws its shadow on the waters for some moments, the dragon-flies disappear as if they wore the invisible cloak of the fairy tale. Only a few of the common species fly alike in shade and sunshine, and early and late. The best known of these is the big, green skimmer, which does not care so much for ponds, but darts over fields and even dashes into our houses, now and then. Probably it is this species which has started all of the dragon-fly slander, for it is full of curiosity, and will hold itself on wings whirring too rapidly to even make a blur, while it examines our faces or inspects the pictures or furniture or other objects which attract it.

Comstock’s Manual.]

Another thing we may note when dreaming by the pond is that the larger species of dragon-flies keep to the higher regions above the water, while the smaller species and the damsel-flies flit near its surface. Well may the smaller species keep below their fierce kindred, otherwise they would surely be utilized to sate their hunger, for these insects are well named dragons, and dragons do not stop to inquire whether their victims are relatives or not. It is when they are resting, that the dragon and damsel-flies reveal their most noticeable differences. The dragon-fly extends both wings as if in flight while it basks in the sun or rests in the shadow. There is a big, white-bodied species called the whitetail which slants its wings forward and down when it rests; but the damsel-flies fold their wings together over the back when resting. The damsel-flies have more brilliantly colored bodies than do the dragon-flies, many of them being iridescent green or coppery; they are more slender and delicate in form. The damsel-fly has eyes which are so placed on the sides of the head as to make it look like a cross on the front of the body fastened to the slender neck, and with an eye at the tip of each arm. There are very many species of dragon and damsel-flies, but they all have the same general habits.

Outdoor Studies, Needham.]