Insect Stories Part 7

"Yes, but weren't you surprised that first time you saw them in the Sentinel year?"

"Mary, you are a quibbler. Well, then, I'll say that I don't think they'll ever make another foreign invasion. There!"

It is time for us to stroll home for luncheon. As we get up from under the live-oak, a stumpy-bodied little gra.s.shopper whirs away in front of us.

"To think that such a little thing could make a summer evasion one thousand miles away from here," said Mary.

"Much littler things have done much bigger things," I reply, with my serious manner of lecturer-after-luncheon.

[Ill.u.s.tration: A CLEVER LITTLE BROWN ANT]

A CLEVER LITTLE BROWN ANT

We were sitting in the warm sun on the very tip-top of Bungalow Hill.

This is a gentle crest that rises three hundred and fifty feet above the campus level, and gives one a wonderful view far up and down the beautiful valley and across the blue bay to the lifting mountains of the Coast Range. Square-shouldered old Mt. Diablo standing as giant warder just inside the Golden Gate, the ocean entrance to California, looms ma.s.sive and threatening directly to our east, while to its south stretches the long brown range with its series of peaks, Mission, Mt.

Hamilton, Isabella, and so on, way down to the twin Pachecos that guard the pa.s.s over into the desert. In the north rises Mt. Tamalpais, the wonderful fog mountain that looks down on the busy life at its feet of San Francisco, and its cl.u.s.tering child cities growing up rapidly these days, while the mother is lying ill of her wounds by earthquake and conflagration. To the south stretch the long orchard leagues of the Santa Clara Valley, with the little white spots of towns peeping out from the ma.s.sed trees so jealous of every foot of fertile ground. And to the west--ah, that is the view that Mary and I lie hours long to look at and drink in and feel,--"our view," we call it.

We think we see things there that other people cannot. We see these things especially well when we half-close our eyes, and describe what we see in a sort of low, drowsy, monotone murmur. Then the fringe of towering spiry redwoods along the crest of the mountain range that lies between us and the great ocean and lifts its forested flanks full two thousand feet above us, becomes a long row of giants' spears sticking up above the battlements of a mighty castle. And the shadow-filled somber slashes and tunnel-like holes of the dropping canons are the great entrances and doors to this castle. At our feet the broad shallow canada that stretches all along the foot of the mountains and was made ages ago by some tremendous earthquake seems, seen through our half-closed eyes, to be full of water and to be really a broad moat shutting off all access to the castle.

The giants themselves we have never yet seen. But some day when the light is just right, and they are stirring themselves to look out at the world, we probably shall. Perhaps if we had been up here that day not long ago when the last earthquake came, we should have seen the giants looking out to see who was knocking at their gates. For it will take an earthquake's knocking ever to be felt in the heart of that mountain castle where the giants keep themselves.

The air was so clear this day that it seemed as if we could see each individual great redwood, each red-trunked, glossy-leaved madrono, each thicket of crooked manzanita and purpling Ceanothus, on the whole mountain side. Straight across through the clear blue-tinged atmosphere above the canada to the shoulders and canons, the forests and clear s.p.a.ces and chaparral of the mountain flanks, we look. And it rests our eyes that are so tired of reading. It is good to be a-stretch on sunbathed Bungalow Hill this afternoon in October. The rains will be coming in a few weeks and then we can't be out so much.

Or at any rate we can't lie close to the warm, brown, dry earth as we can now. But the rains will bring the fresh, green gra.s.ses and the flowers. If they come early enough the manzanitas will have on their little trembling pink-white lily-of-the-valley bells by Christmas-day, and the wild currants will be all green-and-rose color, with little leaves and a myriad fragrant blossoms.

But Mary has found something. She had turned over a little flattish stone and under it was--life! Living things disturbed in their work, their play, their laying up of riches, their care of their children; little animate creatures revealed in all the intimacies of their housekeeping and daily life.

But they didn't lose their presence of mind, these active, knowing little ants, when the Catastrophe came. There was work to be done at once and wisely. First, the saving of the children; and so in the moment that pa.s.sed between Mary's overturning of the stone and our immediate s.h.i.+fting into comfortable position on our stomachs, head in hands, for watching, half of the racing workers had each a little white parcel in its jaws and was speeding with it along the galleries toward the underground chambers.

"Ants' eggs," said Mary.

"No," said I. "That's a popular delusion. These little white things are not ants' eggs, but ants' babies. They are the already hatched and partly grown young ants, the larvae and pupae, which are so well looked after by the nurse ants. For these young ants are quite helpless, like young bees in the brood-cells in a honey-bee hive. And they have to be fed chewed food, and as they have no legs and so can't walk, they have to be carried from the cool dark nurseries up into the warmer lighter chambers for air and heat every day almost, and then carried back down again. See how gently the nurse ant holds this baby in its jaws; jaws that are sharp and strong and that can bite fiercely and hold on grimly in battle."

And I hand Mary my little pocket-lens through which she tries to look with both eyes at once. She could, of course, if she would keep her blessed eyes far enough away, but as she persists in holding the gla.s.s at the tip of her nose as she has seen me do, and as she cannot shut one eye and keep the other open, as I can, and have done now so many years that I have wrinkles all round the shut-up eye, why, she makes bad work of it. So she hands back the lens with a polite "thank you," and sticks to her own keen unaided eyes. And sees more than I do!

For in the next breath she cries, with a little note of triumph in her voice: "But some of the ant babies _are_ walking. See there! And you said they have no legs. I can see them; little stumpy blackish legs sticking out from their soft white body! And some of the ants are carrying these babies with legs; I can see them!"

I squirm around nearer Mary. True enough there are some little white chubby creatures walking slowly around in the narrow runways. But I _know_ they cannot be ant larvae. For ant larvae have no legs and simply can't walk. What are they? I get out the little pocket-lens.

And the mystery is solved. They are the "ant-cattle," the curious little mealy-bugs that many kinds of ants bring into their nests and take care of for the sake of getting from them a constant supply of "honey-dew." This "honey-dew" which the mealy-bugs make and give off from their bodies is a sweetish syrupy fluid of which almost all ants, even those most fiercely carnivorous, are very fond. And as the mealy-bugs and plant-lice that make the honey-dew are quite defenceless, soft-bodied, mostly wingless and rather sedentary insects, the bright-witted ants establish colonies, or "herds," of them in their nests, or visit and protect colonies of them living on plants near the ant-nest. Some kinds of ants even build earthen "sheds," or tents, over groups of honey-dew insects on plant-stems.

The mealy-bugs are white because they cover their soft little bodies with delicate threads or flakes of glistening white wax which they make in their bodies and pour out through tiny openings in the skin.

We watch the busy, excited ants until they have carried all their babies and cattle down into the underground nursery chambers, out of harm's way. Then we put the stone carefully back in place, and roll back again to where we can watch the wonderful mountains in the west.

The redwood-fringed crest stands so sharply out against the sky-line that we really can distinguish every tree that lifts its head above the crest, although they are several miles away from us. These great trees, which are the giants' jagged spears, are one hundred and fifty feet high, some of them, and as big around at the base as one of the ma.s.sive columns in the Cologne Cathedral.

Finally I say, rather lazily, "Mary, shall I tell you about the special way the clever little brown ant of the Illinois corn-fields takes care of its cattle?"

"Yes, please, if it isn't too long," says Mary.

Mary and I are on perfectly frank terms. We are polite, but also inclined to be honest. And Mary is not going to be an unresisting victim of a garrulous old professor. But Mary need not be afraid that I sha'n't know when I am boring her. We have wireless communication, Mary and I. That's one, probably the princ.i.p.al, reason why we are such good companions. No true companions.h.i.+p can possibly persist without wireless and wordless communication.

"All right," I answer, "here goes, Mary. Say when!"

"I forget how many millions of bushels of corn were raised in the state of Illinois last year, but they were very many. And that means thousands and thousands of acres of corn-fields. Now in all these corn-fields there live certain tiny soft-bodied insects called corn-root aphids. Their food is the sap of the growing corn-plants which they suck from the roots. Although each corn-root aphid is only about one-twentieth of an inch long and one-twenty-fifth of an inch wide and has a sucking-beak simply microscopic in size, yet there are so many millions of these little insects all with their microscopic little beaks stuck into the corn-roots and all the time drinking, drinking the sap which is the life-blood of the corn-plants that they do a great deal of injury to the corn-fields of Illinois and cause a great loss in money to the farmers.

"So the wise men have studied the ways and life of these little aphids to see if some way can be devised to keep them in check. The aphids live only two or three weeks, but each one before it dies gives birth to about twelve young aphids. Now this is a very rapid rate of increase. If all the young which are born live their allotted two or three weeks and produce in their turn twelve new aphids, we should have about ten trillion descendants in a year from a single mother aphid. Ten trillion corn-root aphids, tiny as they are, would make a strip or belt ten feet wide and two hundred and thirty miles long!

"Some other kinds of aphids multiply themselves even more rapidly. An English naturalist has figured out that a single-stem mother of the common aphis, or 'greenfly' of the rose, would give origin, at its regular rate of multiplication and provided each individual born lived out its natural life, which is only a few days at best, to over thirty-three quintrillions of rose aphids in a single season, equal in weight to more than a billion and a half of men. Of course such a thing never happens, because so many of the young aphids get eaten by lady-bird beetles and flower-fly larvae and other enemies before they come to be old enough to produce young.

"However, besides this rapid increase of the corn-root aphids, there is something else that helps them to be so formidable a pest. And this is that they find very good and zealous friends in the millions of little brown ants that also live in the Illinois corn-fields. These swift, strong, brave little ants make their runways and nests all through the corn-fields, and are very devoted helpers of the soft-bodied helpless aphids. For the aphids pay for this help by acting as 'cattle' for the ants.

"This is what Professor Forbes, a very careful and a very honest naturalist, found out about the ants and the aphids. The eggs of the aphids, hosts of s.h.i.+ning black, round, little seed-like eggs, are laid late in the autumn. These eggs are gathered by the ants and heaped up in piles in the galleries of their nests, or sometimes in special chambers made by widening the runways here and there. All through the winter these eggs are cared for by the ants, being carried down into the deeper and warmer chambers in the coldest weather, and brought up nearer the surface when it is warm. When the sunny days of spring begin to come, the eggs are even brought up above ground and scattered about in the suns.h.i.+ne, then carried down again at night. The little ants may be seen sometimes turning the eggs over and over and carefully licking them as if to clean them of dust-particles.

"In the late spring the aphid eggs hatch, and the young must have sap to drink right away. Their little beaks are thirsty for the plant-juices that are their only food. But there are no tender corn-roots ready for them in the fields because the corn has not yet been planted. What, then, shall the hungering baby aphids and their foster-mothers, the little brown ants, do?

"This is what happens. Although it is too early yet for the corn to be growing, there are various kinds of weeds that begin to sprout with the coming on of spring, and two of these, especially, the smart-weed and the pigeon-gra.s.s, abundant and wide-spread in all the Mississippi Valley, are sure to be growing in the fields. While the aphids much prefer corn-roots to live on, they will get along very well on the roots of smart-weed or pigeon-gra.s.s. So the clever little brown ants put the almost helpless baby aphids on the tender roots of these weeds, and there their tiny beaks begin to be satisfied. Don't you call that clever, Mary?"

"Clever! Gracious!" says Mary. "Do you know Professor Forbes? Is he really--does he always tell the--"

I interrupt. I am sensitive about such questions. I answer rather sharply. "Yes, I _do_ know him; and yes, he always tells the truth.

Don't interrupt any more, please, for there is still more of the story." Mary is silent.

"Well, the aphids stay on the smart-weed roots until the corn is planted, which is in about ten days, and the kernels begin to germinate and to send down the tender juice-filled roots. And then the little brown ants take the aphids, now getting larger and stronger, of course, but still too helpless or stupid to do much for themselves except to suck sap, and carry them from the smart-weed roots to the corn-roots--What's that, Mary?"

But Mary had said nothing; just drawn in her breath with a little sound. Still I think it best to remind her that I _do_ know Professor Forbes and that he really _does_ always tell the truth. In fact, I quote to Mary this honest professor's exact words about this transfer of the aphids from the weed-roots to the corn-roots. This is what he writes in his intensely interesting account of the whole life of these little insects: "In many cases in the field, we have found the young root aphis on sprouting weeds (especially pigeon-gra.s.s) which have been sought out by the ants before the leaves had shown above the ground; and, similarly, when the field is planted to corn, these ardent explorers will frequently discover the sprouting kernel in the earth, and mine along the starting stem and place the plant aphids upon it."

"And the little brown ants do all this so as to get honey-dew from the aphids?" asks Mary.

"Exactly," I reply. "The ants take such good care of the aphids not because they pity their helplessness or just want to be good, but because they know, by some instinct or reason, that these are the insects that, when they grow up, make honey-dew, which is the kind of food that ants seem to like better than any other. Indeed not only the little brown ants alone take care of the corn-root aphids to get honey-dew, but at least six other kinds of ants that live in the Illinois corn-fields do it. But the little brown ants are the most abundant and seem to give the aphids the best care."

"It is exactly like keeping cows, isn't it," says Mary. "But they don't have to milk them."

"Well," I reply, "I don't know what you would call it, but some other ants that take care of some other kinds of honey-dew insects seem to have to carry on a sort of milking performance to make them pour out their sweet liquid. The ants have to pat or rub them with their hairy little feelers; sort of tickle them to get them to squeeze out a little drop of honey-dew. The truth is, Mary, if I should tell you the really amazing things that ants do, you simply wouldn't believe me at all. But the next time we go out, I'll take you to see for yourself an ant community right on the campus that does some remarkable things.

I'd much rather have you see the things yourself than tell you about them."

"I'd rather, too," says Mary, which isn't exactly the nicest thing she could say, but I know what she means. It's that seeing is better than being told by anybody.

And then the up-and-down "ding, dang, dong, ding," of the clock-bells begins its little song in four verses that means the end of an hour.

And then come the six slow deep calls of the biggest bell that tell what hour it is. It is the hour for us to go home.

[Ill.u.s.tration: AN HOUR OF LIVING OR THE DANCE OF DEATH]

AN HOUR OF LIVING; OR, THE DANCE OF DEATH