The History of a Mouthful of Bread by Jean Macé (great novels to read txt) 📕

vertebral column, so clearly marked in other fishes, where it forms the large central bone, is only faintly indicated in certain species of lampreys, by a soft thread (or filament), which is rather a membrane than a bony chaplet, and at the top of this mockery of a vertebral column is the creature's mouth. If you ever had leeches on, you will remember the sharp sting you felt when the little beasts bit you. Well, the lamprey feeds herself just in the same way as the leech does. Her mouth forms a completely circular ring, which sticks to the prey, and through which runs backward and forward a small tongue armed with lancets. This darts out to pierce the skin, and draws in the blood as it retreats. Round your lips well; dip them so into a glass of water, and draw back your tongue, and you will at once feel the water rise into your mouth. It is by a similar sort of proceeding that leeches relieve people of the blood they want to get rid of; and in the same way the lamprey draws out the blood of the animals upon which she fastens.

What a long way we have come already! How very far we find ourselves here from the little mouths we first talked about as chewing their eatables so prettily! With the lamprey we bid adieu to the class Vertebrata-the nobility of the animal kingdom-among whom nevertheless we must distinguish between the peer, who approaches nearest the person of his sovereign, and the inferior provincial lords who live at a hundred miles' distance. There is only one step from the lamprey to the mollusks or soft-bodied animals, and this is the course which animal organisation seems really to have taken in its progress. But nature never moves forward in a single straight line. In passing from the mollusk to the fish to get thence to the higher vertebrates, she turned aside in another direction toward a class of animals which rises far above mollusks, but which leads to nothing beyond.

One would think there had been a check here, as if the creative power, having discovered that it was going in a wrong direction, had retraced its steps; if it be allowable to apply common ideas and expressions to our conceptions of that Great Intelligence which has arranged the plan of the mysterious ladder of animal life.

The animals we must examine next, on account of their superiority to the rest, are insects. Small as the ant is, it would not be right to let her be preceded by the oyster.


LETTER XXXVII.

INSECTA. ( Insects. )

Before speaking of insects, my dear child, it will be necessary, in the first place, to tell you to what primary division they belong and on what characters this division has been established. And here I find myself in a difficulty. We have been but too learned already, and now we run the risk of becoming still more so, if we commence an attack on the three primary divisions which follow the vertebrates. We shall have to encounter terrible names and tedious details, besides having to take into account a thousand things of which we have not yet spoken. We are going on quietly with the history of the feeding machine which occupies the middle of the body, and learned men never looked in that direction for the establishment of their divisions; between ourselves, it was not accommodating enough. They have fallen back upon the locomotive apparatus ( movement machine ) which affects the body all over, and which they have proclaimed to be the leading feature of the animal organization, without noticing however that it is, after all, but the servant of the other. It is true that the great divisions are more easily established upon this point than the other, because the differences are more decided. It separates what the other unites, and thus it is that nature carries on that beautiful combination which the Germans have so accurately named " Unity in Variety " that is to say, she is always at work, as I have already told you, on the same canvas, but always embroidering it with a different pattern. Wait! I have something to promise, if you are very good, and if this history (that of the feeding machine) should have given you a taste for inquiry. I will tell you another time the history of the movement machine, and there the classification of our learned men will come in naturally very well. In the meantime we will do as they do, and just shut our eyes to their divisions, in which the feeding machine can have no interest, because they were established without reference to it. We will content ourselves, then, without further pretension to science, with modestly examining the last transformations of our pet machine in the principal groups of the inferior animals; of which groups I will now tell you the names in their proper order. They are as follows: Insects, Crustaceans, Mollusks, Worms, and Zoophytes. You must take these names on trust; those which you do not understand will be explained in their places.

1. Insects. -I know not where it was I once read that there are said to be something like a hundred thousand different species of insects; and I verily believe this is not all. Of course we shall not attempt to review the whole of this formidable battalion. Let us take one of those you are most familiar with-the cockchafer, for instance- and examine what goes on in his inside. The history is nearly that of all the others.

"Fly away, cockchafer, fly!" says the song; and surely it is a bird that we have here, and a bird which will appear to you even more wonderful than those of which I have already spoken, when you have considered the simplicity, and at the same time the strength, of his organization. His mode of flight is rather lumbering, it is true; he is, in comparison with the large flies, what the ox is to the deer; but when you contrast the weight of his thick body with the delicacy and narrow dimensions of the two membranes which sustain him in the air, you may well ask yourself how those little morsels of wings, thin as gold-beater's skin, can carry such a mass along. In fact, they only accomplish this feat of strength by dint of an excess of activity almost startling to think of. When you run as fast as you can, how many times, think you, do you move your legs in one second? You would be somewhat puzzled to say; and so should I: but I defy you to count ten. Now the bird makes his wing move much oftener when he beats the air with rapid blows as he flies; but even he does not strike a hundred strokes in a second: and what is this to the feats of the cockchafer's wing? It is not hundreds but thousands of times that he flaps his wings in a second; and here let me hint, by-the-by, that when people seriously wish to find out a method of travelling in the air, they will lay aside balloons, of which they can make nothing in their present condition, and will set to work to fabricate machines with wings which shall beat the air as fast as those of the cockchafer. This sounds extravagant, but I have seen an electric pile fixed in a stand with glass feet, which caused a little hammer to beat thousands of times in a second: and surely the hammer could have been made to communicate its movement to a small wing! Forgive me this little castle in the air! The idea came into my head a long while ago, and the cockchafer has just reminded me of it. I will not, however, pursue the subject, neither will I offer to explain the method used for counting the beats of an insect's wing. That would carry us farther than would be desirable.

To return to our little animal. I leave you to imagine the enormous amount of strength required for such precipitate motion. We have spoken of the rapid course of the blood in birds during flight: who shall calculate its comparative rate in this fabulously wonderful locomotive, the cockchafer? And if we lift up the cuirass which encases it, what do we behold? Not a single trace of all the complicated circulation-apparatus you have learnt to know so well; neither heart nor veins nor arteries; only a quantity of whitish liquid, equally distributed throughout the whole internal cavity. Not a trace of lungs, nor any apparent means of renovation for this seemingly motionless blood; for blood it is, in spite of its color, or, at any rate, blood in its first stage of formation. It also has its globules-ill-formed, it is true, and altogether in balls-like those found in the chyle with us; which chyle, be it observed, is the same color as the blood of insects, and may also be considered blood in its apprenticeship. By what magic, then, is this raw, imperfectly-formed steward, who seems altogether stationary, enabled to accomplish exploits which would stagger his higher-bred compeers, agile and perfected as they are? Where does he pick up the oxygen necessary for such repeated movements, it being an established fact that no animal can move at all without consuming oxygen, and that the quantity consumed is in proportion to the rate of motion? Look under his wings for an answer. There, all along his body, you will observe a number of small holes, pierced in a line, at regular distances, and furnished with shutters of two kinds. They are the mouths of what are called tracheæ , or breathing tubes: and from them branch out a multitude of little canals, which, spreading in endless ramifications through every part of the body, convey to the whole mass of the blood, from all directions, the air which makes its way into them through the tracheal holes. In this case, you see, it is not the blood which seeks the air, but the air which seeks the blood; whence arises a new system of circulation, whose action is all the more energetic because it is unintermitting, and makes itself felt everywhere at the same time. A little while ago we were wondering at the twofold respiration of birds; yet this is far less surprising than the universally-diffused respiration of insects, who may well be able to do without lungs, seeing that their whole body is one vast lung in itself.

For the rest, do not trust to appearances, nor imagine that the blood of our friend the cockchafer in reality remains motionless around the air-tubes, idly drinking in the oxygen which is brought to it. Though not flowing in enclosed canals, it is not the less continually displaced by regular currents, which sweep through and renew this apparently stagnant pool. Nor is this the only instance of such a current presented to us by nature.

Guess, however, if you can, where you will have to look for the counterpart to the circulation of the cockchafer. In ocean itself! But, remember, nothing is absolutely little or great in nature, who applies her laws indifferently to a world as to an atom. The blood of our world is water, which contains in itself all the germs of fertility, and without which, as I have already told you, life is impossible either in the animal or vegetable kingdom. The water of brooks, streams, and rivers, flows along in channels, which, when figured in a map, present to the eye of the beholder an exact picture of the system of circulation found in the vertebrated animals. But the waters of the sea are borne along, like the blood of