Half Hours with the Lower Animals: Protozoans, Sponges, Corals, Shells, Insects, and Crustaceans

Charles Frederick Holder

Half Hours with the Lower Animals

Protozoans, Sponges, Corals, Shells, Insects, and Crustaceans

EAN 8596547058038

DigiCat, 2022

Contact: [email protected]

Table of Contents

PREFACE

I. INHABITANTS OF A DROP OF WATER

II. THE SPONGES

III. THE JELLYFISHES

IV. THE SEA ANEMONES

V. THE CORALS

VI. THE STONE LILIES

VII. THE STARS OF THE SEA

VIII. OCEAN HEDGEHOGS

IX. THE SEA CUCUMBERS

X. THE WORMS

XI. THE TWO-VALVED SHELLS

XII. THE UNIVALVES

XIII. THE CUTTLEFISHES

XIV. THE CRUSTACEANS

XV. FROM BARNACLES TO LOBSTERS

XVI. THE CRABS

XVII. LUMINOUS CRABS

XVIII. THE INSECTS

XIX. LOWER FORMS OF INSECTS

XX. THE SPIDERS

XXI. SOME SIX-LEGGED INSECTS

XXII. SOME MIMICS

XXIII. THE GRASSHOPPERS AND LOCUSTS

XXIV. THE BEETLES

XXV. THE BUGS

XXVI. FLIES AND MOSQUITOES

XXVII. THE BUTTERFLIES AND MOTHS

XXVIII. THE ANTS

XXIX. THE BEES AND WASPS

INDEX

ELEMENTARY NATURE STUDY

Burnet's Zoölogy

Birds of the United States

Baldwin's School Readers

PREFACE

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At the present day education is not complete without definite courses of nature study. We are living in an age of strenuous business life and activity, where the best equipped students along the various lines secure the best positions. Time was when zoölogy, botany, and kindred nature studies were classed with music and the so-called dead languages, and were taken up as incidentals or were employed in mind training; but to-day there are a thousand branches of trade and commerce which require knowledge that can be obtained only through nature study.

It is not necessary that the student, unless he intends to be a teacher of science or a professional naturalist, should be able to pass examinations in the abstruse classification of animals or delve into difficult anatomical studies. What the average student needs is a broad and general idea of animal life, its great divisions, and notably the relationship of the lower animals to man in an economic sense, the geographical distribution of animals, etc. It is vastly more important for the coming lumber merchant to know the relationship which forests bear to the water supply, and to have a general idea of forestry and the trees which make forests, than to be able to recite a long formula of classification or analysis, of value only to the advanced student or specialist. The future merchant who is to deal in alpaca, leather, dye, skins, hair, bone products, shell, pearl, lac, animal food products, ivory, whalebone, guano, feathers, and countless other articles derived from animals is but poorly equipped for the struggle for business supremacy if he is not prepared by nature study, nature readings, and other practical instruction along these lines.

It is believed to-day by those who have given the subject the closest attention that the initial move of the teacher should be to call the attention of the child to the beauties of nature, the works of the Infinite, and thus early inculcate a habit of observation. The toys of the kindergarten should be fruits, flowers, shrubs, trees, pebbles, and vistas of mountains, hills, lakes, and streams, and nature study in some form should be continuous in school life.

In the following readings the story of lower animal life has been presented on broad lines, divested of technicality, and at almost every step supplemented by forceful and explanatory illustrations as ocular aids to the reader. The subject has been divested of dry detail, and I have introduced notes and incidents, the results of personal observation and investigation in various lands and seas, and have given attention to the often neglected fauna of the Pacific coast as well as that of other regions.

While the volume is a supplementary reader, the matter is so arranged that it can be used by the teacher as a text-book, and the pupil who undertakes the various half-hour readings of this series will have covered in the main the ground of the ordinary text-book for intermediate grades in the form of readings. In a word, I have endeavored to make this volume a popular combined review and supplemental reader on the lower forms of animal life from the Amœba to the insects inclusive, and the series to follow will present the entire subject of animal life or zoölogy, voluminously illustrated, on a similar plan.

CHARLES F. HOLDER.

Pasadena, California.

I. INHABITANTS OF A DROP OF WATER

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The most unobserving stroller through the forest or by the seashore can not fail to be impressed by the abundance and variety of animal life; yet the forms visible to the naked eye really constitute but a fraction of the vast horde which makes up what we call life.

In the year 1901 a strange phenomenon appeared off the coast of southern California. The ocean assumed a reddish muddy hue which was traced for four hundred miles up the coast and from one to twenty miles offshore; hence, at a conservative estimate, the reddish color occupied a space of ten thousand square miles. At night it assumed a greenish light, and when the wind rose and formed whitecaps, each became a blaze of light, and the ocean as far as the eye could reach was converted into a mass of seeming flame. The sands of the beach gave out flashes of light when touched; the footsteps of dog or man on the sands left an imprint of vivid light, and figures made on the sands with a finger or stick stood out in lines of light. Ten thousand square miles of phosphorescent light; ten thousand square miles of living beings, each so minute that it was almost if not quite invisible to the human eye. Who could estimate the individuals in one square mile, one square foot, or even a drop of this reddish water? This illustrates the fact that the greater number of the earth's population are unseen, even though not invisible to the unaided eye.

These minute animals are as interesting as the larger forms. Equipped with a microscope, we are prepared to explore the regions in which they live and observe their habits. A favorite hunting ground for this small game is some long-standing water in which plants have been growing. Placing some of this, with the green scraping of the glass, on the slide, we shall soon make out, moving mysteriously along, something which resembles the white of an egg, an atom of slime or jelly. Now it stops and throws out parts of itself which seem to fuse together again; now it is long, now short and compact, again circular. You almost believe it is a mere atom of slime, yet it is an animal which eats and lives its life cycle in a drop of water, one of the lowest of all animals.

It is called Amœba (Fig. 1), and although it is hardly a hundredth of an inch in diameter, yet if we devote some time to it we shall find that it is a very remarkable animal. Thus if it wishes to move in any given direction, a portion of the body becomes a seeming leg and protrudes in that direction, the rest of the body following, drawn along in some mysterious manner. If it wishes to eat, it is not obliged to twist around to bring the food or victims opposite the mouth, as a mouth forms there and then; the Amœba merely glides around it and covers it up.

We may even notice a difference in the parts. Thus the center calls to mind ground glass; it is blurred or granular, while around the edges is a little border which is transparent, like ordinary window glass. So the Amœba is a minute mass of jelly inclosed in a layer a little clearer.

Fig. 1.

—Amœba proteus, with the pseudopodia (false feet) protruded, enlarged 200 diameters (after Leidy): n, nucleus; c, contractile vesicle; v, one of the larger food-vacuoles; en, the granular endosarc; ec, the transparent ectosarc; a, cell of an Alga taken in as food (other cells of the same Alga are obliquely shaded).]

Floating in the granular portion is seen a minute round body called the nucleus, clearer than the fluid in which it rests, and not far away another clear, circular body, which from time to time contracts or sometimes disappears in a marvelous fashion, but always returns. This is called the contracting vesicle, and here our discoveries end, so far as organs and structure are concerned, as these are nearly all that have been found; yet the Amœba eats, doubtless sleeps, and grows.

Fig. 2.

—Amœba eating: Pv, contracting vesicle.]

We may watch it at its dinner. When a victim is found, an animal smaller than itself, out shoots a little cape or extension from the clear rim, creeping slowly up the side of the animal; and if we watch very closely, we shall see the thicker portion of the Amœba, that which calls to mind ground glass, running or flowing into it. Then another false foot, as it is called, slowly creeps out on the opposite side and joins its companion, more of the ground-glass matter slides or pours into this, filling it out, and, presto! the two arms merge one into the other. The victim has been swallowed and is now being digested (Fig. 2, d).

Fig. 3.

—Amœba separating.]

That this minute atom has its likes and dislikes is evident, for if the food is too large, or not to its taste, it retracts, or even draws away from it after it has swallowed it. The shells of its victim, if it has them, are rejected in a manner equally simple; the Amœba flows away from them. Jar it with a needle point and it contracts, showing that it can be irritated. At times the body is seen to divide and two Amœbæ are formed (Fig. 3), each of which has a separate existence from then on. Such is one of the lowest of all animals. It is made up of but a single cell. All the members of the other great branches of the animal kingdom and the higher plants are made up of many cells; hence we see that the Amœba is the simplest and lowest of all animals.

Fig. 4.

—Ciliated Infusoria: A, Bursaria; B, Nyctotherus; C, Amphileptus; D, Ceratium; E, Monosiga; f, flagellum; n, nucleus; c, contractile vesicle.

In looking into our drop of water our attention has perhaps been distracted by other animals. In point of fact, it is very difficult to keep the eye on this mass of slime in its slow movements, for about it, over it, and constantly bumping into it are countless other forms whose motions convey the impression that life to them is very active. The most numerous are little objects (Fig. 4) resembling hats or bells, which go rushing along, bumping aimlessly into all others, and always in a hurry. Around the edge of the bell or hat are numerous hairs (cilia) which are really locomotive organs by which the little animals whirl themselves along. Near them we see numbers of similar objects, each one forming the cup of a seeming flower, each having a long stem. These are Bell Animalcules (Fig. 5) or Vorticellæ, among the most beautiful and graceful of all the minute animals, but much higher in the scale of life, as they have a permanent mouth and form. Among them, swimming rapidly, comes a giant by contrast, the Paramœcium (Fig. 6) or Slipper Animalcule, so called from its resemblance to a slipper. It, too, is a higher form than Amœba, as it has a permanent shape; yet in other ways it is as simple as Amœba. The Paramœcium has a marvelous array of oars which cover its body. Under the glass they look like eyelashes or whips, and by their rapid movements they drive the animal along. On the side is the mouth opening, into which the animal fans minute animals, and they can be seen swept along by the irresistible current, caught by the mouth if desirable, or tossed off if not to the taste of the wonderful living slipper. After glancing at the drop of water for a few moments the observer is convinced that here is a world in itself, with a population growing, increasing, developing, devouring its prey, and in such multitudes that the mind can not grasp the figures.

Fig. 5.

—A, Stentor; B, Vaginicola; C, group of Vorticellæ; D, bud of Vorticella.

Fig. 6.

—Paramœcium: e, mouth; v, contracting vacuoles.

Fig. 7.

—Nummulites.

If the reader visits Egypt and climbs the pyramids, he will be impressed by these the greatest works of mankind. If a small portion of the stone from which they are constructed is placed under the glass, it will be found in many instances made up almost entirely of beautiful shells (Fig. 7). These are the shells of an amœba-like animal known as a Nummulite, which lived millions of years ago, and whose fossil remains formed the stone from which the early Egyptians in turn built the great piles or monuments of their kings. Man is powerful, but in this instance one of the most insignificant of animals made his work possible. These shells are of great beauty and variety (Fig. 8). Many are perforated, and through the minute holes are seen the false feet of the Amœba reaching out for food. They illustrate the boundless resources of nature, and suggest that the very lowest of creatures are not too insignificant to be dressed in most beautiful garbs, as all these forms vie with one another in the delicacy of their designs (Fig. 9) and the grace of their shapes. Some of these shelled forms are giants two inches across. All these minute shells perform a marvelous work in building up the crust of the earth, forming the bottom of deep seas and the platforms of coral reefs. The chalk cliffs of England are composed of shells of unestimated millions (Fig. 10), which were once dropped upon the bottom of a deep sea and piled upward until some were crushed into a shapeless mass of lime, others retained their shapes (Fig. 11); and all,