Chapter III: Front Matter (3)

The child can have his little aquarium at home, which may consist of a glass globe plentifully supplied with some pretty water weed and a goldfish or two. Fishes do not like the bright light all around them, and should be provided with some sort of refuge, like the water weed, or if the tank is large enough, with stones piled up to make a cave. For the same reason, the globe should not be set in the window or on the middle of a small table, but should be placed where at least one side of it may be shadowed by something. Pebbles should be put in the bottom of the tank and not too many fishes crowded together. They need room to move freely, and also plenty of fresh water for breathing. At the bird-stores small aquaria can usually be bought and fitted out with the proper amount of water plants to balance the breathing of the fishes. For the impurity breathed out by the fish is the same as that breathed out by all creatures, the carbon dioxide which it discharges into the water being just what the water plant needs to grow on. Also the water plant returns pure oxygen to the water, which is just what the fish needs to breathe. This story of the interdependence of the two, and the possibility of so balancing the plant and animal life in the tank that it is never necessary to change the water, can be made very interesting, and, needless to say, very illuminating. The fish cannot live out of the water, and yet it breathes air. There is always air in the water unless it has been artificially removed as by boiling, and this little bit of air is enough for the fish, which is cold-blooded and does not need so much fuel to keep its vital forces burning. But this little it must have, and it will suffer for the want of it, just as we suffer in a very close, unventilated room; and if the supply should become too small, the fish will die, just as we should die in a room where no fresh air could enter. So the fish must have the water changed unless there is enough plant life in its tank to keep the air pure. When suffering for air, the fish shows signs of distress, which should never be ignored. If it keeps close to the surface of the water with its mouth up and frequently swallows the outside air, that is a sign it needs fresh water. If it does not have it after a while it will die, as it cannot live on air undiluted by water.

Fishes need very little feeding, particularly if there are water plants in the tank; they find food from them. The best way is to follow the directions of the man who sells you the fishes. If too much food is given them it quickly fouls the aquarium, and then the water must be changed and everything cleaned up. In changing the water, care should be taken to have that which is put in about the same temperature as that taken out. A sudden application of too cold water is not good for the fishes. The children should take care of their pets themselves and see that they do not suffer.

The motions of the fish are what make it so attractive. How does it swim? Not with its fins to any extent. The whole back part of the body, including the tail, is moved from side to side as the fish swims. It moves its tail as a paddle is used at the stern of a boat, and so the fish paddles himself along. The fins are used more as balancers. They keep the fish upright in the water. As soon as it stops using them, it turns over on one side.

The fish opens and shuts its mouth constantly; it appears to be swallowing water. And so it is, so far as its mouth is concerned, but the water it takes in does not go down into the stomach. It is not really swallowed, but passes out at the gills, which are also constantly opening and shutting. The gills are red inside and are covered with a fine network of blood vessels. The air in the water moves against these delicate blood vessels, which are able to take what they need--the oxygen--from it. Thus the fish uses gills instead of lungs for breathing.

Sometimes, fishes pick up pebbles in their mouths and drop them again. Some fishes, but not goldfishes, make noises.

The adaptation of the fish to its surroundings is interesting. Not only is its form the very best for moving quickly through the water, but its covering is peculiarly appropriate, many fishes having a hard, protecting coat of shining scales. These scales, besides being beautiful and useful, are interesting in another way, for we know that they are only modified hairs, growing from the skin as hairs grow but having their form and size developed in special ways to serve their purpose. Scales and feathers are only another form of hairs.

Many interesting stories of fishes can be told or read to the children, and among other things they can learn about the swim-bladder, the large, strong air-sac, which can be compressed or distended at pleasure, making the fish lighter or heavier and enabling it to rise to the surface of the water or sink to the bottom. In Nova Scotia, where many codfishes are caught, the swim-bladders are called sounds, and are cooked as a delicacy.

In the spring of the year we eat the roe of fish, which is nothing more nor less than fish eggs. Wherever shad are used, the children will be familiar with the shad roe; and in the South mullet roes are universally used. The people there dry them in the sun, and the children particularly are very fond of them. The Russian caviare is the eggs of a species of fish, and is considered a great delicacy by some people.

Where do these eggs come from? The fish market or the kitchen on fish day will answer the question. The child who is privileged to pass part of the summer at the seashore where fishermen ply their trade will have ample opportunity to know, as will the child who goes fishing in any brook or pond and is allowed (as he always should be) to clean and cook the fish he has caught. Also the smelts, which are cooked whole, only the intestines being removed through a hole near the gills, will answer the question.

The eggs of the fish are contained in a sort of double pouch or sac, shaped something like an old-fashioned silk purse. These sacs open into the intestine near its exit. They are the ovaries of the fish. From the inside of each ovary the tiny eggs, or ova, grow, just as the ovules grow in the plant ovary or seed-pod. At first they are a part of the ovary; later they grow larger and fall loose, until the ovary is filled with them. The ovary is always inside the fish. It is there when the fish is born, and even then there are the tiniest hints of ova in it. But the ova do not grow large until the fish is mature; they wait until the fish has developed its strength, its bone, and muscle. Then in the springtime they grow rapidly. They grow until they are ripe, when they lie free in the ovary; and others grow and are freed in the same way until the ovary, which has also enlarged to accommodate them, is quite full. The female fish is larger than the male, and looks plump and rounded at this season. In course of time the eggs thus developed will be shed--or born--whether they are fertilized or not. But, if they are not fertilized, no further growth will take place in them, and they will soon perish.

The child, knowing about the fertilization of flowers, can easily be led to see that the fish ova, like the flower ovules, cannot develop without pollen. The anthers containing the pollen are found in the male fish, and look like the ovaries, only they are not so large and their contents are not so firm. They seem filled with a formless substance instead of with little globular eggs. Under the microscope this formless substance is seen to be made of a semi-fluid material in which are held millions of pollen grains! Only we no longer call them pollen grains. We may call them fertilizing cells if we please, though there are several names for them. But they are essentially the same as pollen. They grow, in the same way, from the inside of the anther (which may now be called the testicle) and become free when ripe. The pollen grains cannot move of themselves; the fertilizing cells can. Each fertilizing cell is like an ovum, excepting that it is not so spherical and is lengthened into a sort of lash by which it can propel itself through the water. When the ova are laid by one fish, the other swims over them and the fertilizing fluid is expelled into the water just as the eggs were. There is no union whatever between the parents for the purpose of fertilization. As soon as a fertilizing cell comes in contact with an ovum it seeks to enter into its substance, and as soon as this has happened, the two cells thus united begin to develop into a very tiny fish. As soon as the change begins, we have the _embryo_ of the fish, which thus corresponds to the embryo of the seed.

There is one great difference between the ovary of the plant and that of the fish. When the plant ovary is ripe, its seeds are shed, and then the ovary itself falls off. The plant ovary thus bears only one set of seeds. In the fish, the ovary always remains in the fish, and after the eggs are shed, it shrinks up to a very small size, and remains so until it again develops and becomes distended with more eggs the following season. The same is true of the fish's testicles. When the time comes, the fertilizing material is expelled. After this the sac shrinks up to small size until the following season.

When the embryo has grown to its perfect form, the egg-shell is broken and out swims the young fish. When it leaves the shell we say it hatches, just as we say the plant embryo sprouts when it leaves the egg-shell or seed-shell. Like the pollen of the flower, the fertilizing cells of the fish cannot act upon any ova but those of its own species.

The young fish, like the young plant, inherits characteristics from both parents. From its father it may acquire a certain shape, certain markings, a certain disposition. Since the father's part in the creation of his offspring is less obvious and apparently less intimate than that of the mother, the child can be helped to put a certain value on the thought of fatherhood which later will strengthen the bond of union between himself and his own father, deepening his love for his father and his confidence in him. That the boy love his father is as necessary to his welfare as that he love his mother, and the mother should, in all the early years in which the sex instruction may fall most heavily on her, impress upon the young heart the beauty and glory of paternity. The sacrifice of the father who gives all his strength and time, scarce allowing himself a moment of relaxation or absence from business that he may provide for the needs of the family, is as great as the sacrifice of the mother who devotes her time and strength to caring for the home and the children. The tendency in teaching young people is to lay all the stress on motherhood and mother love, which is a manifest injustice to the human father, who deserves not only the natural love of his children, but the deeper, more consecrated love which comes from a pure and perfect knowledge of fatherhood.

Perhaps nothing will help a young man at the most critical age of his life so much as his love and faith in his father. And perhaps nothing will tend to lift the whole subject of paternity in the popular mind to the plane where it belongs, as will this love and knowledge, when it is bred in the child from his early years. Many difficulties in handling this subject that become insuperable might never even exist if the knowledge of fatherhood, if love and respect for it and for the father as the giver of life, were bred into the boy at an early age. Moreover a certain shyness, which often makes it more difficult for fathers to talk to their sons on these matters than for the mothers to do so, would not have existed if they themselves as children and youth had been educated to a complete knowledge of the sex-life by one or both parents. The cause of this shyness is in many cases ignorance of how to present the facts, and a misconception of the difficulties of speaking to a pure-minded child about them. Nothing surprises the parent more than the way difficulties vanish when once the course of instruction to the youth has been entered upon.

In the lower life the father seldom cares for his offspring; and this is true among the fishes, where neither parent as a rule assumes any other responsibility than properly disposing of and fertilizing the eggs. Where, however, any care is taken, it not infrequently devolves upon the father instead of the mother. This is true of the fresh-water black bass and of the stickleback, where the father protects the eggs until they are hatched, and protects and cares for the young fish. In the case of the stickleback, the father even makes a nest to contain the eggs.

Thus far, the process of the renewal of life is, so to speak, impersonal. The eggs are laid by one fish and fertilized by the other, this being necessary to the development of the young. The parents are endowed with an instinct which informs them when the time is at hand; and the male fish guided by this instinct applies the fertilizing material where it is needed,--that is, over the surface of the fresh-laid eggs. The number of eggs laid by fishes should be noticed, as it is a fact which will be useful later. Several millions of eggs have been counted in the ovaries of one fish. The number of fertilizing cells in one testicle would be incalculable. Fish eggs and young fishes are liable to many fatalities; they are destroyed in immense numbers. Consequently, if the race is to survive, there must be an almost inexhaustible supply.

Fishes kept in confinement will not as a rule multiply. Nothing is so sensitive as the reproductive system. Lacking certain stimuli which it finds in its natural surroundings, it will not become active. The goldfish in the globe will, if a female, have the ovary containing undeveloped ova, the male will have the testicles containing the fertilizing cells, but these will not mature. It is as though the whole system of the fish missed the freedom of space, the changes of season, the variety of substances at the bottom of the water,--all that goes to make "home" for it, and so languished in body as well as spirits.

The child who, in connection with a multitude of other interesting facts concerning fish life, learns those concerning its multiplication, will look upon them as perfectly natural and matter-of-fact.

But, some one objects, will not the child at this point guess the whole truth? Suppose he does? Is not that just what we want him to do? Is it not a sign that he has a good reasoning mind? He may arrive at the right general conclusion, but he has a conception that is very general, vague, not at all personal, and entirely lacking in any material for malodorous thoughts and feelings. By constantly turning his thoughts to the wonders and truths of heredity and to the marvel of the development of living things from such insignificant yet momentous beginnings, and by telling him interesting facts of animals and plants along these lines, his thought can be kept general and on a high plane. Where details are demanded, the parent ought to be thankful that these are presented to him for elucidation instead of to some incapable outsider, and he can meet the demand according to circumstances,--all of which will be discussed more fully presently.

If the parent keeps ever in mind the fact that the child _must know_ some time, and ought to gain a high conception of the subject before being exposed to degrading influences, if he asks himself in all honesty, "Unless I answer this, who will? and how?" he will be helped to do what in his own heart he knows to be his duty.

Moreover, there is a great gain to many a child in learning the main facts at an age where they do not appeal powerfully to his imagination nor move his senses. Later, when any reference to the subject may have this effect, and when there is enough to understand and meet without going back to the rudiments, it will be much less difficult to give the needed aid with this background, which causes the child to feel that he has "always known." To have always known a thing robs it of any great special interest. We pay no attention to the sun that shines upon us, but if this were a phenomenon of very rare occurrence we should be thrilled by it and aroused to curiosity and special observation and interest.

The child's knowledge of the sexuality of nature should be as much a matter of fact as any other knowledge, and the mystery of it should be presented to him as a sublime and beautiful mystery, creating an impression he cannot wholly escape from when he finds himself caught in the vortex of his own adulthood.

IX

AMPHIBIOUS LIFE

To the parents who desire to lead the child's mind through a long sequence of thought from the lower to the higher life, the amphibian affords an easy step in this ascending scale. And among amphibians that familiar and picturesque harbinger of spring, the frog, and his cousin the friendly toad, are the best adapted.

Children are always interested in frogs because they jump so well. This suggests a starting-point for making their closer acquaintance. Why do they jump so well? It is because of their long hind legs. A little watching of either frog or toad will show exactly how the legs are used and wherein they differ from, and also resemble, the child's own legs. The little hands of the frog and toad, their way of sitting, leaning on their short arms, their eagerness to snap up a tempting fly, the queer tongue fastened the other way round from ours, and its lightning-like speed which is a result of this same position in the mouth,--a hundred interesting things can be learned about the toads and frogs.

Toads are very easily tamed, and make most amusing as well as useful pets if there is a garden to be protected from marauding insects. They generally have a hole or corner to which they come home regularly at night, and with a little patience can be so tamed that they will take food, of living insect or even of scraps of meat, from the child's hand. Their power to gormandize seems unlimited, and the number of insects they can swallow without protest is almost incredible. They will keep a small garden quite free from slugs and other pests. They have no bad habits, do not bark at night, or chase cats, or bite, or steal, or insist upon coming into the house, or scratch up the flower-beds. Some accuse them of causing warts, but this is not true. When handled, they sometimes give forth an acrid liquid from the skin, which stings the mouths of tormenting dogs and smears meddling fingers. But this, though unpleasant, does no harm. Many people have handled toads freely and never had a wart; many others who have never touched a toad have had many warts.

The toad may be ugly to look at, but that is not his fault. To many, he is more comical than ugly, and no creature has more beautiful eyes than this same homely toad. He is one of the most useful of animals, and should never be killed or ill treated.

The frog is less familiar to us than the toad, living as he does in the water or in wet places. Boys often take delight in killing him, having theories of the terrible influence he exercises in the affairs of man. He is as harmless as the toad and of value in keeping down insect pests, since these are also his food.

In the spring of the year, the frogs and toads will be heard chirping, the frog in particular sometimes filling the night with his din. The earliest of these voices comes from the smaller green frogs, or "peepers," as they are often called because of the peeping noise they make. The deep bass croak comes from the large bull-frog, so named from his size and not from his sex, for there are female bull-frogs. When the frogs begin to peep, the children will enjoy making an excursion in quest of frogs' eggs. These will be found in any pond where the voice of the frog is heard, and can be taken with a long-handled dipper or by wading,--the latter practice to be cautiously indulged in northern latitudes at this time of year, as the water may yet be very cold.

The eggs are gray, spherical, about as large as sweet-pea seeds, and have a black spot on one side. They are found embedded many together in a colorless jelly-like substance. The egg-mass should be handled carefully and put whole into a jar or pail of water and thus carried home. It should not stand with the sun shining directly on it, and when the water is changed, every other day, that which is used should be of about the same temperature as that removed. Water drawn cold from the pipes will sometimes kill the eggs.

If all goes well, in a few days the eggs will hatch. Out of them will hatch, not frogs, but tadpoles, or pollywogs, as they are also called. Everyone likes to watch a tadpole--certainly every child does. As soon as the eggs hatch, the surrounding jelly substance may be thrown away, merely as a matter of convenience. Its use is to protect the eggs and to afford the first food for the tadpole. If left too long in the water, it becomes broken up, discolored and unpleasant. The tadpoles should have fresh water every day or two, care again being exercised not to use it too cold, and they must be fed. They will eat almost anything, crumbs of crackers or bread, and bits of raw meat or fish being very acceptable. If they are well fed on meat or fish, they will grow faster and change earlier into frogs. Indeed, by underfeeding tadpoles a person can keep them a whole year from undergoing the changes they would have normally undergone in a few weeks. The large bull-frog tadpoles naturally take two years to develop, though a very nutritious diet may possibly hasten them.

The tadpole has very small eyes, a very small mouth, and tiny gill openings like a fish. Indeed, so far as its life at this stage is concerned, to all intents and purposes it is a fish. It cannot live out of the water, it breathes by gills, it swims by its tail, but it has no fins. It wiggles about the jar or tank in a very lively way, and ought to have water weeds or stones to hide under, and pebbles or gravel in the bottom of the receptacle.

The ordinary tadpole, if well fed, astonishes and delights his young keepers in a few days by putting forth a pair of tiny hind legs, which generally trail behind him when he swims, though he often kicks with them, perhaps for exercise. He grows larger and his legs longer, and one day a row of fingers may be seen peeping out of his gill slit, as though out of an armhole, and then he will thrust out a forearm, then another from the other gill slit. After this, changes are rapid, and his keepers should put a stone or some firm object in the water, reaching above the surface, so that he can climb up into the air; for now his lungs are rapidly forming, and soon he can no longer breathe by gills. At this stage, his tail begins to disappear. It does not fall off, as some think, but its substance is absorbed into his body until no tail is left. Finally, his head changes its shape, his baby mouth is replaced by a wide frog mouth, his eyes stand out with projecting lids, his ear-plates showing back of them, and we have a full-grown frog.

To the child who understands the origin of the fish eggs a few questions which he can easily answer himself will be enough to call attention to the important differences, and also to deepen the impression of the unity of life as expressed in flower, fish, and frog. The ova of the frog develop in an ovary exactly as do the ova of a fish; they develop in the same way and at the maturity of the animal. The fertilizing cells develop like those of the fish. In both cases, the reproductive elements are laid, shed, or born, when the time comes. Before the eggs of the frogs and toads are laid they have no albuminous covering. The moisture that envelops them swells up into the jelly-like mass upon coming in contact with water.

There are important differences between the frog and the fish. The frog is a more complex animal and, so to speak, more difficult to create, and it lays fewer eggs. Since there are fewer eggs they must be more carefully fertilized; that is, the fertilizing material must be sure to come in contact with all of them. Consequently at the moment when the eggs are finding their way into the water they are fertilized; not within the female body, but just as they are leaving it.

The child accustomed to notice what he sees will observe the paired frogs in the pond. He can be told that they take this position just before the eggs are laid so that every egg will surely be fertilized. In the amphibious animals the relation of the two parents is closer than in the fishes, but yet there is no union between them, that appearing only when it is necessary. The stern law of necessity governing every step of the reproductive function may be made very impressive to the young mind; also _the reign of law_ throughout life.

To explain frankly, simply, and scientifically such phenomena as that of the paired frogs will tend to rob them of dangerous interest. Not to speak of them will not prevent the child's seeing them, and his imagination may foster much less wholesome thoughts.

There are frogs and toads that care for their young, but parental affection in this form of life is rare. The eggs are laid in a favorable spot, and then left. Toads as well as frogs lay their eggs in the water. The instinct of the toad leads it to seek the water at the egg-laying season, as its tadpole, like that of the frog, can live only in the water. At other seasons of the year the toad does not enter the water.

Frogs' eggs are laid in compact masses, while toads' eggs are laid in strings or ropes; and in this way they can be recognized, though after they have once hatched the tadpoles of both are so much alike that they cannot be told apart. Sometimes the children will be disappointed because the tadpole does not change into a frog nor yet into a toad. It gets its four legs but does not lose its tail; it never loses its tail. In short, it is not a frog or a toad, but a salamander or water-lizard, which lays eggs similar to those of the frog, and whose young upon first hatching look very much like young tadpoles.

If eggs are found in a pond where frogs are not heard or seen, they will almost always turn out to be the eggs of a salamander.

X

THE BIRD

From the flower to the bird is a step easily taken if the parent prefers to omit the intermediate steps, or, after the story of the bird has been told, the stories of fish and frog can follow as occasion offers, instead of preceding it. The bird is peculiarly valuable in teaching the origin of life to the child, since in it we have such highly developed home and family instincts, the father bearing his share of the burden, illustrations of which are rare in the lower forms of life. As everywhere else, the best starting-point is with the life and interests of the bird itself, and for this caged birds are far better than the free ones, even though they may be only the sparrows and pigeons of the city streets.

The flight of birds is that which particularly interests children as well as every one else. Birds will soon learn to come to a place where they are fed regularly; and the style of flight, depending upon the size and shape of the wing as well as the shape of the bird's body, is a very interesting study. Many a country child knows the common birds by their flight even when the bird is too far away and moving too fast to be distinctly seen. What he generally does not think of is _why_ the bird has this peculiar flight, and to have his attention called to it may increase his interest in watching the living bird.

Whatever increases the boy's interest in the live bird tends to decrease his desire to make it a dead bird; and the numerous good bird-books, as well as the substitution in so many cases of the camera for the gun, has tended to preserve the lives of the birds and to create a sentiment in favor of their preservation. If the young child is taught to watch the birds and care for them, he will not often, when older, thirst to take their lives.

While the flight of the bird may engage the first interest of the child, its manner of eating and drinking is worth attention, and the nature of its food is of the greatest importance. The shape of the bird's beak will decide, at least in a general way, the kind of food it eats; and a little study of birds will convince any one that all birds are useful to the agriculturist, either as destroyers of noxious insects or of weed seeds. While some birds swallow the seeds whole and pass them again unharmed, thus spreading the plant, others crack the seed coat and eat the contents, which of course destroys the seed. Even where the birds are the means of sowing seeds they do more good than harm; for the seeds thus sown are not often harmful, and those same birds destroy a vast number of noxious insects. Even owls and hawks, by destroying mice in the farmer's fields, do him a service that much more than compensates for the loss of an occasional chicken.

While the birds are of inestimable value to the farmer and to any one who has a garden, their influence on our lives in another direction is also very great, as difficult to estimate perhaps, as that of flowers. Who can doubt that these little brothers of the air are one of the most civilizing and elevating factors in man's daily life? Their song, their flight, their thousand and one charming or entertaining habits, their strong expression of personality, their poetical and mysterious comings and goings, appeal powerfully to the higher imagination.

The migration of birds is alone enough to fill the mind with enchanting dreams. To know that every night in late summer and in autumn there is a stream of birds moving high in the air along the line of the sea-coast and of the great valleys is enough to awaken fancy. This winged procession moving along its aerial highway is made of the small and timid birds that dare not fly by day for fear of hawks and other enemies; they may be as high as three miles above the surface of the earth, their height being estimated by watching them through the telescope as they cross the surface of the moon. Imagine looking through the telescope at the face of the full moon some night and seeing an endless procession of little birds speeding across its shining face!

The amazing power of birds to see and hear, and, most interesting of all, their nest-building habits are calculated to arouse the wonder and admiration of every observer. What child would not watch with intense interest the bringing of the straws or other materials, and the deft weaving of them into the home which is presently to receive the precious eggs? Even the city sparrow may here be a boon to the mother. Sufficiently encouraged, it will accommodatingly build almost anywhere.

The child who knows the story of fish life and frog life will need little telling here, and that is one argument in favor of taking all the gradual steps from flower to bird. By this time the main ideas are firmly lodged, the child will readily draw his own conclusions as to the rest; but there are one or two facts connected with the origin of the bird which are of great value in fixing the idea of _necessity_ which is at the foundation of all reproductive phenomena. Everything is as it is because it is necessary that it should be so. In the frog the higher development made necessary greater economy in the production of the egg and the fertilizing cell, and this economy of material necessitated the more certain fertilization of the egg.

In the bird a great step upwards has been taken. Here we have something much more complex in every way. The frog was cold-blooded, comparatively sluggish, and comparatively simple in structure. The bird is warm-blooded, intensely active, and very much more complex both in bodily structure and in mind development. Here the reproductive activity is yet more economically conducted, and instead of thirty or more eggs, the bird produces often not more than six in a season, and even a smaller number if it is single-brooded, some eagles, for instance, rearing only two young in a season. Naturally these few eggs must be very carefully protected. Since they are not laid in the yielding medium of water, they cannot have so soft a covering as the eggs of the fish or frog, but are enclosed in a hard shell. This shell must of course be formed before the egg is laid, and the egg must be fertilized before the hard shell encloses it and thus makes forever impossible the entrance of the fertilizing cell.

The ovaries of the bird are in the small of the back close to the backbone, and there is a tube called the oviduct or egg-duct, leading from the ovary down to the lower end of the intestine, which it enters. There is no separate opening for the oviduct into the outer world.

There are two ovaries, with their oviducts, in the young bird, but these are so small that it is very difficult indeed to find them. As the bird approaches maturity, one ovary and its oviduct enlarge, and the ova, which develop from the inside of the ovary just as the ovule develops inside the flower ovary, also become large. Although the bird is born with two ovaries, but one, usually, develops, generally the one on the left side.

When the bird comes to maturity, there is born in it a yearning for home and offspring. As the eggs develop, the bird turns to the nest and to the mate who is to share with her all this beautiful life. When the mate has been chosen, both prepare the nest to receive the eggs, which will soon be ready. It is during this period that the fertilizing fluid is placed in the lower end of the egg-duct, whence the fertilizing cells, by their power of motion, quickly make their way to the egg, which has just begun its journey down the oviduct and is as yet without a shell. The shell-less egg is well known to most country children, as hens often lay one; and this will always happen where there is not lime enough in the food of the poultry.

After the egg is fertilized it continues its slow journey down the oviduct, which enlarges to accommodate it. At first the egg consists of the yolk alone. This grows to its full size before it leaves the ovary. The yolk in short _is_ the egg. But there is not enough food material in it for the development of the bird, so as it passes down the egg-duct it becomes coated by the so-called "white" of the egg, which is a substance secreted from the lining of the egg-duct and is not alive, as is a certain part of the yolk. It is merely stored-up food like that in the morning-glory seed, for this egg is the seed of the bird. At the lower end of the egg-duct there is secreted a limy liquid which covers the shell-less egg and hardens, making the shell. So finally the fertilized egg has its shell and is ready to be laid. When this time comes, the bird seeks her nest, and the egg is laid or born, and lies warm and living, like a jewel in the nest.

It is hardly necessary to add that the fertilizing cells in the male bird have an origin similar to that of the ova. The testicles and their ducts are too small to be easily seen in the young bird and in the winter-time, but can be seen during reproductive activity. The male bird can usually be told from the female by differences in color and plumage, but where this is not the case the two sexes cannot be told apart without actually killing and dissecting the birds, so very simple are the generative organs.

The ripening of the reproductive elements in the bird occurs in the spring of the year, and is always with a few exceptions accompanied by the instinct of nest-making. The birds instinctively and joyfully prepare the home for their young at this time, both parents joining to make the pretty structure. With the child the higher emotions which always accompany reproductive activity in the bird life should be kept ever prominent,--the affection between the parents, their care and love for each other, the care and love for the helpless young, their happiness in this duty as shown in their song and bright colors. Unlike the fish and the frog, the bird cannot develop unless the egg is kept warm, and after it hatches the young bird cannot take care of itself for several weeks. It must be carefully nurtured, and finally even taught how to fly and find its food.

The maternal hen can be a treasure to the mother seeking to impress the lesson of love and care; the only defect is the indifference of the father, which is in marked contrast to the interest shown by other birds, though there are many proofs that the cock is not without parental love, as where young chicks have been abandoned he has been known to rear them.

The love of both the birds for their helpless young, and their devotion to each other, can be impressed on the young mind in many a picture of beauty. Many birds pair for life, returning to the same nest year after year. Nor should the instruction fail to impress upon the young mind the advance of love and tenderness on the parent for the offspring as we ascend the scale of life. The flowers, the fishes, the frogs, entrust their offspring to the care of Mother Nature; the birds cannot do this. The mother and the father of the helpless little creatures take deep joy in sacrificing their own freedom and strength and time to this loving duty. A bird will even lose its life for its young, trying to drive off an enemy; and every one knows how dangerous it is to approach the nest of any large bird, eagles and even cranes sometimes killing men and boys who try to rob them of their young.

The plumage of birds is a pretty subject of study. The wonderful way in which feathers are adapted to their use, in keeping the bird warm without greatly increasing its weight or impeding its flight, may be made very interesting; also their beauty both of structure and color, and the fact that at maturity the plumage often undergoes remarkable changes. Young birds are colored like the mother. The brilliant male of the Baltimore oriole gets his bright dress at maturity, but until that time he is as soberly clad as his quiet little mother.

The inheritance of the young bird from its father should be enlarged upon. At the beginning, though the male birds resemble the mother in appearance, at maturity they wake up to the characteristics of their father. Then the brilliant colors begin to play over their feathers--his colors. Then the song trembles from their throats--his song; and the beautiful creatures might sing as their wonderful wings flash through the air, "All this loveliness I owe to my father: it is from him I received this glorious heritage of beauty and song."

The child can learn the terrible consequences to the birds of their feathers being taken as ornaments by human beings. The children can be told that the plumage is most beautiful at the mating and nesting season, and that thousands of birds, both male and female, are slain then, that the eggs and young birds consequently die, and that some species have been almost if not quite exterminated in this cruel way. The Audubon societies are organized for the purpose of instructing young people about the birds and getting their cooperation in opposing this needless slaughter. Some of these organizations are extremely interesting in their field and lecture work on birds; every neighborhood could have its Audubon society, to the great pleasure and profit of the members as well as to the profit of the birds.

Where the mother desires to pass directly from the flower to the bird, this can be well done by comparing the two, so far as their generative processes are concerned, at every step. She can remind the little one of how the flower seed is treasured in the ovary until it is able to go out into the big world, and can then tell him that the wonderful seed of the bird, which we call the egg, is treasured in the same way; this to be followed by the story of the care needed by the bird's egg after it is born,--how it cannot be left to shift for itself, but must be watched over and kept warm by its loving little parents until it is fit to leave the shell, how it then breaks its prison and comes forth so weak and helpless to be yet further loved and cared for and taught by its faithful parents.

The question is often asked, should not the story of motherhood precede that of fatherhood in all this early teaching? Up to a certain point it may be well, and the story of the life and development of the egg can be told to young children, with the father-bird merely an aesthetic factor, so to speak. His care of the young, and protection of the mother-bird can be dilated upon without going any farther. This is a course, however, which it will not be wise to follow too long, particularly with boys, whose interest will be greater when they know that the father too has a vital interest in the life of his offspring. Moreover, there is a certain spiritual value in connecting the equal need and responsibility of both parents in the creation of their offspring. The child then knows that he has the whole truth, and half truths are never quite safe.

If the child knows the story of flower, fish, and frog life, he will draw his own conclusions about the birds, and it will be wiser frankly to tell him this part of the story. If he knows nothing of the earlier work, and the mother begins with the young birds in the nest, according to his age and surroundings he should be told more or less, the mother always remembering that if she defers too long somebody may anticipate her with the kind of information she particularly desires to avoid.

Another question often asked concerning the bird is, "Would the egg be laid if it were not fertilized?" It might be or it might not. In all forms of life the sensitive reproductive system responds with peculiar readiness to its environment. In birds if it does not receive the stimulus that comes from mating, the ova may not develop at all, but remain small and attached to the ovary. Or, a few may be completed and laid, as is often seen in the case of caged female canaries. But these eggs of course could never hatch. They are perfect so far as the ovum is concerned, but lacking fertilization they cannot continue their development.

Another question often asked, and of peculiar meaning, is, "If the reproductive system be not exercised, will it not perish for lack of exercise?" The latest word of science on this subject is that it will not, either in the bird or elsewhere. In a healthy organism it can safely remain inoperative with the certainty of becoming active at a later period if then it receive the normal stimulus.

The lessons to be learned from the birds are many. From them can be answered all questions, for now we have passed that most difficult of all points, the relation of father to child in the animal world, and everything else can be explained through the knowledge already gained. The well-taught child will recognize the justice and necessity for the existing processes of life. He will realize their deep meaning, their far-reaching influence, and their tremendous importance in preserving upon the earth the multitudes of living forms that inhabit it.

The flower and the bird are the two most important helps in imparting the facts concerning the renewal of life throughout nature.

XI

THE MAMMAL

The mother who has conducted the child through the various life forms up to the mammal will not be likely to wish to stop there. Having gone thus far, it will be easy to continue and reveal to the child the wonderful life that yet remains.

The question is often asked, whether country children are not much more likely to learn these truths naturally and without instruction than city children. The answer is that they are more likely to learn the facts, but knowing the facts is by no means understanding the subject; and whether knowledge of the facts is good or bad for the child depends entirely upon the impression it makes upon him. Undoubtedly the country child is in a better position to receive instruction, but whether this instruction tends to refine his feelings and elevate his heart depends altogether upon how it is given. Probably the average country boy has no more spiritual conception of the matter than the average city boy, though he may have a more wholesome and, so to speak, utilitarian thought of it. His interest at least reaches out to results, for the successful multiplication of the stock on the farm may be a matter of vital importance to him.

The extension of knowledge from the bird to the mammal may be made through the medium of the family pets. Fido, puss, the pet rabbits, or squirrels may serve to elucidate the subject. Indeed, at this stage the well-instructed child himself will be ready to give all the essential facts, and will feel free to ask questions concerning the facts he does not understand. If he has traced the continuity of the egg from the flower to the bird it will not be difficult for him to realize that even the higher animal has its origin in the same way. The mother can very reverently explain to him that the cat too has ovaries; that from these develop ova which are few in number and need very special care. They cannot be laid in a nest like the bird's egg. They are very tiny, no larger than the head of a small pin, and they have no hard shell.

It is their destiny to remain in the oviduct and develop. That is, instead of being born like the bird's egg and then being hatched, these eggs first develop and afterwards are born. But if not fertilized they would not continue to develop. The cat has two ovaries, which develop at maturity and ripen the ova, and these pass into the oviducts, which are tubes like the oviducts of the bird. Here the egg remains a certain length of time, and then if it is not fertilized it is passed away; but if it is fertilized a marvellous change takes place in this tiny cell: it remains within the oviduct and is there supplied with nourishment by blood-vessels essentially as the flower seed is supplied with food from the sap. Generally three or five of these ova develop at the same time, some in one oviduct, some in the other. When these tiny eggs have developed into kittens strong enough and perfect enough to make entrance into the world safe, they are born just as the egg is born. Unlike the oviduct of the bird, which opens into the intestine, these ducts unite just before the end, and have separate openings of their own.

As soon as the young are born the mother begins to care for them. For several weeks they depend upon the milk she secretes for their food, and upon her constant care and loving watchfulness for their life. The thought of parental love and care should be much more strongly emphasized at every step than the mere physical facts, though it is necessary that they too be clearly comprehended. The sacrifice of the parent for the child is one of the most universal and unselfish facts of life, and many stories illustrating it can be collected and told. It is not necessary to tell them as obviously pointing a moral, yet they should be told as dramatically and interestingly as possible, that the child may get a strong impression of this great force. Among mammals it is true, (but this need not be dwelt upon with the child,) that many males pay no attention to their offspring; though some, as the cattle, defend the females and young if a herd is attacked by savage animals, by putting them in the centre and themselves forming a circle about them. It is the mother love and care, however, which are here most prominent; but the child who knows the facts concerning paternity should not be allowed to forget the great factor of inheritance, and that the offspring gets its characteristics from the father as well as from the mother.

There is only one more step to be taken in the _modus operandi_ of reproduction, and that is in the higher mammal, where the ovum passes down through a slender oviduct into an enlarged chamber or womb, where it remains a certain length of time, finally if unfertilized, to pass away unnoticed; if fertilized, to develop into a young animal which in time will be born helpless and dependent upon the love and care of the mother. In some of the higher mammals, as the sheep and the goat, there are generally two ova developed in the womb at the same time; that is, twins are born. In the larger ones, as the horse and the cow, but one ovum generally develops, though the development of two is not uncommon.