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HOW SEATTLE IS STRIKING AT THE RAILROADS FOR OCEAN TRADE. The corporations having gobbled up the salt water frontage. Seattle is putting through a fresh water canal. Lakes Washington and Union are links in this canal.

plenty of deep water, but its citizens. feel they must be up and doing in order to handle the increased shipping expected.

To the ordinary individual the gigantic proportions of the Panama trade are not apparent. But when it is known that eighty-two million dollars' worth of merchandise, originating in the United States crossed the Isthmuses of Panama and Tehuantepec last year, some idea of the enormous trade that will be opened by the canal may be gained. Most of this merchandise was moved across the isthmuses for the mere purpose of transferring it from one section of the United States to another; from the eastern to the western coast or from the western coast and Pacific islands to the Atlantic seaboard. Fifty million dollars' worth of this total originated on the eastern coast and moved westwardly across the isthmuses, four-fifths of it then passing northward to the Pacific Coast of the United States, the other fifth being distributed along the coast of Mexico, Central and South America.

Thirty-two million dollars' worth of goods went eastwardly, two-thirds of it originating in Hawaii and the remainder along the western coast of the United States. The Hawaiian sugar which formerly went around the Horn, now passes over the isthmus by railroad and is transferred to boats and taken to the refineries of Philadelphia and New York. The

returning steamships carry merchandise for the western coast.

Figuring even on the present commercial conditions of the section of country surrounding Los Angeles only, $20,000,000 in freight rates on non-perishable goods alone will be saved in a year when the canal is completed. It is estimated conservatively that a million tons of non-perishable freight moves between the eastern states and the Los Angeles territory. The present rate is $26 a ton, while the all-water route will make the rate less than $6, thus effecting the enormous saving. A saving of $6,000,000 to the orange growers of southern California will be made.

When the canal is finished Pacific ports will be within twelve to fourteen days of New York in eighteen-knot vessels. This is figuring that it takes twelve hours to get through the canal. Between the Pacific Coast and European ports the trip should be made in three weeks in eighteen-knot ships. This is a comparatively short trip for the modern vessel. So the Pacific Coast folks do not feel that they will be extravagant in spending one hundred millions of dollars in improving their harbors. They figure that with the canal trade in full swing the hundred million could be saved in a year or so, in the reduction of freight rates. Besides, it's worth it to get this hearty swipe at the railroads.

LIKE PARENT LIKE CHILD

By

RALPH BERGENGREN

N the basement of a large stone building at Forest Hills, Massachusetts, there are several thousand mice and rats. Fortunately for the other occupants of the building they are all in wire cages. Unlike ordinary rats and mice in ordinary basements, they are cheerfully fed and nicely taken care of. And to complete this extraordinary situation the same basement contains several hundred rabbits and guinea pigs.

The stone building is the Bussey Institution, the headquarters of the agricultural department of Harvard University, and the basement is occupied by the animals used by Dr. William Ernest Castle, of the Harvard Zoological Department, as material for a continuous series of important scientific experiments. Without going so far as to consider this host of guinea pigs, rabbits, rats, and mice literal representatives of the human race they nevertheless pass their lives in affording material for the study of phenomena upon which the continuance of the human race, at its progressively highest level, is obviously dependent. The problems in which they are the living factors in the equation are those of heredity-the transmission of traits from parents to offspring and the possibility of determining in advance the characteristics that will appear from the mating of individuals with whose own characteristics the investigator is already familiar. Despite the occasional startling announcements of sensational journalism, however, men of science generally admit that human beings are more complicated than guinea pigs; and students of heredity in the lower animals turn their practical attention rather to improving live stock than to improving its owners.

Granting all this, and at the same time remembering Mr. Gilbert Chesterton's remark that the first thing the perfect

race of men produced by scientific marriage would do would be to smash the system of scientific marriage, it is fair to argue that the fundamental principles of heredity revealed in the color of a flower or of a guinea pig exist also in the more complicated cases of human inheritance. If study of guinea pigs can throw light on human inheritance, knowledge of the mysterious world we live in is advanced in proportion. The "reversion to type," for example, that every now and then produces a human being surprisingly unlike either of his parents has its analogy when a yellow rabbit is mated with a black rabbit and the result is just such a little gray rabbit as runs wild in the woods. Black rabbit or yellow, each parent contained a different element of the ancestral gray condition from which they had descended. And the combination of these two elements reproduced the gray color of the little rabbit, just as oxygen and hydrogen when brought together produce water. And this, moreover, happened in accordance with a wellestablished law of heredity. The law was discovered fifty years ago by an Austrian monk studying the flowers in his cloister garden; and it has been proved just as true of animals as of plants by such experiments as those of Dr. Castle with his scientific menagerie in the Bussey Institute basement.

Mendel's Law of Heredity, as this principle is known to scientists, was the result of a series of experiments in the cultivation of garden flowers. The good monk, Gregor Mendel, having leisure, curiosity, and a scientific mind, crossed different varieties of ordinary garden peas and carefully noted what happened. Long continued experiment showed that under certain conditions certain results would follow with sufficient uniformity to establish a law. If a pea with yellow

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The ovaries of the black

guinea pig were trans-
planted into the body

of the albino.

ALBINO MALE GUINEA PIG WITH WHOM THE ALBINO GUINEA PIG WAS MATED.

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cotyledons-as botanists call the seed leaves of young peas-was crossed with one having green cotyledons all the peas that grew from this crossing would have yellow cotyledons. Appar

crossing, but this color characteristic did not become visible until two of the peas in which it was latent were brought together; and in every four descendants from this second crossing only one individual showed the inherited green seed leaf color. Yellow, in short, was dominant, in that it was most likely to perpetuate itself and green was recessive because it could be expected to appear visibly only in a minority of the peas that inherited it. But when it did appear visibly, the result of a union between two of these peas was a continuation of the characteristic green color in the whole family of descend

BLACK FEMALE GUINEA PIG THREE WEEKS OLD. Her descendants would normally be black.

ently what had happened was the extinction of the green characteristic, and if these peas were crossed with other peas that had yellow seed leaves, yellow was still the characteristic seed leaf color in the immediate descendants. But if the peas descended from the first crossing were self-pollinated, or crossed with each other, the result was an average of one green seeded pea for every three yellow ones; and if these green seeded peas were separated and self-pollinated the resulting peas were all green seeded.

In other words, each of these little peas had inherited a characteristic-the green color of the seed leaf-from the first

ants.

Mendel's Law of Heredity divides transmissible characteristics into these two kinds-dominant and recessive. A recessive characteristic will be invisible in all descendants of the first generation, but will reappear, usually in the propor

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THE DESCENDANTS OF THE TWO ALBINO GUINEA PIGS.

The black color of these little pigs shows that black was the dominant color characteristic and was contributed by the transplanted ovaries of the black guinea pig. In other words, although born of albino guinea pig No. 2, these little guinea pigs are apparently the descendants of black pig No. 1 and albino pig No. 3.

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tion of one to three, whenever the offspring of this first generation are mated together; and the recessive characteristic will then breed true or perpetuate only itself. The definite proportion of one to three is said by those scientists who devote themselves to heredity to be "as fundamental to a right understanding of heredity as the law of definite proportions in chemistry." It applies to guinea pigs, mice, rats, and rabbits as uniformly as it applies to the garden flowers. And one of the results of scientific observation of the development of hereditary traits in these little animals points to an explanation which would undoubtedly have deeply interested the Austrian pioneer in his flower garden. The characteristic of color, green or yellow, in the peas with which he was experimenting was resident not in the flowers themselves but in the germinal material which formed the seed leaves of these flowers; and the germinal material of a yellow seed leaf, could it have been transplanted into the body of a flower whose seed leaves were normally green, might have gone on producing yellow seed leaves in its descendants just as if it had never been transplanted. In the case of the animals at the Bussey Institute it has been shown that a surgical operation can make a white guinea pig capable of bearing black offspring.

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SKULLS OF THREE RABBITS.

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Size usually expresses itself as a blending of maternal and paternal characteristics. The maternal skulls are on the right; the paternal on the left. The skulls of the descendants are the intermediate ones, in the middle.

To say that science watches and records the development of hereditary peculiarities in these lower animals has perhaps already set the reader wondering how these characteristics can be detected. To most of us one guinea pig or rabbit looks very much like another, and one mouse or rat very much like another mouse or rat. Fortunately for science,

there are a considerable number of useful differences. There are albino guinea pigs; black guinea pigs; guinea pigs that are only part albino; guinea pigs with long hair like an angora kitten; and yet other guinea pigs that are "rosetted"-a word that describes them when their hair grows in such fashion that they look as if they were always out in windy weather and the wind blowing from every point of the compass. Rabbits have been so long bred as pets that the fanciers have developed many characteristics that are immediately useful in tracing heredity. Rats and mice in bewildering variety have also been produced by the hit-or

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miss methods of fancy breeding, and England has "mice clubs" whose members, just for the fun of it, have long been interested in obtaining fancy house mice with pink eyes and variously colored overcoats instead of the uniform gray costume of the usual victim of the domestic mouse trap.

All these differences, secured apparently by chance but really, it now appears, in obedience to a law of heredity, are of direct value in still further testing the uniformity of the law and in getting new lines on the problems of inheritance. In this scientific menagerie the guinea pigs, rabbits, rats, and mice include specimens of practically all the varieties yet produced by experimental breeding. Each has a pedigree, so far back as it can be traced, neatly recorded in a card catalogue, and, as the experiments inspire no fear or distrust of their keepers, they are most of them tame and easy to handle. The rabbits in particular behave very much like those that inhabit little Johnny's coop in a suburban back yard.

A typical working out of the Mendelian law of heredity may be seen in the mating of an albino and a black guinea pig. If a pure bred black guinea pig is mated with a white one all the young guinea pigs in the first litter are black. These baby pigs are apparently the offspring of black parents, although, as a matter of fact, the white parent has contributed something of her own color characteristic and the contribution is unseen because the black color characteristic is dominant and conceals it. According to the Mendelian law the white. color characteristic, being recessive, can appear visibly only from the union of two germ cells in both of which this characteristic predominates-and that is exactly what happens when the black children of this black guinea pig with an

albino partner are in turn mated. Two black guinea pigs are presumably as surprised as a hen that has hatched ducklings by the appearance of one white guinea pig for about every three black ones in the family circle. The original cross had brought together two characteristics, B (black) and W (white), to make a single individual, B W, which showed only the dominant black characteristic. When these individual B Ws formed germ cells for the continuation of their species there was a return to original conditions; B became the sole characteristic of some of these germ cells and W the sole characteristic of others. When these germ cells united to create a new individual there were necessarily three possible combinations-B B, B W, and W W, the combination BW evidently occurring twice as often as either of the

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others. And, as any individual containing the dominant characteristic B would be black in color it follows that the combination W W would alone produce a white individual and would be likely to occur on an average of about once in four offspring. Evidently, too, in the case of individuals represented by B B and W W one characteristic had been doubled and the other eliminated.

By applying the Mendelian law in scientific breeding new combinations of individuals or races can be obtained in the course of a few generations. Thus when a guinea pig with a dark and smooth coat is mated with one whose coat is smooth and white, the young will exhibit a wholly new combination, dark and

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