possible to see almost any evening a truck crawling slowly down the street; it cannot run faster because its engine is partly disabled. It is filled with the former idols of the Russian capital, the pride of Russian art. Among them you note Ershov, Akimova, Bosse, Cherkassky, Makletzova, Smirnova, Vill, Luckom. Their faces betray their fatigue and irritation. No doubt, it is not the first time that evening that they have been thus transferred from one theatre to another. Here is another truck. In it you discover Vedrinsky, Domasheva, Brian, Leshkov. Where are they being dragged now? It was in just this way, in the time of serfdom, that peasant-musicians were shipped from one landlord's estate to that of his neighbor.

Actors permit themselves to be dragged thus from one theatre to another because it brings them extra piles of colored paper-so necessary if they so necessary if they and those dear to them are not to

starve.

Equally tragic is the lot of painters. They have nothing to paint on, nothing to paint with: no canvas, no colors. Those who get these have no place to work, for their own living quarters are too cold and cramped. And to this is added the constant, soul-extinguishing thought of food; and the eternally corrupting question: 'How much will we get?'

This question may be read always in the eyes, and heard from the lips, of scientists, professors, famous singers. 'What will they give us?' That is the opening phrase of every conversation

and its closing chord.

Worst of all, most tragic of all, is the fate of writers. By the first anniversary of their régime, the Bolsheviki could already boast that their cultural work in this field was done. There was not a newspaper, a magazine, a publishing house left, except those which the Soviet

government owned and controlled. Not a periodical to write for! No opportunity to print! Only an author can understand the tragedy of these words, only a person who lives for his writing, for whom it is just as essential to write as to eat or breathe. In Soviet Russia, the writer, the poet, the man of letters is like a prisoner chained in his cell. He is robbed of his most elementary need, the freedom of travel. In order to go ten versts out of Petrograd, you have to spend weeks in different Soviet institutions, begging for permits. Recently even a finger-print system has been introduced. The writer has no opportunity to get new impressions. A realization that he is cut off from the rest of the world encloses and stifles him like prison-walls.

Every time a theme is born in the writer's mind, every time an artistic image rises before him, every time words begin to string themselves into periods, this sentence of doom sounds in his ears: 'That cannot be written. What if there should be a sudden search? They might hale you before the Extraordinary Commission for that!' For the government's motto is: 'All who think different are anathema.' Therefore the inspired words die away, the image disappears, the theme fades into nothing

ness.

Literary talent is like a spirit in a cage, like thought bound with fetters. It loses faith in itself, languishes, and finally expires.

Besides all this, the writer, the poet, must at any hour of the day, in the midst of his hopeless composition, be prepared to dig trenches, shovel snow, clean the streets. I have before me two orders. The first reads as follows:

'By order of the Commander of Internal Defense in Petrograd, the House Committee of Poverty informs you that you have been assigned for work in building the defenses of Petrograd

for this afternoon, November 2. Report at one o'clock to the 30th Ward, 59 Pushkarsky Street.-To A. F. Damansky.'

rected the farce; and we wondered, almost incredulous, at the open hypocrisy they exhibited. But we followed these instructions, knowing as well as the

'The list of those mobilized for the second shift on November 20 at house No. 19, Karpovka, is as follows: 1. E. M. Dmitrieva. 2. A. F. Damansky.' And we reported there. In obedience to those orders, we attempted to dig the frozen ground. We went through the farce of pretending to excavate trenches, which looked like anything under the sun but trenches. With amazement we listened to the absurd orders given by the engineers who di

would no more than hold back a herd of small pigs trying to raid a near-by orchard.

Yes, writers are forced to clean streets, load garbage on trucks, shovel snow. Their labors do not help matters appreciably; but scores of writers, teachers, professors, forced thus to toil at unaccustomed tasks beyond their strength, have fallen ill and have been called forever from their appropriate work and no substitutes can be found to take their places.

PROFESSOR ARTHUR KEITH has recently made the interesting suggestion that the difference in racial type, as seen for instance between the white, the yellow, and the black races, is due to alterations in the balance of the various glands of internal secretion. By this means, too, he seeks to explain the occasional appearance in white races of individuals of a Mongolian cast of face where no admixture of Mongolian blood can have occurred.

We shall return shortly to the question of the glands of internal secretion. Now let us for a few moments invade another field, the field of diets and foodsubstances and their effect on growth.

As most people know by now, the established classifications of foodstuffs

is into proteins, carbohydrates, fats, and mineral salts. The carbohydrates include the sugars and starches; they resemble the fats and oils in being built up out of the three elements, carbon, hydrogen, and oxygen, but differ from them in the proportions of these various elements. The proteins, on the other hand, contain nitrogen in addition to the other elements named.

By a rough analogy, the human body may be compared to the engine of a motor-car. It derives its energy from the combustion of fuel, and it utilizes that energy by being constructed in a special way. To keep the engine working, you must not only supply fuel, but also repair the parts as they wear out. So in the body: the carbohydrates and

fats are for the most part utilized simply as energy-fuel, while repair of the tissues, which are constantly in need of a small amount of renewal, is provided for by the proteins. While the animal is growing, conditions are somewhat different; for not only must the old living machinery be repaired, but new molecules must be continually laid down. Until a very few years ago, the matter had not progressed much beyond such very general notions. Now, however, we are beginning to know that that was far from all. To start with, all proteins are by no means equally good for maintenance (as simple repair is usually called) or for growth. Further, a wholly new class of food-factors has been discovered, without which growth and life itself cannot continue. These are the so-called vitamines.

It is as well to know at the outset that nobody yet knows what a vitamine is, chemically; nobody has yet succeeded in isolating one. We know, however, what they do, and where they occur; and that is already a great deal. As usual, the matter has been approached by two convergent roads. In the first place, certain diseases were found, in the slow course of years, to be associated with deficiencies in diet. The best known of these is beri-beri, which was traced to its source through the observation of a Dutch doctor in Java. This was the chain of evidence: (1) Beri-beri was common in the asylum under his charge; (2) the fowls in the asylum yard were fed on the patients' leavings; (3) these same fowls developed a disease very like beri-beri; (4) the patients' diet consisted very largely of polished rice.

It was eventually shown quite clearly that rice from which the husk and the germ had been removed by milling and polishing was deficient in a something which was christened vitamine, and

that a long-continued diet of such rice led to the development of beri-beri. Supplying the vitamine again, in any form, leads in a wonderfully short space of time to recovery.

This side of the matter does not concern us so much. What is of interest is the fact that it takes some time for the polished-rice diet to produce the symptoms of disease. In other words, a balance is gradually upset.

It is the effect of vitamines on growth that is especially interesting to us. Our knowledge of this chapter of biology we owe largely to Professor Hopkins, of Cambridge. He discovered that, if a diet was made up of protein, carbohydrate, fat, and salts, all chemically pure, young animals - rats in this case would not grow on it, although it contained ample substance both for energy and for repair. They not only would not grow, but soon lost weight, and died within a week or so. The addition of an apparently negligible quantity of milk, however, — a mere two or three cubic centimetres a day, restored the animals to health at once.

The substance lacking in the original diet was what is now generally called fat-soluble vitamine A.

Through the vitamines we are introduced to a new class of food-factors substances which, though absolutely necessary for growth, for health, and for continued life itself, need yet be present only in infinitesimal quantities to produce their effects. That this discovery has not been without far-reaching and important results is shown by the fact that not only beri-beri, but also two other widespread discases, scurvy and pellagra, have been shown to be caused by an analogous deficiency of diet, and to be therefore preventable; and now Dr. Mellanby, working at the Lister Institute in London, has made it more than probable that rickets, which especially interests us as being a

disease of growth, is due to the same cause. For instance, dogs fed only on separated milk, bread, and linseed oil developed all the symptoms of rickets; while those whose diet contained codliver oil, or butter, in place of the linseed oil, grew and throve normally. Rickets (like slums) is a by-product disease of our type of civilization. It should now be possible to wipe it out within half a century at the utmost.

Meanwhile, other workers, notably Osborne and Mendel in America, had been investigating the properties of single pure protein substances, as tested by feeding them to rats and mice, both growing and mature, as the sole protein constituents of an otherwise adequate and ample diet. The proteins are themselves very complex substances, and are built up out of a number of less complex units, each containing nitrogen, hydrogen, carbon, and oxygen, and known as amino-acids. Some proteins are deficient in some amino-acids, others in others. Some of them are correspondingly able to support life for an indefinite time, others are not.

Various most suggestive facts have emerged from the investigation. To start with, it has been shown that some proteins, such as zein from maize, will not by themselves support life at all. Many others, such as edestin from hemp-seed, though capable of maintaining a growing animal in health for a very considerable portion of its life, are yet somehow, in the long run, inadequate. A long period of health and growth is followed suddenly by a sharp loss of weight and premature decay, which can be arrested at once by placing the animal on a normal diet containing several proteins, but otherwise leads inevitably to death. To this upsetting of the balance we shall return.

Then we have the startling fact that certain substances will suffice to keep a grown animal in health, but will not

permit of growth in a young animal. Gliadin, a protein derived from wheatkernels, of which it forms about forty per cent of the protein content, is such a substance. Grown rats or mice fed with this not only continue active and healthy, but are capable of reproduction. Normal young rats may be born on this diet, and will grow actively as long as they are being suckled by the mother. But if, after weaning, they are continued on the same diet, growth ceases at once. Regarded as a chemical factory, -as every organism cán, under one aspect, be rightly regarded, the adult rat is obviously working in a different way from the young. The young animal cannot manufacture some substance which is missing from the make-up of gliadin. But once this substance has been manufactured in sufficient quantities, and growth is over, there has somehow been introduced into the organism a new bit of chemical machinery, which is capable of so transforming the gliadin as not only to make the missing substance in amounts adequate to keep the tissues in repair, but to nourish a litter of growing young, both before and after birth. That the chemical processes going on in a growing animal are different from those in the same animal when growth is over, is clearly a fact on which there hinge immense new possibilities, alike of knowledge and of control.

This property of gliadin has been utilized to produce another and remarkable result. If a half-grown animal is fed with gliadin as its sole protein, it will be able to maintain its weight, but not to add to it; it lives, but does not grow. If, however, other proteins are added to the diet, it will at once begin to grow again, and that even if the limit of the normal growth-period has been overpast. One rat was started on this late growth after 277 days of gliadin feeding and 314 days of life, and finally

reached normal size; and this in spite of the fact that growth in rats is normally over at 180 days or thereabouts. What is more, the animals kept on gliadin look as old as their size, not as old as their age in days, and are indistinguishable by inspection from young normal animals of the same weight. Obviously, we next want to know whether, when the growth of such an animal is finished, its period of maturity will be as long as that of normal animals, or if its extra period of youth must be deducted from its old age. This, however, has not yet been determined one way or the other for gliadin-fed animals. From experiments, later to be mentioned, on lower animals, we know that there is at least no theoretical reason against its maturity lasting the normal period in other words, against its usual span of life having been actually lengthened by the amount of time during which growth was stopped. But whether this is so or not further experiment alone can decide.

Such a prolongation of life would constitute a very real positive achievement. Otherwise, these experiments, while giving us a clear insight into the conditions of growth, may all be called negative in outcome. Addition of more vitamines, of more growth-promoting proteins beyond the limit necessary for normal growth does not result in an increase of growth. We can upset the self-regulating machinery in one direction, but not in the other.

Now let us turn to some other experiments which have achieved positive results, although this time their effect is more on differentiation than on growth. Everyone is familiar with the development of the frog-how the how the eggs are transformed into embryos within their jelly-membranes; how these hatch into tadpoles which are to all intents and purposes fishes, breath

ing by gills and swimming with their tail-fins; how these grow; how from their sides there sprout out the rudiments of limbs, and how finally a sudden change, an Ovidian metamorphosis, overtakes the organism, the bodyshape and the color alter, the tail shrivels and is absorbed into the body, the gills disappear, and the intestine, remodeling its lengthy coils into a simple loop, becomes adapted to a flesh instead of to a vegetable diet.

Development in tadpoles is a variable quantity. Food, temperature, light, and many other factors somewhat affect the rate of growth and the time of metamorphosis. Within the last ten years, however, one factor has been found, which is definite and powerful in its action; that is, the amount of thyroid substance present in the animal. If tadpoles are fed on ox- or sheepthyroid, — and that is an experiment anyone can try for themselves if they go to the butcher and get him to cut away the thyroid from either side of the wind-pipe just below the larynx, they will begin to metamorphose within a week or ten days, whatever their age. Even if no leg-rudiments are present at the start, they will appear; and the other changes follow in due

course.

If the animal is too small, it will attempt the transformation, but fail. There is a limit of size below which metamorphosis may be begun, but can only lead to death. However, the limit is so low that, by means of thyroid, young frogs can be produced no larger than flies, and not a quarter of the bulk of those that change at the normal time.

More than this: the converse experiment has been tried, and has succeeded. Allen, in America, succeeded in removing the thyroids from young tadpoles of about a quarter of an inch in length

no

mean operation! Such animals, unless they are fed with thyroid, will