読者です 読者をやめる 読者になる 読者になる

暗黙の焦点 別宅。

Michael Polanyiに捧げる研鑽の日々。

ヴァヴィロフ v.s. ルイセンコ その1

Michael Polanyi

Science, Faith and Society (Phoenix Books)

Science, Faith and Society (Phoenix Books)


1964年に再刊された本書にはマイケルによる'BACKGROUND AND PROSPECT(背景と展望)'という序文が追加されており、18年前の1946年当時本書を出版した意図を改めて語っている。

When I read that Vavilov's last defence against Lysenko's theories, in 1939, was to evoke the authority of Western scientists, I had to acknowledge that he was appealing to one authority against another: to the authority accepted in the West against the authority accepted in Soviet Russia. The meeting had been called by the editors of the journal Under the Banner of Marxism. Their acceptance of Lysenko's authority was based on their philosophy of science. What philosophy of science had we in the West to pit against this ? How was its general acceptance among us to be accounted for ? Was this acceptance justified ? On what ground ?
Marxism has challenged me to answer these question: the essays republished here were written in reply to them.

【拙訳】()内は訳者補記========
ルイセンコの理論に対抗するため1939年の会議でヴァヴィロフが強調したのが西欧の科学者(が遺伝学の理論に基づき築き上げてきた)の成果であったことを読んだ私は、ソ連で受け入れられている科学的権威ではなく西欧の科学的権威をヴァヴィロフが希求していたことを知ったのだった。その会議は『マルクス主義の旗の下に』編集局が主催し、(編集長のミーチンが主導する)編集局はその(マルクス主義の)科学哲学に基づきルイセンコ理論に同意した。では我々西欧の科学者はこれに対抗するどんな科学哲学を持っていたのか。どのようにしてその科学哲学に我々は同意していたのか。その同意は正しいものだったのか。どのような根拠で正しいとしたのか。
私はマルクス主義がもたらしたこのような疑問に答えを出したかった。今回再刊された論文はその答えとして書いたものだ。
========

ソ連共産党中央委員会書記局の指示により『マルクス主義の旗の下に』編集局が主催したこの「遺伝学の諸問題に関する討論会」は1939年10月7日〜14日に開催された。150名以上が参加し53名が発言した。マルクス主義に共鳴する欧米の科学者を中心に創刊(1936年)されたScience and Society誌は1940年の夏号でこの(約1年前の)会議の内容を紹介し、ヴァヴィロフ/ルイセンコ/ポリャコフの3名の演説を掲載した。マイケルはこれを読んだのである。

ヴァヴィロフの迫害と死が、マイケルの転向(化学⇒科学哲学)の大きな理由の1つとしてあげられるネタ元がこの文章だ。そしてこうした問題意識を持って本書は読み進めなければならないのだが、マイケルが「答えを出さないといけない!」と半ば使命感を感じてしまったヴァヴィロフの演説(途中のルイセンコからのヤジを含めて)がどれほどショッキングだったのかを知るには、1930年〜40年にかけてのヴァヴィロフを取り巻くソ連の状況を押さえておくのがベターだ。科学史・科学哲学・科学社会学として面白いテーマだし、遺伝学を巡る論争としては最終的にマイケルの生命論との関係でも大変に(皮肉な結果になるが)面白いのだ。一言でまとめれば、ヴァヴィロフは前成説であり帝政ロシア的であり、一方ルイセンコは後成説でありロシア革命的であったのだ。そして、科学的探求の立場としてはヴァヴィロフを支持したマイケルだが、Personal Commitmentは明らかに後成説的なのであった。

ヴァヴィロフの演説の一部は複数の邦訳書で紹介されてはいるが、改めて全文を記録しておこう。
(これは、いつか全訳する)

Source: Science and Society Volume IV, No. 3, Summer 1940;
Genetics in the Soviet Union: Three Speeches From the 1939 Conference on Genetics and Selection

ALL developments of genetics in our country date from the establishment of the Soviet regime. Professorial chairs in genetics have been established, the first in 1919-20. Soviet work in the sphere of genetics and selection has progressed rapidly. Especially since 1927, the date of the Fifth International Genetics Congress in Berlin after the Imperialist War, research has been in progress in the Soviet Union in practically every field.

We have no crises here. On the contrary, there is an expansion. A large active school of research workers has been created, embracing all the most important branches of contemporary genetics and, especially interesting for the section of philosophers, a division of experimental study of evolution.

What is the situation regarding genetics abroad? There, as is well known, far-reaching economic crises have taken place, sharply reflected in science as well. We see how Goldschmidt and Stern, important geneticists, had to flee Germany. Even in such a wealthy country as the United States one of the outstanding genetics institutes is closing--the Bussey Institute, near Boston, connected with Harvard University. In wealthy America the editorial board of the magazine Genetics must appeal to its readers for donations in order that publication of the magazine may continue. A number of selection institutions have been closed.

During the short space of time between the two last congresses, i.e., between l932 (the date of the Sixth International Congress of Genetics in the United States) and 1939 (the Seventh Congress in Scotland) major advances have been made in our knowledge of the material bases of heredity, in elaborating the chromosome theory of heredity. The development of the work of Muller in mastering the mutation process leads to the deepening of our knowledge about the hereditary variations of mutation sequences. The findings of Painter have led to significant extension of our knowledge concerning the material basis of heredity and the structure of chromosomes. New tendencies are to be observed in the study of the causes of mutation. A series of interpretative works devoted to physiological genetics is coming out. If you were to take the program of the last congress, you would see that it was to a considerable degree devoted to problems of physiological genetics. It is necessary to remember that the leader of American genetics, Morgan, besides being a geneticist, is an important embryologist.

The Soviet scientist must not pass by these major events. We are now raising the teachings of Darwinism to grand heights. In this connection the great progress in world science through experiments in genetics must not be underestimated.

Let us turn to practical selection abroad. I shall indicate two important facts. On the basis of genetic research conducted by theorists and not by practical workers in the United States during the last few years, methods were devised for improving the yield of maize by outcrossing. The method was so widely used that in 1938 over 15 million acres of Indian corn were sown by this technique. According to official information received-from the United States Department of Agriculture, this increased the yield by two and one-half million tons. In 1939, the acreage was considerably increased to 25 million acres. In our country about 5 million acres of maize are under cultivation.

The second major practical achievement of selection abroad on the basis of contemporary genetic theory is the discovery, in 1938, of an immune species of wheat in Canada. After one hundred years of effort it is now possible to stop the epidemic of stalk rust which here, in the U.S.S.R., is one of the greatest evils in the culture of spring wheats. Thanks to the immune species discovered by means of the crossing of various species the epidemic has been checked in Canada. The biology of rust is understood, in a significant measure, on the basis of the methods of genetics, which have led to increased understanding of the origins of new races of parasites. This is a novel, highly interesting branch of parasitology, worked out completely on the basis of genetics and cytology. These facts are undeniable. The newly discovered immune species were sown in great quantity last year in Canada, in regions infected with rust. These new species stopped the epidemic and saved millions of tons of grain. Many other examples could be cited from various countries.

The last few years have witnessed the appearance of a great number of important general works and original monographs. After almost a ten year delay, the five volume manual on selection is being published in Germany under the editorship of Romer and Rudorf, summing up Western European practice and theory, and using to a great extent our Soviet experiments. This fundamental manual on selection shows clearly, both in its general discussion and in application to particular crops, the great significance of modern genetic theory in selection. At about the same time, there appeared the Yearbook of the United States Department of Agriculture comprising about 3000 pages in two volumes, devoted to the application of genetics to breeding, both of plants and animals. The very publication of these two volumes is historic. It shows that in the field of agronomy in the United States genetics plays the most active role.

I shall not enumerate a whole series of other publications on selection.

Voice: Could you, Nikolai Ivanovich, give the titles and authors?

Vavilov: "Yearbook of the U. S. Department of Agriculture" for 1936-1937. These volumes are published in huge editions (150,000) and are sent to farmers. Their contents show that the practical Yankees, who have given a great deal of attention to selection, are guided throughout by modern genetic theory. That is an indubitable fact. I do not know a single manual on selection in America or other countries, which does not give three-fourths of its space to genetic theory.

The rapidity of advances in genetics is shown by the fact that general introductions to plant cytology and genetics are obsolete before they appear. The fundamental work of Darlington on genetic cytology, which appeared four to five years ago, has already appeared in a second edition. Sansome's book, Recent Advances in Plant Genetics, published five years ago, was published this year in a second edition. Important works appear nearly every month.

Partly because of our disagreements, we are learning mainly from obsolete works, for example, Sinnott and Dunn, the basic American text book, which is used in our schools in a translation from the 1932 edition. If you open the new American edition of 1939, you would not recognize many chapters. It is a completely new book, quite unlike the one from which we learn in our country.

We can point to a number of new books on genetics, such as Waddington, Sturtevant and Beadle, published this year. I dwell on these facts in order to show the activity in this field.

It is proposed that all this be repudiated. Soviet selection and genetics face a series of contradictions. It is impossible for this reason not to express deep appreciation to the editorial board of the magazine Pod Znamenem Marksizma for convoking this conference. It is hoped that it will dispel the prevailing unhealthy atmosphere.

Our first basic difference is in the interpretation of hereditary and non-hereditary variables. The foundation of contemporary study in selection and genetics appears to be, judging from all past work, the distinction between hereditary and non-hereditary variables, as exemplified in the terms genotype and phenotype, introduced by Johannsen. As the history of selection here and abroad shows, the most important achievements are closely linked with the acceptance of these concepts in the practice of selection.

Svalof selection station has been accepted by the common consent of geneticists and selectionists as the leading selection institution in the world for both theoretical and practical work. The practical results of this station are so important that even in our country, with a climate that differs from that of southern Sweden, we are able to make wide use of such varieties of oats as Victory, Golden Rain, Eagle, and others developed by this station. These varieties cover millions of acres in our country. In connection with the fiftieth anniversary of this station two years ago reports were issued reviewing the great work which it had accomplished and the errors in methods which the station had overcome. You will see from these accounts that at the basis of all practical attainments lies the conception of phenotype and genotype, the differentiation of inherited and non-inherited variations. In an empirical manner, the station succeeded in applying individual selection to self-pollinating plants even before Johannsen. This method is grounded in theory and widely infused into practice since the research of Johannsen.

And now Academician Lysenko appears to tell us that there is no distinction between genotype and phenotype, that it is not fitting to differentiate between hereditary and non-hereditary variables, that modifications are not distinguishable from genetical variations. Furthermore, affairs have gone so far that the People's Commissariat of Agriculture, which follows attentively the developments in science, as is indeed fitting in our country, has decided to change radically the methods of the selection stations, according to the suggestions of Academician Lysenko who believes that the inherited structure of species can be changed by upbringing, by the influence of agro-technical methods. These changes in methods are being carried out at present under obligation in all our stations, although no experimental data whatever has shown the necessity for the departure from concepts experimentally worked out and accepted.

This question is basic to selection, and in order to change the methods of selection of self-pollinating forms, substantial reasons and experiments are needed. These are not as yet in evidence.

Let us pass on to a subject which will be developed, of course, more fully by other speakers, i.e., the chromosome theory. I shall content myself with the statement that the chromosome theory has been in process of elaboration for not less than eighty years. Embryology is based on it. It is founded on a colossal amount of factual material. One can hardly name another branch of biological science which has been so carefully studied. Those who have become acquainted with the chromosome theory are astonished by the quantity of work and its verification on the most diversified material. When I studied in the laboratory of Dr. Morgan, and worked side by side with the most noteworthy representatives of this school, I saw with my own eyes on what truly extensive, and exceedingly precise experimental material the chromosome theory rests.

Great events have occurred in recent years in the application of the chromosome theory to the sphere of remote hybridization of unrelated forms. What greater miracle can we imagine in our biological science, comrades, than we are witnessing in the transformation of completely sterile hybrids into fertile seed and pollen bearers, accompanied by a reduplication of the chromosomes under the influence of specific factors.

Lysenko: Which factors?

Vavilov: Physical and chemical factors of which we know a great number. Particularly we must note the remarkable work of Academician A. A. Shmuk in our country who founded the theory of chemical induction invoking polyploidy in hybrid and non-hybrid forms. Dozens of chemical compounds are available for this purpose. The latest work of Academician Shmuk, who is unfortunately seriously ill at present, showed that one of these substances is colchicine, a readily soluble compound which acts on many diverse kinds of plants. Physical agents, such as temperature, and biological factors, as for example, the incision of plants, may also be effective.

This subject has particular interest, because more than half of all flowering plants are members of polyploid series. There is no doubt that polyploidy has played an important role in evolution. Polyploid induction has thus great practical as well as theoretical significance.

To deny the role of the chromosomes, to attempt tot explain everything in terms of organism as a whole or of the cell, is to set biological science back a century.

The third issue which has aroused sharp and fundamental debate is Mendelism and the phenomena of hybrid inheritance. This matter has already been developed in great detail. I will content myself with asserting, as a plant breeder, that in the field of hybridization of plants reproducing sexually, it is now impossible to conceive of work without applying the laws of Mendel. I. V. Michurin had a somewhat skeptical attitude towards Mendel's generalizations, because he himself worked with fruit trees which are reproduced asexually, making it possible to disregard many phenomena of extreme importance in sexual reproduction. Moreover, Michurin was aware of the complex heterozygous nature of the fruit varieties and species he used. He understood perfectly why it is possible to dispense with the laws of Mendel in the case of vegetatively reproducing fruits. But Michurin paid great attention to the achievements of genetics. I knew him intimately from 1920 on. It fell to me to persuade him of the necessity of preparing for the press the results of his work and to take part in the publication of his work in 1922-23.

I must point out that I. V. Michurin valued modern genetics so highly that he directed his students to your humble servant, i.e., a hundred per cent Mendelian and Morganist, at the Institute of Genetics, and some of his closest students are to a certain extent my students too, whom I infected with Mendelism and Morganism. They are here.

Voice: Are they still your followers?

Vavilov: I spoke at the beginning of my speech about the "mutation process" which has taken place in recent years, and perhaps you will explain the nature of this mutation process and possibly cause me to mutate too. (Laughter.) That is the reason, obviously, why we are here.

At the beginning of my work I too doubted the truth of Mendel's laws. Working at first chiefly on the problem of immunity of plants to infectious diseases, I went to England in order to study in this field under Professor Biffen whose works on the application of Mendelism to immunity were considered classic at that time. However, I came to doubt the Mendelian conclusions of Biffen. In the course of experimental study I became convinced that in many cases physiological properties depend upon many genes, that they cannot be disposed of in terms of simple relationships. But in the course of this work I also became convinced that in many cases simple genetic relations obtained, especially for morphological characters. I satisfied myself of the facts of the Mendelian relationships.

If you assembled a hundred of the most important practical selectionists of Western Europe and America, with great achievements to their credit, beginning with Nilsson-Ehle, Okerman, Rudorf, Romer, and said to them that there is a tendency among us to hold that it is not only necessary to remove Mendel from the list of classics, but also to regard his work as full of harmful generalizations, they would look at you, at the very least, as a very strange person.

I say this in order to show all the depth, all the practical importance of our divergences. All the practical advances connected with the application of hybridization to seeding plants, all the varieties introduced by way of hybridization, were obtained in the last decades by the application of the laws of Mendel. We must consider, of course, that many physiological characters are genetically very complex. We do not always deal with simple relationships. Some simple relationships do exist, for example the black and white color of ears of grain. The relationships are enormously more complicated when we go to physiological characters. If we study such a property as the baking characteristics of flours from different varieties of grain, it is very difficult to deal with it genetically. But even when we work with complex characters we must be guided by the rules established by Mendel, by the theory of polymorphous characters worked out by Nilsson-Ehle.

I go on to the next point. They tell us: "Stop engaging in sex hybridization. Replace sex hybridization by vegetative hybridization. The latter is much simpler."

Lysenko: Who said that and where did he say it?

Vavilov: In recent months I have had the opportunity of visiting a number of selection stations, and have seen how the work on ordinary hybridization was being abandoned, and the workers, especially the young ones, were engaged particularly with grafts.

Voice: At what station?

Vavilov: For example at the Polar Station.

Voice: There they have abandoned it altogether.

Vavilov: Yes, they have stopped occupying themselves with the hybrids of wheat and barley, and changed over to "vegetative hybridization." The only department where sexual hybridization is still applied, is concerned with potatoes.

As a matter of fact, is it not tempting to take the easier path instead of dealing with distributions, with generations, instead of carrying out long calculations and observations? It is simpler that way. Just graft an unstable variety on a stable sort and even on another stable variety, and then go ahead, multiply the scion on which the stock has to act in corresponding fashion.

M. M. Zavadovsky: Each stalk by itself?

Vavilov: Yes, I must say that here and there, this method is proposed.

Lysenko: Who proposes and where? You have not said that.

Vavilov: I said that this is being practiced in a number of stations.

Lysenko: Who proposes it and where?

Vavilov: Obviously, under your influence. It may be that I have misunderstood. If that is so, I should be extremely glad. In any case, it is your influence.

Lysenko: My influence has lasted only a year; yours has lasted more than twenty.

Vavilov: I don't want to speak either of my influence or yours. I have to speak of the modern point of view, supported by enormous Soviet and foreign experience. I consider it my duty to tell of this as a worker who has devoted three decades to plant husbandry. I consider it my duty to describe the situation in order to get a balanced account. What is happening is a serious disagreement not only with Vavilov, but with contemporary developments of biological science.

Prezent: Including Burbank.

Vavilov: Burbank was theoretically weak. I suppose I had better opportunities than others did to study Burbank and his work and his practical achievements. In the field of theory we need not take Burbank into account.

In approaching this question, we must once more keep in mind that we have a great deal of scientific experience in this subject. There are notable works of Winkler, Baur, and in this country, the works of Aseyeva and of Isayev on hydras, notable works which unfortunately are little known, because they were published in full only in English. These works show that even in the special case where the tissues of one form were interlaced with the tissues of another form, where they gave rise to complicated chimaeras, nevertheless the cells of the separate species did not vary their inherited individuality. This is brilliantly shown by experiments. Darwin considered vegetative hybridization to be possible, basing his opinion on some experiments known to him. But we must take into account the time at which these experiments were carried out. Great investigations carried out in the twentieth century have shown that sexual hybridization could not be replaced by vegetative hybridization. The very term of "graft hybrids" has disappeared from scientific literature.

I remember my student years at the Timiryazev Academy, when in a club of scientific amateurs, I had occasion to review Winkler's interesting work entitled "Tale of Gardeners." In this article the history of the study of the so-called graft hybrids was reviewed, which phenomena after all proved to be non-existent.

I am afraid of wearying you. I had occasion to go closely into this question, working on immunity to diseases. There were attempts to vary the immunity by way of "graft hybrids." Unfortunately, they did not give any results.

The physiology of grafts, the action of the scion on the stock and the converse, is another matter. This question evokes great interest. This subject merits investigation. It is possible that new facts of practical importance will be discovered here. We must also take into account the after-effects, including the first sexual generations. In any case, the data of modern experimental physiology do not give us any ground for speaking of the possibility of the equation of sex hybridization to vegetative hybridization.

Let us pass over to the question of hereditary variation. No one among contemporary geneticists and selectionists upholds the unchangeability of the genes. In fact, genetics is the study of the variation of the hereditary nature of organisms. Mutation theory is the basis of genetics, as its history shows. However mistaken were many of the conclusions of De Vries, it is extremely significant that from the very beginning the phenomena of mutation were of the greatest interest to geneticists. As for the cause of mutations, and their production experimentally, that is another matter. It is essential to note that certain of the founders of genetics, for instance, De Vries and Johannsen, were outstanding physiologists. Nevertheless, even these leading physiologists were unable to control the mutation process in their day rowing to experimental difficulties, although this was the primary aim of their experiments. But in contemporary work, it must be admitted that the experimental control of mutation is one of the most important branches of genetics.

The gene, in our opinion, cannot be regarded as absolutely unchangeable, although it remains stable and practically unchangeable over a period of generations. The study of cultivated plants shows that in practice we encounter a definite stability of form. We know that many varieties persist over long periods, sometimes even without further selection or purification. Even Johannsen, the author of the doctrine of pure lines, did not regard them as absolute. He observed the phenomenon of mutation in a series of plants. We may also recall the attitude of selectionists toward this doctrine. Our teacher, Professor Rydzinsky, tried for a number of years to refute the doctrine of Johannsen. In particular, attempts of this kind were made in Germany. Fruwirt, the author of a fundamental guide to selection, for a long time hesitated to accept the doctrine of pure lines among self-pollinators. Consequently, it is noteworthy that in the preface to the new edition of the German handbook under the editorship of the great practical selectionists Rudorf and Romer, published in 1938, they confirm the practical value of the doctrine of Johannsen on the basis of extensive tests of wheat, barley and oats.

I would like to dwell briefly on two matters connected with my own work on evolution in its application to cultivated plants.

Many years ago, on the basis of the study of variation in cultivated plants and of their close wild relatives, I proposed the law of homologous series in hereditary variation which is a development of the position laid down by Darwin in his book Variation of Animals and Plants under Domestication. Having noted the phenomena of the most extensive parallelism in evolution within the limits of species among closely related types and species of cultivated plants, we permitted ourselves to generalize them in the form of a law. The number of parallel hereditary divergences of this sort among related and unrelated species, especially among the first, is very great and each year opens up thousands of new facts.

The nature of this homologous variation consists, as I see it, primarily of a kinship of the genetic structure of closely related species and types. Likewise, it is the result of the activity of the environment of selection in a definite direction under definite conditions. In recent years we have observed a large number of instances of parallelism of ecological variation. We are not giving up and cannot give up this conception, for millions of facts attest to the prevalence of these phenomena. To ignore them is sheer blindness. A systematic as well as ecologic geographic study of cultivated plants leads us to recognize the great significance of this class of phenomena, which is not at all contradictory to phenomena of differentiation and divergence of species. These phenomena indicate a definite parallelism in the evolution of types which often possesses great practical significance. On the basis of this law I proceeded in recent years to study physiological characters and learned to find, in predictable regions, analogous forms for which we were searching.

We are accused of attempting to fit the phenomena of variation into some sort of Procrustean bed. This accusation appears to us to have no factual basis. On the contrary, our theories have led us to discover a great number of new forms involving both physiological and morphological characteristics.

On the basis of our researches on the evolution of cultivated plants we have come in our day to the geographical theory of origin, to the notion of original species-forming regions of cultivated plants. We stand on that conception which appears to us to be purely Darwinian, for Darwin himself considered the facts of geographical localization of centers of origin of species as a fundamental biological law, and rye only apply it in relation to cultivated plants.

Summing up the findings on the immense amount of new material, in part still unpublished, we may say that, in actual fact, there are regions in which the process of species formation is particularly developed. The majority of formed species, among them cultivated plants, have not gone beyond the borders of the region of their origin. This is well shown in the case of wheat and rye here in the Caucasus, where recently a large number of endemic species have been discovered.

In developing the teaching of Darwin concerning the centers of origin of species of cultivated plants, we discovered a large number of new species particularly in primary regions. However, we do not wish to imply that species could not arise on the periphery, in secondary localities. On the contrary, we pay a great deal of attention to these secondary localities, and in the case of the most important cultivated plants we were able to establish extremely important secondary regions of species formation of cultivated plants. The authenticity of these findings compels every botanist and zoologist to reckon with the localities of origin and settlements of plant and animal species. Our opponents, while claiming to be consistent Darwinists, are, as it appears to us, in full opposition to Darwin. They try, with very little plausibility, to refute the role of fundamental regions of species formation, in essence a fundamental phase of evolution.

We have, of course, other differences. I have dwelt on the most important. The opposing point of view is in contradiction not only with a group of Soviet geneticists but with all modern biological science. I repeat that I do not know of one manual in genetics and selection which would support the views propounded by the school of Academician Lysenko. A peculiarity of our differences is also that under the name of progressive science it is suggested that we return, in essence, to views which science has outgrown, that is, to views current in the middle of the nineteenth century.

In order to do away with the anomalies which exist in the development of genetic science and the theory of selection in our country, I should like to propose, along with the widely distributed organ Vernalization:

(1) The publication of another organ, which would print genetic works, not merely of a narrowly specialized character which we now print only in abbreviated form, in the News and Reports of the Academy, but also general articles, which could critically report on diverse views including those opposed to the ideas which are currently popular.

(2) That the publishing house prepare and publish translations of the best foreign general works on selection and genetics. We are often obliged to use translated manuals ten years behind the times.

(3) That conferences and sessions be called devoted to questions of genetics and selection, in order that various points of view may be aired.

(4) That since the solution of many disputed questions is attainable only by means of direct experiment, it is necessary to facilitate the fullest experimental work, including, of course, that based on conflicting points of view.

(5) And finally the last thing that I feel it my duty to stress as a scientific worker in the land of the Soviets, is the necessity of the introduction into the practice of selection only of tested and verified scientific experiments, of fully proved results. In order to introduce them into production, we need a scientific, exact test of proposed measures.