296 Sammelreferate

SOME INTRACELLULAR ASPECTS OF LIFE AND DISEASE

By JEROME ALEXANDER

Received for publication, June 5, 1931

Beginning with such grosser visible domains as taxonomy and anatomy, biologists and physicians have worked progressively downward through the microscopic zone, until their advance guards, the cytologists and bacterio- logists, reached the threshold of microscopic resolvability. Meanwhile chemists and physicists had been working upward from the simpler atomic and mole- cular groups to larger and still larger aggregates. The ultramicroscope, by bringing into visibility particles within the intervening colloidal range, bridged the gap between the two groups of investigators who had been tunnelling towards each other, and definitely removed any area which might serve as a limbo for baffled theories, or as a refuge for vital forces or enteleehies. How- ever difficult the task, it became obvious tha t many, if not all of the mysteries of life and disease must be sought in the complicated interrelations of discrete particles; for a clear continuity is evident between the particulate units of biology (organisms, cells, chromosomes, etc.) which can be actually seen, and the still smaller particulate units of physics and chemistry (molecules, atoms, electrons), whose real existence we admit under HERBERT SPEC~CER'S criterion - - the contrary view (i. e., tha t no physical reality underlies phenomena) is unthinkable.

As science advanced, it became increasingly evident tha t although innumerable problems in biology and medicine were to some degree compre- hensible on the basis of visible, microscopical, or chemical phenomena, the newly cultivated field of "neglected dimensions", as WOLFGANO Os'rWALD called it, held many of the hidden facts of life, health, and disease. "Colloids" became a term to conjure with, and, unfortunately, a screen for loose thinking and for ignorance.

Especial praise is due to the geneticists, whose painstaking researches demonstrated that the t iny chromosomes, which lie toward the lower limits of microscopic resolvability, contain immense numbers of ultramicroscopic but highly specific units (genes), which have the power of self-duplication, and whose presence dominates the future of the living unit (biont) and its progeny. I t is, indeed, reasonable to maintain that genes, and perhaps other

Sammelreferate 297

units which may prove to have like properties (e. g. mitochondria), may, at least in a limited sense, be considered as the only truly living things in any organism, the remaining material representing merely the highly specific milieu in which they function. Thus the water in the body, the free fat, carbohydrate, protein and salt meleeules, are not alive per se, and apparently differ in no way from similar molecules made by the processes of synthetic chemistry, or found naturally in nonliving aggregates. Comparison between the behaviors of genes and catalysts (especially enzymes), indicates that the essential difference between them is this-- the living gene can duplicate itself, but the nonliving catalyst cannot 1.

Enzymes are eat~alysts incapable of self-duplication, whose production in the cell is dominated directly or indirectly by the genes or other living cellular units. With the self-reproducing genes, enzymes share the following general properties common to all catalysts:

1. High degree of specificity. 2. Activity modified or destroyed by chemical or physical alteration: 3. Active areas not microseopicMly resolvable. 4. Activity shows thermal optimum varying with the catalyst. 5. Promotors exist; also inhibitors or depressors. 6. Igeversible and irreversible "poisoning". 7. pH of the milieu influences activity.

Recent research indicates that the activity of catalysts is due mainly to certain specific areas, where the outwardly directed free fields of force, or residual electronic valencies, form an electronic mosaic whose specificity depends not merely on the ultimate chemical analysis of that particular portion of the surface, but also on the structural arrangement of the atoms, ions, or molecules there ~. Surface catalysis may be envisaged as a direction and/or acceleration of chemical change (synthetic or analytic) due essentially to molecular or atomic distortion by the highly specific outwardly directed electronic fields of force of the catalyst. Any change in the nature of the milieu or dispersion medium, e. g. changes in the solvent itself, or in H or other ion concentration, will generally register an effect not only on the electronic configuration of the catalyst, but also on the molecular units coming within its electronic jurisdiction.

1 An enzyme particle which could duplicate itself would have to be considered as a living unit. See ALEXANDER and BRIDGES, in "Colloid Chemistry, Theoretical and Applied", Vol. II.

2 Thus it is possible that the activation of ergosterol upon irradiation is due to specific displacements of its atomic arrangement, and that its new electronic confi- guration permits it to function as a catalyst or else to be fixed by some nerve or endo- crine-producing cell, so that it may produce results quite out of proportion to its mass.

2 9 8 8ammelreferate

Temperature changes affect both the nature of the catalyst surface fields and the ease of atomic or molecular distortion in the material acted upon by the catalyst. Within relatively narrow temperature ranges these influences are generally submerged in a more important effect, the consequence of thermal agitation. At a certain temperature, which varies with the catalyst, the reactants and the conditions, the beneficial effects of increased thermal agitation, which are due largely to increase in the number of successful mole- cular presentations per unit time at the active catalyst area, are overbalanced by decrease in the number of successful presentations. This decrease is con- sequent upon the fact that, with increase in temperature, increasing numbers of presenting particles exceed the critical kinetic velocity beyond which re- actants are under the electrostatic domination of the catalyst for a period of time insufficient to distort and direct them into a lasting chemical trans- formation. This is a major factor in the thermal optimum. Besides the other two factors mentioned above, decomposition or re-combination of the end products may become dominant, especially where temperatures run high and the end products cannot be immediately removed from the reaction zone to stable conditions. In some cases this instability of the products of catalysis may also fix a thermal optimum.

Gone forever is the concept of atoms as incompressible little balls and of molecules as groups of these. Today we are compelled to regard both atom and molecule as vibrant, sensitive, electronic complexes, subject to distortions of many kinds. One of the ways in which an active catalyst area may undergo modification, is by the introduction of a new atom, molecule, or other particle into the surface within or adjacent to the active area, so that the free elec- tronic fields of the new particle may influence the fields already existing there. If the new substance effects changes that accelerate the catalytic process, it is known as a promotor. Promotors may work singly or in groups.

If the active catalyst areas are completely covered or occluded by particles (adsorbed or chemically bound) which maintain their positions, catalysis ceases. If the inhibiting particles cannot be dis]odged under existing conditions, we say the catalyst is "poisoned"; e. g. platinum used to catalyse the reaction SO 2 d- 0 = SOs is poisoned by arsenic, but V~O 5 used for the same purpose is not poisoned by arsenic. If the modifying or masking par- ticles may be dislodged without ruining the catalyst, the "poisoning" is reversible. In some cases adsorption by the catalyst of specific particles from the milieu may suppress undesirable alternative reactions, giving what is known as "beneficial poisoning". High concentrations of particles which the catalyst can adsorb slightly or not at all, may by their mere presence inhibit or greatly slow down normal catalytic action. Anesthesia and narcosis seem to involve reversible cellular catalyst inhibitions, which become lethal only if irreversible changes follow.

Sammelreferate 299

Reviewing the whole question of enzymes; especially in the light of the researches of W. M. BAYLISS, a . WILLSTATTER, A. FODOR, O. WARBURG and others, it would seem tha t enzymes may consist of at least two part iculate units, first, the carrier, generally present in larger amount , and second, the active substance, stabilized by and held in active orientation by the carrier. As the former is refined away beyond a certain limit, the lat ter m a y lose in activity, so tha t efforts to produce a " p u r e " enzyme substance have ge- nerally failed. J . H . NORTnRUP has reported the product ion of crystalline pepsin and trypsin. I t is quite possible tha t a definite crystallizible individual may be a catalyst , and even an enzyme. The "ca r r i e r " may simply hold such particles in an efficient position or orientation.

But in view of what is s tated above, it is likely that , in m a n y cases at least, both the carrier and the active substance (or substances) take par t in producing the specific fields of force to which the enzyme owes its activity. Thus neither a feather, a shaft, nor an arrow-head is an arrow; but the three, when properly coupled together, make an arrow and function as an arrow. We m a y conceive WARB~:~G'S oxidation ferment to consist of an iron-containing compound held in, and perhaps act ivated by, an organic carrierL

The fact that enzymes consist largely of organic matter, which is much more readily distorted than are metals and most inorganic catalysts, means tha t enzymes are relatively sensitive to physical agencies (e. g. heat) and chemical action (e. g. salts, acids, alkalis). Considering the genes as enzyme- like catalysts capable of self-duplication, we see that , apar t from their self- duplication, they dominate, by their catalytic control of chemical changes, what is to happen in their neighborhood. Normal functioning of a gene de- mands tha t its milieu contain an adequate supply of the " r a w mater ia ls" needed for these catalyzed reactions and also for genic self-duplication, and fur thermore tha t the supply of its " r a w mater ia ls" and the removal of meta- bolic products proceed at suitable rates of speed. While it is quite conceivable tha t there m a y be living entities (bionts) which consist of but one gene, and even t h a t a gene m a y be a single molecule, in practically all cases we are confronted with large groups or strings of genes, e. g. in the chromosomes of individual cells. The question natural ly arises as to what influence each

1 I t is curious to see the various directions in which nature has developed oxidizing enzymes or oxygen carriers. Thus with the higher animals the iron-containing hemo- globins are the active compounds; with the Crustacea, hemocyanin, a copper-containing compound; with the ascidian Phall~tsia, a vanadium-containing compound; with mussels, the manganese-containing pinnaglobin. Chlorophyll, an important plant catalyst, contains magnesium as an essential constituent, although the presence of iron seems necessary for the formation of chlorophyll.

300 Sammelreferate

gene exerts on the catalytic power of its neighbors. The existence of "pro- motors" in the case of enzymes is known, but is obscure. Thus small amounts of asparagin activate diastase (Effront).

The view is here advanced that genes, like other catalysts, are subject to modifications. This is something quite different from mutation, even though the tendency to become modified may result from a mutation and thus be trans- mitted to descendants. Mutation involves a change in one or more genes, capable of hereditary transmission. By modification, we understand the fixation, at an active catalytic area of a gent or other catalyst unit, of some par- ticle (electron, ion, atom, molecule, or colloid particle) which changes either the ~utture and/or rate of the catalysis occurring there, without, however, in any way affecting the nature of the new gene formed by self-duplication. The effect on catalytic activity of the gene is quite similar to the introduction of a "promotor" (or a "depressor") in an inorganic catalyst, but is appa- rently effected more readily, because of the complexity and ready "distor- tabili ty" of the gene, which has the plasticity of an enzyme rather than the "stiffness" of an inorganic catalyst. It is quite possible that enzymes may also be modified within a cell, and this may lead to catalytic variations analogous to those consequent on gene modification, though of more transient character, unless there were a steady supply of modifying particles.

Genes occupy the inmost citadel of life. To modify them, molecules or other particles must be present in sufficientnumbers and/or must possess such diffusive mobility and specificity that they can (1), penetrate the mem- brane-like cell wall or interface between the cell and the milieu; (2), run the gauntlet of the cytoplasm, with its enzymes, mitochondria, vacuoles, etc. ; (3), penetrate the layers of the chromosome, including its interfaeial wall, and reach the gene within the ehromonema; (4), be fixed, reversibly or irrever- sibly, by some gene. What is said of the genes may be applied with equal force to mitoehondria; for whether these be symbionts or cytoplasmic in- clusions, they apparently reproduce and are efficient in directing chemical changes within the cell (either directly or through enzyme formation), and behave somewhat as if they are free living genes or gene groups.

The stability of genes and the efficiency of the protections surrounding them, are evidenced by the regular and orderly sequences normal to life, which show that gene mutations are quite rare, and abnormal gene modi- fications unusual. Since viable gene mutations are transmitted by heredity, they are basic factors in evolution; for beneficial mutations tend to survive and dominate, whereas harmful ones tend to die out. If mutation makes a gene more susceptible to an abnormal modification, that is one method whereby the effect of the mutation may become evident.

Let us consider some aspects of normal life and of abnormal life (disease) in view of the principles outlined above.

Sammelreferate 301

D I F F E R E N T I A T I O N OF CELLS AND TISSUES

Embryology confronts us with the astounding fact that from a single zygote, a fertilized cell resulting from the union of a male with a female gamete, there gradually emerge the most diverse kinds of cells, tissues, organs, and bodily structures. With surprising precision the developing zygote repeats the essential transformations leading to the completed organism the possibility of whose formation was foreordained by the genes and cyto- plasmic inclusions transferred to the zygote by the parents.

Considering the progressive division of the original cell to form the blastula and then the morula, it is evident that, as the clone 1 of cells increases, a marked difference must develop between the exterior cells and those on the inside of the clone. The exterior cells have first call on needed material from the milieu, and their reaction products can readily diffuse away. This means that the exterior cell layer tends to reproduce more rapidly; and since the cells cohere, the more rapid duplication of the outside layer would tend to express itself in an invagination of the morula to form the gastrula. Within the gastrula cavity a new type of surface develops, with concentrations of reactants and reaction products quite different from those of the milieu.

As the clone of cells increases in size, differential diffusion appears as another factor of importance. Ions, molecules, and colloidal particles differ greatly in diffusive mobility, and the consequent differences in ionic concentrations which may be inappreciable or ineffective when the clone is very small, may become marked throughout the clone as it becomes larger. The gastrula cavity, when it forms, enforces a new complication of surface, diffusion, and concentration conditions.

Concentration variations will affect not only the structure of interfaces and septa, the degree of dispersion (and therefore the kinetic mobility) of particles and the rate of catalytic activity, but they may also lead to the emergence of suppressed or alternatively possible catalyses, with the result that effective quantities of new substances are formed. Fixation of these or of other substances from the milieu could readily lead to gene or enzyme modification, with a result that entirely new types of catalyses would appear, and develop further new substances. Once the formation of a modifying substance is established in a cell, the tendency would be for the progeny of that cell to be affected in like manner (especially if the "modifying" ma- terial does not readily diffuse away). Cytoplasmic inclusions may include modifiers. On this basis the development of organs and of other structures composed of differentiated cells is comprehensible.

1 The term clone (also spelled clon) is derived from the Greek klon, meaning twig, apparently also the origin of the Gaelic word clan*~. It indicates a cluster of cells des- cended from a common progenitor.

302 Sammelreferate

BACTERIAL DISSOCIATION

The change of the lZ (rough) forms of e.g. tubercular bacilli to the S (smooth) forms, and vice versa, appears to involve reversible gene modification, the new strain, sometimes tending to continue when once established, but being generally convertible into the original form. Perhaps a careful check on the variations in the minor products of yeasts, bacteria, etc. grown under different conditions may give some insight into the possibilities of gene modi- fication. The " t ra in ing" of bacteria, e. g. by SCHOEN, DUBOS, and others, is along similar lines.

IMMUNOLOGY

Immunological specificity, like all other kinds of chemical specificity, is consequent on the outwardly directed electronic fields of the units involved in precipitation, agglutination, lysis, etc. The minimum sensitizing dose of egg albumin approximates 0-000"05 milligram; and in general the minute quantities of antigens demonstrable by immunological methods cannot be detected by any other known method. How shall we account for the potent effects of such incredibly minute quantities, and also for the fact that if an animal be bled, the temporary drop in the titer of antibodies in the remaining blood is retrieved and even surpassed ? Furthermore, the blood of a non- sensitized animal may be used to replace the blood of a sensitized animal, without impairing the sensitivity of the animal or of its isolated tissues.

These facts point to the formation, within the cells themselves, of new specific catalysts which are able to direct the formation of antibodies. Three possibilities present themselves as the method whereby specific antigens produce specific catalysts which in turn determine specific antibody formation : 1. modification of a gene; 2. modification of a non-genic catalyst ; 3. fixation of the antigen particle by a non-catalyst cytoplasmic particle in such a manner that the combiuation functions as a specific catalyst. Nature may utilize any or all of these methods, and perhaps others unthought of at present.

All three of these possibilities involve the idea that the antigen becomes an essential part of the directive surface of a catalyst particle, which would tend to determine the formation of particle groups having essentially a reverse of the electrostatic charge pattern of the active catalyst surface and therefore of the antigen, or else of particle groups which can acquire essentially such a reverse pattern when they are detached and removed to some other part of the organism. Changes in hydrogen ion or other ion concentration might readily account for such detachment and changes, which could be in the nature of an electroversion. In its simplest form this concept may be illus- trated by the following diagrams 1, wherein positively charged areas are repre-

Sammelreferate 303

sented as depressions below, and negatively charged areas as elevations above, the dotted line representing neutrality.

;iiiii :::/ i; i ilii ..... Active "antigen area" in modified

catalyst.

. . . . .

"?" ??i ?:.'i":.'i~'~ ?::i ??~ ??~i'?i~'??i ??i-'?.:i~'i ?;'ii~'~ i'?i ??*i'[.~ Oppositely changed area in antibody

formed by modified catalyst.

The applicability of EMIL FlSCHE~'S well-known analogy of lock and key, which he applied to the fitting of enzyme to substrate, is at once manifest. That such an antibody particle would tend to unite with particles of its specific antigen, seems obvious; and the neutral units would tend to flocculate if conditions would permit - - presence of precipitating ions, absence of colloidal protectors. Twenty years ago the author with Dr. J . G. M. BUI,LOWA ob- served the specific mutual congulation of antigens and antibodies in the ultramicroscope (diphtheria and tetanua).

The effectiveness and lasting effect of minute quantities of antigens becomes comprehensible on the basis of this view, for in theory at least, one single molecule or colloidal particle would be sufficient to convert a cell or an extracellular catalyst into a potential producer of a specific antibody. Furthermore, there is no reason why large numbers of different antigens may not simultaneously or successively affect the same cell with its many thousands of genes and other catalyst particles - - which corresponds to the experimental facts. As long as the antigen-catalyst complex continues to function to produce the specific antibody, so long will the production of immune bodies continue, despite bleeding. Variations in the duration of immunity would correspond to variations in the persistence of the antigen- catalyst complex, while inability to establish immunity would indicate the non-formation of such a complex (or destruction of the antibody). All these phenomena appear in "vaccinations", a general term indicating introduction of antigens with the hope that immunity will result.

Without at tempting to discuss here the EItaLIC~ theory and the views of its earlier critics (e. g. ARRHE~IVS, BORDET), it may be noted tha t the ideas above expressed introduce the basis of specificity into the so-called "colloid" views regarding immunity. Colloid particl.es or molecular aggre- gates which are cast into or moulded against a specific surface, must have their adjacent areas determined by the mould. A specific mould, once formed, could function continuously in forming such antibody particles, until irre- versibly injured.

1 The actual fields of force extend in three dimensioas.

30~ Sammelreferate

W. H. MANWARING 1, in a recent cr i t ique of the EttRLICg theory , outl ines an enzyme theory of a n t i b o d y format ion, wherein he envisages two main processes: f irst , ex t race l lu lar und in t raee] lu lar cleavages) whereby the ant igen is b roken into s impler components ; second, chemical syntheses, coagulat ions, conjugat ions, adsorpt ions , etc. be tween the ini t ia l an t igen or i ts cleavage products , and normal or dena tu red ext race l lu lar or in t race l lu lar proteins.

The view here advanced is much s impler and in accord wi th genetic da ta . I t appears to reconcile m a n y of the conflicts between the " c h e m i c a l " , the " c o l l o i d " and the "enzyme" theories of immuni ty .

CANCEI~

This disease, or r a the r group of diseases, in the absence of et iological knowledge, is descr ibed on a pa thologica l basis as follows: A growth of cells of the body, which is progressive and invades hea l thy tissue.

A b o u t six years ago genetic considerat ions led me to believe t h a t if any body cell underwent a m u t a t i o n of such a na tu re t h a t the new cellular uni t had an abnorma l ly high reproduc t ive veloci ty , there would t end to develop wi th in the organism a large clone of cells of ever- increasing size, often wi thou t adequa te vascular supply. Such a neoplasm would t end to present any or all of the clinical aspects of c a n c e r - - t u m o r , u lcera t ive break- down~ metas tases , etc. I n fact , as far back as 1902 BOVEm 2 suggested t h a t cancer might be due to genetic factors. Fo r over five years pas t I have freely discussed this view of cancer wi th medical and o ther scientific friends, wi thou t being able to f ind any evidence which would nega t ive the idea t h a t cancers are due mut inous or m u t a n t cells. The following brief s t a t emen t was in- c luded in a sect ion S ent i t led " S o m e Colloid Chemical Aspects of Life, Muta t ion , and E v o l u t i o n " , which was based on a paper of the same t i t le by ALnXA~DnR & BRIDGES4 :

" T h e cancer cell m a y be considered as a t y p e of evil mu ta n t , which, being formed or ac t iva t ed in a larger organism, dupl ica tes i tself specifically wi th in i ts host , wi th des t ruc t ive consequences. This view harmonizes wi th the fact there are several different k inds of cancers, as well as the evidence

1 See "The Newer Knowledge of Bacteriology and Immunology", edited by JORDAN and FALK (University of Chicago Press, 1928).

,,Zur Frage der Entstehung Maligner Tumoren." Tm BOVERI (Jena 1914). a "Colloid Chemistry", page 231, by JEROME ALEXANDER, 3rd ed. 1929 D. Van

Nostrand Co. Science for Oct. 4th, 1930, 72, 425, prints a similar view by R. S. and R. P. Me Combs.

a Chapter I "Colloid Chemistry, Theoretical & Applied", Vol. II , Biology and Medicine, edited by JEROME ALEXANDER, Chemical Catalog Co., 1928. See also Science, 1929, 19, 508.

Sammelreferate 305

that a eancer-mntant may be produced or ac t ivated by several different types of proximate causes, especially by those which produce gene-mutation - - X-rays, heat, and chemical substances (certain tars). Since cancer cells reproduce true to type, even when transplanted, genie changes are evidently involved".

Work of Dr. ~FLOI~ENCE R. SABIN and collaborators 1 on the activity of various fractions of the tubercule bacillus, show that certain of the fat ty acids in the lipin fraction are responsible for tubercule formation, the tuber- cules showing polynuclear giant cells which had evidently arisen from a single epithelioid cell. Although the chromosomes had undergone some kind of division, thus yielding increased nuclear material, the cell as a whole was unable to undergo cytoplasmic division. Here, the foreign molecules had apparently prevented the completion of cell-division; but we cannot tell whether this is due to fixation of these highly polar molecules at catalyst, or at other interfaces. In the cancer cell, however, cell-division carries through ; but the chemical and physico-chemical processes involved occur at a super- normal rate, the net result being more rapid reproduction of the cells. The nature of these processes also seems to differ qualitatively, to some extent, from those in normal cells.

By formation of a cancer-mutant, we understand that one or more genes in a normal cell undergo a mutation transmissible on cleavage. Acti- vation of a cancer-mutant may be understood from the following conside- rations: Suppose that somewhere along the line of descent of the organism there had occurred a mutation in a gamete, leading to transmission of an heredity tendency toward gene-modification. The descendants of this parent would not inherit the modification: but might inherit a tendency toward modification, which would come into evidence only i f and when the modifying particles were present. Thus persons with an inherited tendency to rag-weed hay fever would not even know it, if they were born and lived in countries free of rag-weed and its pollen. I t is conceivable that an ultrafiltrable virus or even specific molecules may cause modifications in receptive genes; and if the modified genes would catalyze the formation of the modifying substance, continuous development of modified cells would ensue. In cases where normal organisms seem to be susceptible (e. g. as in tar-cancers), it is not even necessary to assume the existence of an inherited abnormal tendency to modification.

A third possible cause of increased rate of cell division might be an upset in the normal balance of genie catalytic activity, consequent on changes in the milieu. These milieu changes may be brought about by deviations from the normal rate of supply of essential ingredients, which in turn might

1 Z. of Exper. Medicine, Dec. 1930, Vol. 52, No. 6, papers by F. R. SABIN and C. A. DoA~-.

Protoplasma. XIV 20

306 Sammelreferate

be consequent on changes in circulatory or diffusion balance, or to abnormal increase or decrease in the formation of these essential ingredients within the organism.

These milieu changes may even indirectly lead to local gene or other catalyst modification; thus, for example, an altered p H might permit the formation of and/or the fixation of a modifying substance. Chronic irritations, well known to be a cause of cancers, may operate by affecting the milieu, as just stated, b y determining the formation of a modifying substance, or pos- sibly by the irritating substance itself effecting modification.

Any one or any combination of these three factors would be sufficient to determine abnormal increase in speed of cell division within a limited area, with the incidence of the clinical symptoms of cancer.

The a t tempt has here been made to bring together and to reconcile certain biological, medical and chemical aspects of life and disease, with the hope tha t workers in various fields will realize tha t the t ruth about such phenomena involves a series of physical size-levels, and that to understand the whole t ruth we must focus our mental microscopes progressively on lower and lower levels, until we have envisaged each one and traced its relations to the rest.

Specialists who never leave a narrow field lose breadth of view, to say the least, however vital their work. New facts and experiments are the life- blood of science; but while opposing a moratorium on experimental work recently suggested by a British divine, we should heed the warning of H. E. ARMSTRONG {Chem. & Ind., Sept. 19th, 1930, p. 784), that we do little to remove the sting of LIEBm'S remark to WSnLl~: ,,An Versuchen und Tat- sachen ist kein Mangel, aber an Verst/~ndnis derselben!"