the mass of one set of isolated leaves is reduced by cutting out pieces from their center while their isolated sister leaves remain intact the mass of shoots produced by the two sets of sister leaves varies approximately in proportion with the mass of the leaves."

If it is true that the geotropic bending of a horizontally placed stem depends upon the mass of material furnished to the stem by the leaf we should expect that a reduction of the mass of the leaf would correspondingly retard the rate of geotropic bending in the stem. The writer has recently carried out such experiments and they corroborate this expectation. If two sets of stems of equal length are suspended in an aquarium, each with one leaf attached to its apical end, and if the size of the leaf is reduced in one set by cutting away pieces of the leaf, the geotropic bending takes place the more slowly the smaller the mass of the leaf. It is difficult to conceive of a more striking experiment. When the mass of the leaf is reduced to zero, the bending is extremely slow.

4. These experiments suggest that the growth of the cells of a horizontally placed stem which gives rise to the geotropic bending is accelerated by substances furnished to the stem by an apical leaf; and that these substances might be the same as those which serve for the formation of roots and shoots in the isolated leaf. If this were true, a leaf attached to a piece of stem should form a smaller mass of shoots and roots than its sister leaf entirely detached from the stem, since in the former part of the material available for shoot formation should go into the stem.

It has been known for some time that a piece of stem inhibits the shoot formation in a leaf of Bryophyllum calycinum, but this inhibition was attributed by former writers to an influence of roots formed on such a piece of stem. By suitable experiments it can be shown, however, that the inhibition takes place also when no roots are formed on the stem.

It seemed to the writer that the inhibiting influence of the stem on the shoot production

3 Loeb, J., SCIENCE, 1917, XLV., 436; Bot. Gazette, 1917 (in print).

in the leaf was due, as stated, to the absorption of material from the leaf by the stem which would have served for the growth of roots and shoots in the leaf if the latter had been detached from the stem; and that the material flowing from the leaf into the stem was causing the growth of the cells in the lower side of a horizontally placed stem, thereby giving rise to the geotropic bending of the stem (and incidentally also to the callus formation at the base of the stem). If this were true there should exist a simple quantitative relation between the inhibiting power of the stem upon shoot formation in a leaf and the increase in the mass of the stem; namely, the two quantities should be approximately equal. The writer has carried out such experiments in large numbers and found that this relation holds true, namely that a piece of stem attached to a leaf increases its weight by approximately the same amount by which the shoot production in the leaf is diminished. For these experiments the following method was adopted.

5. A piece from the stem of Bryophyllum, containing one node with its two leaves, is cut out from a plant and the stem split longitudinally in the middle between the two leaves, leaving one half of the stem attached to each leaf. The half stem is removed from one leaf and weighed directly. The leaf whose half stem is cut off and the leaf with a half stem still attached to it serve for the experiment. After several weeks the amount of shoots in both leaves is determined by weight and it is found that the leaf without stem had produced a larger mass of shoots than the leaf with a piece of stem attached. The latter is then removed from the leaf and weighed. It is invariably found that it has increased in weight and that this increase approximately equals the diminution in the mass of shoots in the leaf under the influence of the stem. The following may serve as an example.

Three sets of experiments were made simultaneously on 6, 7 and 7 pairs of sister leaves prepared in the way described above; one leaf was without stem and the other with one half of the split stem. The three experiments dif

leaves without and with stems the inhibiting action of the stem. This quantity should equal approximately the sum of the mass of shoots produced in the axil of the leaf attached to the stem plus the increase in weight of the stem attached to the leaf during the duration of the experiment. The ratio of the two values should therefore approximately equal 1 (Table I.).

The experiments show that within the limit of error the mass of the stem increased in such a way as to approximately equal the inhibiting effect of the stem on shoot production in the notches of the leaf. The mass of roots produced in the leaves is neglected since it is small compared with the mass of stems.

27.898 grams of shoots and the leaves with stems 9.797 grams. The inhibiting action of the stems, i. e., the difference in shoot production between the leaves without stems and their sister leaves with stems was therefore 18.101 grams. According to our theory the weight of the stems which were left attached to the leaves should have increased by the same amount. The actual increase in the weight of the half stems attached to the one set of leaves was in the same time 16.695 grams. This includes the increase due to shoot production in the axil of the leaf, which was slight, amounting in all to less than 1.5 grams. The two values, 18.101 and 16.695 differ by 8.5 per cent.

It seems, therefore, probable that the inhibiting effect of the stem upon the mass of shoots produced in the leaves is due to the absorption of a corresponding quantity of material from the leaves by the stem.

6. Summary and Conclusions.-(1) The writer had shown in a former note that the mass of shoots produced in isolated sister leaves of Bryophyllum calycinum is in direct proportion to the masses of the leaves and that this remains true if the mass of one leaf is reduced by cutting out pieces from the center of the leaf, while the sister leaf remains intact. In this paper it is shown that the rate of geotropic bending of horizontally placed stems of Bryophyllum calycium, if one apical leaf is attached to the stem, occurs at a rate increasing with the mass of the leaf. When the mass of the leaf is diminished by cutting away pieces the rate of geotropic bending is diminished also.

(2) It had been known for a long time that when a piece of stem is attached to a leaf of Bryophyllum calycinum the shoot production in the latter is diminished or completely inhibited. It is shown in this paper that the mass of a piece of stem attached to a leaf increases by approximately the same amount by which the shoot production in the leaf is diminished through the influence of the stem. The inference is drawn that the inhibiting effect of the stem upon shoot production in the leaf is due to the fact that the same material which would have been available for shoot production in the leaf, had the latter been detached from the stem, is now absorbed by the stem.

(3) This material gives rise in the stem to callus formation and to that growth of certain cells of the cortex which causes the geotropic bending; and if the buds of the stem are not removed it causes also shoot production on the stem. The comparatively large masses involved indicate that this material must consist chiefly of the common material required for growth, i. e., water, sugars, amino acids, salts; but the accessory substances and the hypothetical specific organ-forming substances of Sachs may be included in this mass;

and this is suggested by the fact that on the lower side of a horizontally placed stem, roots grow out, while shoots grow out from the upper side. There must, therefore, be associated with the material which causes geotropic bending also something which favors the growth of roots and this may be one of the hypothetical substances of Sachs.

(4) These facts give a simple explanation of the "resourcefulness" of the organism referred to in the beginning of this paper, namely that plants may restore their lost apex either by the growth of the hitherto dormant buds near the wound or by a geotropic bending of former horizontal branches next to the wound (fir trees). Our experiments suggest that the cause is the same in both cases, namely, a mass action of the nutritive, and possibly also of some specific substances, upon the cells of dormant buds or upon the cells of the lower side of horizontal branches which leads to a rapid synthesis and growth in these cells. Without the removal of the old apex this growth would not have taken place, for the simple reason that the nutritive material would have had no chance to collect near the wound in masses sufficient for the growth.

(5) The phenomena of geotropism thus turn out to be phenomena of mass action, probably of the common nutritive material circulating in the sap and they are apparently of the same nature as the growth of dormant buds, which is also due to a mass action of the same substances. Gravity need play only a passive rôle, allowing masses of liquids to "seek their level." In the literature of geotropism this phenomenon is treated as a case of "stimulation," but this treatment misses the essential point, namely, the chemical mass action involved, and it substitutes a fictitious factor, the "stimulus" of gravitation, which in all probability does not exist. The case is similar to that of heliotropism when the orientation of animals to light is treated as a "reaction to a stimulus" instead of as an instance of the photochemical law of Bunsen and Roscoe.

JACQUES LOEB

THE ROCKEFELLER INSTITUTE FOR

MEDICAL RESEARCH

THE AMERICAN CHEMICAL SOCIETY

II

ORGANIC DIVISION

J. R. Bailey, Chairman

H. L. Fisher, Secretary

Some oxidation reactions: H. D. GIBBS and C. CONOVER. The investigation of the cause of coloration of some compounds begun some years ago by the writers while in the tropics was described. Since all of the reactions which were encountered were catalyzed by light, the studies were greatly facilitated by the intense sunlight of the tropics. These investigations are now being extended to other catalytic reactions which promise some commercial importance.

The action of aluminum chloride upon aromatic hydrocarbons: GUSTAV EGLOFF and ROBERT J. MOORE. Benzene, toluene, xylene, cumene and cymene were distilled over a period of twenty-four hours with ten per cent. by weight, of aluminum chloride in order to determine the percentage yields of reaction products. The results in terms of percentages, were as follows:

The naphthene formed during the above reactions proved to be hexahydrotoluene. Traces of phenol were noticed in all the reactions, the toluene, in particular, yielding one per cent.

A study of the nitrogen distribution in different soil types: C. A. MORROW. The study was made on two peats, one muck, seven mineral surface soils and one subsoil, all from Minnesota. The method of Van Slyke's protein analysis was used throughout the investigation because the nitrogen could be separated into a larger number of frac tions than by the employment of earlier methods. The most significant fact brought out by this study is that the organic nitrogen distribution in different soil types is very uniform. This is to be expected, since the nitrogen distribution in soils is an average distribution of all the plant and animal nitrogenous products that find their way to the soil.

New derivatives of arsanilic acid: OLIVER KAMM. A new series of acyl derivatives of arsanilic acid has been prepared; viz., the halogen-benzenesulfonyl derivatives, and their physiological action has been studied. The introduction of halogens increases the toxicity of these arsenic compounds.

Tetraphenylmethane: OLIVER KAMM. The action of phenylmagnesium bromide upon various ethers of triphenyl carbinol has been studied. This reaction was found very convenient for the preparation of tetraphenylmethane, the yield in the case of the phenyl ether being 20 per cent.

Oxidation products of alkaline copper sulphate on lactose: W. LEE LEWIS. The products are mainly galactasido acids whose hydrolysis yields galactose and acids containing from one to six carbon atoms. One hundred grams of anhydrous lactose gave 9.65 gms. of carbon dioxide, 3.06 grams of formic acid and 97 grams of nonvolatile syrupy acids. The hydrolysis of these later gave 29.30 gms. of galactose, 52.90 gms. syrupy acids and 0.486 gms. of oxalic acid. The analysis of these syrupy acids has so far yielded 14.26 gms. of mannonic lactone, 4 gms. of glycollic acid and the residue gives evidence of trioxy butyric acid and d-1 glycerinic. The origin of these acids is found in the explanation of Nef. Intermediate galactasido hexose dienols are formed whose dissociation and oxidation logically account for the products. The presence of such large amounts of mannonic lactone, obtained also from maltose, must originate in a benzillic acid rearrangement of galactasido-glucosone, and sharply differentiates the oxidation of the simple hexoses from the reducing disaccharoses. The glucosido acids clearly explain the lesser reducing power of the latter.

The oxidation of ethyl alcohol by means of alkaline potassium permanganate: WM. LLOYD EVANS and JESSE E. DAY. In neutral aqueous solutions of potassium permanganate at 25°, 50° and 75°, ethyl alcohol is oxidized exclusively to acetic acid; in alkaline solutions of the same reagent, acetic, oxalic and carbonic acids are the reaction products. A continuous increase in the concentration of the potassium hydroxide produces a corresponding increase in the yield of oxalic and carbonic acids, and a diminution in the yield of acetic acid. An increase in the temperature of the reaction tends to increase the yield of oxalic and carbonic acids and a diminution in the yield of acetic acid.

The oxidation of acetaldehyde by means of alkaline potassium permanganate: WM. LLOYD EVANS and HOMER B. ADKINS. The same general results

were obtained in the oxidation of acetaldehyde in alkaline potassium permanganate solutions as are described for ethyl alcohol in the previous abstract.

DIVISION OF WATER, SEWAGE AND SANITATION E. H. S. Bailey, Chairman

H. P. Corson, Secretary

Seasonal distribution of soil and fecal strains of the colon-aerogenes group in surface waters: MYRTLE GREENFIELD and W. N. SKOURUP. A survey was made of five surface water supplies, equipped with rapid sand filters, with the object of determining the variation of the organisms of the colon-aerogenes group during wet and dry weather, and their response to treatment. During rainy weather, the soil strains of the colon-aerogenes group predominated in raw water. During extremely dry weather, fecal strains of the colonaerogenes group predominated in raw water, particularly if there was much sewage pollution. There seemed to be no difference between soil and fecal strains isolated from raw water in their resistence to treatment.

Legal status and work of the water and sewage laboratory of the state board of health: C. C. YOUNG. The laboratory was for many years dependent for support upon direct appropriation to the university by the legislature and there never were adequate funds with which to do the work demanded. The 1915 legislature passed a law requiring annual analyses and inspections of water supplies and providing for rules and regulations to be drawn up by the State Board of Health and fees to cover the cost of the work. There has been practically no objection to the law, which has been in operation since July 1, 1915. Six thousand samples were examined last year and abundant data have been collected on the operation of the purification plants of the ground-water supplies.

The problems of water supply of a great railroad system: ORTON T. REES. Railroads have to deal with all sorts of water conditions, dependent upon the location of their lines. As the road develops old sources of water supply become inadequate or are found harmful. Water surveys become necessary in order to secure the best possible supplies. The relatively small number of suitable waters for boiler use make it necessary to treat the greater number of waters in order to render poor water supplies suitable for boiler use. The extent of water treatment as practised by the A. T. & S. F. Ry. system. The means employed

to furnish pure drinking water to the traveling public and the employes of the railroad system.

Well waters of Chicago: EDWARD BARTOW. An investigation was made of the source, quality and method of obtaining the thirty million gallons of well water used each day in Chicago and the effect of removing this quantity of water. Water can be obtained from wells in the Chicago area in sufficient quantities for many manufacturing purposes. Amounts of water up to 20 gallons per minute can be obtained from wells less than 500 feet deep. For larger amounts, wells should be sunk to a depth of 1,600 feet. Salt water is reached at about 1,700 feet. Water from less than 500 feet can be used satisfactorily in boilers, but the water from the deeper wells can not be used without softening. For cooling purposes water from 350 feet having a temperature of 52° Fahrenheit and from 1,600 to 1,700 feet having a temperature of 57° Fahrenheit is available. Hydrogen sulfide is found only in water from the Niagara limestone. Water free from hydrogen sulfide can be obtained by casing off the Niagara limestone, extending the casing through the Maquoketa shale.

The vertical distribution of dissolved oxygen and the precipitation by salt water in certain tidal areas: J. W. SALE and W. W. SKINNER. It was shown that the lower layers of certain tidal waters under investigation contain less dissolved oxygen than the upper layers. Evidence is presented to show that this phenomenon is caused by the stratification of the water due to the specific gravity of the under-run of sea water which cuts off vertical circulation, and to the subsequent depletion of the oxygen in the lower layers by natural agencies. The depletion of oxygen is found to be greatest in September. The precipitation and sedimentation of matter in tidal areas by sea water is presented in graphic form. Those data are considered to be of particular interest from the viewpoint of fish and shell fish life.

DIVISION OF PHARMACEUTICAL CHEMISTRY

L. F. Kebler, Chairman

George D. Beal, Secretary

The volatile oil of Monarda fistulosa: EMERSON R. MILLER. In addition to the compounds previously identified in this oil the presence of d-a-pinene (nitrol benzylamine, m.p. 123°-124°) has been proved and probably butyric and valeric aldehydes (p-nitrophenyl hydrazones).

The volatile oil of Nepta cataria: EMERSON R. MILLER. Two samples of this oil had the density