Dr. Merriam published an excellent summary of the physical geology of the John Day region in 1901. No detailed mapping of the geology had been done, however, before the present program was initiated. The region is a key area for the whole northern Great Basin Province in that a larger number of postJurassic formations is exposed here than at any other locality. In no other district are the great Columbia lava fields dissected so as to expose earlier Tertiary formations so extensively.

To facilitate geologic mapping the U. S. Geological Survey, under a cooperative arrangement with the Carnegie Institution, has made topographic maps of two areas: the Mitchell Quadrangle of about 750 square miles, and the Picture Gorge Special Quadrangle of about 56 square miles (on large scale). The writer has finished the geologic mapping of the latter area and has nearly completed the Mitchell Quadrangle. The areal and structural studies are as detailed as the scales of the two maps permit.

The formations exposed are: a pre-Cretaceous crystalline complex; Chico, upper Cretaceous; Clarno, Eocene or Oligocene; John Day, upper Oligocene; Columbia lavas, middle or upper Miocene; Mascall, middle or upper Miocene; and Rattlesnake, Pliocene. All the contacts excepting the Columbia lava-Mascall and perhaps the Clarno-John Day are very striking nonconformities. Both an exceedingly eventful geologic history and a very interesting series of gemorphic changes are evidenced by the results of the mapping.

The investigations in all phases of the John Day program are being continued during the summer of 1927.

SCIENTIFIC APPARATUS AND

LABORATORY METHODS THE STUDY OF RHIZOPUS IN THE GENERAL COURSE OF BOTANY

IN many botanical laboratory courses it is the custom to study bread mold as a mass of hyphae covering bread or some other medium and to mount some of the mycelial mass on a glass slide, teasing it out for further observation of the vegetative structure. This method has seemed unsatisfactory, and I wish to suggest another method which has been used with success in the course in general botany at Macalester College.

Between two glass slides (5 cm. × 111⁄2 cm.) are

as the glass slides, the interior portions of which have been cut out so as to form a border of filter paper about one centimeter wide. A small piece (2 or 3 cu. mm.) of the moist bread on which the culture is growing is placed between the glass slides in the center of the band of filter-paper. The slides are then tied together with thread, the filter-paper moistened by dipping the edges of the slides in water and the whole mount placed under a bell-jar. In about two or three days the stolonifers will extend outward in various directions from the moist bread, and wherever they come in contact with the glass surface rhizoid-like hyphae and sporangiophores are produced. This may now be studied either with the compound microscope or with the binocular micro

scope.

This enables the student to trace the stolonifers with ease from their origin to their attachments to the glass and to study the sporangiophores and rhizoid-like hyphae in their natural positions without any disturbance of the hyphae or any danger of their drying during the study.

The above described damp chamber is practically the same as that used by Dr. R. E. Jeffs in his studies of root-hair elongation and described in the American Journal of Botany 12: 577-606, 1925. W. J. HIMMEL

MACALESTER COLLEGE, ST. PAUL, MINN.

SPECIAL ARTICLES

THE VARIABILITY OF LONG DIFFRACTION SPACINGS IN PARAFFIN WAXES

So much interest is being manifested in the polymorphism of long chain compounds, particularly the fatty acids (Piper, Malkin and Austin, J. Chem. Soc. 1926, 2310; deBoer, Nature, 119, 50, 635 (1927); Thibaud, Compt. rend. 184, 24, 96 (1927); Müller, Proc. Roy. Soc. 114-A, 542 (1927), that it seems advisable to report the results of some X-ray experiments with ordinary commercial paraffin waxes. Only one mention of X-ray studies of these complex mixtures of many hydrocarbons has been made, that of Piper, Brown and Dyment (J. Chem. Soc. 127, 2194 (1925) who found that the lines of the C28 hydrocarbon appeared alone for a paraffin wax although this fraction furnished only 16 per cent. of the mixture and other members as high as C32 were probably present.

In the present investigation samples were prepared from waxes melting at 135, 130, 125 and 120° F. by solidifying on glass plates and photographing in an oscillating spectrograph with copper Ka rays.

It is interesting to note that the translucency of the films measured with a Martin polarizing photometer varied directly with the spacings, a property of practical importance in the manufacture of transparent waxed paper. The single exception is the wax containing soap. Lead oleate itself has a spacing of 37.5 A.U. and when added to paraffin wax, even in so small amount as 1 per cent., seems to impress its own spacing upon the layers. It is still a matter of astonishment, not only that the principal spacing of a paraffin wax may be varied within limits almost at will, but also that these mixtures of as many as 18 hydrocarbons with widely differing molecular lengths form equidistant parallel diffracting layers at all. The explanation of the variability of the long spacing for the same wax is complicated by the fact that under different conditions different molecular lengths in the mixture predominate and also varying tilts of the molecules to the diffracting layers are possible.

GEORGE L. CLARK MASSACHUSETTS INSTITUTE OF TECHNOLOGY, CAMBRIDGE, Mass.

CROPS NATURALLY INFECTED WITH SUGAR BEET CURLY-TOP CURLY-TOP of sugar beets, transmitted by the beet leafhopper (Eutettix tenella Baker), has caused enormous losses to farmers and beet-sugar companies in the western part of the United States. In California and other western states many beet-sugar factories have been dismantled and moved out of the state, while other mills have been closed permanently or have remained idle during disastrous outbreaks of the disease. Unless efficient parasites of the beet leafhopper can be imported and established or a beet resistant to curly-top can be developed, the industry in many localities of the western part of the United States will perish.

In years when a severe outbreak of sugar-beet curly-top occurs, other crops are seriously damaged by the same disease. During the outbreak of the beet leafhopper in 1919 in California, cantaloupes were a failure in the San Joaquin Valley. During the past two years cantaloupes have been demonstrated to be naturally infected with curly-top in the Salinas Valley, and the symptoms resembled those observed in the San Joaquin Valley in 1919. Spinach was also found to be naturally infected in 1919, and in many localities in later years.

A simple method was adopted in testing plants to determine whether they had been naturally infected.

Leafhoppers which had been non-infective for many generations were fed on stunted diseased plants removed from the field and were then transferred to sugar beets. If the beet developed curly-top it was evident that the original plants had been naturally infected with the disease. Cross inoculations with non-infective insects fed on healthy crops or weeds grown from seeds or apparently healthy crops or weeds removed from the field failed to transmit the disease.

During the outbreak of the beet leafhopper in Idaho in 1924, a disastrous epidemic disease of beans occurred in Twin Falls County. Carsner1 came to the conclusion on circumstantial evidence that the beet leafhopper may have transmitted curly-top to beans, although he did not see the disease in the field. I have demonstrated by the method described above, that a large number of field and garden beans growing in California are naturally infected with, and susceptible to curly-top.

During the outbreak of the beet leafhopper in California in 1925, squashes and pumpkins were also proved to be naturally infected with curly-top. In 1926, McKay and Dykstra,2 of the Oregon Agricultural Experiment Station, found curly-top of squash occurring severely in many places in Oregon, Washington and Idaho, resulting in a general failure of squash in the northwest.

It has been known for a long time in California that curly-top of sugar beets and western yellow blight of tomatoes show some correlations. In 1919 and 1925, curly-top destroyed most of the late plantings of sugar beets and seriously reduced the tonnage of early plantings in the San Joaquin and Sacramento Valleys, and interior regions of the Salinas Valley; in the same years western yellow blight of tomatoes destroyed most of the crop in the same valleys. Both diseases are subject to regional variations, being more severe in the natural breeding areas of the beat leafhopper in the San Joaquin and Salinas Valleys than in the coastal regions.

During 1925 and 1926, non-infective beet leafhoppers after feeding on tomato plants affected with western yellow blight transmitted curly-top to sugar beets. Curly-top was also transmitted from tomatoes showing symptoms only of mosaic; this transmission to beets demonstrated that the tomatoes were also naturally infected with the causal agent of curly-top. Recently McKay and Dykstras came to the conclusion on the basis of circumstantial evidence that western yellow blight of tomatoes is caused by the virus of sugar beet curly-top. They state that typi1 Jour. Agr. Res., 33: 345-348, 1926.

2 Phytopath., 17: 39, 1927.

3 Phytopath., 17: 48-49, 1927.

cal symptoms of western yellow blight developed in the greenhouse by infecting tomatoes by means of the beet leafhopper.

The following crops have been found to be naturally infected with curly-top in California:

CHENOPODIACEAE, GOOSEFOOT OR
SALTBUSH FAMILY

Sugar Beet (Beta vulgaris).
Beta maritima.

Mangel Wurzel or Stock Beets (B. vulgaris): Giant Yellow; Golden Tankard; Half Sugar; Mammoth Long Red; Red Eckendorf; Yellow Eckendorf and Sludstrup. Garden, Table or Red Beets (B. vulgaris). Swiss Chard (B. vulgaris cicla).

Spinach (Spinacia oleracea): Bloomsdale Savoy.

LEGUMINOSAE, PEA FAMILY

Field and Garden Beans: Bountiful, Cranberry, Kentucky Wonder, Long Red Kidney, Small White, Stringless Green Pod, White Seeded Kentucky Wonder (Phaseolus vulgaris); Baby Lima or Henderson Bush (P. lunatus) and Blackeye (Vigna sinensis).

Alfalfa (Medicago sativa): Hairy Peruvian.

CUCURBITACEAE, GOURD FAMILY

Pumpkins and Squashes: White Scallop, Summer Crookneck, Delicata (Cucurbita pepo): Chicago Warted Hubbard (C. maxima): Winter Crookneck and Banana (C. moschata).

Watermelon (Citrullus vulgaris): Klondyke and

Excell.

Cucumber (Cucumis sativus): Early Fortune, Long Green and a variety either Chicago Pickle or Long Green. Muskmelon (C. melo reticulatus): Green Nutmeg, Pollock and Tip Top.

Cantaloupe (C. melo cantalupensis): Salmon Tint.

SOLANACEAE, NIGHTSHADE FAMILY

Potato (Solanum tuberosum): Unknown variety. Tomatoes (Lycopersicon esculentum): (Curly-top was transmitted to sugar beets from tomatoes affected with western yellow blight and mosaic).

Peppers: Anaheim Chili (Capsicum frutescens); Paprika (C. annuum); Pimento (C. annuum, C. annuum perfecto) and Mexican Chili (C. frutescens).

CRUCIFERAE, MUSTARD FAMILY, CRUCIFERS Horse-radish (Armoracia rusticana).

Radish (Raphanus sativus): Variety questionable, probably Red Globe.

Garden Cabbage (Brassica oleracea capitata): Unknown variety.

Turnip (B. rapa): Purple Top Globe.

UMBELLIFERAE, PARSLEY FAMILY Plain Parsley (Petroselinum hortense).

HENRY H. P. SEVERIN

VOL. LXVI

AUGUST 12, 1927

No. 1702

PHYSICAL INDETERMINISM AND

VITAL ACTION

SCIENCE and philosophy, but especially science, have found great difficulty in reconciling the apparent indeterminism of many vital manifestations, particularly voluntary action, with the strict determinism of physical science. The traditional problem of freedom, with all its vast implications, is the classical expression of this difficulty. One characteristic aspect of this problem seems peculiarly significant, especially when considered in relation to the present state of discussion on the foundations of physical science. This is the qualified nature of freedom as expressed in external action; there is always a large element of restriction or external determination. No one has claimed that vital indetermination is complete, although Bergson speaks of the living organism as exhibiting a maximum of indetermination.1 To take a simple illustration: the evidence for levitation is doubtful; even its most accomplished exponent would hesitate to launch himself from the edge of a cliff, however firmly he might be convinced of the freedom and efficacy of his own will. And he would continue to rely daily on the mechanical dependability and physically determined regularity of his own bodily organism. I allude to this inconsistency with no merely satirical intention, but simply in order to define as clearly as possible a crucial aspect of the problem. It is undeniable that the organism is subject to rigid physical determination in a large part of its activities; it seems equally undeniable that it is free in others; the difficulty is to decide where determinism ends and indeterminism begins. Intuition gives an overwhelming impression of freedom in voluntary action. Yet analysis, in tracing down the sources of such action, seems always to reinstate determinism; it shows the will to be motivated; motives have their natural origins; actions not consciously motivated either are habitual and referable to past motivation, or are instinctive and determined by heredity. In either case we seem to have a mechanistic determination. Physiology finds in the organism a nexus of physico-chemical determination differing from that in non-living nature only in its complexity; in fact the organism can be shown to depend for its survival on the constancy and stability of its proc

1"'Creative Evolution,'' English translation, Chapter 2; cf. e.g., p. 126.

esses, i.e., on their strict physical determination. Although voluntary action effects mechanical change and seems free, the "energy balance-sheet" of a man shows no conflict with the law of conservation, indicating that there is no creation of energy within the organism. It might be held that the will can direct energy even if unable to create it; but since by Newton's first law force is required to change the direction of a motion as well as to initiate it, we must conclude that a system unable to create energy would be equally unable to direct it arbitrarily. Classical physics thus seems definitely incompatible with the idea of freedom; accordingly scientific men-and somewhat curiously biologists in larger proportion than physicists have commonly regarded freedom as a delusion. In so doing they may have created more difficulties than they have resolved; certainly the inner conviction of freedom has not been abolished in the minds of most thinking men. But if we accept freedom as a fact, we are bound to consider whether at least a certain measure of physical indeterminism may not also be a fact. Such a residue of indeterminism, if it could be shown to exist, would conceivably explain the indeterminism or inner freedom seen in voluntary action; the evidence for its existence thus becomes a matter of great biological and philosophical interest.

When we inquire into the special physical peculiarities of living as distinguished from non-living systems we are struck by the fact that in the former the determining and controlling events are invariably on an extremely small scale.1 The microscope is the chief instrument of biological investigation. In this respect biological phenomena are at the opposite pole from astronomical phenomena. In the latter the possibility of exact prediction attains its maximum; in vital phenomena, on the other hand, prediction is possible only within certain limits; variability seems inherent; indeed in the highest manifestations of life prediction is not possible at all. It is especially such manifestations that we call "free." Such considerations suggest the question: do events cease to be predictable and become free when their spatiotemporal scale becomes sufficiently small? At least we must regard it not as a coincidence but as highly significant that the only region where physical science gives evidence of experimental indetermination, i.e., of externally uncontrolled or individual action, is in the field of ultramicroscopic phenomena. At present quantum phenomena are the subject of debate as to the universality of the rule of unequivocal physical

1a I.e., small relatively to the scale of human senseperception and adjustment.

determination.2 Even on the relatively large scale of Brownian movement any single configuration of a group of particles is as possible as any other, although the different configurations differ in probability. In other words, a given special configuration or grouping is determined by conditions of probability rather than by definitely assignable physical causation. It is well known that Maxwell and Boltzmann have ascribed a purely statistical significance to the second law of thermodynamics; and Svedberg's observations on Brownian movement, confirming the theoretical deductions of Einstein and Smoluchowski, have shown experimentally that within a sufficiently small space and time the second law does not necessarily hold.3 It follows that the regularity of macroscopic phenomena, in which determinism is for all practical purposes complete and trustworthy, is in reality a statistical regularity. We are not justified in ascribing a similar regularity to single events in the ultramicroscopic field. To a given macroscopic arrangement or condition any one of an infinite number of detailed microscopic configurations may correspond. Our microscopic picture of the world is not complete, but it already seems clear that many of the physical laws with which we are familiar in the realm of macroscopic phenomena cease to apply on the scale where events are determined by quantum relations or by the "chance" fluctuations of molecular movement. Ultramicroscopic phenomena thus give evidence of an ultimate indetermination (defining determination in the usual physical sense of quantitative specification of conditions), i.e., of control by individual action rather than by statistical or mass action.5 The laws relating to such action-assuming such laws to exist -are as yet imperfectly known, but they are certainly entirely different from physical laws as hitherto understood.

Direct evidence of physical indetermination or freedom is thus to be sought primarily in the behavior of individual particles in the ultramicroscopic field; derivatively, however, we may expect to find it in processes of a larger scale, provided these processes are in some way controlled by the ultramicroscopic events. Now vital processes appear to be processes

2 Cf. P. Jordan: "Philosophical Foundations of Quantum Theory," Nature, 1927, vol. 119, p. 566.

3 Cf. T. Svedberg: "Colloid Chemistry," New York, 1924, pp. 118 seq. "It is obvious that in microscopic systems fluctuations of entropy occur (p. 120).

4 See the recent interesting book of Professor C. E. Guye, "Physico-chemical Evolution," New York, 1926. 5 Cf. F. G. Donnan: "Concerning the Application of Thermodynamics to the Phenomena of Life," Journ. Gen. Physiology, 1926, Vol. 8, p. 685: also Scientia, 1918, vol. 24 (2), p. 281.