see a book giving information on the behavior of the air, for the benefit of airmen. There can be no doubt of the utility of such a volume, and both the editor and Mr. Gregg are to be congratulated on the publication of a book that for the present meets the need. There is no valid reason why every pilot should not be well versed or at least fairly familiar with the more frequent types of air structure, the processes of cloudy condensation, the formation of fogs, icestorms, hail-storms and thunder-storms, the shift of wind direction with increasing height, the significance of a change in velocity, the nature of a zone of discontinuity and what it portends, the frequency of favoring and unfavoring winds, the average height of clouds, the meaning of each type and its growth or dissipation; and in short, as much as possible of what Sir Napier Shaw calls "The Air and its Ways," with particular emphasis on the "ways." We group them all under the general term aerography-the science of air structure. No land explorer should be without a knowledge of geography, no seaman scorn a knowledge of hydrography, neither should a flier be without a knowledge of aerography.

There have been decided changes in our knowledge of the structure of cyclones and anticyclones. By persistent recurrence to his idea of thermal stratification of the atmosphere, Shaw has brought us to new conceptions of cyclonic structure, and we now rule out former notions of inrushing, rising warm air and the condensation of vapor, as the prime movers in a cyclone, and on the other hands descending dry cold currents as the essential feature of an anticyclone. This old idea of a cyclone, says Dr. Simpson (Address, Section A, British Association for the Advancement of Science, August, 1925) was tersely expressed by Sir Oliver Lodge in a letter to the Times last year, as follows:

A cylindrical vortex with its axis nearly vertical rolling along at a rate conjecturally dependent partly upon the tilt and with an axial uprush of air to fill up a central depression which depression nevertheless was maintained and might be intensified by the whirl, the energy being derived from the condensation of vapor.

But unfortunately for the theory, observation does not sustain it. The air does not move in a continuous spiral, and there are decided discrepancies in the distribution of temperature. Air streams are discontinuous and seem to retain their temperatures. Rain does not fall where it should according to schedule; and so we come to explanations based more upon energy derived from readjustment of the center of gravity of the air mass as a whole, the whole being made up of blocks of air of diverse origins.

Here is where observations in strata one thousand

meters and more above the earth become so important, and where knowledge of the vertical structure lets us understand what is really taking place. The diurnal range of temperature, for example, so characteristic of surface readings, fades out at about one kilometer.

Gregg gives with some detail charts showing average temperatures, pressures and densities at the 3 km level, for the United States, east of the Rocky Mountains.

The chapters which most directly bear upon aviation are those on the "Winds" (Chapter IV), and Chapter IX on "Forecasting."

At the surface the air does not flow parallel to the isobars because of friction and viscosity, so that one must rise about five hundred meters to find the gradient wind, or wind parallel to the isobars. But the gradients aloft may be and generally are not in close agreement with surface readings, hence the winds will also change in direction and intensity.

The shifting of winds with altitude into a westerly quarter is shown in detail. With regard to changes in velocity, it is shown that there is a marked increase from the surface up to five hundred meters, then a more gradual increase, and decided seasonal variation in the upper levels.

At usual flying levels the wind factor is 3.5 meters per second; and in the author's opinion it is now possible to fix schedules for aircraft that can be guaranteed any desired percentage of the time-so far as winds are concerned.

There are some good reproductions of cloud photographs. The typography and general make-up reflect credit upon the Ronald Press Company.

ALEXANDER MCADIE

SPECIAL ARTICLES

THE EFFECT OF SODIUM SILICOFLUORIDE SPRAYS ON THE PEACH AND ON THE

CONTROL OF BACTERIAL SPOT

SOME preliminary experiments by the writer during the summer of 19251.2 indicated that sodium silicofluoride in dilute solution (two pounds to fifty gallons of water) had a decided effect in checking the bacterial spot of peach on the leaves. Unfortunately there was no fruit on the trees, and it was not until the summer of 1926 that the action of this chemical on the fruit could be studied. The results this year confirmed those of 1925 in so far as control of the disease was concerned and interesting information on a unique effect on the fruit was secured.

1 Phytopath. 16: 79-80, 1926.

2 Trans. Ill. Hort. Soc. 59: 266-272, 1926.

EFFECT ON FRUIT

Spraying experiments were conducted in two widely separated orchards, one in central Illinois and the other in the extreme south part. The results obtained were quite similar so far as the effect on the foliage and fruit was concerned.

No injurious effect was noted on the fruit until shortly before harvest and even then no burning or marking of the fruit could be seen. It was observed, however, that the fruit on all the sodium silicofluoride plots ripened from four to six days ahead of that on unsprayed plots or on those sprayed with dry-mix lime and sulfur. In addition, the fruit had a higher color and was somewhat smaller. At the tip was an area varying considerably in size and shape with a color range from dark green to yellowish green. These areas were conspicuous in contrast to the deep red and light yellow of the surrounding portion. The taste of the entire fruit was insipid and in some cases rather bitter. Cracking was somewhat more marked on the sodium silicofluoride plots than on the others, but this might have been due in part to the difference in the time of ripening. A similar effect on the peach was observed by Mr. R. L. McMunn, of the Department of Horticulture, in 1924 on some trees sprayed with Flu-Sul. This is a commercial product containing barium fluoride as one of the active ingredients.

EFFECT ON FOLIAGE

The effect of the sprays containing sodium silicofluoride on the leaves varied somewhat throughout the season. On the whole little injury was observed although rather severe burning at the tips and along the edge occurred on some trees. This could not be correlated with temperature or other weather conditions and was never serious enough to cause alarm. At the end of the season the trees, however, were in as good condition as those sprayed with other materials.

CONTROL OF BACTERIAL SPOT

At Urbana, where the spray applications were made at weekly intervals starting June 21 and continuing until July 26, almost perfect control on the fruit was secured. The checks received a “shuck” spray of lead arsenate and lime, but no other sprays. The fruit was harvested the latter part of August and all the peaches were examined from five sprayed trees and three check trees. On the sprayed trees 0.48 per cent. of the fruit was diseased, while on the check 86.7 per cent. showed serious spotting.

At Ozark, Illinois, where the sprays were applied at ten-day intervals, starting with the "shuck" spray, the sprayed trees showed 11.5 per cent. diseased fruit,

while an unsprayed check had 69.5 per cent. diseased peaches. On a sulfur-lime-dusted plot the percentage of spotted fruit was even higher than on the check, while on a dry-mix sulfur lime plot 65 per cent. of the fruit was diseased. The control of the disease on the leaves was not as successful as that on the fruit. At Urbana, where careful counts were made, the sprayed trees had 38.3 per cent., while the checks had 84.5 per cent. diseased leaves.

In spite of the fact that both in 1925 and 1926 the southern peach-growing sections suffered from severe droughts during the spring and early summer, leaf spot was unusually severe. This, together with numerous other observations, tends to support the theory that the bacteria are carried to the leaves and fruit in dust particles. It has been proved3 that the pathogen can survive the winter in dead leaves and that the bacteria are extremely resistant to desiccation. It would seem logical, therefore, to account for the widespread infections in dry seasons by assuming that the dust arising during the process of cultivation and through high winds are responsible for conveying numerous bacteria to the leaves and fruit, where moisture from dew or light rains would give them a chance to enter the stomates and bring about infection.

Sodium silicofluoride sprays in a schedule starting with shuck fall gave much better results than when started a month later, although the disease did not become evident until much later. It seems possible, therefore, that the bacteria in the dust particles may be present for some time on the fruit and leaves without bringing about infection and that the sodium silicofluoride solution kills the bacteria when the particles of dust become moist enough to start the activity of the bacteria.

It is not considered safe for the growers to use any spray containing sodium silicofluoride until further experiments are made as to the effect of different climatic conditions on the amount of injury. Also, further work must be done on determining the chemical changes which take place after the material is applied to the trees.

The sodium silicofluoride used in these experiments was kindly donated by Jungmann and Company, of New York, and was known as their "L & V" commercial sodium silicofluoride. While this material upon analysis proved to be remarkably pure for a commercial product the recent article by Roark* indicates that chemical reactions taking place during mixing and application will change the composition

3 Anderson, H. W., "Overwintering of Bacterium Pruni," Phytopath. 16: 55-58, 1926.

4 Roark, R. C., "Fluorides vs. Silicofluorides as Insecticides," SCIENCE 63: 431-432, 1926.

The liquefaction of gelatin No. 2 would be rated as rapid, while that of No. 1 would be comparatively slow. This No. 2 gelatin was not less than eighteen years old at the time of the experiment. The Digestive Ferments Company gives the information that the present-day gelatins have considerably more gelation power than those of twenty years ago. The liquefaction of gelatin by bacteria observed twenty years or more ago should be deduced on this basis.

It is generally understood that the age of the gelatin culture medium is a factor in the liquefaction time; that is, a gelatinolytic organism may bring about liquefaction quite rapidly when inoculated into freshly prepared gelatin, and much more slowly if introduced into the same medium sometime later.

THE fifteenth annual meeting of the Oklahoma Academy of Science was held in Stillwater with the Oklahoma A. and M. College, November 26 and 27. This meeting was held under the presidency of J. H. Cloud, professor of physics, O. A. M. C.

One hundred and eleven papers were presented. These included 54 papers in the section of biology, 21 geological papers, 16 papers in physical science and 17 in social science. Three general addresses were also given.

The Oklahoma division of the American Chemical Society met in conjunction with section C, the section of physical sciences.

Officers for the year 1927 were chosen as follows: President, Charles N. Gould, of Oklahoma Geological Survey.

Assistant Secretary-Treasurer, Herbert Patterson, O. A. M. C.

Vice President, Section A, L. B. Nice, University of Oklahoma.

Assistant Vice President, Section A, Robert Stratton, O. A. M. C.

Vice President, Section B, A. H. Koschmann, O. A. M. C.

Vice President, Section C., F. E. Knowles, Phillips University.

Vice President, Section D, J. Dowd, University of Oklahoma.

The membership at the time of the meeting was 173, of whom 62 are also members of the American Association for the Advancement of Science. At this meeting 95 new members were elected.

The activities of the academy are expanding very rapidly and its influence is of increasing importance.

A. RICHARDS,

Secretary-Treasurer.

The American Association for the Advancement of Science:

Diverse Doctrines of Evolution, their Relation to the Practice of Science and of Life: PROFESSOR H. S. JENNINGS

The Nation and Science: THE HONORABLE HER-
BERT HOOVER

Arnold Edward Ortmann: DR. W. J. HOLLAND
Scientific Events:

The Pan-Pacific Science Congress; Program of the
American Engineering Council; The American
Museum of Natural History; Anti-evolution
Legislation and the American Association of
University Professors; Dinner in Honor of Sir
J. J. Thomson

Scientific Notes and News

University and Educational Notes
Discussion:

Early Days of Anti-vivisection: DR. W. W. KEEN. Helium in Deep Diving: DR. ELIHU THOMSON. About the Accusation of Plagiarism of the Late Director of the Pulkovo Observatory, Otto Struve: A. A. IVANOFF. The Dissolution of Insulin into Two New Active Substances: DR. CASIMIR FUNK 35 Quotations:

"Narcosan"' and Drug Addiction Scientific Books:

Freundlich on Colloid and Capillary Chemistry:
PROFESSOR HARRY N. HOLMES. Zane Grey on
Deep Sea Fishing in New Zealand: DR. DAVID
STARR JORDAN

Scientific Apparatus and Laboratory Methods:
"AFS," a New Resin of High Refractive Index
for mounting Microscopic Objects: G. DALLAS
HANNA. The Culture Medium for Drosophila:
TAKU KOMAI

Special Articles:

On the Origin of Sun-spot Vortices: PROFESSOR FERNANDO SANFORD. Bacterial Filters and Filterable Viruses: DR. S. P. KRAMER Science News

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Χ

DIVERSE DOCTRINES OF EVOLUTION, THEIR RELATION TO THE PRACTICE OF SCIENCE AND OF LIFE1

As a fresh unhackneyed subject for an after dinner address I propose to talk on evolution. Some doctrines of evolution are not so hackneyed as others. My own favorite doctrine has been only too much neglected. I now discover with pleased surprise that this very doctrine is coming into fashion. No longer can its exposition be described as a voice or two crying in the wilderness. Philosophical congresses discuss it, eminent zoologists discant upon it; still more significant, it has acquired a name that identifies it. Naturally, therefore, while it is in sight, I seize this opportunity to greet its emergence; to promote its publicity. Therefore, prepare for propaganda. See that your defense complexes are in working order. One needs nowadays to keep them ready for instant use; so you will not complain at my giving them a bit of drill.

The name that the doctrine has acquired is Emergent Evolution. This may be a poor name, but any name is better than being nameless; so one must be thankful. The different ways of conceiving the evolutionary process have diverse bearings upon one's attitude toward the world; upon the temperament and outlook of the student of science; upon the course that science takes. What I wish to do is, not to expound emergent evolution as a doctrine, but to inquire into its bearings on these matters, as compared with those of other ways of looking at evolution; to set forth my own notions of these bearings. You will see that to me this doctrine appears an edifying one. My thesis is that the conscious acceptance of the doctrine of emergent evolution and of its implications would greatly ameliorate biological science as practiced and as preached; would much moderate, mitigate and amend its influence on the human outlook and the practice of living. I speak therefore as a hopeful uplifter.

Evolution is often identified with perfect mechanism; or at least held to be consistent and coincident in its operation with mechanism. According to that doctrine in its perfection, the universe as a whole, or

1 Address of the retiring chairman of the Zoological Section of the American Association for the Advancement of Science, December 28, 1926.

any limited sample of it, is a set of particles, of one or a few kinds, moving according to certain few invariable laws; the consequent successive groupings of the particles constituting the universe at diverse periods. The process of transformation of the groupings is evolution. From examination of any small sample of the universe, at any time, it is possible to discover the laws of action, of grouping, for all its parts, and for all periods. Consequently, after such an examination of the configuration and motions of the particles at any given moment, the clever observer armed with an adequate computing machine could compute and therefore predict the entire course of evolution; all that will occur or exist at any later period. Evolution is the working of a great machine that never alters its mode of action nor the nature of its product. Science is the examination of what this machine does and produces. Its ideal method is by computation-from a few elementary observations of the constituent particles, their distributions and motions. Science is therefore mainly rationalistic; to but a minimal extent empirical. Nothing essentially new or unexpected can come out of this machine. The thing that hath been is that which shall be, and that which is done is that which shall be done, and there is no new thing under the sun. Such is the soul stirring vision which illumines the path of much of evolutionary science. Even where this vision is not in conscious view, it has induced a subconscious complex which dominates theory and practice. Evolutionary doctrines in large measure adopt the attitudes appropriate to this vision; admit the conclusions based upon it, and regulate their practice accordingly.

The doctrine of emergent evolution rejects this vision as an illusion; explicitly denies the propositions it bodies forth; substitutes for them others that are irreconcilable with them, and with the practical and theoretical conclusions drawn from them. It holds that the conception of the universe as nothing but a set of one or a few kinds of particles moving according to a few immutable laws exemplified at any time and anywhere that particles occur, is pitiful in its inadequacy. The notion of computing the entire farther course of evolution from the situation at a given moment, it considers one of those raw and naively incompetent ideas to which at early and unsophisticated periods of culture man is prone. It asserts that the method of science based upon this notion is a false one, not from lack of a sufficiently clever computer with an adequate computing machine; but because at any given time or place the data required for the computations do not exist. It holds that new things, not thus computable, appear as evolution progresses. It holds that with these emerge new methods of action, following new laws; methods not

before exemplified; methods that falsify the results of computations based on former methods of action. Concretely, it holds that such new things and new modes of action distinguish the living from the nonliving, the sentient from the non-sentient, the reasoning from the non-reasoning, the social from the solitary. It affirms, under correction, that the same is true for the steps from electrons to atoms, from atoms to molecules, from molecules to crystals. It holds that the properties of atoms do indeed depend on those which the electrons have when they are in the atom; the properties of molecules on those which the atoms have when they are in the molecules. It holds too that the properties of living things depend on those of their physical constituents when the latter are in living things; the activities of thinking beings on the action of their physiological constituents when the latter are part of a thinking being; the activities of societies on those of their unit individuals when these individuals form part of the society. But it contends that the constituents of each grade acquire new properties, new modes of action, in becoming part of the "emergent" thing of "higher" grade. It holds that the physics of atoms, of molecules, is not fully known till these are studied in the living as well as in the non-living. It holds that the physiology of bodily constituents separated from the living organism is in essential respects diverse from their physiology in the living organism. The constituents of the emergent unit partake of the properties which they showed before becoming parts of that unit; but with additions or modifications. The properties of the emergent unit itself depend on these altered properties of its constituents.

But my present purpose does not require me to expound or defend emergent evolution as a doctrine. That has been done of late by others; by Lloyd Morgan, Ritter, Lovejoy, Wheeler, Parker; by many. I need now but to identify the doctrine. There it stands. What I wish to ask is, in rude parlance, "What of it?" What differences does it make? Where does it take us if we adopt it and act upon it,-in place of following the vision of mechanical evolution?

It seems to me to make a great difference as to where we go; a great difference to the practice of science; a great difference to the temperament and bearing of the man of science; a great difference to one's outlook upon life and the universe. Let us look into this.

Look first at the relation of the two kinds of doctrine to our own professional work; to the technique of scientific investigation and formulation. For mechanical evolution, the ideal scientific method is mainly rationalistic. We should require but a few