shock."' Edward Frederick Adolph, "Quantitative study of the interrelations of oxygen and carbon dioxide with hemoglobin in blood." ILLINOIS: Alma Jessie Neill, "Comparison of the rate of diffusion of certain substances.'' INDIANA: Paul Montgomery Harmon, "Influence of temperature and other factors upon the twosubmitted contraction curve of the gastronemius muscle of the frog."

JOHNS HOPKINS: Helene Connet, "Effect of adrenalin on the venous blood pressure." "" LELAND STANFORD: Rollin Guizot Myers, "Studies on the blood of marine animals.'' YALE: George Eric Simpson, "Effect of diet on the excretion of indican and the phenols."

Psychology

CATHOLIC: Othmar Solnitsky, "Factors in economic learning."

CHICAGO: Joseph Ussery Yarbrough, "Influence

of time interval upon the rate of learning in the white rat." Chih Wei Luh, "The conditions of retention." Edward Stevens Robinson, "Some factors determining the degree of retroactive inhibition." Guy Thomas Buswell, "Experimental study of the eye-voice span in reading." Forrest Alva Kingsbury, "A group intelligence scale for primary grades." Margaret Wooster, "Certain factors in the formation of a new spatial coordination.''

CLARK: Francis Cecil Summer, "Psychoanalysis of Freud and Adler.''

COLUMBIA: Dean R. Brimhall, "Family resemblances among American men of science.''

Evelyn Gough, "Effects of practise on judgments of absolute tone." Myra Elizabeth Hills, "Standardization of the analogies test." Georgina Ida Strickland, "Individual differences as affected by practise."' CORNELL: Hubert Sheppard, "Foveal adaptation to color." Louis Benjamin Hoisington, "On the non-visual perception of the length of lifted rods." Cheves West Perky, "An experimental study of the imagination." Michael Jacob Zigler, "An experimental study of visual form." Homer Guy Bishop, "An experimental investigation of the positive after-image in audition.'' Claire Comstock, "An experimental study of meaning and imagery." Forrest Lee Dimmick, "Visual movement and the phi phenomenon." Robert Thomas Holland, "The after-image of pressure." Alice Helen Sullivan, "An experimental study of kinesthetic imagery."

GEORGE WASHINGTON: Dudley Ward Fay, "A psycho-analytic study of some psychoses associated with frank endocrine disorders." HARVARD: Charles Arthur Coburn, "Heredity of wildness and savageness in mice." George Humphrey, "Conditioned reflex in education." Yueh Tang, "Affective factors in perception." Charles Hart Westbrook, "Measurement of ability in reading." Zenas Clark Dickinson, "Study of the psychological theory of action with reference to economic theory.' ILLINOIS: Coleman Roberts Griffith, "Organic and mental effects of repeated bodily rotation.'' INDIANA: Hazel Irene Hansford, "Mental and social survey of a degenerate family." Luella Winifred Pressey, "Measurement of intelligence and school attainment in the first three school grades.''

IOWA STATE: Clarence Frederick Hansen, "Serial action as the basic measure of motor capacity." JOHNS HOPKINS: David June Carver, "Immediate psychological effects of tobacco smoking." Wilbur Harrington Norcross, "Experiments on the transfer of training."

LELAND STANFORD: William Thomas Root, Jr., "Socio-psychological study of 53 supernormal children.'' James Leroy Stockton, "Definition of intelligence in relation to modern methods of mental measurement." Arthur Sinton Otis, "Absolute point scale for the group measurement of intelligence. MICHIGAN: Sarah Davina MacKay Austin, "Study in logical memory."

OHIO STATE: Jeanette Chase Reamer, "Mental and educational measurement of the deaf by the group method."

PRINCETON: Edgar Arnold Doll, "Growth of intelligence."

YALE: Arthur Dart Bissell, "Role of expectation in music."'

Zoology

CALIFORNIA: Henry Homer Collins, "Studies of the pelage phases and of the nature of color variations in mice of the genus Peromyscus." CHICAGO: Benjamin Harrison Willier, "Structures and homologies of free-martin gonads.” COLUMBIA: Clara Julia Lynch, "Unisexual sterility in Drosophila." Shellby R. Safir, "Genetic and cytological examination of primary nondisjunction in Drosophila melanogaster." Franz Schrader, "Sex determination in the white fly." Mary Bertha Stark, "Hereditary tumor in the fruit fly, Drosophila.”

CORNELL: Walter Norton Hess, "Studies on the Lampyride."' Clarence Hamilton Kennedy, "Study of the phylogeny of the Zygoptera."' Fred Waldorf Steward, "Development of the cranial sympathetic ganglia in the rat." Benjamin Percy Young, "Attachment of the abdomen to the thorax among Diptera." Laura Florence, "Hog louse, Hæmatopinus suis, Linné: its biology, anatomy and histology." Walter Housley Wellhouse, "Insect fauna of the genus Cratægus."

GEORGE WASHINGTON: Benjamin Schwartz, "Hemotoxins from parasitic forms.'' Frank Alexander Wetmore, "Body temperature of birds.'' Thomas Elliott Snyder, "Colonizing termites.'' HARVARD: Vasil Obreshkove, "Photic reactions of tadpoles in relation to the Bunsen-Roscoe Law."' James Montrose Duncan Olmsted, "Experiments on the olfactory and gustatory organs of Amiurus nebulosus (Lesueur)." Herbert Greenleaf Coar, "Shell of Balanus eburnus.'' liam Norton Barrows, "Modifications and development of the arachnid palpal claw, with especial reference to spiders." Leslie Clarence Dunn, "Linked genes in mammals." Alfred Charles Kinsey, "Studies of gall-wasps (Cynipida hymenoptera).”

Wil

ILLINOIS: Hachiro Yuasa, "Classification of the larvæ of Tenthredinoidea."'

INDIANA: William Marion Goldsmith, "Comparative study of the chromosomes of the tiger beetles (Cicindelidæ).” William Ray Allen, "Studies of the biology of freshwater mussels.'' IOWA STATE: Gertrude Van Wagenen, "Coral Mussa fragilis, and its development. JOHNS HOPKINS: Bessie Noyes, "Experimental studies on the life history of a rotifer reproducing parthenogenetically (Proales decipiens).' Hoyt Stilson Hopkins, "Conditions for conjugation in diverse races of Paramecium." KANSAS: Paul Bowen Lawson, "Cicadillidæ of Kansas.''

MICHIGAN: Walter Norman Koelz, "Coregonine fishes of Lake Huron."

MISSOURI: Erwin Ellis Nelson, "Chemical composition of the ovaries and skeletal muscle of the fresh water gar, Lepidosteus.'

PENNSYLVANIA: Joseph Hall Bodine, "Factors influencing the water content and the rate of metabolism of certain Orthoptera." PRINCETON: Wilbur Willis Swingle, "Germ-cell cycle of Anurans. I. The male sexual cycle of Rana catesfrava." Elmer Lentz Shaffer,

"Germ-cells of Cicada septemdecim (Homoptera)." WISCONSIN: Bert Cunningham, "Some studies in the natural history and early development of Chrysemys cinerea." George Holman Bishop, Title for thesis not given. Archie Evans Cole, Title for thesis not given.

YALE: Harry Hayward Charlton, "Spermatogenesis of Lepisma domestica." Ruth B. Howland, "Experiments on the effect of removal of the pronephros of Amblystoma punctatum." CALLIE HULL, Technical Assistant

RESEARCH INFORMATION SERVICE,
NATIONAL RESEARCH COUNCIL

SPECIAL ARTICLES

A METHOD OF STUDYING THE ABSORPTIONTRANSPIRATION RATIO IN NUTRIENT MEDIA

SEVERAL writers have shown that the water content of plants varies with the hour of the day. This variation is of course due to differences in the rates of water entrance and exit. Wilting takes place when the ratio of the rate of entrance to the rate of exit is less than unity whether caused by excessive transpiration or by a decrease in root absorption. These two plant processes may easily be studied as a laboratory exercise in plant physiology by using water culture plants exposed to different environmental conditions or placed in solutions of different osmotic pressures. The following experiment will serve to illustrate the manner in which changes in the strength of solutions affect the ratio of absorption to transpiration. The method here described is practically the same as one used by the writer in a series of experiments reported by Livingston.1

The roots of a tomato plant were passed through a hole in the rubber stopper of a large mouth bottle of about 600 c.c. capacity. A water-tight seal of chewing gum was made around the stem of the plant; a 2 c.c. pipette, graduated to 1/20 c.c. and a thermometer were inserted into the bottle through the stopper. 1 Livingston, B. E., "Incipient Drying and Temporary and Permanent Wilting of Plants, as Related to External and Internal Conditions," Johns Hopkins Univ. Cir., March, 1917, pp. 176–82.

The bottle and pipette were then filled with the nutrient solution, care being taken that no bubbles were inclosed beneath the stopper. Loss in weight of the plant and container gave the amount of transpiration, while the loss of solution from the pipette gave the amount of root absorption after temperature corrections were made. These temperature corrections were made by comparing these pipette readings with those of a pipette in a similar bottle containing no plant, but exposed to the same set of conditions. Transpiration was measured in grams while absorption was measured in cubic centimeters, but as the variations in density of the solutions for these temperature ranges were small in comparison to the actual values dealt with this correction was not made. The experiment was performed on November 6, 1919, in the diffused light of the laboratory during a period when variations in tempera

periods the ratio values decreased very much.
This decrease was mainly due to lower absorp-
tion rates since the roots were surrounded by
a solution much stronger osmotically during
these two periods than during the first two.
The rates of absorption for the last two periods
were greatly increased by placing the roots in
distilled water.
EARL S. JOHNSTON

LABORATORY OF PLANT PHYSIOLOGY,
MARYLAND AGRICULTURAL

EXPERIMENT STATION

THE AMERICAN MATHEMATICAL

SOCIETY

THE two hundred and twelfth regular meeting of the society was held at Columbia University on Saturday, October 30, 1920, extending through the usual morning and afternoon sessions. The attendance included thirty-five members. President Morley occu

election of the following persons to membership in the society: Dr. P. M. Batchelder, University of Texas; Miss Vevia Blair, Horace Mann School; Mr. E. H. Carus, La Salle, Ill.; Mr. W. E. Cederberg, University of Wisconsin; Mr. R. P. Conkling, Newark Technical School; Mr. P. H. Evans, Northwestern Mutual Life Insurance Company, Milwaukee, Wis.; Mr. B. L. Falconer, U. S. Civil Service Commission, Boston, Mass.; Mr. J. A. Foberg, Crane Junior College, Chicago, Ill.; Dr. Gladys E. C. Gibbens, University of Minnesota; Professor L. E. Gurney, University of the Philippines; Professor Archibald Henderson, University of North Carolina; Miss Jewell C. Hughes, University of Arkansas; Miss Claribel Kendall, University of Colorado; Mrs. M. I. Logsdon, University of Chicago; Mr. R. L. McNeal, General Motors Laboratories, Detroit, Mich.; Mr. H. L. Olson, University of Michigan; Professor Leigh Page, Yale University; Captain H. W. Rehm, Aberdeen Proving Ground, Md.; Mr. Irwin Roman, Northwestern University; Mr. Raleigh Schorling, Lincoln School, New York City; Mr. E. L. Thompson, Junior College, Joliet, Ill.; Dr. Bird M.

Turner, University of Illinois. Four applicacations for membership in the society were received.

A committee was appointed to audit the accounts of the Treasurer for the current year. A list of nominations of officers and other members of the council was adopted and ordered printed on the official ballot for the annual meeting in December. The treasurer of the society to be elected at the annual meeting was made curator of all property belonging to the society.

It was announced that the next summer meeting of the society will be held, in conjunction with that of the Mathematical Association of America, at Wellesley College.

The following papers were read at the October meeting:

H. S. Vandiver: "On Kummer's memoir of 1857 concerning Fermat's last theorem."

R. L. Borger: "On total differentiability." Elizabeth LeStourgeon: "Minima of functions of lines."

Joseph Lipka: "Complete geometric characterization of the dynamical trajectories on a surface for any positional field of force."

Joseph Lipka: "Complete geometric characterization of the brachistrochrones, catenaries, and velocity curves on a surface."

Dunham Jackson: "On the convergence of certain polynomial approximations."

J. F. Ritt: "On algebraic functions which can be expressed in terms of radicals."

A. A. Bennett: "The Schwarz inequality for a given symmetrical convex region and given bilinear form."

Edward Kasner: "Determination of an Einstein gravitational field by means of the paths of free particles."

O. E. Glenn: "An algorism for differential invariant theory."

T. H. Gronwall: "Some inequalities in the theory of functions of a complex variable." W. L. G. Williams: "Fundamental systems of formal modular semi-variants of the binary cubic."

The Southwestern Section will meet at the University of Nebraska on November 27. The annual meeting of the society will be

held in New York, December 28-29. Its western meeting will be held at Chicago, December 29-30. F. N. COLE, Secretary

THE NATIONAL ACADEMY OF

SCIENCES

THE program of the autumn meeting, held at Princeton University, was as follows:

"Some

TUESDAY, NOVEMBER 16

Morning Session

approximate computations of x-ray

wave-lengths," by W. Duane.

"The Peltier effect," by E. H. Hall. "New facts bearing on the structure of the helium atom," by R. A. Millikan.

"The measurement of the ionizing potential of metallic surfaces," by R. A. Millikan.

"Further progress in the extreme ultra-violet," by R. A. Millikan.

"Fluorescence and chemical change in very intense light fields,'' R. W. Wood.

"A high speed photographic recording galvanometer for laboratory or technical use," by A. Trowbridge.

"Explosions of mixtures of coal gas and air under constant volume conditions," by A. Trowbridge.

Excursion to the Rockefeller Institute (department of animal pathology). Inspection of grounds and buildings, followed by luncheon as guests of the institute.

Afternoon Session

"A post-war use of war material," by L. O. Howard.

"The investigation of the flora of northern South America by the United States National Museum, the Gray Herbarium of Harvard University and the New York Botanical Garden," by N. L. Britton.

"The segregation and control of the light producing substances in organisms,'' by U. Dahlgren (introduced by E. G. Conklin).

"Rose Atoll, Samoa," by A. G. Mayor. (By title.)

"The tectonic conditions accompanying the intrusion of basic and ultrabasic igneous rocks," by W. N. Benson (introduced by Arthur L. Day.) (Read by title.)

"The oldest forest," by John M. Clarke.

"The evolution of the Proboscidea," by H. F. Osborn.

"The struggle between sun and ice for the past ten thousands of years," by Baron Gerhard DeGeer (introduced by H. F. Osborn).

"Unusual features of sedimentation in the Pennsylvanian strata, Bingham Canyon, Utah," by J. F. Kemp.

"Some geologic conclusions from geodetic data," by W. Bowie (introduced by A. O. Leuschner). "Origin of the North and South American faunas," by W. B. Scott.

"The red layer, a contribution to the stratigraphy of the White River Oligocene," by W. J. Sinclair (introduced by W. B. Scott).

Reception by President and Mrs. Hibben for members of the Academy and guests, at "Prospect."

Lecture, complimentary to the citizens of Princeton. "Lessons of the Grand Canyon," by Professor W. M. Davis. Room 301, Palmer Laboratory. Following this a smoker was held at the Nassau Club.

"The molecular state of water vapor," by J. Kendall (introduced by M. T. Bogert).

"The correlation of solubility, compound formation, ionization and electroaffinity in solution,'' by J. Kendall (introduced by M. T. Bogert).

"The Corbino effect in iron," by E. P. Adams (introduced by H. N. Russell).

"The application of a differential thermometer in ebullioscopy," by W. C. Menzies (introduced by Oswald Veblen).

"Occurrence of copper and zinc in marine animals and calcareous muds," by A. H. Philips (introduced by W. B. Scott).

"The adsorption of gases by metallic catalysts,' by Hugh S. Taylor (introduced by Oswald Veblen).

"Experiments on electrical conduction in a hydrogen alloy," by Donald P. Smith (introduced by Oswald Veblen).

Afternoon Session

"Biological aspects of the process of infection," by Theobald Smith.

"Typhus fever; with description of the etiol ogy," by S. B. Wolbach (introduced by W. T. Councilman).

"Changes in the ear of the rat on the inception of hearing," by H. H. Donaldson.

"Experiments on the development of the gills in amphibians," by R. G. Harrison.

"An important period in the process of synapsis," by C. E. McClung.

"The sexual cycle of the larval bull-frog," by W. W. Swingle (introduced by E. G. Conklin). "The basal metabolism of girls 12 to 17 years of age," by F. G. Benedict.

"Growth on diets poor in true fats," by L., B. Mendel. (By title.)

"The measurement

of differences between

races," by F. Boas. (By title.) "Anthropology in the army," by C. B. Daven

port.

"Further data on population growth," by Raymond Pearl. (By title.)

"The duration of construction of blood vessels by epinephrin," by John Auer (introduced by S. J. Meltzer). (By title.)

"On a life-saving action of epinephrin—with a lantern slide demonstration," by S. J. Meltzer. (By title.)

"Nature of the effect of double vagotomy in rabbits," by Martha Wollstein (introduced by S. J. Meltzer). (By title.)

Subscription dinner of the academy. Proctor Hall, Graduate College.