Digital Commons Network^™

Nutritional Factors In Plant Growth And Development - Paper Presented At The Fifty-Sixth Annual Meeting, W. F. Loehwing

Proceedings of the Iowa Academy of Science

The large number of recent publications on the physiology of plant development reflects a widespread, contemporary interest in this subject. Researches in this area deal chiefly with the effects of specific growth substances and mineral nutrients on functional and structural ontogeny. The major contributions on the physiology of growth substances have already been conveniently assembled in certain excellent monographs (36, 53, 283, 339, 424) and reviews (37, 422, 192). Recent researches on nutrition in relation to plant development have not as yet been comprehensively reviewed. Data in this field as a whole are extremely diverse, especially as they relate to …

Anode Effect In A Commercial Radio Tube, A. Owens

Proceedings of the Iowa Academy of Science

The anode effect has been studied on the grid and found to he in agreement with results previously published. Attention was then shifted to the plate where the anode effect was studied at larger current densities. It is to be noted that the building up of the effect can more easily be observed on the plate and the decay more easily observed on the grid.

A Preliminary List Of Bryophytes Of Linn County, Iowa, R. V. Drexler

Proceedings of the Iowa Academy of Science

In the rather extensive literature on Iowa bryophytes little mention is made of Linn county. Published records, however, do not represent all collecting for Dr. H. S. Conard of Grinnell College has collected fifty species and one variety of mosses and fifteen species of liverworts. Of the above number nine species of mosses and seven species of liverworts have not been collected by the author. This paper is an attempt to bring together under one title the names of bryophytes collected in Linn County.

The Measurement Of Visual Phenomena By Means Of The Electroretinogram, Theodore Louis Jahn

Proceedings of the Iowa Academy of Science

Whenever light strikes the eye of an animal there is a voltage difference produced between the front and back of the eye. This voltage difference originates in the retina of the vertebrate eye and in the sense cells of the compound eye. A record of the voltage change may be obtained by means of an oscillograph and is referred to as an electroretinogram (ERG). The electroretinogram may be used for the study of various visual phenomena.

Electrodialysis Of Sugar Borates, George H. Coleman, Aaron Miller

Proceedings of the Iowa Academy of Science

The reaction of glycols with boric acid in aqueous solutions to form an easily saponified ester has long been known. This acid ester is a stronger acid than boric acid and an increase in conductivity results.

The Effect Of Varying Illumination On Distance Perception Of Objects Subtending, A. R. Lauer, Merwyn Winterstein

Proceedings of the Iowa Academy of Science

The problem relates to the effect of distance judgment under conditions of semi-scotopic vision. The levels of illumination ranged between .01 and 1.30 foot candles. Two series of experiments are reported. The first series used 16 subjects with illumination levels ranging between .04 and 1.30 foot candles. The second series used seven subjects between the ranges of .01 and .04 foot candles. Time and errors were used as the criteria of performance. Both showed considerable variation throughout the series but greatest effects are noted below .03 foot candles. The time for setting varied more than the error score. Differential settings …

College Catalog 1941-1942, Iowa State Teachers College

UNI Programs and Courses Catalogs

Table of Contents:

College Calendar for the Year 1942-43 ... 7
State Board of Education ... 8
Officers of Administra tion ... 9
Officers of Instruction ... 10
Department of Directed Observation and Supervised Student Teaching ... 17
Extension Service ... 20
Other Officers and Assistants. ... 21
Faculty Committees ... 26
General Information
Historical Sketch ... 29
Buildings and Grounds ... 29
Enrollment and Registration ... 35
Fees ... 35
The Residence of Women Students ... 37
The Residence of Men Students ... 39
The Commons ... 40
Resume of a Student's Expenses per Year ... 41
Employment ... …

Title Page - Front Matter

Proceedings of the Iowa Academy of Science

No abstract provided.

Ring Closure Of N-Methylcycloheptylamine, George H. Coleman, Joseph J. Carnes

Proceedings of the Iowa Academy of Science

No abstract provided.

Vapor Pressure Of Iodine Monochloride, Jacob Cornog, Eldon Bauer

Proceedings of the Iowa Academy of Science

The Pearce and Snow dynamic method of measuring vapor pressure has been adapted to the measurement of the vapor pressure of iodine monochloride in the solid and liquid phases. Heats of sublimation, vaporization and fusion were obtained by application of the Clausius-Clapeyron equation.

Three Comparisons Of Retroactive And Proactive Inhibition, Benton J. Underwood

Proceedings of the Iowa Academy of Science

Retroactive inhibition (RI) has long been recognized as one of the most potent factors in forgetting. Of relative recent treatment is the forgetting produced by the operations defining proactive inhibition (PI). If RI is defined as a decrement in the recall of an activity as a result of other activity intervening between the original learning and recall, PI may be defined as a decrement in recall as a consequence of an activity which took place prior to the original learning.

A Preliminary Study Of The Insect Galls Of Iowa, Gordon Carstensen, H. E. Jaques

Proceedings of the Iowa Academy of Science

The abnormal growths frequently found on plants and known as insect galls have led to much study of their origin and manner of development. These abnormal plant structures may vary from a simple fold-like gall on a leaf to a highly complex structure resembling a fruit. Insect galls are found on at least 80 families of American plants. Some twelve plant families account for a large percentage of the known galls. Insects produce galls on many species of plants. Practically every part of a plant such as roots, stem, twigs, leaves, buds, flowers and fruits may develop galls.

A Peculiar Polytrichum, R. V. Drexler

Proceedings of the Iowa Academy of Science

This moss was collected from a wet, shaded habitat in the Quetico Provincial Park of Ontario. It has the physiogamy of an Atrichum but seems to be clearly related to Polytrichum gracile Smith. The plant differs from any Polytrichum species in that it has a wide leaf limb and a poorly differentiated leaf sheath.

The Preparation Of Colorimetric Standards, Ferrin B. Moreland

Proceedings of the Iowa Academy of Science

In colorimetric determinations it is often found when the color is developed that the standard and unknown differ too much for accurate readings. Usually this is remedied by beginning the determination again and using a different amount of standard or unknown sample. It would be quicker to increase the color by the addition of more standard directly to the paler of the two colored solutions, if it were known that the increase in color intensity were proportional to the amount of added standard. The present investigation established the proportionality between increased color and additional standard added after color has been …

Some Insoluble Residue Correlations Of Missouri And Virgil Strata In Iowa, E. H. Wenberg

Proceedings of the Iowa Academy of Science

Iowa geologists have long experienced great difficulty in isolating good key beds in the younger Pennsylvanian strata. This difficulty is due to the cyclothemic nature of the sediments. The marked success of the Missouri Geological Survey in distinguishing southward extensions of these strata in Missouri on the basis of their insoluble residues has led to a similar attempt in Iowa.

The Prediction Of Scholastic Success In A College Of Law, Michael Adams

Proceedings of the Iowa Academy of Science

The present study was undertaken as part of a research program directed toward making available to personnel counselors at the University of Iowa a more adequate basis for advising students who contemplate entering the University College of Law. Specifically, it was the purpose of this study to investigate the value of pre-law grade point averages and certain aptitude test scores as predictive indices of success in first year law at the State University of Iowa.

Reaction Time Under Different Stimulus Conditions, Fred Kroeger, George D. Lovell

Proceedings of the Iowa Academy of Science

For military purposes it was desired to know the relation between two types of reaction time tests. These tests were: (1) a simple reaction time test of the usual type, (2) a "clock reaction time" test in which the subject attempted to stop the moving hand of a clock at a certain predesignated point on the face, by pressing a standard telegraph key. Seashore, Buxton, and McCollom (1940) have reported that certain factors corresponding to motor skills have been "isolated in terms of qualitative similarity in the pattern of action, including perceptual activity, involved in various tests rather than to …

The Use Of The Wechsler-Bellvue Intelligence Test In The Study Of Mental Deterioration, Bernard Webb

Proceedings of the Iowa Academy of Science

It has been suggested that the Wechsler-Bellvue intelligence test may be useful in the study of mental deterioration. The general purpose of this paper, then, is to investigate the usefulness of this test in measuring mental deteriorations and discerning its nature. This, in turn, involves two problems: (1) Do the various types of mental deterioration show characteristic test score patterns? (2) Is it possible, by the use of the differential test score method (balancing of certain sub test scores affected by mental deterioration against the sub test scores of those which are relatively unaffected), to devise differential indices for the …

The Teaching Of Botany - Appraisal And Forecast, W. F. Loehwing

Proceedings of the Iowa Academy of Science

In undertaking a discussion of biology in education it is highly desirable to view the subject against the general background of American education as a whole. Among the nations of the world, the United States possesses the unique distinction of having mass education. We owe this policy to the shrewd foresight of the fathers of the American Revolution, to their recognition of the fact that the success of representative government depends upon an enlightened electorate. As an object of primary importance, George Washington enjoined the new nation to "promote institutions for the general diffusion of knowledge." In his first inaugural …

Tetraploidy In Melilotus Alba Induced By Colchicine, I. J. Johnson, J. E. Sass

Proceedings of the Iowa Academy of Science

Seedlings of sweet clover were treated with colchicine. Plants that responded to treatment either were tetraploid in all new root tissues, or had sectors, or islands of tetraploid tissue in the root tips. Cutting made from the plants in the latter category were tetraploid throughout.

Notes On Iowa Fungi. Ix., G. W. Martin

Proceedings of the Iowa Academy of Science

DELACROIXIA CORONATA (Cost.) Sacc. and Sydow. Figs. 4, 5. This interesting member of the Entomophthoraceae was first described by Costantin from France as Boudierella coronata (Bull. Soc. Myc. France 13: 38. 1897) and shortly afterwards transferred by Saccardo and Sydow (Syll. Fung. 14: 475. 1900) to Delacroixia. In the United States it was first isolated in Wisconsin by Gilbert (Trans. Am. Microsc. Soc. 38: 263-269. 1919), who did not, however, ascribe a name to it. A few years later it was isolated from wood in Iowa and published, on what at that time seemed sufficient warrant, as Conidiobolus villosus Martin …

The Genus Thelephora In Iowa, Paul L. Lentz

Proceedings of the Iowa Academy of Science

The genus Thelephora, as defined by Fries (Syst. Myc. 1:428. 1821), includes many of the present members of the group and many more which are now placed in other genera. Citing Ehrhart, Crypt. Exsic. No. 178. 1785, as his basis, Fries defined the genus as composed of those fungi having a compact, homogeneous pileus which is coriaceous and persistent. T. terrestris Ehrh. is designated the type species. Thelephora, as envisioned by Fries, included five "tribes" in the genus proper. In addition he listed Stereum, Phylacteria and Leiostroma as subgenera. Some of these subgroups had been treated as genera by earlier …

Systems Of Chemical Compounds, Geo. Glockler

Proceedings of the Iowa Academy of Science

The nitrogen system of chemistry is well known through the work of Franklin (1935) and others and the numerous relations existing between the nitrogen and oxygen systems of compounds, are illustrated by many examples in the monograph just cited.

Reports: Executive Committee; Secretary; Treasurer; Staff Reports; Committee Reports

Proceedings of the Iowa Academy of Science

No abstract provided.

In Memoriam: John Alexander Mcgeoch; Edgar W. Timm; Oliver W. Muelder; Maria M. Roberts, Carl E. Seashore, E. W. Lindstrom, Ben H. Peterson, Gertrude A. Herr, Helen F. Smith

Proceedings of the Iowa Academy of Science

No abstract provided.

Science In A Changing World - Paper Presented At The Fifty-Sixth Annual Meeting, Roy A. Nelson

Proceedings of the Iowa Academy of Science

This year Iowa Wesleyan College celebrates the Centennial Anniversary of its founding and the Iowa Academy of Science pays tribute to that institution by holding its Fifty-sixth Annual meeting here in Mount Pleasant. Scarcely a decade after the first permanent settlers had taken up their abode in what later became the state of Iowa, this institution had its beginnings. It ranks among the oldest institutions of higher learning west of the Mississippi River.

New Light On Intelligence - Paper Presented At The Fifty-Sixth Annual Meeting, George D. Stoddard

Proceedings of the Iowa Academy of Science

Discussions of the meaning of intelligence frequently begin with attempts to separate heredity from environment, or nature from nurture. Such studies can be carried out only in a population in which control can be exercised over the two sets of factors. The control of hereditary factors increases as we go from unrelated children to siblings to twins. When we think of the individual child, we must recognize at once that he is a product of nature and nurture. It is not feasible to assume either that the human organism can develop independently of its genetic basis or that any set …

Table Of Contents

Proceedings of the Iowa Academy of Science

No abstract provided.

Extra-Floral Nectaries In Bryophyllum Calycinum, James H. Craft

Proceedings of the Iowa Academy of Science

Among the interesting features of Bryophyllum calycinum Salisb. is the occurrence of foliar embryos in the notches of the leaf (Fig. 3) which under favorable conditions will give rise to new plants. In the apices of the crenations are hydathodes (Fig. 3) whose structure has been described by Berge (1877) and Yarbrough (1932, 1934). A hydathode typically occurs at a vein ending in a leaf margin, but in Bryophyllum calycinum the hydathode consists of a vascular plexus surrounding an epithem which is associated with a special group of stomata on the lower side of the leaf. The cells of the …

The Dwarf Leaf Of Cercis Canadensis, Robert B. Wylie

Proceedings of the Iowa Academy of Science

For morphological investigations the selection of material is of primary importance. This is especially significant in the comparative study of leaves since these organs may have marked differences in size and structure on a given branch or on a single twig. During development they are responsive not only to environmental conditions but also to factors operating within the plant. Trees often develop diminutive foliage and insertion of the dwarf leaf on the axis may be very close to others of larger growth. This anisophylly is pronounced in many plagiotropic shoots and may also be associated with basal-apical relations. Such dwarf …