Life Sciences Commons^™

A Systematic Treatise Of The Coccidae (Scale Insects) Of Brookings County, South Dakota, Merrill K. Riley

Electronic Theses and Dissertations

It is the purpose of this paper to present in an introductory manner a systematic treatise of the scale insects of South Dakota, by making an intensive study of all species represented in Brookings County. It can be asserted that this paper is a complete treatise of all species present, but a thorough attempt was made to obtain specimens of all existing species. This treatise involves only the species now present, though at times other forms have been reported. Notes have been included giving the plants, location, and abundance.

Truancy In The Public Schools : Its Cause And Cure., Kathleen Miller

Electronic Theses and Dissertations

In this age in which we live it is not hard to find a problem but it is often difficult to choose one. These problems have arisen as a result of the complex social and industrial institutions which have evolved as a result of human inventiveness and the competition among men to better our living conditions and increase our comforts. According to statistics compiled by the General Federation of Women's Clubs, the proportion of those who enjoy these modern conveniences is small when compared to those who have suffered as a result. The problem of this study is one which …

The Ontogeny Of The Vascular Elements In Zea Mays, George L. Cross

Electronic Theses and Dissertations

1. The vascular bundles of Zea mays are of the monocot type, except that true amphivasal bundles are found only in the leaves.
2. The xylem and phloem are arranged collaterally, with the xylem occupying the part of the bundle nearer the center of the stem.
3. The xylem is composed of from 2 to 4 protoxylem elements, and two pitted vessels. The elements of the protoxylem are arranged in a radial row, and consist of 1 or 2 annular on the inside, and 1 or 2 spiral elements on the outside. Sometimes the outermost element (in respect to the stem) is a …

The Introduced Plants Of South Dakota, William Houk

Electronic Theses and Dissertations

The vascular plants, native and introduced, in the herbarium of South Dakota State College total 97 families, 511 genera, and about 1279 species. The representation of introduced plants as indicated in the list given below is: 22 families, 75 genera, and 110 species. Only two families have over twelve species; these are Gramineae and Cruciferae, with 30 and 15 respectively.

A Study Of Pollen, Sterility, And Blossoming Dates Of Plum Varieties In The Experimental Nursery At South Dakota State College During The Spring Of 1926, Russell W. Vance

Electronic Theses and Dissertations

The Agricultural Census of the United States for 1920 shows that plums rank second to apples in value in comparison with the other orchard fruits, small fruits and grapes produced in South Dakota. There was an eighty-two percent increase in the value of all orchard fruits produced during the year 1919 over the year 1909. The fact that the majority of the more important commercial varieties of plums are entirely self-sterile and others more or less self-sterile is often one reason for the total or partial failure of the orchard to produce fruit when a plot is planted to one …

A Study Of Certain Physical And Chemical Characteristics Of Flaxseed And Of Linseed Oil, With Especial Reference To Date Of Harvest, Leo F. Puhr

Electronic Theses and Dissertations

From the review of the foregoing literature on flax, it is evident that little work has ever been done on the chemical composition of flax. Most of the work on flax up to the present time has been confined to the diseases of flax, principally the securing of varieties that are resistant to wilt. In an attempt to secure information in regard to the factors affecting the physical characteristics and chemical composition of flaxseed the following work has been done in this experiment: 1. The effect of time of harvesting upon physical characteristics of the seed. 2. The relation of …

A Study In The Metabolism Of The Adult Honey Bee, M. D. Farrar

Electronic Theses and Dissertations

The study of metabolism in the higher forms of life has been carried on for many year and much has been found out that has been of great importance in understanding the way things live and grow. It has been only in the last few years that attention has been given to this phase of the work in insects. The extensive work that has been carried on concerning metabolism in men and animals is the basis for the more recent researches on the lower forms including the microorganisms. Before this work could be carried out on the small forms it …

A Consideration Of Methods Of Securing Historical Price And Production Data And A Survey Of Their Relationship For South Dakota, Owen L. Dawson

Electronic Theses and Dissertations

In our studies of prices we will analyze the present prices; discuss the use of price date now available and consider methods of collecting further data. As South Dakota is one of several states or countries producing a surplus of crops and livestock for market, production for the United States and for the world, of certain products, must be considered as affecting the farm prices in South Dakota.

The Effect Of Treatment With Ethylene Chlorhydrin Gas Upon The Respiration Of Dormant Potato Tubers, Leon M. Pultz

Electronic Theses and Dissertations

Chemicals have long been in use as mean of eliminating or abbreviating the rest period of various plant organs. Usually, however, they have been in the hands of workers who were interested only in forcing the resting parts into growth and not in determining the physiological effect of the chemicals upon them. Since Appleman (1) presents a very comprehensive review of the earlier literature pertaining to the subject, it will not be again presented here. More recently Denny (4, 5) has given now impetus to this work by demonstrating that ethylene chlorhydrin and various other chemicals will greatly shorten the …

A Study Of The Forage Plants Of South Dakota With Their Fungous And Insect Enemies, David Griffiths

Electronic Theses and Dissertations

The main object of this study being a better acquaintance with fungous parasites, the work on the host plants has been considerably abridged in order that the discussion might be shortened. It was the plan at first to include in this paper a carefully written description of each of the principal forage plants of the state. The futility of such a plan, however, soon became apparent, and it was accordingly decided to omit the description and include simply Distribution,

Habitat, Value as Forage, and the Fungous Parasites of each host. There are, therefore, several of our best forage plants omitted …