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Articles 961 - 986 of 986
Full-Text Articles in Life Sciences
The Development Of The Floral Organs Of Glycyrrhiza Lepidota, Richard L. Matteson
The Development Of The Floral Organs Of Glycyrrhiza Lepidota, Richard L. Matteson
Electronic Theses and Dissertations
This is the first of a proposed series of papers, coming from the Botanical Laboratory of South Dakota State College, on the developmental anatomy of the prairie legumes. The recorded investigations of the legumes deal mostly with the cultivated species, and the greater part of this work considers the taxonomy and cytology of flowers. These papers proposed above deal with the floral development and the floral vascular anatomy of this family.
Some Effects Of A Constant Temperature And Different Relative Humidities Upon Egg Laying Of Melanoplus Bivittatus Scudder., Millard Jewell Hatten
Some Effects Of A Constant Temperature And Different Relative Humidities Upon Egg Laying Of Melanoplus Bivittatus Scudder., Millard Jewell Hatten
Electronic Theses and Dissertations
Of the various species of grasshoppers occurring in rather extensive numbers year after year in the northwestern plains states, Melanoplus bivittatus is one of the most prevalent and destructive. It was thought that a study of the influence of different temperatures and relative humidities upon the reproductive potential of this species might reveal some information and that this information might be of some value in an attempt to forecast the abundance of this grasshopper in years following others in which the factors of temperature and relative humidity were known.
The Morphology Of The Seminal Vesicles, Accessory Glands, And The Ejaculatory Canal Of Melanoplus Differentialis (Thomas) And An External Morphological And A Histological Study Of The Seminal Vesicles, Accessory Glands, And Ejaculatory Canal Of This Grasshopper, Wilbur T. Reierson
Electronic Theses and Dissertations
The purpose of this thesis is to record the results of an investigation, by the writer, upon the reproductive system of Melanoplus differentialis (Thomas) with special emphasis placed upon the external morphology and the histological study of the seminal vesicles, accessory glands, and the ejaculatory duct; and also to record conclusions as to the probable function of these organs.
Farm Mortgage Experience Of Life Insurance Companies Lending In South Dakota, Harry Allan Steele
Farm Mortgage Experience Of Life Insurance Companies Lending In South Dakota, Harry Allan Steele
Electronic Theses and Dissertations
Life insurance funds play an important part in supplying farm mortgage credit. This source of credit has increased rapidly during the last twenty years and is now one of the principal sources of farm mortgage loans in the United States. Because of the nature of the institution of life insurance, its investments should be conservative. It is with this view in mind that the state insurance laws are designed to regulate the investments of the life insurance companies. Investments of the well established life insurance companies have generally been made on a conservative basis.
Anatomical Study Of Water Shoots And Ordinary Twigs, Dorothea I. Bingham
Anatomical Study Of Water Shoots And Ordinary Twigs, Dorothea I. Bingham
Electronic Theses and Dissertations
Water shoots or long shoots are those which appear low on the trunks of trees, or about stumps of trees recently cut down. The ordinary twigs are those found at the ends of branches. Interest in the cooperative study of water shoots and ordinary shoots on trees was aroused by the very marked differences, even in a single years growth, in length and the diameter of two types. The former is greater in diameter , much longer, and with more nodes, longer internodes and longer leaves than the twigs which grew ordinarily at the ends of branches. The object of …
The Effect Of A Varying Moisture Supply At Different Periods Of Growth On The Development, Yield And Quality Of Flax, William K. Soule
The Effect Of A Varying Moisture Supply At Different Periods Of Growth On The Development, Yield And Quality Of Flax, William K. Soule
Electronic Theses and Dissertations
In the flaxseed producing section of the United States consisting of the states of North Dakota, South Dakota, and Minnesota and Montana, periods of drought frequently occur during some part of the growing season. The time of occurrence varies from early spring to fall. Such periods have a profound effect on the normal growth of the plant.
A General Discussion Of Trichinella Spiralis (Owen), An Investigation Of Infection Of The Brown Rat, And A Life History Study Of The Parasite In The White Rat, Carl A. Johnson
Electronic Theses and Dissertations
The purpose of this treatise is threefold: first, to present a general discussion of Trichinella spiralis,; second, to present the results of an investigation of infection with trichinae of 100 brown rats; and third, to present the results of infecting white rats under laboratory conditions.
Greenhouse Studies On The Relationship Of Age Of Wheat Plants To Infection By Puccinia Graminis Tritici, George W. Eade
Greenhouse Studies On The Relationship Of Age Of Wheat Plants To Infection By Puccinia Graminis Tritici, George W. Eade
Electronic Theses and Dissertations
The resistance of wheat to the stem-rust organism (Puccinia graminis tritei) has been under investigation for a number of years. Although rust resistance has been investigated from various angles, there still remains a question as to the nature of resistance, the time when resistance first appears in plants and whether or not it is of a stable character. Peltier found that environmental conditions could change the degree and type of stem rust infection on wheat plants; Miss Hart proved that stomatal behavior was very important in the rust resistance, and Harrington and Aamodt studied the inheritance of rust resistance and …
Comparative Metabolism Of Several Calcareous Minerals In Poultry Feeding, John T. Tripp
Comparative Metabolism Of Several Calcareous Minerals In Poultry Feeding, John T. Tripp
Electronic Theses and Dissertations
In part one of this study it was found that chickens when given oyster shells, in addition to their regular diet, produced a greater number of eggs and eggs of greater shell strength than did the chickens that were given the other calcareous materials used in this experiment. Oyster shell was followed in the order of their effectiveness by clam shells, Black Hills limestone, Nenno chalk stone, and Wisconsin dolomitie limestone.
Certain Cultural Characteristics Of Digitalis Pupurea, (Linne) With A Proposed Chemical Assay, Clark W, Eidsmoe
Certain Cultural Characteristics Of Digitalis Pupurea, (Linne) With A Proposed Chemical Assay, Clark W, Eidsmoe
Electronic Theses and Dissertations
Since its introduction into modern medicine digitalis has occupied a very important position in our material medica. Its widespread use as a remedy in conditions of failing heart, and its effectiveness as a diuretic in certain dropsical conditions have gained for it a reputation which is equaled by few other drugs. The opinion of pharmacologiate and physicians as to its mode of action and its field of clinical usefulness has been revised a number of times, and there is much diversity of teaching as to its use in special ailments. Among some workers there is a tendency to restrict its …
Studies In The Life History Of The Croton Bug, Blatella Germanica (Linnaeus), Laurence Adams Carruth
Studies In The Life History Of The Croton Bug, Blatella Germanica (Linnaeus), Laurence Adams Carruth
Electronic Theses and Dissertations
The Croton bug, or German Roach as it is commonly called, has been widely known for centuries. In the past, a considerable amount of work was done in attempting to find methods of controlling this insect, but relatively little attention was given to a study of its morphology, time of development, or to the finer details of the life history. this lack of information is probably due, in part to the fact that there are several similar common species of roaches and also because the Croton bug has probably received less attention than the other roaches, at least from a …
A Study Of The Farm Shop Curriculum, Robert B. Fall
A Study Of The Farm Shop Curriculum, Robert B. Fall
Electronic Theses and Dissertations
The building of a course to teach the principles underlying mechanical operations on farms has been and still is under criticism, and probably will continue to be for some time to come; but it is such an important brench, or part, of farming that was thought that any contribution which could be made to assist in a better understanding of the problem would be worth while, hence this study.
Abortive Stamens And Carpels In Lychnis Alba, Gus B. Ulvin
Abortive Stamens And Carpels In Lychnis Alba, Gus B. Ulvin
Electronic Theses and Dissertations
Botanists have long been interested in the manner of "sex expression" in plants. Some plant shave perfect flowers, that is, both sexes are expressed in a single flower, with no variation from this condition within the species. Other plants have flowers in which only one or the other sex is expressed, while still other plants occur in which "pure staminate or pure carpellate and all intermediate degrees" occur.
The Anatomy Of The Germinating Bulbil Of Lilium Tigrinum, Katherine Harris Tripp
The Anatomy Of The Germinating Bulbil Of Lilium Tigrinum, Katherine Harris Tripp
Electronic Theses and Dissertations
Apparently very little, if any, anatomical investigation has been made of the bulbil of Lilium tigrinum, though it has often been used as a propagating organ and consequently, the problem suggested attractive possibilities in an almost virgin field of investigation. Collections were made from five different plants beginning Sept. 27, 1928 until July 22, 1929. The older bulbils were removed from the axils of the foliage leaves and fixed in formalin acetic alcohol. They were gradually dehydrated by treatment with alcohol increasing the percentage 10% from 50 up to 100%. Xylol treatment in increasing percentages was then resorted to, until …
The Morphology, Life History, And Control Of Some Common Species Of Oniscoidea Found In South Dakota, M. T. Fredricksen
The Morphology, Life History, And Control Of Some Common Species Of Oniscoidea Found In South Dakota, M. T. Fredricksen
Electronic Theses and Dissertations
Since practically no work has been done upon the life history and development of the common pill bugs or sow bugs, it is the aim of this paper to record the investigations of the life history and development as carried on by the author. The morphology was added in order to give the reader a definite idea of the organization and structure of these species.
A Systematic Treatise Of The Coccidae (Scale Insects) Of Brookings County, South Dakota, Merrill K. Riley
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.
A Contribution On The Staminate Flower Of Cucumis Sativus, Kenneth W. Simons
A Contribution On The Staminate Flower Of Cucumis Sativus, Kenneth W. Simons
Electronic Theses and Dissertations
In Heimlich’s recent paper (2) on the staminate flower of Cucumis sativus, the conclusion was reached that the tetrasporangiate stamen was complete while the bisporangiate stamen was only half complete. In Miller’s more recent investigation of Schinocystis lobata (4), the bisporangiate stamen was shown to be complete and the tetrasporangiate stamen double. These opposing points of view suggest the advisability of further investigation in the Cucurbitaceae. Since Heimlich described two separate apical prolongations on each tetrasporangiate stamen and only one on the bisporangiate stamen, it seemed to the present writer that these prolongations might indicate the double and single natures …
The Effect Of Treatment With Ethylene Chlorhydrin Upon The Respiration Of Sweet Potatoes (Ipomea Batatas), Leon J. Tyler
The Effect Of Treatment With Ethylene Chlorhydrin Upon The Respiration Of Sweet Potatoes (Ipomea Batatas), Leon J. Tyler
Electronic Theses and Dissertations
- Treatment with ethylene chlorhydrin produced marked results in the respiration of four of five varieties of sweet potatoes tried.
- Not all varieties of sweet potatoes respond alike to the same treatment. Porto Rico variety of sweet potatoes did not respond to the treatment.
- There was a considerable difference in the amount of CO2 respired by different varieties.
- The need for further research here with respect to the specific effect of chemicals upon the cell system becomes apparent and again emphasizes the importance of Biochemistry.
- There was possibly an accelerative effect on sprouting due to increased respiratory processes brought about …
The Introduced Plants Of South Dakota, William Houk
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 In The Metabolism Of The Adult Honey Bee, M. D. Farrar
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
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
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 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 …
The Ontogeny Of The Vascular Elements In Zea Mays, George L. Cross
The Ontogeny Of The Vascular Elements In Zea Mays, George L. Cross
Electronic Theses and Dissertations
- The vascular bundles of Zea mays are of the monocot type, except that true amphivasal bundles are found only in the leaves.
- The xylem and phloem are arranged collaterally, with the xylem occupying the part of the bundle nearer the center of the stem.
- 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 …
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
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 The Forage Plants Of South Dakota With Their Fungous And Insect Enemies, David Griffiths
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 …