Digital Commons Network^™

The Fresh-Water Fishes Of Maine, Flavia Lucile Richardson

Electronic Theses and Dissertations

The purpose of this investigation is to determine the present status of the fish fauna of Maine. Data assembled during the course of this study includes descriptions of native and introduced species, records concerning their present distribution, and the extent of the official introduction of non-indigenous species. From this material may be derived conclusions respecting the survival of the introduced species and the probable capacity of the native species to successfully compete with them. Through the use of descriptive material assembled during the investigation of species it has been possible to construct a key as an aid in identifying any …

Distributional List Of The Birds In Utah, Clarence Cottam

Theses and Dissertations

Systematic ornithology has been woefully neglected in Utah. While this state has a number of men who know her birds and who have aroused interest in them, they have produced no published record of what we have. So far as the writer knows there is no adequate, representative, or systematic collection of Utah species within the state. Utah has, however, been fortunate in having a nuraber of expert ornithologists collect and study the bird life of different sections of bar territory.

A Study Of The Seasonal History Of Alfalfa Flowers As Related To Seed Production, John W. Carlson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A few researches have been concerned with the structure and pollination of alfalfa flowers. Others have considered the biological problems concerned in the pollination and fecundation of the flowers. In none of these studies, however, has an attempt been made to follow carefully the alfalfa flowers through various stages of development. Nor has any effort been made to determine what effect the condition and duration of these stages may have upon the resulting seed crop.

The work that follows is a study of the changes through which the alfalfa flowers pass during the season while functioning as organs of seed …

Entomological Technique As Referring To The Life History Of Insects, Andrew Jefferson Wheeler

Masters Theses

According to the statement of Kellogg in American Insects, man's real competitors are not the larger creatures that inhabit the Earth with us. These are relatively few in number and easily controlled; but the tiny creatures - the insects and insect-like creatures are the ones that present a real problem to us. They conquer us many times because they are so prolific and so numerous and because they are so small they often go unnoticed. Our Nation has realized the problem and has appropriated millions of dollars annually for the control of insects. This expenditure, however, is not sufficient and …

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

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 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

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 …

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 …