Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Life Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 158881 - 158910 of 159257

Full-Text Articles in Entire DC Network

The Insects And Mites Injurious To Poultry In Nebraska And Their Control, M. H. Swenk, F. E. Mussehl Dec 1928

The Insects And Mites Injurious To Poultry In Nebraska And Their Control, M. H. Swenk, F. E. Mussehl

Nebraska Agricultural Experiment Station: Historical Circulars

There are a number of different kinds of insect and mites (arthropods) that are more or less injurious to poultry in Nebraska. This circular is designed to give practical information concerning these pests and their control.


Initiation Of Development In Arbacia, E. E. Just Jun 1928

Initiation Of Development In Arbacia, E. E. Just

Faculty Reprints

No abstract provided.


Bulletin No. 206 - Treehopper Injury In Utah Orchards, Charles J. Sorenson Jun 1928

Bulletin No. 206 - Treehopper Injury In Utah Orchards, Charles J. Sorenson

UAES Bulletins

Treehopper injury is a problem that has given many fruit growers in Utah some concern during recent years. These people have observed that their young fruit trees and the twigs and smaller branches of older trees have been attacked during the autumn of each year in a manner that produced numerous cuts which later formed scars. The trees frequently became unthrifty, and more or less deformed and stunted, as a result of these annual attacks.

The investigation reported in this publication was made for the purpose of ascertaining the present status of the treehopper situation in Utah orchards.


Initiation Of Development In Arbacia, E. E. Just Jun 1928

Initiation Of Development In Arbacia, E. E. Just

Department of Biology Faculty Publications

No abstract provided.


Sporogenesis In Botrichium Virginianum Swartz, Lewis Abel Stocking Jun 1928

Sporogenesis In Botrichium Virginianum Swartz, Lewis Abel Stocking

Bachelors’ Theses

The earliest resultful work done in Pteridophytes, very closely similar to Botrychium Virginianum Swartz, was the work of Goebel (1890) on the Ophioglossales. Bower (1890) followed Goebel in his work on the Ophioglossales. He completed a work in 1896, which according to Burlingame (1907), who also did valuable work on the Ophioglossales, is the most comprehensive and satisfactory that has thus far been done. This work had a stimulating effect upon the early study of Botrychium Virginianum Swartz because of the almost entirely similar histology of the two plants. Burlingame’s (1907) work in the Ophioglossales, was done in 1907. He …


The Anatomy Of The Honeybee, Carol M. Steib Jun 1928

The Anatomy Of The Honeybee, Carol M. Steib

Bachelors’ Theses

The honeybee has lived In a society under such complex laws and has executed such varied and difficult labors that it has attracted the attention of men and women from the very earliest of times. Aristotle, Cato, Varro, Pliny, Columella, Pollodius, all studied the bee; as also did Arlstomachus (who, if we are to believe Cicero, watched them for forty-eight years) and Phylisius whose writings have been lost.


Branched Cells Of Pteris Cretica L., Var. "Albo-Lineata, Hort And Pellaea Viridis (Forksk) Prantl", Mary Elizabeth Trechter Jun 1928

Branched Cells Of Pteris Cretica L., Var. "Albo-Lineata, Hort And Pellaea Viridis (Forksk) Prantl", Mary Elizabeth Trechter

Bachelors’ Theses

The fern gametophyte offers a large field for experimental work, not only in the reproductive processes but in the development of prothallia from the germination of the spore. The ordinary fern spore germinates on soil or in water. Prothallia, which have formed branched cells, have been found by a number of workers, and attempts have been made by some to explain the cause of the branching.


The Development Of The Gametophyte And The Apogamous Embryo Of Pellaea Viridis (Forksk) Prantl, Eugene Stowell Mcdonough Jun 1928

The Development Of The Gametophyte And The Apogamous Embryo Of Pellaea Viridis (Forksk) Prantl, Eugene Stowell Mcdonough

Bachelors’ Theses

A sporophyte tissue element in the cells of a fern gametophyte was first reported by Leszcyc-Suminski (1848) who found tracheids near the apical notch of the prothallium of Pteris sulcata L.


Favorable Cultural Conditions For Tuber Development In Nephrolepis Cordifolia (L.) Presl. (Nephrolepis Tuberosa (Bory.)Willd.), Hazel Mae Henderson Jun 1928

Favorable Cultural Conditions For Tuber Development In Nephrolepis Cordifolia (L.) Presl. (Nephrolepis Tuberosa (Bory.)Willd.), Hazel Mae Henderson

Bachelors’ Theses

Recently there has been brought to the attention of writers a number of plants that produce water-storing organs commonly known as tubers. Luerssen, (Campbell, 1905) refers to special reproductive bodies or tubers in Marsilia hirsuta. These tubers are thought to survive long periods of drought, and to germinate under favorable conditions. Nephrolepis cordifolia (L.) Presl., one of the Boston ferns, which produces tubers in large numbers has interested a number of investigators.


The Anatomy Of The Timber Rattlesnake, Ruth H. Heinemann May 1928

The Anatomy Of The Timber Rattlesnake, Ruth H. Heinemann

Bachelors’ Theses

Snakes are the most highly specialized of all reptiles. The absence of limbs, in itself, is a great specialization. They possess a great modification of the jaws which enables them to engulf large prey entire. Probably the most out­ standing specialization is the remarkable modification of dentition in the venomous snakes. The so-called fangs are nothing more than teeth modified to a great degree.


Christ Crucified: A Book Of Sermons Together With A Lecture On Evolution, G. C. Brewer Jan 1928

Christ Crucified: A Book Of Sermons Together With A Lecture On Evolution, G. C. Brewer

Stone-Campbell Books

No abstract provided.


Trends And Silvicultural Significance Of Upland Forest Successions In Southern New England, Harold J. Lutz Jan 1928

Trends And Silvicultural Significance Of Upland Forest Successions In Southern New England, Harold J. Lutz

Yale School of the Environment Bulletin Series

The problems encountered in the silvicultural treatment of southern New England forests are many. They result largely from the extremely diverse and complex conditions under which the forest is developed. Due to the glaciated nature of the region the soil character changes radically within relatively short distances. With changes in soil from place to place come minor changes of forest composition. One of the chief reasons for the problems which the silviculturalist encounters in this region is the large number of species which make up the stands. There are approximately thirty commercially important forest trees in southern New England. The …


A Research Delusion, George L. Peltier Jan 1928

A Research Delusion, George L. Peltier

Department of Plant Pathology: Faculty Publications

With the administrative heads of many of our educational institutions demanding a doctorate of every member of the permanent staff, as it is supposed to be a prerogative for research, and the issuing of a list of titles published each year by their staff, the urge for so-called research, namely, a list of titles, goes madly on. In fact publication sometimes becomes a sort of self-defense, for the absence of any titles over a brief period of years stamps one either as lacking the ability of doing research or inefficient. Likewise, such a policy has permeated the staff, so that …


Wild Birds Introduced Or Transplanted In North America, John C. Phillips Jan 1928

Wild Birds Introduced Or Transplanted In North America, John C. Phillips

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The early history of the introduction of foreign birds into this country is mostly clothed in darkness. The records of many attempts, if such there were, have long since been buried in back numbers of local newspapers, and if any experiment was unsuccessful it was soon forgotten. Hence, one trying to get an accurate idea of what has happened soon realizes that he is following a hopeless quest. It is much the same with the transplanting of native birds, especially game birds, which have been carried about all over the country from west to east and from east to west …


The Structure And Development Of Corallobothrium With Descriptions Of Two New Fish Tapeworms (With Five Plates), Hiram Eli Essex Jan 1928

The Structure And Development Of Corallobothrium With Descriptions Of Two New Fish Tapeworms (With Five Plates), Hiram Eli Essex

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Introduction

Representatives of the genus Corallobothrium from American fish have never been described. Marshall and Gilbert (1905) report two members of this genus taken from Ameiurus melas (black bullhead) caught in the lakes at Madison, Wisconsin. La Rue (1914) refers to an undescribed species of Corallobothrium encysted in the livers of A. melas and A. nebulosus (common bullhead) from the Illinois River. Ward (1918) noted the presence of a species of Corallobothrium in lctalurus punctatus (channel-cat) at Milford, Nebraska. Aside from these incidental references, the American literature contains no information on this interesting group of fish tapeworms.

The acquaintance of …


Biological And Psychological Study Of Twenty Pairs Of Twins Ranging From Seven To Eighteen Years Of Age, Albert C. Worden Jan 1928

Biological And Psychological Study Of Twenty Pairs Of Twins Ranging From Seven To Eighteen Years Of Age, Albert C. Worden

University of the Pacific Theses and Dissertations

Although twins have always been of great Interest the only early data available are upon conjoined twins. The first record of such twins, which 18 known, 1s of the Bid-dendent Maids in the year 1100 A. D. From that date to the year 1824 when the Siamese Twins were born and later made famous by Barnum and Bailey's Circus, there have been many Interesting accounts of conjoined twins, but the nature of the present work and the probable unreliability of these accounts would make any discussion on the subject of these early conjoined twins not worth while.


Circular No. 68 - Summary Of Publications Jul 1927

Circular No. 68 - Summary Of Publications

UAES Circulars

Circular No. 68 contains a summary of publications issued by the Utah Agricultural Experiment Station, thru its Publications Division, since September 1, 1926. The publications of this Station are no longer sent to a general mailing list (except in cases of libraries and state editors) but are sent only on request. Therefore, copies of any of the publications listed will be sent without charge to those requesting them as long as the supply is available. However in the case of abstracts of scientific and technical papers the supply is very limited and the requests for these should be limited …


The Development Of The Gametophyte And Apogamous Sporophyte In Cheilanthes Feei, Moore, Florence Madeline Steil Jun 1927

The Development Of The Gametophyte And Apogamous Sporophyte In Cheilanthes Feei, Moore, Florence Madeline Steil

Bachelors’ Theses

Since Leszeye-Suminski's (1848) discovery of tracheids near the apical notch of the prothallium of Pteris sulcata, problems pertaining to apogamy or related phenomena have offered a wide field for botanists. Nearly all workers interested in the study of apogamous ferns, have contributed something of physiological or cytological interest


Some Methods Of Vegetative Reproduction In Nephrolepis Cordifolia, Presl, Mildred Frances Hubel Jun 1927

Some Methods Of Vegetative Reproduction In Nephrolepis Cordifolia, Presl, Mildred Frances Hubel

Bachelors’ Theses

Nephrolepis cordifolia, Presl is reproduced by means of spores, rhizomes, runners, and tubers. Little work has been done, however, on the tubers. In fact, the tubers are generally thought to be for storage only and consequently of little importance. At the Royal Palm Nurseries, Oneca, Florica where the plants for this study were obtained, the tubers were removed and thrown away. When a request was made for a large plant with the tubers, they replied: "We cannot supply the large cordifolia with the bulbs, as they were pruned off all our plants. They do not present a very attractive appearance …


Forty-First Annual Meeting Of The Iowa Academy Of Science, May 6 And 7, 1927, Iowa Academy Of Science May 1927

Forty-First Annual Meeting Of The Iowa Academy Of Science, May 6 And 7, 1927, Iowa Academy Of Science

Iowa Academy of Science Documents

No abstract provided.


Distributional List Of The Birds In Utah, Clarence Cottam May 1927

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 May 1927

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 …


Bulletin No. 201 - Economic Insects In Some Streams Of Northern Utah, James G. Needham, Reed O. Christenson Apr 1927

Bulletin No. 201 - Economic Insects In Some Streams Of Northern Utah, James G. Needham, Reed O. Christenson

UAES Bulletins

The food of trout in our mountain streams is mainly insects. It is, in part, land insects that fall on the water and are taken as they float upon its surface, but in a much larger part it is insects that grow up in the water and are taken in their immature stages. These are the constant and dependable food-supply. They have been little studied hitherto. This bulletin is a report of a preliminary examination of some Utah streams, made for the purpose of discovering what forms of life are present in the streams and in what relative abundance. Some …


The Pine Tipmoth In The Nebraska National Forest, M. H. Swenk Apr 1927

The Pine Tipmoth In The Nebraska National Forest, M. H. Swenk

Nebraska Agricultural Experiment Station: Historical Research Bulletins

On May 8, 1911, Mr. Smith Riley, the District Forester, with headquarters at Denver, in a letter to Acting Supervisor Pierce at Halsey, requested that the Nebraska Agricultural Experiment Station take up energetically the investigation of the pine tipmoth in the Nebraska National Forest. This request being presented to the Department by Mr. Pierce later in the month resulted in the presentation of the problem to the Experiment Station Council as a proposed Station project. The project was approved on May 31, 1911, and the expenses of the investigations of 1911 and 1912 that are reported upon in this bulletin …


Preliminary Notice Of A New Proboscidean Amebelodon Fricki, Gen. Et Sp. Nov., Erwin Hinckley Barbour Jan 1927

Preliminary Notice Of A New Proboscidean Amebelodon Fricki, Gen. Et Sp. Nov., Erwin Hinckley Barbour

Bulletin of the University of Nebraska State Museum (1924–2023)

Pursuant to advice from Mr. A. S. Keith of Freedom, Frontier County, Nebraska, the first Morrill Geological Expedition of the year was organized with Mr. Philip Orr in charge, and Mr. Keith's farm was visited at once, and on April 4th, 1927, the mandible, one rib, and a toe bone of a new proboscidean were procured.


The Testing Of Coniferous Tree Seeds At The School Of Forestry, Yale University, 1906-1926, James W. Toumey, Clark L. Stevens Jan 1927

The Testing Of Coniferous Tree Seeds At The School Of Forestry, Yale University, 1906-1926, James W. Toumey, Clark L. Stevens

Yale School of the Environment Bulletin Series

Quality in forest tree seed centers in (a) origin; (b) genuineness; (c) purity; and (d) viability. The purchaser should insist on knowing the origin of the seed and the locality where it was collected.

Without seed testing establishments for investigating forest tree seeds by standardized methods under an established technique, nurserymen and foresters will continue to sow seed beds and undertake direct seeding without an adequate knowledge of the origin, genuineness, purity, and viability of the seeds used.


Factors Controlling Germination And Early Survival In Oaks, Clarence F. Korstian Jan 1927

Factors Controlling Germination And Early Survival In Oaks, Clarence F. Korstian

Yale School of the Environment Bulletin Series

There is little information available upon the seed and seedling characteristics of the American oaks. Among the fundamental problems in American silviculture, those which relate to seed efficiency are especially important. The future productiveness of the hardwood forests in which chestnut has been an important·element rests largely upon seed and sprout efficiency. Seed efficiency is governed by (I) seed production, (2) seed distribution, and (3) the factors affecting the reproductive value of the seed, such as viability, storage of seed in the litter of the forest floor, and destruction by insects and rodents.


A Revision Of The Nematodes Of The Leidy Collection, Arthur C. Walton Jan 1927

A Revision Of The Nematodes Of The Leidy Collection, Arthur C. Walton

Harold W. Manter Laboratory of Parasitology: Library Materials

Through the courtesy of Dr. Henry Baldwin Ward of the University of Illinois, and of Dr. J. Percy Moore of the University of Pennsylvania, the extensive nematode collection assembled by the late Joseph Leidy, and now housed in the museum of the University of Pennsylvania, has been made available for critical study and the present report is the first of a series covering this material. The writer wishes to express his hearty appreciation of the kindness of these two men, and also of that of Dr. Joseph Leidy, Jr., in making this opportunity possible. To make the study more complete …


Some Ecological Aspects Of Agriculture In The Prairie, J. E. Weaver Jan 1927

Some Ecological Aspects Of Agriculture In The Prairie, J. E. Weaver

Department of Agronomy and Horticulture: Faculty Publications

It is of more than passing interest that the cereal crops, namely: corn, spring and winter wheat, oats, barley, sorghum, and millet, have their center of greatest production in that portion of the United States originally covered by grassland. In fact, some are grown almost entirely in the grassland region, and other crops, as alfalfa and flax, which are similar in growth habits to wild legumes, wild flaxes, etc., growing among the grasses, also have their greatest acreage in grassland. Likewise, the largest areas of fruit production, including such tree fruits as apples, peaches, pears, and bush fruits as blackberries, …


The Differential Reaction Of Strains Within A Variety Of Wheat To Physiologic Forms Of Puccinia Graminis Tritici, T. A. Kiesselbach, George L. Peltier Dec 1926

The Differential Reaction Of Strains Within A Variety Of Wheat To Physiologic Forms Of Puccinia Graminis Tritici, T. A. Kiesselbach, George L. Peltier

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Black stem rust of wheat (Puccinia graminis tritici (Pers.) Erikss. & Henn.), which occurs in Nebraska and thruout most of the wheat producing regions of the world, is of a composite nature, in that it consists of a number of physiologic forms which can be determined by their action on different varieties of Triticum species, as shown by Stakman and Levine. The ordinary commercial variety of wheat may likewise be regarded as a mixture, in that it consists of numerous strains, which differ in some more or less important characteristics, as has been frequently indicated in the literature concerning …