Life Sciences Commons^™

The Inheritance Of A Recurring Somatic Variation In Variegated Ears Of Maize, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

The inheritance of variegation has special interest and importance in genetics. It is with forms of variegation that the only two certainly known cases of non-Mendelian inheritance have had to do. I refer to Baur's experiments with Pelargonium, in which crosses of green-leaved and white-leaved forms exhibited somatic segregations in F₁ that bred true in later generations, and to Correns 's work with Mirabilis, which showed green and white leaf color, to be inherited through the mother only. De Vries's con- ception of "ever-sporting" varieties was apparently founded largely upon the behavior of variegated flowers in pedigree …

Multiple Factors Vs. "Golden Mean" In Size Inheritance, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Groth's preliminary note on the "golden mean" in the inheritance of sizes in SCIENCE of April 17, 1914, pp. 581-584, deserves the attention of geneticists. Its publication is of such recent date that I need only call attention to one or two points that seem to me of particular moment.

In brief, Groth's hypothesis is that the mode

of inheritance in F_l not only of surfaces and

volumes, but also of linear dimensions is to be

expressed by √ab rather than by a + b /2

where a and b are parent sizes. The hypothesis

is based upon …

Alfalfa Inoculation Tests, C. W. Pugsley

University of Nebraska Historical Extension: Bulletin

During the winter of 1909-10 an effort was made to secure cooperators among the farmers of Nebraska to test the value of inoculating newly seeded alfalfa fields. This investigation was 8uggested by reports received from correspondents during 1909. The names of farmers willing to cooperate were secured by correspondence and by conferences at the various Short Courses held during that year.

In the spring of 1910 about thirty-five farmers, located largely near Broken Bow, Cambridge, Franklin, and Blair, agreed to test the effect of cultures sent by the United States Department of Agriculture, soil from well-established alfalfa fields, and farm …

The Inheritance Of Quantitative Characters In Maize, R. A. Emerson, E. M. East

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The experiments conducted by one of the writers were begun at the Connecticut Agricultural Experiment Station at New Haven in 1906 and removed to the Bussey Institution of Harvard University at Forest Hills, Massachusetts, in 1909. The materials employed in this study consisted principally of crosses of Tom Thumb pop with Black Mexican sweet and of Watson flint with Leaming dent. The number of rows per ear were noted in several other crosses, the parents of which are listed later in this paper. The experiments of the other writer were begun at the Nebraska Agricultural Experiment Station at Lincoln in …

Growing Crops In Western Nebraska: Report Of Experimental Substation, North Platte, Nebraska, W. P. Snyder, W. W. Burr, E. A. Burnett

University of Nebraska Historical Extension: Bulletin

No abstract provided.

A Dry Rot Of The Irish Potato Tuber, E. Mead Wilcox, George K.K. Link, Venus W. Pool

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The first specimens of the dry rot herein described were received by the department of Agricultural Botany during the winter of 1907-1908 from western Nebraska. A preliminary survey of the situation showed clearly the importance of this new rot, and an exhaustive investigation of the disease was outlined and has been continued to the present time. The present publication gives the results secured to date in our investigation of this disease.

Some Of The Next Steps In Botanical Science, Charles E. Bessey

School of Biological Sciences: Faculty Publications

When one who has worked long in any

field of science speaks before an audience

such as this he is expected to say something

about the condition of his branch of science

when he began work with meager and

poorly adapted apparatus, to contrast it

with its greatly improved condition to-day,

and to dwell with pride upon the finely

equipped laboratories with costly apparatus

especially designed for particular

experiments, to be found by the twentieth

century scientific student. And 1 must

confess that the temptation to do so was

one difficult to resist, for we who have

grown old in …

Two Lincoln (Nebraska) Typhoid Fever Epidemics Of 1911 And 1912., Herbert H. Waite

School of Biological Sciences: Faculty Publications

On August 29, 1912, I was requested by the Board of Health of the city of Lincoln to make an investigation to determine if possible the origin and cause of an outbreak of a disease reported as typhoid fever which was then prevailing. This outbreak was said to be most prevalent in one particular portion of the city and consequently attention was turned to that portion. Of the cases reported an investigation was made of over 60 individuals and after considering all the probable causes for the majority of those affected the conclusion was reached that all could be logically …

Ectoparasiten Und Abstammungslehre, Heinrich Fahrenholz

Harold W. Manter Laboratory of Parasitology: Library Materials

Bei Studien an parasitischen Milben im Jahre 1907 tauchte mir die Frage auf: Lassen sich aus dem Vorkommen gleicher oder verwandter Schmarotzer auf verschiedenen Wirten Rückschlüsse auf die Verwandtschaft letzterer machen?

Shorter Articles And Discussion Simplified Mendelian Formulae, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

I was somewhat surprised by 'Morgan's and Castle's suggestions for a simplification of Mendelian formulae. My surprise was not occasioned so much by the forms these suggestions took as by the fact that any pronounced changes were deemed necessary. I had not only employed the usual formula in my own work but had found no difficulty worth mentioning in understanding the formula used by most other workers in Mendelian fields. My experience with students in elementary courses in genetics had not prepared me for the idea that such formula were particularly difficult. Nevertheless I believe in simplifying the formulae if …

The Possible Origin Of Mutations In Somatic Cells, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

That mutations are accompanied by some change in the germ-plasm is, I take it, indisputable. Have we, however, any reason to suppose that the change takes place within the germ cells? I am not sure, as a matter of fact, that genetists in general regard the gametes as the place of origin of mutations. It is true, however, that experiments in the artificial production of mutations in plants have been limited largely to treatments of the ovaries from about the time of the reduction division to about the time of fertilization. This suggests a belief on the part of investigators …

Shorter Articles And Reports: The Simultaneous Modification Of Distinct Mendelian Factors, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

In another paper on the inheritance of a recurring somatic variation in variegated ears of maize, it was shown that the amount of red color developed in the pericarp of variegated seeds bears a definite relation to the development of color in the progeny of such seeds. The relation is such that the more color there is in the pericarp of the seeds planted the more likely are they to produce plants with wholly self-red ears and correspondingly the less likely to produce plants with variegated ears. Self-red ears thus produced behave just as if they were hybrids between self-red …

Beef Production., H. R. Smith

University of Nebraska Historical Extension: Bulletin

Contents: Part I. Comparison of Rations. Part II. Comparison of Breeds and Types.

Some American Lebertia, Ruth Marshall

School of Biological Sciences: Faculty Publications

The genus Lebertia of the water-mites is easily recognized by the character of the epimera. It belongs to a small group of genera, the subfamily Lebertiinae, characterized by the union of the four pairs of epimera into a single group, with their more or less complete fusion. This forms a shield which covers a large part of the ventral surface of the body.

Spraying Apple Trees

University of Nebraska Historical Extension: Bulletin

The degree of success in spraying depends almost wholly upon when the materials are put on and how they are applied. 'The two principal pests that concern Nebraska apple growers are the apple scab and the codling moth worm. There are other injurious insects and fungous diseases common to the orchard, but if the orchard is properly treated for those two the others will in a large measure be controlled.

A Consideration Of The Physiology And Life History Of A Parasitic Botrytis On Pepper And Lettuce, George L. Peltier

Department of Plant Pathology: Faculty Publications

During the autumn of 1911, while gathering the peppers (Capsicum) in the vegetable plat of the Missouri Botanical Garden, the writer observed a fungus which was appearing as a parasite on the fruits. The peduncles were covered with a dark brown mass of conidia and mycelium, which so weakened the tissues that the fruit soon fell to the ground. On opening the peppers a number of large, flat, crust-like sclerotia, 1 cm. long and .5 cm. wide, were found to fill the interior. In most cases the seeds were also covered with the crust-like masses. The conidial stage …

The Unexpected Occurrence Of Aleurone Colors In F2 Of A Cross Between Non-Colored Varieties Of Maize, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Before the Mendelian methods of analysis became available, considerable wonder would doubtless have been excited by the "mysterious" appearance in F₂ of one colored grain-purple or red-to every five or six white ones in case of a maize cross, both parents and F, of which had only white grains. An occurrence of this sort has recently been noted in one of my maize cultures and the F2 numbers are explained here as a trihybrid or tetrahybrid ratio. The crosses in question were made primarily for a study of size inheritance and fairly large numbers have been grown. The varieties …

Spraying As An Essential Part Of Profitable Apple Orcharding, R. A. Emerson, R. F. Howard, V. V. Westgate

University of Nebraska Historical Extension: Bulletin

It was therefore planned from the start not merely to demonstrate the possibility of controlling apple insects and diseases but also to determine whether they could be controlled profitably. To accomplish this it was necessary to know: exactly what it cost to spray, what sprayed fruit yielded, and what it was worth in comparison with unsprayed fruit from the same orchards. In every spraying demonstration the time spent in mixing and applying the materials and the quantity of material used were recorded. The cost of labor of men and teams per hour was taken at the orchard owners' estimates and …

The Present Methods Of Teaching Entomology, J. H. Comstock

Department of Entomology: Faculty Publications

The present methods of teaching entomology followed in the United States have been developed almost entirely by men now teaching this subject. A second generation of teachers has begun its work; but the first is still on the stage. We h3i¥e progressed far enough, however, to make it worth while for the teachers to compare methods, in order that each may profit by the experience of the others. In a conference of this kind the contribution of each to the discussion will be, naturally, at first, merely a statement of the methods evolved in our several widely separated institutions. Then …

Present Methods Of Teaching Entomology, H. T. Fernald

Department of Entomology: Faculty Publications

In teaching entomology, much depends upon the ultimate aim of the student. A course in introductory entomology, whether as a required or an elective subject is sure to include many students who will not continue the subject farther. It is at least probable, that these students will form over half of the class, and accordingly, the introductory treatment should be arranged on the basis of the greatest good to the greatest number. This will usually mean some slight knowledge of insect anatomy, particularly external anatomy, and a general survey of insects as a group, with special attention to the pests …

The Present Methods Of Teaching Entomology, Herbert Osborn

Department of Entomology: Faculty Publications

In a discussion of the methods of teaching entomology, it is almost necessary to take a hasty view of the growth of the subject and of the different methods of imparting knowledge in it during the past half century. We need scarcely go back of this, because for the United States, at least, the growth of the teaching of entomology as a subject included in a college curriculum has had its growth within that time. In fact, practically all of the development of the teaching outside of two or three localities has been within the last twenty-five' years. Naturally the …

New Elementary Agriculture, Charles E. Bessey, Lawrence Bruner, Goodwin D. Swezey

School of Biological Sciences: Faculty Publications

This is an agricultural nation. The products of the soil are the basis of her industries and her prosperity. The children of our great Commonwealths should be familiar with our crops, our grains and grasses, our flowers and fruits, our trees and shrubs and weeds, our domestic animals and birds and insects. Our children should have a practical knowledge of the management of a farm, of the composition of the soil, and of the adaptability of the farm and its soil for the cultivation of certain plants and the counter effect of such plant growth upon the soil. They should …

Present Methods Of Teaching Entomology At The University Of Nebraska, Lawrence Bruner

Department of Entomology: Faculty Publications

'When our Secretary sent out his preliminary notification of this meeting and asked me to take part in a discussion of "present methods of teaching Entomology," the matter at first seemed of little importance so far, at least, as the speaker was concerned. However, after giving the subject some thought I have decided that it might be well at least to take the time and trouble to attempt to explain briefly a few of the methods by which the student in Nebraska is enabled to absorb some entomological information. In order to do this with an unbiased feeling it might …

Botanical Teaching, Charles E. Bessey

School of Biological Sciences: Faculty Publications

Some months ago a suggestion was made that at this dinner we should ask ourselves the question: Why is it that with the enormous classes we are having in botany there is a marked dearth of properly trained men who can serve as instructors in colleges and universities?

Discussion And Correspondence Coupling Vs. Random Segregation, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

To the editor of science: The suggestion offered by Morgan, in SCIENCE of September 22, to account for the coupling and repulsion of factors for various characters in inheritance in such forms as Abraxas, Drosophila, fowls, sweet peas, etc., incites this note.

Briefly Morgan's hypothesis is (1) that the materials representing factors that couple are "near together in a linear series" in the chromosomes; (2) that, when pairs of parental chromosomes conjugate, "like regions stand opposed "; (3) that "homologous chromosomes twist around each other," but that the separation of chromosomes is in a single "plane"; (4) that, thereby the …

New Studies Of The Arrhenuri, Ruth Marshall

School of Biological Sciences: Faculty Publications

Since the publication of "The Arrhenuri of the United States," in 198, the author has been fortunate enough to secure enough more material to justify the publication of a supplementary paper on this large genus of water-mites. This material consists of collections from new localities in the United States, and of additional material from old collecting grounds, together with a few specimens from other countries. The author's own collections were made in Wisconsin and Illinois. A few new places were visited, as the lakes about Milwaukee ; and more extensive collections were made in previously known bodies of water, as …

Testing Seed Corn, E. G. Montgomery, C. W. Pugsley

University of Nebraska Historical Extension: Bulletin

Testing every ear of seed corn will cost about 5 to 10 cents per acre, and may mean 5 to 10 bushels per acre increased yield. Do it now before the rush of farm work. In many parts of the state not one-half the seed corn will grow. Reports from Farmers' Institutes in various sections indicate that the vitality is very low.

Fearsome Creatures Of The Lumberwoods: With A Few Desert And Mountain Beasts, William T. Cox, Coert Du Bois

Nebraskiana Publications: Resources and Materials on the 37th State

Every lumber region has its lore. Thrilling tales of adventure are told in camp wherever the logger has entered the wilderness. The lumber jack is an imaginative being, and a story loses none of its interest as it is carried and repeated from one camp to another. Stories which I know to have originated on the Penobscot and the Kennebec are told, somewhat strengthened and improved, in the redwood camps of Humboldt Bay. Yarns originating among the river drivers of the Ottawa, the St. Croix, and the upper Mississippi are respun to groups of listening loggers on Vancouver Island. But …

The Inheritance Of Sizes And Shapes In Plants, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Some years ago Lock reported a cross of a tall race of maize with a shorter race which produced an intermediate height in F₁ and exhibited no segregation in F₂ when crossed back with one of the parents. Castle's results with rabbits are very similar to those of Lock with maize. Castle summarizes his results in part as follows:

A cross between rabbits differing in ear-length produces offspring with ears of intermediate length, varying about the mean of the parental ear-lengths. . . . A study of the offspring of the primary cross-breds shows the blend of the …

Oats, E. G. Montgomery

University of Nebraska Historical Extension: Bulletin

There is no more serious question confronting .the Nebraska farmer today than the oat problem. During the past few years, farmers generally believe they have lost money on the crop. It is necessary to grow some spring grain crop, and while many are looking for a substitute, such as barley, speltz, and spring wheat, yet none of these crops takes the place of oats in a satisfactory manner. While soil fertility must receive immediate attention, still our yields would be decidedly increased thru the. use of varieties best adapted to the region, with good preparation of the seed·bed drilling with …