An introductory study of the oxidation mechanism of nickel

Call number: LD2668 .T4 1952 W5Master of Scienc

The Polyporaceae of Fayette Iowa

The Polyporaceae are a group of most interesting fungi which have of recent years assumed a position of prime economic importance as it has been demonstrated that many of them cause the decay of timber trees which formerly they were supposed to follow. The parasitic nature of these fungi has added a new incentive to their careful study. Some species are found only on the diseased portion of living trees, while others appear to inhabit only dead timber. Of these it is not improbable that a considerable number may be able to infect living timber and later to maintain themselves on the wood as long as those portions remain which furnish them with their food

The Morphology of Basidiophora kellermanii

This interesting fungus was first brought to the notice of mycologists in 1889. It was originally collected two years earlier by Dr. W. A. Kellerman at Manhattan, Kansas. It has since been frequently collected from Kansas and Colorado northward and eastward to Manitoba and Wisconsin. Specimens are variously labelled in herbaria under Albugo, Plasmopara, Peronospora and Basidiophora. The fungus is abundant and conspicuous in the field on its single host, Iva xanthifolia Nutt.. The first impression is that of a downy mildew, but a closer view suggests a white rust. The taxonomic position of this fungus has been a puzzle to mycologists. It presents some problems of great morphological and phylogenetic significance. The conidia are borne above the epidermis, on conidiophores quite similar to those of Basidiophora, but grouped into a sorus as in Albugo. This last character distinguished it from the Peronosporaccae while the production of spores singly on the short branches of the conidiophore separate it from Albugo

Preliminary List of the Parasitic Fungi of Fayette County, Iowa

That northeastern Iowa is a rich field for the mycologist is well known to those in any degree acquainted with the work of Prof. Holway while a resident of Decorah. From this region came numerous new species and here was gathered much information concerning others already known. While from its nearness to Decorah the region about Fayette cannot offer such facilities for pioneer work as did Decorah, yet it is a most excellent base from which to study the mycological flora of this section of Iowa. Lying as it does on the borderland between the Transitional and Upper Austral zones and midway between the plains of the west and the forests of the east this section of the state is a strategic point, so to speak. It was, therefore, with no small pleasure that I looked forward to my field work in this region. The results have far excelled my expectations

Noteworthy Iowa Fungi

During the summer of 1929 a number of collections were made of parasitic fungi which for one reason or another should be made a matter of record. The following notes concern 17 species of which 4 appear to be new to the state. Of the hosts, 20 in number, ten are new. The fungi are listed in systematic sequence. The numbers in parenthesis following the names refer to the number of the species in Gilman and Archer. The host and locality are then given, with such notes as the specimens warrant

Some Protozoa from Fayette, Iowa

During the past autumn several cultures were made from ponds, springs and streams in the vicinity of Fayette for the purpose of providing material for class use. As the number of species of Protozoa represented appeared to be much greater than the author had observed elsewhere, a record of their identity and abundance was kept. A partial result of this work is the present list of thirty-three species, in addition to which several others were observed, but not identified. Inasmuch as Dr. Edmundson\u27s Protozoa of Iowa formed the basis of the taxonomic portion of the work, the Euglenidae are included in the list, although the author is by no means convinced of their animal nature

Some Problems in the Classification of the Fungi

The variation in the method of oosphere behavior as well as the method of germination of the conidia in the Oomycetes has been a field fruitful of speculation as well as observation by mycologists. The members of this group are exceptionally susceptible to external conditions so that there is considerable diversity in reported observations and the interpretation which has been placed on them. There has also been considerable diversity of opinion as to the taxonomic value of some of the observed peculiarities

An Anomalous Hickory-Nut

During the fall of 1914 the writer observed in the vicinity of Iowa City a tree of the common shag-bark hickory (Carya ovata (Mill.) K. Koch.) which produced a number of abnormal nuts.. As none of these were found with the husk intact no data can be given except for the nuts themselves. Bicarpillary fruits were not uncommon on this tree as at least a dozen examples were found without making a careful search. In most instances the paired nuts separated readily and showed no tendency toward adhesion. They were, however, very much flattened on the appressed surfaces. A cross section of these nuts showed them to be normal except in shape. Both lobes of the embryo were well developed, but somewhat distorted by the pressure. The walls of the shell were of about the same thickness on the free sides as were those of normal unicarpillary nuts from the same tree, while the inner appressed walls were very thin

An Exobasidium on Armillaria

In one locality near Iowa City Armillaria mellia was attacked by a parasitic fungus which caused extensive hypertrophy of the upper region of the pileus of its host without rendering the gills sterile. The parasite developed a hymenium which spread over a series of thin, sharp-edged and highly convoluted ridges or gills. The microscopic characters show the fungus to be closely related to that which has been designated Exobasidium mycetophilum (Peck) Burt

Scleroderma vulgare and Its Iowa Allies

The Sclerodermitaceae, or so-called hard puffballs, have been very inadequately studied by American mycologists. Indeed it has been too common a custom to group all the material together as Scleroderma vulgare Hornem, without regard to external markings, the thickness of the periderm, or the mode of rupture for spore dispersal. Probably one of the most comprehensive treatments of the American forms is that by Lloyd in connection with his studies on Australian species. His treatment has been followed with some variations by Hard and by McIlvane, each adding variations to the treatment of species. Several of the eastern forms have ben figured by Murrill in Mycologia. However, no systematic account of the American forms has come to the notice of the writer