Life Sciences Commons^™

University Of Richmond Herbarium, W. John Hayden

Biology Faculty Publications

The Department of Biology at the University of Richmond, Richmond, Virginia, maintains an herbarium of approximately 15,000 specimens. Although recently assigned the acronym URV, this collection has not yet been included in Index Herbariorum and, consequently, few botanists outside of Virginia are aware of its existence. This note provides a brief account of the history of URV, a summary of its contents, and a short bibliography of works pertaining to the collection.

Wood Anatomy And Relationships Of Neowawraea (Euphorbiaceae), W. John Hayden, Dorthe S. Brandt

Biology Faculty Publications

Wood anatomy of three specimens of Neowawraea phyllanthoides Rock, a rare and endangered member of Euphorbiaceae endemic to the Hawaiian Islands, is described and compared with woods of other genera of subfamily Phyllanthoideae. Neowawraea has often been associated or synonymized with Drypetes Vahl. Wood of Neowawraea is diffuse porous, perforation plates are simple, imperforate tracheary elements are thin-walled septate fiber-tracheids, rays are heterocellular and crystalliferous, and axial xylem parenchyma is restricted to a few scanty paratracheal and terminal cells. In several respects these results differ from earlier published descriptions of the wood of this taxon; these earlier descriptions are shown …

Effects Of Adrenalectomy On Hemoconcentration And Blood Ph, Urea And Electrolytes In The Mongolian Gerbil (Meriones Unguiculatus), Magally Aellos De Cova

Master's Theses

The effects of adrenalectomy on some blood profiles of the Mongolian gerbil, Meriones unguiculatus, were studied in order to clarify the possible causes of its short survival after adrenal ablation. Measurements of hematocrit, pH, urea and electrolytes were made 18, 24 and 30 hours after surgery. Results show the expected alterations: hemoconcentration, metabolic acidosis, high values of urea and disturbances in electrolytes. While hyponatremia was significant only after 24 hours, important hypochloremia was not present at any time. Hyperkalemia was the most significant alteration observed. It occurred as early as 18 hours after surgery, suggesting that it may be an …

Wood Anatomy And Relationships Of Betula Uber, W. John Hayden, Sheila M. Hayden

Biology Faculty Publications

Wood anatomy of Betula uber (Ashe) Fernald is described and compared with woods of other birches belonging to series Humiles and series Costatae. Anatomically, wood of B. uber is typical of birches in general. On the basis of pore size and frequency, fiber characteristics, axial xylem parenchyma distribution, and absence of aggregate rays, it is argued that B. uber is properly classified in series Costatae. Resolution of its relationships within series Costatae is not apparent from wood data.

Characteristics Of A Ca++ Atpase Enzyme In The Epidermis Of Molting Blue Crabs, Callinectes Sapidus, Joanne Elizabeth Lapetina

Master's Theses

Epidermal Ca⁺⁺-activated ATPase was investigated in relation to the molt cycle of the blue crab, Callinectes sapidus. Premolt and postmolt tissue samples demonstrated significant elevations in Ca⁺⁺-activated ATPase activity in comparison to intermolt tissue samples. These results support the suggestion that this enzyme may participate in demineralization of the old cuticle, as well as calcification of the new cuticle.

The enzyme is localized in the heavy particulate-nuclear fraction and is distinguished from mitochondrial Ca⁺⁺ ATPase found in other tissues by differences in sensitivity to mersalyl acid. 0 The enzyme is most active at 49 C …

The Effects Of Photoperiod And Melatonin Injections On The Reproductive System Of The Male Mongolian Gerbil (Meriones Unguiculatus), Luis Jose Cova Marchan

Master's Theses

This work was undertaken to study the effects of photoperiod and melatonin on fertility in male Mongolian gerbils (Meriones unguiculatus). Four groups of fifteen animals each, were placed in different photoperiods (ambient, ranging from 14L:10D to 11.3L:12.3D; 24L:10D; 14L:10D; and 1L:23D). After 35 days, three gerbils from each photoperiod condition were sacrificed and the testes, epididymides, seminal vesicles, prostate, kidneys, adrenals, thymus and hypophysis were weighed. The testes and epididymides were placed in Bouin's fixative and used for histological studies. Also, two males from each photoperiod condition were paired individually with a female. The remaining animals of each photoperiod condition …

Curatorial News From The University Of Richmond Herbarium, W. John Hayden

Biology Faculty Publications

The Department of Biology at the University of Richmond maintains a herbarium of approximately 15,000 specimens. In an effort to make this collection better known to Virginia botanists, this note describes some recent curatorial improvements upon the UR Herbarium and outlines its contents.

Wood Anatomy And Relationships Of Neowawraea (Euphorbiaceae), Dörthe S. Brandt, W. John Hayden

Honors Theses

Wood anatomy of three specimens of Neowawraea phyllanthoides Rock, a rare and endangered member of Euphorbiaceae endemic to the Hawaiian Islands, is described and compared with woods of other genera of subfamily Phyllanthoideae. Neowawraeahas often been associated or synonymized with Drypetes Vahl. Wood of Neowawraea is diffuse porous, perforation plates are simple, imperforate tracheary elements are thin-walled septate fiber-tracheids, rays are heterocellular and crystalliferous, and axial xylem parenchyma is restricted to a few scanty paratracheal and terminal cells. In several respects these results differ from earlier published descriptions of the wood of this taxon; these earlier descriptions are shown …

Systematics And Palynology Of Picrodendron Further Evidence For Relationship With The Oldfieldioideae (Euphorbiaceae), W. John Hayden, W. T. Gillis, D. E. Stone, C. R. Broome, G. L. Webster

Biology Faculty Publications

Although known to botanical science for 285 years, the genus Picrodendron Planchon has been poorly understood for most of this time. The most pervasive problem has been that of discerning familial relationships, and there have been additional difficulties in typifying the generic name (Hayden & Reveal, 1980) and in distinguishing its three nominate species. This paper provides a systematic treatment for Picrodendron and demonstrates its relationships with Euphorbiaceae subfam. Oldfieldioideae Kohler & Webster as evidenced by data on gross morphology, palynology, anatomy, and cytology.

Leptodactylus Podicipinus (Cope, 1862) Y Leptodactylus Chaquensis Cei, 1959 (Anura, Leptodactylidae), En El Uruguay, Raúl Vaz-Ferreira, Rafael O. De Sá, Federico Achaval, Annelise Gebrau

Biology Faculty Publications

En base al estudio de las colecciones obtenidas principalmente en excursiones a la zona NO de Uruguay con motivo del relevamiento faunístico del área de Salto Grande, se avanzó considerablemente en el conocimiento de la distribución de Leptodactylus podicipinus (Cope, 1862) y Leptodactylus chaquensis (Cei, 1950), en nuestro país.

Se cita el material estudiado y las observaciones de campo realizadas; se dan los caracteres generales de ambas especies, se describen los hábitats, y se tratan las características de las vocalizaciones.