A Catecholamine storage in the pancreatic A2-cells of owl monkey (Aotes trivirgatus)

Summary The fluorescence method ofFalck andHillarp was used to study the occurrence of biogenic monoamines in the islets of Langerhans of monkeys. A storage of a catecholamine was demonstrated in the A₂-cells of owl monkey, whereas no histochemically demonstrable amount of monoamines could be seen in the islet cells of marmoset,Rhesus monkey, squirrel monkey, andCebus monkey.Supported by grants from the Swedish Medical Research Council (No. B69-14x-712-04C) and by the National Institutes of Health (No. 06701-02).     

The cell types in the endocrine pancreas of the human fetus

Summary Morphological and histochemical studies of the developing human islet cells are facilitated by the characteristic localization of the different islet cell types from about the third intrauterine month. By combining light microscopical analyses of silver impregnated and granule stained pancreatic sections with electron microscopy of osmium fixed material, the following four types of islet cells could be identified: (1) A₁ cells containing faint globular granules. These granules could be visualized only with the electron microscope. (2) A₂ cells containing electron-dense globular granules. It is uncertain whether the observation of a light and a dark variety of the A₂ cells reflects different stages of maturation or signifies cells with different secretion products. (3) B cells with irregular granules, which were often accumulated at the capillary pole of the cells. (4) Agranular islet cells. Mixed forms of A cells containing both faint and dense granules were also encountered. The difficulties in evaluating in the light microscope what may be called D cells in the human fetal islets were obvious from the observation of more cells stained with light-green than A₁ cells. Except for acid phosphatases, the histochemical tests for different phosphatases and esterases revealed rather weak or negative reactions in the islet cells. The development of phosphatase and esterase activities in the islets seemed far from complete, when morphologically differentiated islet cells could be recognized.Supported by the United States Public Health Service [grants RF-83(01) and TW-83(02)] and the Swedish Medical Research Council. The authors are indebted to Professor Carl Gemzell and Dr. Ulf Elvkull at the Department of Obstetrics and Gynecology, University Hospital, Uppsala, for the generous supply of the fetal pancreatic material.     

Early postmortem changes in the Organ of Corti (guinea pig)

Summary Early post mortem changes in the Organ of Corti are described. 15 minutes after death, when kept at room temperature, 20° C (63° F), an oedematous swelling is observed within the cytoplasm of hair cells and nerve endings, the latter being more severe affected. After 30 minutes post mortem the mitochondria of the hair cells have also become significantly swollen. Three hours post mortem the general character of the hair cells is still recognizable, but most of the nerve endings have been completely destroyed. Acknowledgement. We wish to express our appreciation of the skilful technical assistance of Mrs. B. Flock, Miss A.-M. Lundberg, Miss Sonja Löfvenius, Mr. G. Bornholm and Mr. Rune Ragnefjell.This work was supported by grants from the Swedish Medical Research Council, the National Institute of Health grant (no NB 03956-02), the Therese and Johan Anderssons minne, the Gustav and Tyra Svenssons fund and the King Gustav V Research Fund.     

Use of immunocytochemical staining of somatostatin for correlative light and electron microscopic investigation of D cells in the pancreatic islet of Xiphophorus helleri H. (Teleostei)

Summary Somatostatin-containing cells have been demonstrated by immunocytochemistry in semithin sections of the pancreatic islet of the teleost fish, Xiphophorus helleri. These cells were shown by correlative light and electron microscopy to be identical with D cells previously defined in this species by the silver impregnation method of Hellman and Hellerström.Supported in part by grants from the British Council and from the Medical Research Council of Great Britain     

Insulin secretion from perifused rat pancreatic pseudoislets

Summary Isolated adult rat pancreatic islets were dispersed into single cells and cultured free-floating for 3 to 4 d, during which time islet cells reaggregated spontaneously into spherical clusters or pseudoislets. The gross morphology of these tissues resembled nondissociated islets. Electron microscopy revealed well-preserved cell ultrastructure and intercellular membrane connections. Immunofluorescent localization of islet cell types showed that A cells tended to be peripherally distributed around a B cell core, with D cells scattered throughtout the aggregate, mass. The dynamics of insulin release from pseudoislets were evaluated in vitro by perifusion techniques. Pseudoislets exhibited clear biphasic dose-dependent insulin responses to 30 min glucose stimulation over the range 5.5 to 30 mM. Repeated 2-min pulses with 22 mM glucose elicited brief monophasic spikes of insulin release of, consistent magnitude.l-Arginine (5 to 20 mM) evoked biphasic insulin release but these responses were not dose-dependent. These data indicate that islet cells reaggregate into structures with close morphologic similarities to intact islets, and that pseudoislet B cells continue to secrete insulin in response to nutrient secretagogues, comparable to that seen with islets in vitro and in situ. This work was supported by grants from the Medical Research Council of New Zealand. D. W. H. was the recipient of a Novo Diabetes Research Scholarship.     

Fluorescence microscopy of the 5-HTP turnover in the exocrine pancreas of mice and rats

Summary The turnover ofl-5-HTP,d-5-HTP and 5-HT in the exocrine pancreas have been studied by means of the fluorescence method ofFalck andHillarp. l- andd-5-HTP are easily taken up by the acinar cells, whereas 5-HT seems to pass into the cells only to a minor extent. After the administration ofl-5-HTP (and in some cases after 5-HT administration), specific fluorescence is seen in the form of apically located granules (probably identical with the zymogen granules) for a short period, which is prolonged, if the animals are pretreated with a MAO inhibitor. Decarboxylase inhibition prevents the appearance of these fluorescent granules. Administration ofd-5-HTP does not give rise to this granular fluorescence but to a diffuse fluorescence throughout the cells. Thus, there are reasons to assume that the granular fluorescence derives from 5-HT. The results obtained in this work correspond well with those from a similar study withl-DOPA and some of its analogues.abbreviations DOPA 3,4-dihydroxyphenylalanine - DA dopamine - NA noradrenaline - A adrenaline - 5-HTP 5-hydroxytryptophan - 5-HT 5-hydroxytryptamine - MAO monoamine oxidase This work was supported by grants from the Swedish Medical Research Council (B68-12X-712-03B and B68-14X-56-04B), the United States Public Health Service (06701-02) and the Faculty of Medicine, University of Lund, Lund, Sweden.     

An electronic model of neuroelectric point processes

Zusammenfassung Eine umfassende Darstellung der Nervenzellmembran wird durch eine Kombination von Hodgkin-Huxley-Beschreibung der elektrisch erregbaren Leitwerte und Eccles-Beschreibung der synaptisch induzierten Leitwerte wiedergegeben. Diese Darstellung wird in einem elektronischen Modell veranschaulicht. Nichtlineare aktive Schaltungen werden benützt, um Leistungen zu entwickeln, die in ihrer Form mit den zeit- und spannungsabhängigen Leitwerten der Beschreibungen übereinstimmen. Die Leistungen werden mit Hilfe von Multiplikatoren in äquivalente Leitwerte umgewandelt. Das elektrische Modell enthält 24 kontrollierbare Parameter, von denen jeder mit einem in der Beschreibung übereinstimmt. Zur Einstellung der Parameter sollte man eine Strategie benützen, die soweit wie möglich die Werte von Hodgkin und Huxley (s. Tafel) als Parameter verwendet. Kleine Abweichungen von diesen Werten werden als mindere Störungen der grundliegenden Zusammenstellung betrachtet. Als Beispiel einer systematischen Untersuchung des Einflusses einer Veränderung verschiedener Parameter wurden die Spannungsschwingungen gewählt. Die Frequenz der ungedämpften Schwingungen beträgt ungefähr 50 Hertz. Verschiedene andere kleine Änderungen der Parameter können Schwingungsfrequenzen von 4 Hertz hervorrufen. Mit großen Störungen der Grundwerte kann man auch Schwingungsfrequenzen im Werte l Hertz erlangen.Es wird vorgeschlagen, daß die kombinierten Eccles- und Hodgkin-Huxley-Beschreibungen die Mehrzahl der neuroelektrischen Vorgänge einzelner Nervenzellen darstellen könnten. Dieser Vorschlag wird durch weitere Ergebnisse bestätigt. Die Beobachtung wird jedoch ausgedrückt, daß die zusammenfassende Darstellung in wenigstens einem Falle, den Nervenzellen des Hummer-Herznervenknotens, nicht zulänglich ist.

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Research sponsored by the Joint Services Electronics Programm under Grant AF-AFOSR-139-67, the Librascope Group, General Precision Systems, Inc., Glendale, California, under Air Force Office of Scientific Research USAF Contract No. AF 49(638)-1232, and by the 6570^th Aerospace Medical Research Laboratories, Air Force Systems Command, USAF Cotract No. AF 33(615)-2464.     

Monoamines in rat thyroid parafollicular cells and the effect of vitamin D2-induced degranulation

Summary Thyroid parafollicular cells of normocalcemic and vitamin D₂-treated rats were investigated by electron microscopy and with the histochemical fluorescence technique of Hillarp and Falck.Administration of high doses of vitamin D₂ caused hypercalcemia and an extensive degranulation of the parafollicular cells.The formation and storage of monoamines in granulated and degranulated parafollicular cells was investigated by fluorescence microscopy after injection of monoamine precursors (DOPA, 5-HTP), alone or in combination with Ro 4-4602, nialamide or reserpine.No fluorescence was observed in parafollicular cells of untreated rats. l-DOPA and l-5-HTP (but not the corresponding D-amino acids) were taken up by a process closely linked to the decarboxylation of the amino acids to the corresponding amines (dopamine and 5-hydroxytryptamine). Treatment with vitamin D₂ did not seem to affect the formation of amines in the parafollicular cells or the formation and storage of amines in other cell systems investigated. The amine itself (dopamine) was not taken up by the parafollicular cells.In normocalcemic rats, the amine formed was retained in the cytoplasm of the parafollicular cells by a partially reserpine-resistant mechanism. The storage of amines is concluded to occur in association with the calcitonin-containing granules.In parafollicular cells of vitamin D₂-treated rats, a certain amount of amine was bound in the cytoplasm in the absence of typical granules. As a considerable amount of calcitonin is known to remain in the thyroid of vitamin D₂-treated rats, the present observations may indicate an association between the amine and the polypeptide hormone calcitonin, whether the latter is confined to typical granules or not.The present study was supported by grants B72-12X-3352-02 and B72-14X-2207-06B from the Swedish Medical Research Council and by grants from Magnus Bergwall's Foundation, Gustav and Majen Lundgren's Foundation, Wilhelm and Martina Lundgren's Foundation and from the Faculty of Medicine, University of Göteborg, Sweden. For skilful technical assistance we are indebted to Mrs. Kirsten Collin and Mr. Pär-Anders Larsson.     

Harvesting and culture of epithelial cells from hollow organs of the female reproductive system

Summary The technique of trypsinization of cells lining the hollow organs applied to the female reproductive tract has proven successful in harvesting living cells which produced luxuriant cultures in vitro.Elements from the oviduct, endometrial cavity and vagina were obtained from 6 rabbits, 2 dogs and 6 surgical specimens by means of bathing the lumen of the organs with the use of a 0.5% solution of trypsin in calcium and magnesium free Gey's balanced salt solution for 30 to 40 min, employing continued gentle agitation provided by a syringe.Epithelial cells so harvested were grown in Rose chambers and in T-30 flasks for as long as 30 days, when they were fixed for study with special stains.No fibrocytic contamination of the cultures was observed.Further applications of the method are under investigation and are briefly outlined in the discussion.This work was performed in the Department of Cellular Biology, Pasadena Foundation for Medical Research, Pasadena, California, and aided in part by a grant from the U. S. Public Health Service, No. 2 G 279 and from the U. S. Army Medical Research and Development Command, Department of the Army, under Research Grant No. DA-MD-49-193-63-G80 administered by C. M. Pomerat.     

Mitochondrion-desmosome complexes in human hepatocytes

Summary Mitochondrion-desmosome complexes similar to those seen in other epithelia were observed in hepatocytes from normal and diseased human livers of children and adults. Their occurrence could not be explained by random distribution of mitochondria in the cells. The close associations of mitochondria with desmosomes supported the hypothesis that the latter might be special areas of intercellular ionic diffusion between hepatocytes.This work was supported in part by United States Public Health Service Grants AI-1059 and TI AM-5384 from the National Institute of Arthritis and Metabolic Diseases, 5 MOl FR 000-50 from the General Clinical Research Center, HD 00674 from the National Institute of Child Health and Development and by a grant from the Life Insurance Medical Research Fund G-65-50.The author is very grateful to Dr. Alex B. Novikoff for the use of the facilities of his laboratory (supported by United States Public Health Service Grant CA-06576), to Mr. Nelson Quintana and Mrs. Julie Windsor for their superb technical assistance and to Miss Marianne Van Hooren for preparation of the photographs.     

Endothelial microvilli in the vessels of the rat gasserian ganglion and testis

Summary In the Gasserian ganglion and testis of the rat the endothelium of the small blood vessels has a singular appearance due to the presence of a high number of microvillous processes. These arise from the luminal surface, either individually, or in small groups. The significance of this structure is not known. It is pointed out that these vessels are particularly sensitive to cadmium intoxication.This investigation was performed during a tenure by Dr. Gabbiani of a fellowship of the Medical Research Council of Canada and was supported by the National Institutes of Health (Grant No. 5R01 HE-08794-04) and the Ministère de la Santé du Québec (projet 604-7-635).The authors wish to thank Dr. S. M. Shea for his advice in the measurement of the villi. The technical assistance of Miss Virginia Gilmore and of Mr. Eduardo Garriga is gratefully acknowledged.     

Electron microscope observations of some peripheral synapses in the sensory pathway of the sucker of Octopus vulgaris

Summary A synaptic axo-dendritic linkage is described between primary receptors lying in the epithelia of the sucker of Octopus and encapsulated nerve cells found near the rim of the sucker in the subepithelial connective tissue. These synapses are postulated to perform a drastic reduction of inputs between the primary receptors of the order of more than ten thousand and the subjacent encapsulated nerve cells of the order of some hundreds. The morphology of these cells as well as that of the synaptic structures are described from electron microscope studies. Aknowledgement. This work was done at University College London, while I was in receipt of a Medical Research Council grant.I am deeply indebted to Prof. J. Z. Young F. R. S. for support and criticism, and to Dr. E. G. Gray for advice and discussion. My thanks are due to Mr. A. Aldrich for the photographs.     

Ultrastructural observations on the droplets of experimentally-induced goitres in Xenopus laevis with especial reference to the development of uhlenhuth colloid cells

Summary Goitres were induced in tadpoles and young toads of Xenopus laevis Daudin by prolonged immersion in aqueous solutions (0.005% or 0.01% w/v) of potassium perchlorate, potassium thiocyanate, thiourea or propyl-thiouracil. Various categories of single membrane-limited droplets were induced and these are described. Also some of the goitrous cells showed an accumulation of colloid droplets leading to the formation of Uhlenhuth colloid cells. The development and significance of these cells in the amphibian goitres is considered.This work was carried out during the tenure by one of us (R. C.) of a Medical Research Council Scholarship and forms part of a programme of research in amphibian thyroid physiology supported by the Medical Research Council to whom we are indebted for their generous assistance.     

Adrenergic nerves in the corpora cavernosa penis of some mammals

Summary The corpora cavernosa et spongiosa penis from Rhesus monkeys, Cynomolgus monkeys and cats have been investigated by means of the method for fluorescence microscopical detection of catecholamines- and tryptamines according to Falck and Hillarp.In all species investigated the smooth muscle cells surrounding the sinusoidal cavities of the corpora cavernosa are densely innervated by varicose adrenergic nerve fibres, which form a typical autonomic ground-plexus. A superficial and a deep plexus have been distinguished, the former being composed of densely packed preterminal, ramifying bundles the latter consisting mainly of terminal varicose fibres. In contrast to this the corpus spongiosum — being mainly composed of collagenous and elastic tissue — receives only a moderate adrenergic nerve supply related to the small bundles of smooth musculature. Whereas arteries of the penis are characterized by a superficial adventitial fibre plexus, the greater veins of the penis are supplied by adrenergic fibre meshes which penetrate the media up to the limiting lamina elastica interna. In addition the paraurethral glands seem to possess a direct adrenergic innervation.According to microspectrographical results it is concluded that the transmitter is noradrenaline. This assumption is supported by the finding of relatively high amounts of noradrenaline in tissue pieces from the erectile tissue of four Rhesus monkeys: 0,67 g/g (± 0,05). No dopamine or adrenaline have been detected.Scattered along the whole length of the urethral epithelium there occur yellow fluorescent cells morphologically resembling enterochromaffin cells. The fluorophore has the spectral properties of formaldehyde-condensed authentic 5-hydroxytryptamine.The possible role of the sympathetic noradrenergic innervation to the penis concerning the initiation and termination of the erection is discussed.

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Zusammenfassung Die Corpora cavernosa und spongiosa penis von Rhesusaffen (Macaca mulatta), Javaneraffen (Cynomolgus irus = Macaca fascicularis) und Hauskatzen (Felis domestica) wurden mit der von Falck und Hillarp entwickelten Methode zum fluoreszenzmikroskopischen Nachweis von Catechol- und Tryptaminen untersucht.Die glatten Muskelzellen der cavernösen Hohlräume werden von einem dichten Geflecht variköser, adrenerger Nervenfasern innerviert. Das Aufbauprinzip dieses Plexus ähnelt dem des autonomen Grundplexus (Hillarp). Der pericavernöse Plexus läßt sich in einen oberflächlichen Anteil gliedern, der aus gebündelten, präterminalen Nervenfasern besteht und in einen tiefen Plexus, der aus varicositätenreichen Endaufzweigungen aufgebaut ist. Im Gegensatz dazu besitzt das an kollagenen und elastischen Fasern reiche Corpus spongiosum nur eine spärliche Nervenversorgung. Während die Arterien des Penis mit einem adventitiellen adrenergen Plexus ausgestattet sind, werden die Venen von einem adrenergen Fasergeflecht innerviert, das alle Schichten der Adventitia und der Media gleichmäßig durchsetzt. Bei allen untersuchten Spezies kommen außerdem adrenerge Fasern in Begleitung der Paraurethraldrüsen vor.Aus mikrospektrographischen Befunden wird gefolgert, daß die Grünfluoreszenz in den Nervenfasern auf die Anwesenheit von Noradrenalin zurückzuführen ist. Diese Annahme wird durch den Nachweis relativ großer Mengen von Noradrenalin im Schwellkörpergewebe von vier Rhesusaffen bestätigt (0,67 g/g ±0,05). Dopamin und Adrenalin konnten nicht nachgewiesen werden.Zwischen den Epithelzellen der Harnröhrenmukosa kommen einzelne Zellen vor, deren Cytoplasma eine intensiv gelb fluoreszierende Substanz enthält. Das gelb fluoreszierende Produkt besitzt die gleichen spektralen Eigenschaften wie formaldehydkondensiertes 5-Hydroxytryptamin.Die Bedeutung der sympathischen, noradrenergen Innervation für die Einleitung und Beendigung der Erektion des Penis wird diskutiert.

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Dedicated to Prof. Dr. Dr. E. Horstmann with the best wishes for his 60 th birthday.

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Supported by the Deutsche Forschungsgemeinschaft and by grants from the Swedish Medical Research Council/project no. B 69-14X-56-05C and the Ford Foundation, grant no. 68-383.     

Occurrence and neonatal development of gastrin immunoreactivity in the digestive tract of the rat

Summary The distribution of gastrin immunoreactivity in the rat gut was examined by immunochemical and immunohistochemical techniques. Gastrin occurs predominantly in the antrum proper, but gastrin is found also in the adjacent part of the oxyntic mucosa and in the duodenum. In the remainder of the gut the gastrin concentration is very low. No gastrin cells and very low gastrin concentrations are observed in the antrum at birth. The gastrin concentration as well as the number of gastrin cells increases progressively with age. The antral gastrin concentration reaches adult or near-adult values 30–40 days after birth.This study was supported by the Swedish Medical Research Council (04 X-1007), by Riksföreningen mot Cancer (660-0 IX), Landsforeningen till Kraeftens Bekampelse, Danish Medical Research Council (512-6) and Fonden for Storkobenhavn, Faeroerne og Gronland.     

Nuclear membranous whorls

Summary Membranous whorls have been seen in the nuclei of peritoneal and testicular cells which had been subjected to various experimental manoeuvres. It seems likely that this is an early manifestation of cell degeneration which is demonstrated readily only by glutaraldehyde fixation, and to that extent can be regarded as a glutaraldehyde artifact. Acknowledgements. This work was supported by grants from the Medical Research Council, and the University of Sheffield Tuberculosis Research Fund, and by a grant to the Department from Unilever Ltd.I am grateful to Professor R. Barer for his advice and criticism, to Dr. G. A. Meek for guidance on electron microscopy, to Dr. E. J. Clegg for permission to use material from joint experiments. Technical and photographic assistance was provided by Messrs. P. GarLick and L. Murgatroyd and by Miss M. Tune.     

The two types of alpha cells during the development of the guinea-pig pancreas

Summary The prenatal and postnatal development of the two types of pancreatic A cells was examined in guinea-pigs. The A₁ and A₂ cells appeared at about the same time and were first seen in 26 days old fetuses, while B cells could not be recognized earlier than on the 39th day of intrauterine life. In all age groups examined with quantitative methods (65 days old fetuses to 9 months old guinea-pigs) the proportion of parenchyma in the pancreatic gland appeared higher in the cauda than in the caput. In the 3 months and 9 months old animals the proportions of the different types of islet cells were also higher in cauda than in caput. In each case the total weights of the A₁, A₂ and B cell fractions showed a similar growth rate relative to that of the body weights. The results are discussed in the light of previous observations in man and rat.Supported by the United States Public Health Service (AM-05759-05), the Swedish Medical Research Council (12X-562-02; 12X-109-03) and the Medical Faculty of Uppsala.     

Tissue culture of an ameloblastoma

Summary Explants of a highly differentiated type of ameloblastoma from the lower jaw of a 44-year-old white female were cultivated in roller tubes.Epithelial elements of squamous type which formed widespread sheets accounted for the major part of the outgrowth from such explants although fibroblastic cells sometimes were present.The epithelial cells were similar in structure and behaviour to those obtained from culture of the enamel organ although in some respects, such as the vigorous movement of undulating membranes, pinocytosis and the formation of perinuclear vacuoles, the tumor cells showed much more activity than those of normal tissue from the enamel organ.The tendency of emigration of the epithelial elements was shown by histological examination of the explants which were kept floating in the fluid medium.This investigation was supported by the Medical Research and Development Board, Office of the Surgeon General, Department of the Army, under Contract Nos. DA-49-007 -MD-447 and DA-49-007-MD-32 administered by Doctors T. G. Blocker, Jr. and C. M. PO-merat respectively.     

The liver of the slender salamander Batrachoseps attenuatus

Summary The structure of the crystalline inclusions found in Batrachoseps liver cells is described and it is shown that the most symmetric unit cell upon which the crystal lattice is built is a face-centered cube. Taking into consideration the physical properties of a face-centered cubic structure, an attempt is made to determine the nature of the macromolecules that comprise the crystal. It is concluded on the basis of available evidence that the macromolecules probably represent serum lipoproteins. The intracellular synthesis of the crystals and the possible functions they may subserve in the animal are discussed. A comparison is made between the crystals and granules in rat hepatocytes discussed by Bruni and Porter (1965).Research supported by grant RG-6729 from the Institute of General Medical Sciences, National Institutes of Health, United States Public Health Service.     

Aspects of D-leucine and D-lysine metabolism in maize and ryegrass seedlings

Summary Maize and ryegrass seedlings (2.5 weeks old), the roots of which were dipped into 10^-3M ¹⁴C-carboxyl-labeled D-leucine and ¹⁴C--labeled D-lysine, readyly absorbed and converted or conjugated within 34 hr some 75–90% of the labeled compound supplied. The metabolic intermediates and products were generally similar for both maize and ryegrass. Radioactive intermediates from the carboxyllabeled D-leucine were L-leucine, N-malonyl-D-leucine (provisionally identified), and -ketoisocaproic acid. Intermediates from -labeled D-lysine were numerous, with greater amounts and numbers detected in roots than in tops. Pipecolic acid was a major intermediate particularly in shoot tissue.Pathways of conversion appeared analogous to those for the L-isomer, and conversion may be by the usual L-configuration machinery, since the labeled L-isomer of the originally supplied ¹⁴C-D-amino acid was always found. How the ¹⁴C-D-amino acid gets to ¹⁴C-L-isomer is not known, but finding significant proportions of unlabeled D-alanine in plants treated with both the labeled L-leucine and D-lysine suggested that formation of the -keto-acid analog and subsequent reamination was possibly an important route.Approved for publication as Technical Paper No. 2,729 of the Oregon Agricultural Experiment Station.Trade, copyright or company names are for identification and reader benefit; their use does not constitute endorsement or preferential treatment by the U.S.D.A.Respectively, Research Associate, Department of Soils, Oregon State University; Research Chemist, Soil and Water Conservation Research Division, Agricultural Research Service, U.S. Department of Agriculture. Present address of senior author: Institut für Bodenkunde D-3400 Göttingen, von Sieboldstraße 4, West Germany.—We thank the Oregon State University Research Council and the Bundesministerium für Ernährung, Landwirtschaft und Forsten, Bonn, Germany, for partial financial assistance to the senior author, and M. Yamamoto for technical assistance.