ALBERT

Notizen: The development of an automated photographic measuring system (APM) is described. A very accurate laser beam scanning microdensitometer is used to digitise the photographic plate and a series of on line computers analyses the data during scanning. The system is available as a national facility for United Kingdom astronomers and guest investigators.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn décrit un systéme automatisé de saisie de données sur cliché. Un microdensitométre à laser numérise la plaque photographique et les données sont analysées en temps réel par ordinateur. Le systeme est destiné aux astronomes du Royaume Uni et aux chercheurs y séjournant.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungBeschreibung eines automatisierten photographischen Messsystems (APM). Ein hochgenaues Laser-Mikrodensitometer wird dabei zur Digitalisierung der Bilder benutzt, undeine Serie von On-line-Rechnern analysiert die Daten während der Abtastung. Das System steht für Astronomen im Vereinigten Königreich und anderen Forschern zur Verfügung.

Notizen: Two complementary measuring instruments are described which use a very simple principle and which take three dimensional measurements or plots directly from small objects. The first instrument can achieve accuracies of ± 0·3 mm on objects whose largest dimension is 300 mm. The second can achieve ± 0·02 mm on objects smaller than a 25 mm cube.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn présente deux instruments de mesure complémentaires el de principe très simple permettant de relever dans l'espace des coordonnées sur de petits objets, le premier avec une exactitude de ± 0.3 mm sur des objets de dimension inférieure à 300 mm, le second avec une exactitude de ± 0.02 mm sur des objets de dimension inférieure à 25 mm.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungBeschreibung von zwei Zusatzmessgeräten, die auf einem sehr einfachen Prinzip beruhen und mit denen dreidimensionale Messungen oder Auswertungen von kleinen Objekten direkt durchgeführt werden konnen. Mil dem ersten Gerät kann eine Genauigkeit von ± 0,3 mm bei maximalen Objekt abmessungen von 300 mm und mit dem zweiten von ± 0,02 mm bein Objekten, die kleiner als ein 25 mm-Kubus sind, erreicht werden.

Notizen: This paper outlines the technical procedures used in commercial orthophotomap production and attempts to identify some of the main differences in technical approach between orthophotomapping and conventional line mapping.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn décrit les techniques industrielles de production d'orthophotocartes et on compare leur emploi avec celui des techniques classiques.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungSkizzierung der Technologien, die bei der kommerziellen Herstellung von Orthofotokarten angewendet werden, wobei versucht wird, die hauptsächlichen Unterschiede der Techniken zur Herstellung von Orthofotokarten und konventionellen Strichkarten aufzudecken.

Notizen: This paper investigates the effect of the deviation of measured points from the standard locations when carrying out a relative orientation of a stereomodel. The analytical solution of more than 100 cases was considered and, for each case, the weights for the elements of relative orientation and the correlation coefficients were evaluated. The stability of the solution was studied by calculating the characteristic roots of the matrix of normal equations.It is shown that, theoretically, the solution of the relative orientation problem can always be achieved whenever the locations of the measured points satisfy stated geometrical requirements. However, the reliability of the solution depends on their exact positions in the stereomodel. When the accuracy is too low, in practice there is no solution.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn étudié l'effet sur l'orientation relative d'un couple de variations de position des points de base. Plus de 100 cas ont été considérés et à chaque fois ont été estimées les précisions des paramètres calculés ainsi que leur correlation. On a de plus, étudié la stabilité de la solution par l'intermédiaire des valeurs propres de la matrice normale.Il n'est pas indispensable, en principe, d'imposer de contraintes précises au choix des points de base; mais de ce choix dépend la fiabilité de la solution, faible s‘il est par trop fantaisiste.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungIn der Arbeit wird der Einfluss der Abweichung der gemessenen Punkte von ihrer Standardlage bei relativer Orientierung eines Stereomodells untersucht. Dazu werden mehr als 100 analytische Lösungen analysiert und für jeden Fall die Gewichte der Elemente der relativen Orientierung und die Korrelationskoeffizienten berechnet. Die Stabilität der Lösung wurde durch Berechnung der charakteristischen Wurzeln der Matrix der Normalgleichungen abgeschätzt.Es wird gezeigt, dass theoretisch immer die Lösung des Problems der relativen Orientierung erreicht werden kann, sobald die Lage der Messpunkte die geometrischen Anforderungen erfüllt. Die Zuverlässigkeit der Lösung hängt jedoch von der exakten Lage der Punkte ab. Wenn ihre Genauigkeit zu gering ist, gibt es praktisch keine Lösung.

Notizen: An automatic plotting instrument development is described where the coordinate corrections are introduced in the optical system and not at the photograph. It is suggested that the opto-mechanical devices used for correction and the proposed use of microprocessors for control of these devices offer the possibility of producing a low cost automatic plotter and stereocomparator.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn decrit une solution au probléme de la correction des coordonnées cliché pour le restituteur analytique et le stéréocomparateur: ces corrections sont introduites dans la partie optique du système et commandées par l'intermédiaire de microprocesseurs. Ceci devrait permettre d'abaisser le coût de ce type d'appareil.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungBeschreibung eines automatischen Auswertegerätes, bei dem die Koordinatenkorrekturen nicht den Bildträgern, sondern dem optischen System zugeführt werden. Es wird angenommen, dass die zur Korrektur verwendeten optisch-mechanischen Vorrichtungen und die vorgeschlagene Verwendung von Mikroprozessoren zu deren Steuerung die Möglichkeit zum Bau eines billigen automatischen Auswertegerätes und Stereokomparators bieten.

Notizen: The paper deals with the analytical plotter and its impact on numerical photogrammetry. A short introductory section is followed by examples of the use of a Zeiss (Oberkochen) Planicomp C100 in analytical aerial triangulation, close range photogrammetry and the generation of digital height models. The examples demonstrate the suitability of the analytical plotter for numerical photogrammetry. Computer assistance and computer control allow for advanced data acquisition of high accuracy and speed. In addition, the minicomputer controlling the analytical plotter can be used for subsequent data processing. As a result, projects involving numerical photogrammetry can be carried out entirely in-house, without the need of an external computer.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméLe restituteur analytique et la photogrammétrie numérique. On cite des applications du Planicomp C100: aérotriangulation analytique, photogrammétrie à courte distance, constitution de modéles numériques de terrain. Efficacité, rendement, haute exactitude, tels sont les avantages du restituteur analytique. On peut d'autre part bénéficier de l'ordinateur pour toutes sortes de traitements ultérieurs.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungDer Beitrag beschäftigt sich mit dem Analytischen Plotter (AP) und seiner Auswirkung auf die Numerische Photogrammetrie. Nach einem kurzen Einführungsteil wird über den Einsatz eines Zeiss (Oberkochen) Planicomp C100 in der Analytischen Aerotriangulation, in der Nahbereichsphotogrammetrie und beim A ufbau Digitaler Höhenmodelle berichtet. Die Beispiele veranschaulichen die Eignung des AP für die numerische Photogrammetrie. Einerseits erlauben Rechnerstützung und Rechnersteuerung eine allgemeine, genaue und schnelle Datengewinnung. Darüberhinaus aber ermöglicht der, für die Steuerung des AP verfügbare Minicomputer die rechnerische Weiterverarbeitung der Messdaten. Auf diese Weise können numerisch-photogrammetrische Projekte ohne Einsatz eines externen Computers vollständig bearbeitet werden.

Notizen: Book Reviewed in this article:SPHERE, SPHEROID AND PROJECTIONS FOR SURVEYORS. By J. E. Jackson.REMOTE SENSING IN ARCHAEOLOGY, CULTURAL RESOURCES TREATMENT AND ANTHROPOLOGY: THE UNITED STATES OF AMERICA IN 1979. By J. I. Ebert and T. R. Lyons.A HISTORY OF ARCHAEOLOGICAL AIR PHOTOGRAPHY IN GREAT BRITAIN. By R. R. Downey.PROCEEDINGS OF THE INDUSTRIAL AND ENGINEERING SURVEY CONFERENCE, LONDON, 1980. Edited by M. A. R. Cooper.ANALYSIS AND ADJUSTMENT OF SURVEY MEASUREMENTS. By E. M. Mikhail and G. Gracie.A HISTORY OF THE ORDNANCE SURVEY. Edited by W. A. Seymour.IN FOCUS: a rated guide to the best in photographic equipment. By J. Holtz.MAPS AND SURVEYS OF MALAWI. By C. G. C. Martin and other contributors.

Notizen: When a member is thought to be domiciled or employed abroad, the name of the country has been added. Errors and omissions should be notified to the Honorary Secretary.

Notizen: A brief review of work on airborne metric camera movement has been made. The tolerances for permissible image movement set by various investigators are discussed.The biggest single fault with most metric camera mountings in current use is that the centre of gravity of the camera is well above the line of action of the resilient elastic restoring forces. This results in coupling between the linear vibration of the airframe and the angular motion of the camera. There is a need for a simple device which can be attached to a survey camera in order to record angular motion during actual survey missions.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméAprès une brève revue des travaux concernant les mouvements d'une chambre de prise de vue en vol, on discute les tolérances couramment admises pour ces mouvements.Le défaut de montage le plus fréquemment rencontré, est que le centre de gravité de la chambre est au-dessus de la ligne d'équilibre des forces agissantes.D'où un couplage entre la vibration longitudinale du porte-chambre et le mouvement angulaire de la chambre. Il faudrait créer un dispositif simple permettant d'enregistrer ce mouvement pendant les vols.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungEs wird ein kurzer Überblick über die Arbeiten zur Bewegung von Luftbildmesskammern gegeben. Die von verschiedenen Autoren für die zulässige Bildwanderung angegebenen Toleranzen werden diskutiert. Der schwerwiegendste Fehler, der am meisten bei den gegenwärtig verwendeten Messkammern auftritt, ist der, dass der Kammerschwerpunkt über der Wirkungslinie der schwingungsdämpfenden Kräfte liegt. Daraus resultiert eine Paarung der linearen Vibration mit der Winkelbewegung der Kammer. Es besteht Bedarf für eine einfache Vorrichtung, die an einer Messkammer befestigt werden kann, um die Winkelbewegungen während des Bildflugs aufzuzeichnen.

Notizen: SYNOPSIS. A chemically defined culture medium has been developed for the soil amoeba Hartmannella rhysodes Singh which contains the minimum essential organic requirements for growth. The medium consists of 7 amino acids, 3 vitamins, a carbon source (e.g. glucose) and inorganic salts.

Notizen: SYNOPSIS. A mutant strain of Astasia longa utilized glucose for growth whereas the parent (J) strain did not. The optimal pH for growth of the mutant with glucose (sole carbon source) was near neutrality; the optimal glucose concentration 0.02 M. Cell-free extracts or cell homogenates produced C14O2 when incubated in the presence of C14-labeled glucose. On the other hand, after incubation with C14-labeled glucose, intact parent cells and their respiratory CO2 showed no radioactivity while the mutant-strain cells and CO2 produced were active. Dissimilation of glucose-1-C14 and glucose-6-C14 yielded the same amount of radioactivity in metabolic CO2 in cell-free extracts of both strains. Of five enzymes assayed, hexokinase, phosphoglucomutase, and lactic dehydrogenase were present whereas glucose-6-PO4 dehydrogenase and glucose dehydrogenase were absent in cell homogenates of both strains. Presumably these two strains of A. longa differ in permeability of the plasma membrane. Further tracer and enzyme studies indicated that the Embden-Meyerhof scheme is the principal pathway of glucose catabolism; the hexose mono-phosphate shunt and the direct oxidative pathway were either not operating or quantitatively insignificant.

Notizen: SYNOPSIS. By means of electron microscopy, a study has been made of the fine structure of the macrogametocytes, microgametocytes and oocysts of Eimeria perforans from the intestine of the wild rabbit (Oryctolagus cuniculus). The parasites lie in a vacuole within the host cell. The surface of the gametocytes is not plain, but displays irregular protrusions. A large intranuclear body can be detected within the macrogametocytes. Similar structures are also found within the cytoplasm. Within the latter there exists a large spread out reticulum, the channels and vesicles of which concentrate especially close to the nuclear membrane. Tubuli are seen in the numerous mitochondria, which often have a dumb-bell shape.In most of the gametocytes irregular, strongly osmiophilic lipid inclusions are observed, which always are surrounded by the endoplasmic reticulum. Strange folded ovoid bodies are found within the cytoplasm of the oocysts. Nothing can be told with certainty of their nature and function. Probably they represent specific storage bodies.

Notizen: SYNOPSIS. Tritrichomonas foetus survived much better on extended storage at -95 than at -28d̀C following slow freezing in the presence of 1.0 M glycerol. There was no significant difference between these temperatures in survival up to 8 days, but thereafter the protozoa continued to die off slowly at -28d̀, whereas their numbers remained essentially constant at -95d̀ for 128 to 256 days. The trichomonads' motility was much better after storage at -95d̀ than after storage at -28d̀, and fresh cultures could be initiated from the former much more readily.Other constituents of the suspending medium besides glycerol affect the survival of the protozoa upon freezing. Survival was much better when the protozoa were frozen in the original Diamond's trypticase-yeast extract-maltose-cysteine-ascorbic acid-serum medium in which they had been grown than when they were frozen in physiological salt solution or in fresh Diamond's medium. There was no significant difference between survival in the latter two suspending media. The speed and time of centrifugation needed to remove the trichomonads from the medium in which they had been grown had no effect on their survival upon subsequent freezing. Presumably some product or products of the trichomonads' metabolism have an additional protective action which supplements that of glycerol.When frozen in the original Diamond's medium in which they had been grown plus 1.0 M glycerol, an average of 15% of the trichomonads were alive after 128 days' storage at -28d̀ and an average of 38% were alive at -95d̀C. When frozen in physiological salt solution plus 1.0 M glycerol, these percentages were 8% and 12% respectively.

Notizen: SYNOPSIS. When Spathidium spathula was exposed to X-ray doses ranging from 1–25 kr this animal was found to be more radiosensitive than any ciliate previously reported. A dose of 1 kr is sufficient to increase the time of the first generation from 5 to about 5 1/2 hours. A dose of 4 kr is enough to approximately double the generation time. Bacteria in the medium during irradiation do not protect the ciliate against injury. Animals irradiated as dry cysts are only slightly more resistant than vegetative forms, requiring 10 kr to double the generation time. One day after exposure, irradiated lines are uniformly poor in growth rate (0–2 daily divisions), but later a bimodal response is noticed, some lines remaining poor and others recovering. Within 24 hours after treatment, a number of irradiated animals show structural abnormalities and are greatly increased in size. The experiments have not determined the reason for the high sensitivity of Spathidium but have made certain alternatives unlikely.

Notizen: SYNOPSIS. When Tetrahymena suspended in water were given increasing doses of radiation, oxygen consumption decreased with increasing dose, reaching 60–90% at 600,000 r. Cells irradiated in 0.07 M phosphate buffer, pH 7.4, showed no significant decrease in oxygen consumption even at 600,000 r. The decrease in respiration observed on irradiation of Tetrahymena pyriformis W in water with 300,000 r of X-radiation was prevented by addition of pyruvate or acetate during or immediately after irradiation. Pyruvate stimulated the respiration of the X-irradiated cells, particularly at 10 and 60 min post-irradiation.Lactate markedly stimulated the respiration of control suspensions of Tetrahymena cells and oxidation of lactate by cells irradiated with 300,000 r was increased by 20 to 100%, depending on the concentration of lactate and the time after irradiation. Pyruvate was considerably more effective than lactate in increasing O2 uptake of X-irradiated cells, particularly at 10 min post-irradiation. Thioctic acid affected neither the respiration of control or X-irradiated Tetrahymena nor the oxidation of pyruvate.The growth lag of Tetrahymena increased proportionately with increasing radiation dose; no cells survived 600,000 r. The presence of metabolites during irradiation did not affect the lag period or subsequent growth rates. The effects observed were discussed in terms of an alteration of the permeability of Tetrahymena after irradiation.

Notizen: SYNOPSIS. A full account of the nuclear changes during binary fission and conjugation in a local race of Blepharisma is presented in this paper. The macronucleus consists of 2 nodes connected by a strand. Number of micronuclei varies from 6 to 18. During binary fission, condensation of macronucleus is followed by elongation and thinning of the middle region which finally breaks. Daughter nuclei later attain the typical vegetative form. Notably, during binary fission some micronuclei appear to complete their mitoses by the time the macronucleus attains the condensed form, while others lag behind and exhibit practically every stage of mitosis.During conjugation, from 6 to 10 micronuclei undergo the first pregamic division, the same number through the second division, and two products of the second division take part in the third division. The rest degenerate. Division products of the nuclei in the paraoral region take part in synkaryon formation. The synkaryon undergoes either 2 or 3 divisions. In the former case, of the 4 products, 2 become the macronuclear anlagen, one the micronucleus and the fourth degenerates. In the latter case, of the 8 products, 3 to 4 become the macronuclear anlagen and the rest become micronuclei. Chromatin elimination has been observed during the division of the macronuclear anlage, followed by an extra metagamic fission of the cell.Comparison with two other races from India and an American race indicates considerable diversity in the structure and behaviour of the nuclear apparatus in different races of Blepharisma undulans.

Notizen: SYNOPSIS. Females of Heterakis gallinae were separated on the basis of their capacity to transmit the protozoan parasite Histomonas meleagridis. Sections of worms, capable of transmitting the protozoon, revealed the organism in both males and females as well as in the eggs. Infected male worms contained histomonads in the gut wall and the wall and lumen of the reproductive system. Female worms infected with H. meleagridis showed the organisms throughout the reproductive system. Histomonads, found in uterine eggs possessing shells, had a larger nucleus and reduced cytoplasm.Because of the presence of the protozoon among the sperm in the male reproductive system, it is believed the organism can be transmitted to female worms through copulation. The cycle in the worms also supports the assumption that H. meleagridis was originally a parasite of the worm.

Notizen: SYNOPSIS. Speculations regarding the mode of transmission of monocystid parasites of earthworms over a period of more than 100 years have never been tested experimentally under controlled conditions. In order to do so a stock of infectionfree Eisenia foetida (Sav.) was raised from cocoons and experimental infections were induced in this host using sporocysts of the gregarine parasites Apolocystis elongata Phillips & Mackinnon 1946, and Nematocystis elmassiani (Hesse, 1909). Experimental infections were obtained by feeding to uninfected worms sporocysts obtained directly from infected host worms. This proved that the intervention of a vector is not a necessary condition of infection. Infections could not be induced by injecting sporocysts through the body wall into the body cavity. Infections are thus probably acquired in nature by the ingestion of sporocysts. Sporocysts do not leave the body of the host by being passed from coelom to lumen of the gut, nor do they pass directly to the exterior through apertures of the body wall. There was no evidence of parasitic autotomy. It is therefore concluded that death and decay of the host is the normal method of dissemination of sporocysts. Sporocysts were not infective after drying in air for three weeks. Other sporocysts lost potency after storage in moist conditions for several months. Infections involving the organisms specified were sporadic and unpredictable; modifying factors, such as variations in host susceptibility and latency in infection, appeared to be operating.

Notizen: SYNOPSIS. By an automatic electronic technique—the Flying Spot Particle Resolver—the effect of a wide range of concentrations of vitamin B12 on the size and growth of the B12-dependent Euglena gracilis was studied. Rate of cell growth was directly proportional, and cell size inversely proportional, to B12 concentration. Gross B12 depletion resulted in gigantism and prolongation of generation times.

Notizen: SYNOPSIS. Previously, the reproduction-inhibiting effects of ablastin could only be shown in vivo. The present report describes techniques for the in vitro demonstration and titration of this antibody. With a medium composed of Hanks' balanced salt solution, rat serum, lactalbumin hydrolysate, yeast extract and rat blood lysate, blood stream forms of Trypanosoma lewisi can be grown for approximately 24 hours at 37d̀C. Starting with the medium containing normal rat serum and inoculated with adult (inhibited) trypanosomes from infected rat blood, 50% or more of the parasites are in various stages of division after incubation overnight. Under similar conditions with ablastic rat serum, the parasites do not reproduce but remain as adults. If the medium is inoculated with reproducing trypanosomes from the blood, parasites in the presence of normal serum continue to reproduce, whereas those exposed to ablastin are almost completely converted to adult, non-reproducing forms. Similar results are obtained when the immune sera used are first adsorbed with living parasites to remove all trypanocidal antibodies. Ablastic serum inactivated at 56d̀C for 20 minutes does not lose its inhibitory activity indicating that ablastin is not complement dependent, and parasites grown on media at room temperature are not affected by the antibody suggesting that basic antigenic differences exist between blood stream forms at 37d̀C and culture forms at room temperature. Studies of the conversion of blood stream forms to culture forms indicate that the critical temperature range for the conversion lies between 28d̀ and 30d̀C. The significance of these results is discussed, and possible applications of the techniques described to studies of the mechanism of ablastic action are considered.

Notizen: SYNOPSIS. Normal swimming behavior of Paramecium multimicronucleatum in an essential mineral element solution with 0.0002 M calcium changed into continuous avoidance reactions upon replacement by equimolar strontium; equimolar barium produced a less pronounced similar effect. In equivalent pure SrCl2 and BaCl2 solutions, avoidance reactions were less frequent than in the balanced solutions. P. multimicronucleatum inoculated into autoclaved calcium- or strontium-containing cultures of the alga Protosiphon botryoides (ultimate food source) multiplied greatly and essentially equally, but died in barium. Accelerated avoidance reaction rates were observed in strontium up to and at 32 days after inoculation.

Notizen: SYNOPSIS. A previous study of parasites from relapsed P. berghei infections of mice indicated that the behavior of the relapse parasites differed from that of their parent strain. Experiments have been performed comparing the behavior of relapse and parent parasite infections in mice under two sets of conditions. In one group of experiments the behavior after antimalarial treatments, designed to result in chronic or latent states of infection, was tested. In all, 8 relapse strains were tested against their parent strains in six different experiments which employed 536 mice. It was observed that the mice infected with the relapse strains had a statistically significant greater mortality after the treatments than did mice infected with parent strains. This difference was observed regardless of how the relapse strain had been previously treated, or of what treatment was used in the experiments. In a second group of experiments, the behavior of infections with relapse and parent parasites was compared in normal mice. Five relapse strains were compared to their parent strains in a total of 5 experiments using 356 mice. It was observed that the mean survival time of mice infected with relapse strains was significantly greater than that of mice infected with the parent strains. It is not known whether this apparent difference in the behavior of relapse and parent parasites is related to the mechanism for relapse of P. berghei infections, or is merely a characteristic of parasites that had survived in an immune host.

Notizen: . Micronuclear mitosis in living Spirostomum teres has been studied by sensitive polarization microscopy, and the dynamic aspects of micronuclear division are described. The small, spherical, interphase micronuclei lie in form-fitting depressions in the macronuclear surface. Nuclear division begins with the rounding and slight swelling of the macronucleus and, coincidentally, the micronuclei move out of the depressions and away from the macronucleus, increase in size, and become weakly birefringent. As mitosis proceeds, the micronuclei increase in uniaxial birefringence and elongate to form irregular ovoids that convert to angular structures displaying principal axes of positive birefringence so divergent as to appear oriented at a right angle to one another. Micronuclei maintain this appearance for as long as 60 min and then abruptly change to rectangular-shaped structures, increase in uniaxial birefringence, and begin anaphase elongation. The somewhat dumbbell-shaped micronuclei lengthen at the constant rate of 2.0 μm/min to reach lengths 〉70 μm. It appears that little half-spindle shortening occurs during spindle elongation. Accompanying the changes in micronuclear spindle length are changes in birefringence. Just before elongation begins, presumably metaphase, the micronucleus is uniformly and intensely birefringent. At the magnifications employed, a chromosome plate is not clearly visible as a region of reduced birefringence. As elongation begins, the putative half-spindles are more birefringent than is the interzone, a condition that is maintained until the spindles have achieved ∼30% elongation, at which time a region of increased birefringence develops at the center of the interzone. This pattern persists for a very short time, then gives way to a uniform birefringence of the entire separation spindle that is maintained until elongation is completed. The rate of micronuclear spindle elongation, changes in micronuclear dimensions, and corresponding changes in birefringence are discussed with respect to possible mechanisms of mitosis.

Notizen: . Studies performed with the basidiomycete Laccaria trullisata collected from the sandy beach at the Hempstead Lake State Park, Long Island, New York, during the growing seasons of 1979 and 1980, have demonstrated a carposphere (equivalent to rhizosphere) effect. This region exerts a positive influence on the population density of amoebae when numbers are compared with those obtained in the bare sand 5 cm away. Moreover, amoebae have been shown to exist in, and have been recovered from, internal tissue of the cap (72%) and stalk (91%) of these mushrooms. A partial characterization of three strains of amoebae isolated from the internal tissue of L. trullisata and established in clonal culture is presented.

Notizen: L'étude, par le protargol, des phénomènes infraciliaires et de leur corrélation avec les phénomènes nucléaires au cours de l'autogamie dans le genre Euplotes montre, par comparaison avec la conjugaison, que les diverses étapes de la morphogenèse sont liées à la progression de l'état nucléaire. Par ailleurs, l'étude comparative des différents types de morphogenèse (bipartition, phénomena sexuel, réorganisation induite par le jeǔne) permet de supposer qu'il existe deux territoires morphogènes soumis à des systèmes de régulation bien distincts. La comparaison des séquences de morphogenèse chez divers hypotriches conduit à dresser un plan général d'évolution de la régulation de l'activité corticale en relation avec l'étendue des remaniements associés à la stomatogenèse.〈section xml:id="abs1-2"〉〈title type="main"〉ABSTRACTThe changes in the arrangement of the infraciliature associated with autogamy in Euplotes are described and compared with similar events associated with conjugation. The successive steps of morphogenesis are strongly correlated with nuclear processes. The comparative study of different types of morphogenesis (binary fission, sexual phenomena, starvation-induced reorganization) leads to the hypothesis that two morphogenetic fields (a ventral one and a dorsal one) depend on separate regulatory systems. From the viewpoint of evolution, the morphogenetic sequences of some hypotrichs have been compared. A general scheme of the evolution of cortical regulation is proposed, taking into account the extension of the area concerned with stomatogenic activity.

Notizen: Mouse omentum was studied after intraperitoneal challenge with tachyzoites of Toxoplasma gondii. Parasites inhabit omental histiocytes, fibroblasts, mesothelial cells, and free peritoneal macrophages. Recently infected cells showed enhanced metabolic and functional activity. Villous projections of the parasitophorous vacuole wall appeared, usually opposite the anterior pole of the parasite. In mesothelial cells, projections formed terminal swellings not observed in other infected cells. Activation of host cells was followed by reduction of the density of the cytoplasmic matrix, autophagosome formation, and intracellular edema, indicating the damage. The wall of the parasitophorous vacuole loses the supporting host cell endoplasmic reticulum that was attached to the vacuole just after entrance of the parasite into the cell. Then lysis of the parasitophorous vacuole and complete cell destruction occurs. The growth of parasites in undamaged cells does not coincide with the inflammatory response. Inflammation of the peritoneum develops only after the start of mass destruction of infected cells. Thus tachyzoites of Toxoplasma exert significant pathogenic effects by their ability to activate the host cell, causing lysis of the parasitophorous vacuole and subsequent destruction of the entire cell.

Notizen: Discophrya collini is a free-living suctorian with retractile tentacles covered by a thick fibrous cortex. The tentacles contain a microtubular central canal surrounded at the base by a fibrous collar. Electrical stimulation induces a reproducible tentacle retraction. With extracellular electrodes, the tentacles nearest the anode respond initially, contracting by up to 75% of their original length. There is an inverse relationship between voltage level and duration of stimulus in producing a threshold response, and at a set voltage, between duration and degree of retraction. With intracellular electrodes, the membrane potential has been measured as -30 mV, and tentacle retraction occurs in response to as little as 1.25 nA when the intracellular electrode is made the cathode of the circuit. SEM studies show that retracted tentacles have a wrinkled cortex, while TEM shows that the microtubular canal bends as it enters the cytoplasm. No consistent changes occur in the microtubule configuration of the canal on retraction, suggesting that the microtubules are not directly involved in the contractile mechanism.

Notizen: A rapid in vitro prescreen for Fe-binding chelators has been developed with growth of Crithidia fasciculata and the sparing of its heme requirement in a defined medium as a test system. The prescreen functions as an index of chelator-mediated Fe transport and as an index of growth inhibition, presumably by the interference with Fe and/or heme metabolism at intracellular chelatable sites. Of 161 chelators examined, 84 were active heme-sparers; 32 of these inhibited growth at low chelator concentrations. Twenty-eight other chelators inhibited growth and another 49 were inactive. Such chelating activity directed at Fe and heme targets in hemoflagellates may provide leads for chemotherapy.

Notizen: Study of microorganism growth kinetics requires measurement of maximal specific growth rate. Standard methods of measurement-batch, semicontinuous and continuous steady state-have sources of imprecision that can be substantially reduced by a modification of the continuous steady-state method. Data are presented, using the ciliate Tetrahymena pyriformis, that indicate that the theoretical foundation of the new method is firm and that precision can be increased.

Notizen: Viable merozoites of Plasmodium knowlesi were isolated and the proteins that were labeled on intact merozoites by lactoperoxidase-catalyzed radioiodination were identified. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and autoradiography of Triton soluble extracts of labeled merozoites demonstrated eight major bands ranging in apparent molecular weight from 150,000 D to 22,000 D. Exposure of intact merozoites to trypsin (10 μg/ml) for 10 min resulted in the loss of the two highest molecular weight proteins (150,000 D and 105,000 D) and the appearance of two new bands at 70,000 D and 62,000 D. Trypsin treatment under these conditions also removed the receptor(s) for merozoite attachment to erythrocytes. Therefore, these high molecular weight proteins are candidates for the merozoite component that attaches to erythrocytes. There was no evidence that the labeled membrane components were serum or erythrocyte membrane components, two potential contaminants in the preparation. Anti-rhesus erythrocyte antibody did not precipitate labeled merozoite proteins. Furthermore, the immunoprecipitation of labeled merozoite proteins by rhesus anti-merozoite serum was not inhibited by erythrocyte ghosts.

Notizen: Species of trypanosomatids without endosymbionts (Leptomonas seymouri, L. collosoma, L. samueli, Crithidia fasciculata, C. luciliae, C. acanthocephali, Herpetomonas megaseliae, H. mariadeanei, H. samuelpessoai, H. muscarum muscarum, Trypanosoma cruzi) and species of trypanosomatids with endosymbionts (Crithidia deanei, C. oncopelti, Blastocrithidia culicis) were comparatively studied by means of electron microscopy. Artificially aposymbiotic strains derived from species with symbiont were also included in the survey. Species with symbiont were found to differ in some ultrastructural aspects from the group of species without symbiont. Paraxial rods of flagella or intraflagellar structure were found exclusively in species without symbiont. Peripheral branching of mitochondria, accompanied by absence of subpellicular microtubules in sites where the mitochondrial branches are appressed to the cell membrane, were found exclusively in species with symbiont. Networks of kinetoplast DNA fibrils were found to be larger and looser in species with symbiont. Symbiont-free strains of species with symbiont retained the same morphological characteristics of their parental species.

Notizen: During a freeze-fracture electron microscopical study of the plasma membrane of Tetrahymena, several different types of organized particle assemblies were observed. Three of these were found only on the protoplasmic face and were localized in the anterior-ventral region of the cell. These consisted of plate-like arrays composed of 4–25 triplet rows of small 3–4 nm particles; long, paired linear arrays localized at the tops of cortical ridges and composed of 7–8 nm particles; and elongated tetragonal arrays located in the grooves between ridges and composed of approximately 10 nm particles. The distribution of these arrays is consistent with roles in cellular morphogenesis, chemoreception, or cell-cell pairing during conjugation. In addition, a unique particle track associated with the cytoproct (anal pore) was observed in the external face of the plasma membrane. Furthermore, the protoplasmic face of the plasma membrane is characterized by a high density of particles organized into localized microarrays, consisting of small paracrystals or strings, which exhibit a loose higher-order patterning most evident toward the anterior end of the cell. Particle distributions on the protoplasmic face do not appear to be significantly altered by conditions that cause clumping of alveolar membrane particles. Taken together, these observations are consistent with the idea that the proteins of the plasma membrane are highly ordered and relatively immobile and that the structure of the plasma membrane is regionally differentiated.

Notizen: . A new species of Dactylosoma (Dactylosomatidae, Piroplasmia), for which the name Dactylosoma hannesi n. sp. is proposed, was discovered in blood erythrocytes of Mugil cephalus, Liza richardsoni, and L. dumerili (Mugilidae) from Swartkops estuary, located east of Port Elizabeth, South Africa. The life cycle of this species differs in some respects from that described for all other known species of Dactylosoma and Babesiosoma. Mature schizonts contain eight nuclei but undergo division only to two to four daughter cells. During cytoplasmic cleavage, schizonts assume triad, rosette, or cruciform shapes. Merozoites are finally produced through a series of binary fissions of these daughter cells which may also be involved in additional nuclear divisions.

Notizen: Electron microscopy was used to examine the flagellar apparatus of Herpetomonas ampelophilae from the gut and malpighian tubules of Drosophila melanogaster. The flagellates attach to the microvilli either by weaving their flagella between the microvilli or by engulfing several microvilli with an external flagellar membrane. The first type predominated in the gut while the second type was limited to the malpighian tubules. Desmosomes were not involved in either type of attachment. A subpellicular collar with emerging microtubules was found to be adjacent to the desmosome of the flagellar pocket of herpetomonads in the gut.

Notizen: Prorocentrum micans Ehrenberg, a free-living marine dinoflagellate, was used to test the intracellular toxic action of cadmium. The cells were cultivated in Erdschreiber medium, with Cd concentrations of 10–100 ppb. Thin sections of treated cells, examined ultramicroscopically, exhibited vacuolations, increased numbers of lysosomes, and severe mitochondrial damage. The first two alterations are a general response to toxicity; the third is Cd specific. Although some chloroplasts were affected by Cd, they were not very sensitive to its action. The nuclear apparatus was not morphologically affected.

Notizen: Toxoplasma-like avian parasites inhabiting mononuclear phagocytes have been called Haemogregarina, Toxoplasma. avian Toxoplasma, Atoxoplasma, and Lankesterella by various authors. My attempts to transmit the parasites by bloodsucking mites or by transfer of blood and tissues of infected sparrows and canaries were unsuccessful. However, it was noted that the infection was exacerbated under conditions that favored transmission of coccidiosis: crowding and lack of cleanliness. Oral inoculation of sporulated oocysts of Isospora resulted in death from overwhelming macrophage infection with Toxoplasma-like organisms. Experiments using sparrows and canaries showed that the Isospora species involved was not cross infectious. Further investigations using canaries demonstrated that after oral oocyst inoculation, infection of macrophages spread from the submucosa of the duodenum to the liver. spleen, and lungs. After several generations in the internal organs, asexual multiplication, occured in the intestinal epithelium of the small intestinc. Fecal oocysts first appeared at the end of 9–10 days. Oocysts continued to be passed in the feces for months after infection. This chronicity may be explained by the relatively long life of the macrophages that serve as host cells for the asexual stages as compared to the intestinal epithelium which is the cell type parasitized by conventional coccidia.

Notizen: Stages of mitosis of the micronuclei of Stentor coeruleus were described as seen by transmission electron microscopy. Cells in division and those regenerating new oral membranelles were studied. Microtubules were found in early prophase in the karyoplasm and interspersed between the condensing chromatin. A monaxial intranuclear spindle is formed by early metaphase, with kinetochore microtubule attachment sites on the chromosomes. The spindle elongates, separating the daughter nuclei at anaphase. A new nuclear envelope, consisting of two unit membranes, begins to form at late anaphase. Small segments of membrane found in the space between the newly forming and the old micronuclear envelopes appear to fuse to form the new nuclear envelope. No ultrastructural differences were found in the mitotic nuclei of cells in division or regeneration.

Notizen: SYNOPSIS. Schizonts were found in the middle and lower third of the small intestine of two calves killed 12 and 14 days after they had been inoculated with pure cultures of oocysts of Eimeria auburnensis. The schizonts ranged from 78 to 250 μ long by 78 to 150 μ wide (mean 92 by 139.9 μ). They were usually located deep in the lamina propria near the muscularis mucosae instead of in the villi where most schizonts of Eimeria bovis are found. The schizonts of E. auburnensis resembled the previously described large microgametocytes of this species but were distinguishable morphologically and by histochemical stains. The microgametocytes were much larger than previously reported; one measured 91 by 287.5 μ.

Notizen: SYNOPSIS. Three new species of Blepharisma are presented: B. seshachari sp. nov., B. intermedium sp. nov., and B. tropicum sp. nov. Two sub-species of Suzuki are elevated to specific rank, B. undulans americanum to B. americanum and B. undulans japonicum Suzuki to B. japonicum Suzuki. Stein's taxa for the species Blepharisma undulans are considered to be diagnostic for that species.Important features of morphology and life-cycle of the above mentioned species are given. Discussion and position of the species Blepharisma undulans are presented and a proposal for the reorganization of the species is made. The possibility of a new key derived from a hypothesis of the phylogeny on an evolutionary basis of the genus is presented. This hypothesis has been extended to include ciliates like Stentor and Spirostomum and its implications discussed.

Notizen: SYNOPSIS. A laboratory colony of Oncopeltus fasciatus was found to be infected with Leptomonas oncopelti. Inasmuch as the parasite is transmitted from parent to offspring an opportunity presented itself to study the biology and transmission of this parasite under controlled laboratory conditions. An apparatus for observing individual bugs was designed and the presence or absence of flagellates in the feces determined. Flagellates were not shed until the bugs became adults after which they appeared in every defecation. Dissection of infected bugs revealed that flagellates were not present in the rectum until adulthood. Further studies indicated that in the midgut of the insect there is a departure from binary fission to budding. The nucleus divides and one of the newly formed nuclei migrates toward a newly formed kinetoplast. Rarely there is still another kinetoplast/nucleus division. In the event the new axoneme grows within the cytoplasmic sheath of the parent flagellum, smaller organisms produced by unequal cytokinesis remain attached. If the axoneme grows free, the smaller daughter organisms become free-swimming. Passage into the rectum of the adult bugs causes a rounding up of all parasites although the leishmaniform organisms continue to divide. It is presumed that infection of clean bugs is accomplished by the ingestion of leishmaniform organisms through a common water source. The reason for the presence of flagellates in the rectum of the adult but not in the nymphal insect and the mechanism responsible for the change from binary to unequal fission are not known.

Notizen: SYNOPSIS. Examination of intestinal contents and feces of Wisconsin red squirrels (Tamiasciurus hudsonicus) revealed two coccidia, Eimeria tamiasciuri and E. toddi n.sp. In the Eastern chipmunk (Tamias striatus), two species, E. vilasi n.sp. and E. wisconsinensis n.sp. occurred. In the northern flying squirrel (Glaucomys sabrinus), a coccidium resembling E. sciurorum was found.

Notizen: SYNOPSIS. A large heterotrich ciliate (Family: Bursariidae) found in a papyrus swamp in Uganda was used for oxygen tension experiments by Beadle & Nilsson, 1959, under the name of Bursaria sp. This organism has now been identified as Neobursaridium gigas Balech. The morphology of the organism was studied in living and stained specimens, especially with the silver impregnation technique, and the present findings are compared to those of Balech.

Notizen: SYNOPSIS. An electron microscope study of thin sections of Babesia rodhaini parasitizing mouse erythrocytes showed that this intracellular parasite feeds on its host cell in the same way as do malarial parasites. Large portions of erythrocyte cytoplasm are engulfed by invaginations of the plasma membrane leading to the formation of food vacuoles. The digestion of hemoglobin seems to be complete in Babesia since no pigment (hemozoin) could be detected either in the food vacuoles or in the cytoplasm.The fine structure of Babesia rodhaini is very similar to that of Plasmodium berghei. In both, typical mitochondria are lacking. Instead a structure was found composed of concentric membranes which it is assumed might perform mitochondrial functions. As in Plasmodium berghei a double-membraned vacuole with a matrix of low density is present in almost all sections. The endoplasmic reticulum is represented by small vesicles; the ground-substance is filled with Palade's small particles. The nucleus is large and surrounded by two membranes. Babesia reproduces by budding and binary fission. Reproduction is not easy to identify since the parasite forms large pseudopods resembling stages in division.

Notizen: SYNOPSIS. The effect of 10 detergents on the inhibitory activity of neomycin was tested against Ochromonas danica. All 4 anionic detergents used were synergistic with neomycin. Evidence is presented that the synergisms were due to the effect of the detergents on the cell membrane. In the presence of Tergitol 7, O. danica is more susceptible to changes in osmotic pressure by increasing concentrations of KCl.

Notizen: SYNOPSIS. All zoologists are affected by provisions in the very recently published International Code of Zoological Nomenclature, the first revised edition of these important rules to appear in over 50 years. Common nomenclatural practices, often malpractices, of protozoologists and parasitologists who work primarily in taxonomic fields are revealed and discussed in light of recommendations and mandatory regulations to be found in the new Code. Some errors have been due solely to carelessness; others have involved misinterpretations of various directives; still others have involved cases not adequately covered by the old Règles. Certain mistakes of the past cannot be changed; but others are to be rectified upon discovery, according to mandates in articles of the new Code. Practical applications of the rules of nomenclature are stressed, and examples are taken from actual situations found to exist throughout all major taxa of the phylum Protozoa.Because of the value of such discussion in both new and revisory work in protozoan systematics, the following major topics are given special consideration: matters of orthography, the original spelling of names and their justified or unjustified emendation; authorships and dates of names, who is responsible and when, and how such data are properly cited; mandatory dates in the new Code, and their effect on both already established names and names not yet proposed; the principles of priority and conservation or continuity, and how the rules attempt to satisfy proponents of both of these diametrically opposed “laws”; the concepts of synonymy and homonymy, and proper methods of treating names which have become involved in such situations; family-group names, and the several special nomenclatural problems they present to protozoan taxonomists; the major problem of types, and the peculiar position of protozoologists with regard to the type concept, especially type-specimens for categories in the species-group; miscellaneous considerations, several unrelated but significant topics not appropriate for inclusion in preceding sections of the paper.

Notizen: SYNOPSIS. In a chemically-defined medium Tetrahymena setifera HZ-1 required a sterol, an alcohol, eleven amino acids, a purine, a pyrimidine, and six B-complex vitamins. The sterol requirement was met by a variety of 3β-OH, C27-C29 sterols including cholesterol and stigmasterol, but not by precursors of cholesterol which precede desmosterol or Δ7-cholestenol. Some combinations of long-chain fatty acids with a synthetic dipalmitoyl phosphorylethanolamine partly substituted for sterol. Ethyl and methyl alcohols (but not a variety of other alcohols and organic acids) satisfied the alcohol requirement.

Notizen: SYNOPSIS. Trichomonas vaginalis grown aerobically slowly metabolizes glucose-U-C14 and succinate-2,3-C14 to CO2 and to amino acids which are then incorporated into protein. Analysis of protein hydrolysates from cells grown on glucose-U-C14 reveals radioactivity in 15 amino acids. Although the data do not permit a direct interpretation and analysis of the sequence of amino acid biosynthesis, it seems likely that a tricarboxylic acid cycle operates. Attempts to prepare cell-free systems carrying out cycle reactions have proved unsuccessful.

Notizen: SYNOPSIS. One hundred eighty-eight fresh-water samples from France (30), Italy (42), Austria (12), Germany (1), Switzerland (35), Holland (20), England (26), and Sweden (22) were examined for T. pyriformis. The habitats included rivers, mountain streams, lakes, ponds, irrigation ditches, roadside ditches, running and dead water canals, and fountains. The temperature ranged from 10° to 30°C, locations from 42° to 68° North latitude, with elevations from sea level to approximately 3,000 feet. Of the samples taken 28 contained T. pyriformis from which 411 clones were established in axenic media. Thirty-three additional samples contained ciliates other than T. pyriformis. All clones grew well in 1% proteose peptone; when screened for their nutritional requirements a few failed to grow on the completely defined medium and several others survived eight sub-inoculations without thiamine.The nuclear and sexual activity pattern followed that of previous collections. In distribution, variety 6 was found in Italy, variety 3 in Austria, and variety 4 in England. A new variety (variety 10) with two mating types was isolated from four different habitats in England. Several strains from Italy, France, Holland, and England constitute one group which mated among themselves, but only a few of which reacted with mating type I of variety 6 from America. This demonstrates the close affinities of the European and American strains, yet shows the possible evolution of a new variety (species).

Notizen: SYNOPSIS. The steroid requirement of a Trypticase-requiring strain, SLT, of Trichomonas gallinae on the Shorb-Lund synthetic basal medium minus ribonucleic acid was fulfilled by cholesterol, 7-dehydrocholesterol(provitamin D3), cholestanol (dihydrocholesterol), and to a lesser degree, by ergosterol (provitamin D2), β-sitosterol and zymosterol acetate. Cholestanol was inhibitory at certain concentrations. All steroids were subsequently checked by gas chromatography. Only cholesterol and zymosterol acetate showed one peak, the others containing 2 to 4 peaks. Repurified cholestanol was active and showed no inhibition of growth, but repurified β-sitosterol was inactive. The following were also inactive: diethylstilbestrol, estrone, dehydroepiandrosterone, progesterone, testosterone, desoxycorticosterone acetate, cortisone acetate, compound A, 5,6-dihydro-ergosterol, dihydroergosterol acetate, stigmasterol, sodium taurocholate, cholic acid, methyl desoxycholate, desoxycholic acid and methyl cholate. Precursors in cholesterol synthesis, acetate, mevalonic acid, mevalonic acid plus a liver extract and squalene were inactive in replacing cholesterol, although acetate is required for growth in the presence of cholesterol. Crystalline fat soluble vitamins, carotene, calciferol (vitamin D2), activated 7-dehydrocholesterol (vitamin D3), menadione (vitamin K3) and tocopheryl acetate (vitamin E acetate) were inactive in replacing cholesterol. Trichomonas species PN from the pig's nose utilized cholesterol, 7-dehydrocholesterol and the impure β-sitosterol sample in a modified SL medium with acetate omitted. A reinvestigation of steroid requirements seems to be indicated when a completely synthetic medium and pure steroids are available.

Notizen: SYNOPSIS. Protoplasm transferred to a multinucleated amoeba is well tolerated if the donor and recipient portions are from the same amoeba, from different amoebae of a single clone, from different amoebae of the same species found in a given location, or from different amoebae of the same species found in widely separated geographic areas. On the other hand, protoplasm is not tolerated and death invariably follows interspecific or intergeneric microtransfers between any two of the three species of amoebae used in this study.Attempts to overcome the tolerance block in heterologous transfers by the use of x-radiation failed although a significant extension of the mean survival time was obtained. The latter can also be interpreted as a limited therapeutic effect of nonirradiated, heterologous donor protoplasm on supralethally irradiated recipients.

Notizen: SYNOPSIS. Cultures of Prymnesium parvum subjected to constant illumination failed to produce ichthyotoxin. On the other hand cultures subjected to alternate periods of light and darkness showed a gradually rising ichthyotoxic activity during the dark period reaching a maximum after about 7 hours.

Notizen: SYNOPSIS. A new species, Crithidia rileyi (Trypanosomatidae), is described from Tabanus epistates. The most characteristic feature of the flagellate is the frequent occurrence of a broad sucker-like posterior end. In contrast to other species of Crithidia it multiplied very slowly in the first few weeks after isolation. A review of the literature shows that trypanosomatids of two generic types, Crithidia and Blastocrithidia, have been described from flies of the family Tabanidae, although they have nearly always been regarded as stages of the same organism. Some or all of those of the Blastocrithidia type are stages of Trypanosoma theileri. The Crithidia are probably not stages in the development of any trypanosome.

Notizen: SYNOPSIS. Gromia oviformis from New Zealand has been examined in thin sections after fixing in osmium tetroxide and embedding in methacrylate. The structure of the protein and acid mucopolysaccharide shell and the canals which pass radially through it are described. Multiple honeycomb membranes located between the shell and the cytoplasm, as well as mitochondria and “Golgi bodies,” none of which has hitherto been seen in light microscope studies, are discussed and illustrated. The previously known stercomata and xanthosomes are considered. Though still regarded as enigmatic cytoplasmic inclusions, observations suggest that they are waste products retained within the animal throughout life.

Notizen: SYNOPSIS. An agar overlay technique developed to investigate the effect of various substances on growth of a selected group of protozoa is described. Test systems employing Crithidia fasciculata (culex), Ochromonas malhamensis, Tetrahymena pyriformis W and Trichomonas foetus were devised to evaluate the effect of known compounds and to assay the activity of antibiotic fermentation beers. This disc-plate method can be summarized as follows: preparation of a foundation layer; overlaying of a mixture of agar, nutrients, protective antibiotics, and inoculum; placing of paper discs with the test material on the overlay followed by incubation and subsequent observation of the plates for zones of inhibition of growth. The concentration of agar in the overlay sufficient to restrict movement of the protozoa without inhibiting their growth, nutrients required for adequate growth and continued viability of the inoculum, and the concentration of penicillin and streptomycin which will not inhibit the assay protozoa but beeffective against the microorganisms in the fermentation beers are discussed. This technique offers a method not only for primary screening for cytotoxic substances but also one which may be adaptable to other studies of protozoa.

Notizen: SYNOPSIS. Acid phosphatase activity was studied in total mounts and sections of agnotobiotic Paramecium multimicronucleatum by the alpha-naphthyl phosphate-hexazotized rosanilin method. Timing was achieved by India ink marking of food vacuoles. Enzyme activity is present in small endoplasmic granules and in the greatest part of food vacuoles. Following an inactive stage (stage I) of an average length of 5 min the activity appears at the periphery of the vacuole, in most cases in the form of granules (stage II). A high activity level (stage III) is attained within 1 1/2 min and maintained for the most part of the vacuolar cycle. The activity disappears only in the latest vacuoles before egestion (stage IV). The appearance of activity is not concurrent with but succeeding to the maximum of vacuolar acidity as ascertained by feeding Congo red stained killed yeast cells. On the basis of these results the food vacuoles may be looked upon as belonging to the lysosomes sensu lato.

Notizen: SYNOPSIS. In Oxytricha fallax, extrusion of all the excretory crystals and some refractile bodies occurs when food is with held. The precystic animals thus resulting become transparent and undergo dedifferentiation of organelles. First the undulating membrane and cytostome are entirely resorbed, producing astomial forms. Then the adoral membranelles vanish gradually, accompanying which the somatic ciliature such as the cirri comes to be resorbed. Occasionally, early precystic animals retaining the intact feeding organelles reorganize spontaneously (physiological regeneration), but they become irreversibly encystable by high-temperature treatment; for hastening resorption of feeding organelles accelerates encystment.When transparent animals at various precystic stages are cut in half the posterior fragment (PF) always encysts faster than the anterior one (AF) from the same parent, except that some of the AFs from early stages reorganize into normal vegetative forms. The time difference for completion of encystment between an AF and PF pair is at early stages larger than at later ones. If the anterior part of AF is further excised, the time difference for encystment between AF and PF from the same source becomes smaller or indistinguishable, with the exception that some AFs from early stages regenerate instead. Further, when the anterior part of whole precystic animals is removed, the time for their encystment is reduced. Also in this case, the fragments from early stages normally regenerate.From these results, it is presumed that the adoral membranelles tend to inhibit the encystment process as they do the initiation of an oral primordium in dividers and regenerants of Stentor and other ciliates. Accordingly, when resorption of membranelles becomes extensive as precystic processes progress, their dominance over and inhibition of cyst formation may be diminishing. From the fact that regeneration of fragments from early stages into normal forms may be due to retention of the undulating membrane, its resorption is considered to be an essential prerequisite for the initiation of irreversible encystment.

Notizen: SYNOPSIS. A partially purified hexokinase extracted from Euglena had the following properties: 1) pH optimum 8.0–8.5; 2) an absolute requirement for Mg++ and adenosine triphosphate with Mn++, Co++, Zn++, and Ca++ less active or inactive under the test conditions. Inosine triphosphate could not be substituted for adenosine triphosphate; 3) an apparent Km (glucose) of 5 × 10−4 M; 4) the enzyme was not inhibited by the usual sulfhydryl agents, but was inhibited 24% by adenosine diphosphate. The extract phosphorylated fructose and mannose. It was not clear whether a separate enzyme phosphorylated fructose. Relative rates of phosphorylation, as determined by labile phosphate analyses, were: glucose, 1.00; fructose, 1.19; mannose, 0.56. The partially purified extract also contained phosphohexose isomerase activity; 6-phosphogluconic acid dehydrogenase was absent. Euglena hexokinase is apparently localized in the cytoplasmic or small-particle fraction of the cell. In most respects the enzyme seems to resemble the well-characterized yeast hexokinase rather than the muscle enzyme.

Notizen: SYNOPSIS. Lankesterella bufonis sp. nov., from toads, Bufo regularis Reuss, in Egypt, described herein, appears to be the first species of this genus to be found in Bufo. Sporozoites of the parasite in circulating blood are usually intracorpuscular, rarely free. Free forms, abundant in smears of internal organs, particularly from lungs, are small, slender, slightly curved bodies with the anterior end more pointed than the other. The small, oval, delicate nucleus is always situated in the posterior third of the parasite, either terminal or more usually subterminal. A single cytoplasmic vacuole is located just anterior of the nucleus and more-or-less centrally. Few darkly stained granules are sometimes seen around the vacuole. Though intracorpuscular forms retain morphological characteristics of the free forms, they frequently undergo peculiar changes: apparently flattening of host-cells during smearing and fixation results in shorter and wider, and sometimes greater width of the parasite. Multiple infection with two and rarely three Lankesterella sporozoites is not uncommon. In liver and spleen smears, certain large cells, apparently of the macrophage or endothelial types, contain forms similar to those described in the peripheral blood, but mostly shorter and broader. Various developmental stages of schizonts were also seen in the liver and lung. In liver, lung, spleen, and kidney sections, numerous young forms, possibly merozoites, were scattered among tissue cells. The present parasite differs morphologically from Lankesterella minima (Chaussat, 1850), L. monilis Labbé, (1894), and L. canadensis Fantham et al., 1942.

Notizen: SYNOPSIS. Ophryoglena mugardi is an Ophryoglena of medium size characterized by its spindle-shaped and bimicronuclear theront, by its rather bulky trophont and by its physiological reproductive cycle. During starvation its physiological evolution causes a secondary and temporary encystment of the theront lasting 6 or 7 days (at 18°C). The ultimate re-encystment leads to cytolysis. Feeding induces the physiological reproductive cycle; if food is given soon after the release of the tomites, it determines a primary cycle, usually allowing eight tomites; if it is dispensed only after the secondary encystment of the hungry theront and after its excystment it causes the appearance of secondary cycles, allowing two or four tomites.When the starved theront, becoming smaller and smaller, is fed it produces trophonts which encyst. These no longer divide; each one delivers one theront only. These theronts, smaller and smaller, are able to produce the original major forms, but only after several successive alimental cycles and without any secondary encystment of the theront.

Notizen: SYNOPSIS. The plastid system of “normal”Euglena gracilis strain Z was found to be extremely unstable. Under normal culture conditions in the light about 1 or 2% of the cells were found to have lost spontaneously the capacity to green on further culturing. Cells treated with streptomycin, heat or U.V. all lost the capacity to green on further culturing. Bleached cells whether appearing spontaneously or by induction with streptomycin, heat, or U.V. light, were all found to possess within them organelles which were identified as proplastids.The proplastids of some “bleached” strains were capable of synthesizing porphyrins when grown in a standard culture medium. Others synthesized porphyrins only after the addition of delta-aminolevulinic acid to their medium, while proplastids of still other strains could not synthesize porphyrins from this precursor. Normal cells when grown in total darkness were found to possess proplastids morphologically identical with those of the bleached strains. Upon exposure to light the proplastids enlarged and greened. In cells which grew under continuous light the plastid system appeared as an interconnected system of tubules. Cells maintained on a schedule of 12-hour light and 12-hour dark had plastids which were detached from each other.

Notizen: SYNOPSIS. Euglena and Chlamydomonas were cultured in an organic medium in the dark and at several light intensities (15, 60 and 150 ft-c) at temperatures from 20d̀ to 35d̀C. Below 32.5d̀, growth of Euglena was independent of light. Chlamydomonas was light dependent at all temperatures where growth occurred; there was no growth in the dark, at 15 ft-c, or at temperatures above 32.5d̀. At 35d̀, growth of Euglena became inversely light dependent; the higher the illumination, the poorer the growth. Multinucleated, giant euglenas were found at 35d̀, a greater percent of abnormal cells appearing at the higher light intensities. Monsters were not observed in Chlamydomonas.To explain the growth-inhibiting, monster-inducing effect of elevated temperatures on Euglena, it is postulated that a dark-formed thermosensitive protein, essential for normal cell division, is denatured. Light may increase the effect of heat on chlorophyll and the chloroplast, possibly by being converted to intraplastidic heat through the plastid carotenoids, thus having some indirect synergistic role in the phenomenon.

Notizen: SYNOPSIS. Erythromycin bleaches Euglena gracilis in a manner resembling that of streptomycin. Erythromycin-bleached substrains have been cultivated 16 months in light on erythro-mycin-free media without greening. Bleached substrains were obtained only if erythromycin was added to actively growing cultures: erythromycin did not bleach if added during the stationary phase of growth of green cultures.

Notizen: SYNOPSIS. Conchophthirus curtus is a thigmotrich that occurs on the gills of Unionid clams (Elliptio complanatus in this study). The anterior third of the endoplasm, unlike the remainder, is relatively firm and without gastrioles; it contains an extensive aggregation of specialized endoplasmic granules and is therefore called granuloplasm. On the surface ventral to the granuloplasm is a thigmotactic area that bears closely set, strongly adherent cilia. There is no evidence that the granules are intracellular microorganisms; they are Feulgen-negative and do not divide, nor do they stain like bacteria. Cytochemical tests show that the granules contain neutral fat, fatty acid, phospholipid, glycogen, and mucin. The evidence indicates that the principal function of the granules and granuloplasm is the production of mucin, which is supplied to the underlying thigmotactic cilia, thereby conferring on them their adhesive properties. Thus, the granules and granuloplasm constitute a mucous organelle, and to the extent that they are osmiophilic and secretory they qualify as Golgi bodies and Golgi material, respectively. Since endoplasmic granule is a general term for any of the granules of protozoan endoplasm, it is recommended that the granules of the present study be called muciferous granules.

Notizen: SYNOPSIS. This is a description of structures seen in EM preparations of the macronucleus of Paramecium aurelia, using both starved and growing organisms, the latter at timed stages after fission. The effects of treatment with RNA-ase, DNA-ase and of the “silver-Feulgen” reaction are described, and comparisons made between structures in the macronucleus and the micronucleus. The appearance of macronuclei in thin (2 μ) paraffin sections, stained by the Feulgen, azure A and pyroninmethyl green methods, and upon examination by ultra-violet micrography, is also considered. From these observations it is concluded that the macronucleus contains a large number of structures, 0.5 μ in diameter, consisting of an outer RNA-containing region and central elements containing DNA. These bodies, which are usually thought to be “nucleoli” by other workers, are now considered to be the most likely candidates for the genetic “sub-nuclei” which have been postulated from genetic work.

Notizen: SYNOPSIS. The longitudinal kineties of the holotrich ciliate Trimyema marinum each bear only three widely spaced cilia; but these cilia are located at identical horizontal levels so that they comprise three helicoidal ciliary bands running around the anterior pole of the organism. The two kineties whose cilia are found most anteriorad, located in a right dorso-lateral position on the body, are exceptional, however: they are prolonged anteriorly, bearing numerous short additional cilia.These two “polykineties” wind clockwise around a kind of apical disc; their distal extremities continue to curve, dipping into a “prebuccal invagination” in which they may be said to constitute a vestibular ciliature.In spite of its rather unique characteristics, the curious anatomy of this ciliate does conform to the organizational type recognized for holotrichs of the order Trichostomatida.

Notizen: SYNOPSIS. A number of small molecules including CO2, certain Krebs cycle acids and certain amino acids stimulated growth and glucose utilization of a colorless strain of Euglena gracilis in a phthalate-buffered mineral salts medium. Their major effect was to shorten markedly the lag period; some compounds also gave small increases in maximum growth rate and total cell yield. The stimulatory substances were effective in small (sparking) amounts. It is suggested that all the stimulatory substances acted similarly, by keeping the internal concentration of oxaloacetate at a sufficiently high level to allow effective operation of the terminal respiratory cycle.Glucose utilization was initiated within a pH range of 3.0 to 5.0. This range could be extended by the addition of glycine to the growth medium. Cells cultured at pH 4.5 could be adapted to growth at pH 7.0 in a phosphate-buffered mineral salts medium containing a small amount of citrate. Neither adaptation nor growth occurred at pH 7.0 in the absence of citrate. Since no evidence of citrate utilization was obtained and since EDTA replaced citrate, it is concluded that citrate was acting as a chelator.The major enzymes of the Embden-Meyerhof-Parnas and pentose phosphate pathways were demonstrated in cell-free extracts. The data presented indicate that glucose metabolism in Euglena is similar to that found in a wide variety of other cells. Indirect evidence was also obtained for the operation of a uridine linked pathway in hexose metabolism.With the exception of hexokinase, for which results were inconsistent, all the enzymes demonstrated were routinely found in the supernatant fraction of the cell-free extracts. The pH optima of a number of the enzymes were found to be between pH 7.5 and 8.6, although the cells from which the enzymes were obtained were grown in acid medium.

Notizen: SYNOPSIS. Cannibal giant Blepharisma undulans americanus, NYU strain, grown in mass culture, showed increased numbers of macronuclear lobes and greater variability in their number, compared to the bacteria-fed form. Feulgen and methyl greenpyronin preparations stained both the DNA and RNA of the cannibals and of the ingested forms within the food vacuoles.During the first 3 to 6 hours of digestion, macronucleus and deoxyribonucleic acid disappear from the food vacuole; during the last 6 hours the ribonucleic acid disappears from the food vacuole; DNA and RNA are therefore presumed to be digested and absorbed.

Notizen: SYNOPSIS. Production of a “vitamin B22-like compound” by Tetrahymena pyriformis mating type II, variety 1, and 3 other tetrahymenids was demonstrated. The compound produced by T. pyriformis was nutritionally active for Escherichia coli and Lactobacillus leichmannii and inert for Ochromonas malhamensis and Euglena gracilis, despite use of a variety of the standard methods for liberating bound B12. By dry-weight it is present in 1 part in 30 million. Its chromatographic and electrophoretic properties are described.

Notizen: SYNOPSIS. Turnix suscitator (Galliformes), Phaenicophaeus javanicus (Cuculiformes), and two passerine birds, Dicaeum cruentatum and Pycnonotus dispar, harbor Plasmodium vaughani Novy and MacNeal in the States of Pahang, Perak and Trengganu. P. rouxi Sergent, Sergent and Catanei occurs in the same localities and in Kelantan too, in the following eight passerines: Chloropsis cyanopogon, Copsychus malabaricus, Geokichla sibirica, Malacocincla rostrata, Pitta megar-hyncha, Pomatorhinus hypoleucos, Pteruthius erythropterus and Pycnonotus goiavier. This is the first report of either parasite from Malaya, and from the hosts listed. Taxonomic criteria are discussed, and it is pointed out that Dr. A. H. Helmy Mohammed's “bow-tie” schizonts are a useful guide to the recognition of P. rouxi.

Notizen: SYNOPSIS. A leptomonad flagellate found in large numbers in the latex of the asclepiad plant Pergularia extensa in East Africa has been identified as Phytomonas elmassiani (Migone). The flagellate is believed to undergo cyclical development in the lygaeid bug Oncopeltus famelicus which feeds on Pergularia. Following the ingestion of infected latex by the insect, the flagellates on reaching the midgut enter a growth phase and increase in size to form giant leptomonads. These probably then migrate to the salivary glands of the bug, possibly by boring through the gut wall, haemocoel and walls of the salivary glands. The salivary gland forms represent a multiplication phase in the life-cycle, and numerous small metacyclic forms are produced which are then injected into a plant host to initiate a new infection.Also infecting the midgut of Oncopeltus famelicus is another trypanosomatid, Blastocrithidia familiaris (Gibbs). It is characterised by the possession of an undulating membrane and the habit of budding off leishmania bodies from its anterior end.These bodies are resistant and serve in the transmission of the parasite from bug to bug.The two flagellates of Oncopeltus famelicus are readily distinguished from one another, not only on morphological grounds but also on their behaviour in vitro. B. familiaris can be cultivated on a monophasic glucose-peptone broth. It then loses its undulating membrane but retains its budding habit. Phytomonas elmassiani will not grow on this medium but when inoculated into a diphasic peptone blood-agar medium the latex forms will undergo development comparable to their insect midgut phase.The plant trypanosomatids appear to form a well-defined group bearing little similarity to the monogenetic insect flagellates of the “crithidia” type. It is suggested that the culture form Strigomonas (=Crithidia) oncopelti, allegedly parasitic in asclepiads and Oncopeltus fasciatus, might be simply an insect parasite, its original plant association being quite fortuitous.

Notizen: SYNOPSIS. Ten- or 12-day cultures of Trypanosoma ranarum in Diamond's SNB-9 medium contain large numbers of slender crithidia and considerably smaller numbers of pear-shaped crithidia, but in fresh media the pear-shaped bodies constitute about 93% of the population after 5 days whereas slender forms make up about 4–5%; the remainder are leishman bodies. Succeeding days show a different cycle in that the slender forms increase to some 93% at 10–13 days and the pear bodies decrease to some 3% of the total at the same time.When washed in Krebs-Ringer phosphate buffer alone, neither morphological type shows endogenous respiration; in glucose containing buffer, O2 consumption becomes evident; pear-shaped crithidia use, on an average, 12.6 μl O2/hr/108 whereas slender forms utilize 17.7 μl O2/hr/108 parasites. Malonate at 0.01 m inhibits O2 consumption of slender forms about 61% as compared to 27% with the pear-shaped bodies. A speculative discussion of the relation between morphological types, O2 consumption in the presence of glucose, and malonate inhibition is presented.

Notizen: SYNOPSIS. Short sections of deoxyribonucleic acid (DNA) in the elongated macronucleus of Euplotes eurystomus were labeled by means of a short exposure to tritiated (H3-) thymidine to follow by autoradiography the fate of the labeled DNA during amitotic reorganization of the macronucleus. During amitosis the radioactive DNA that was restricted during interphase to short sections of the nucleus is dispersed and becomes evenly distributed throughout each daughter macronucleus.Although the reorganization bands normally originate only at the ends of the macronucleus, additional bands can start at other places on the macronuclear surface. Bands of the same macronucleus originate with a high degree of synchrony. DNA synthesis is a constant feature of the rear zone of every reorganization band.

Notizen: SYNOPSIS. Thin sections of Lankesterella garnhami were examined by electron microscope and the morphology of trophozoites and sporozoites is described. The envelope of the organism consists of a double membrane, which (in the presumed sporozoite) is broken at one point posteriorly by the microphyle. The anterior end possesses characteristic organelles, which include an open apical ring leading to a collar or conoid and to 30 peripheral fibrils, a paired organelle, and numerous “lankesterellonemes.” Typical mitochondria and a Golgi apparatus are found in the cytoplasm and a nucleus of heterogeneous nature.

Notizen: . Strains of Tetrahymena thermophila were examined in an attempt to establish what role certain ions (Na+, K+, Li+, Ba++, Ca++, Mg++, Mn++, Al+++, Fe+++) play in influencing cell survival time in a culture medium. In short-term experiments (20–30 min), cell survival time in a 1% peptone medium is directly related to the valence of the ion employed. Long-term observations (lasting up to five days) in a 1% peptone medium containing lower ion concentrations revealed that the effects on cell-cycle time are not correlated with the valence state of the ion. Comparisons were made among the ionic resistances of strains of T. thermophila, of T. pyriformis sensu stricto, and of two subspecies of T. pigmentosa. Strains within a species are highly correlated in their patterns of ionic response, while marked differences between species occur. The most distinctive group of strains examined came from one of the subspecies (syngen 6) of T. pigmentosa.

Notizen: . A two-stage chemostat modified to accommodate the growth of adhesive organisms was used to determine the yield constant, Y, of a representative soil amoeba, Acanthamoeba polyphaga, utilizing as its prey Pseudomonas paucimobilis. The first stage consisted of a glucose-limited bacterial culture in steady state. The second stage consisted of a simplified predator-prey system, nongrowing bacteria serving as the limiting substrate for amoebae. A refined methodology to more accurately determine Y was developed, and Y for Acanthamoeba polyphaga in batch and continuous culture was determined to be 19.1%.

Notizen: . The swiftness of thermotaxis of Paramecium caudatum has been investigated for various populations of organisms by measuring the transient spatial distribution of the gathering process of organisms that are transferred to a temperature-gradient cell from the culture medium. The dispersion obtained from the spatial distribution for each population is found to decrease linearly with time and finally reach a steady state value. The gathering rate determined by the slope of the dispersion strongly depends on population; it increases with population.

Notizen: . Blastocystis hominis, an anaerobic intestinal protozoan parasite of man, has a generation time (GT) in axenic culture of 8.5–19.4 h, depending on the strain tested. Average GT of the eight strains was 11.7 h. Zero growth time cell counts of 5.0 × 105/ml to 2.0 × 106/ml rose in 3–5 days to 1 × 107 or 1 × 108 cells/ml. The GT was determined for the 24-h period during which the most rapid growth occurred; about 2% of the B. hominis cells were in division during this time. Division under the culture conditions provided was by binary fission, the usual mode for B. hominis in vitro as well as in vivo. Division times were determined also by direct observation of individual dividing cells in slide cultures. These were usually ca. 40–60 min but sometimes as low as 20 min.

Notizen: In contrast to the situation in 13 other species of the Tetrahymena pyriformis complex, in which the condensed degenerating old macronucleus lies in the posterior end of the cell during the late stages of conjugation, in Tetrahymena tropicalis that nucleus is found in the anterior portion. This developmental characteristic may be useful for taxonomic purposes as well as being of value in investigations on nucleocytoplasmic interaction.

Notizen: Eimeria nuttalli oocysts were found in 58% (21/36) and E. procyonis oocysts in 25% (9/36) of raccoons Procyon lotor in Illinois, and sporocysts of Sarcocystis sp. in 17% (2/12) of other raccoons in Illinois. The oocysts of E. nuttalli were ellipsoidal to ovoid. 15–21 × 12–17 μm, with a one-layered, smooth, colorless wall. The oocysts of E. procyonis were 22–28 × 18–22 μm, with a rough, striated, brownish, two-layered wall. The sporulated sporocysts of Sarcocystis sp. were 11–13 × 8–10 μm. Attempts to infect baby pigs by feeding them sporocysts of Sarcocystis sp. from the raccoon failed.

Notizen: Comments are made concerning the work reported at this Conference by Dr. Edith Box. The importance of stress on the animals used in experimental work is emphasized. Difficulties in identification of isosporan species in birds are mentioned.

Notizen: A trypanosomatid flagellate, Leptomonas sp., develops and multiplies in the macronucleus (only) of natural and laboratory-reared populations of the ciliate Euplotes. Up to 90% of the natural populations of Euplotes in our test pond had such nuclear infections. Laboratory infections were transmitted to this ciliate by feeding it liberated parasites. Paramecium resisted infections. All laboratory-induced infections were lethal to Euplotes, while control clones of the uninfected ciliates remained viable. This leptomonad, unlike Leptomonas karyophilus (found in Paramecium), shows no leishmanial forms in its several ciliate hosts and shows a varied pattern of locomotion.

Notizen: Some generalizations of a decade ago are reexamined in light of modern advances in coccidiology. Perhaps surprisingly, not many modifications need or can yet be made. Future successes of significance will be in areas of immunology and chemical genetics.

Notizen: Stocks of the Tetrahymena pyriformis complex have been collected in North America and their mating reactivity has been studied. In addition to stocks mating with Tetrahymena americanis, T. borealis, T. pigmentosa, T. hyperangularis, and T. australis, stocks belonging to old syngen 5 and three new mating groups, numbers 13, 14, and 15, were discovered. Syngen 5 and groups 13 and 14 are distinct “biological” species, based on their reproductive isolation from other groups and on the ability of withingroup crosses to produce immature progeny. These species have been named T. hegewischi n. sp., T. sonneborni n. sp., and T. nipissingi n. sp., respectively. The cross between the two group 15 stocks did not produce immature progeny, and there is not sufficient evidence to conclude that this pair of stocks represents a separate species. Temperature tolerance measurements have been made on stocks representing all known micronucleate members of “pyriformis” complex. Within each species, the range of temperature tolerances is narrow; the average within-species standard deviation is 0.63°C. The species averages range from 32.7 to 40.7°C. Using syngen numbers, the order from lowest to highest temperature tolerance is 9, 8, 10, 7, 6, 4, 13, 14, 12, 11, 5, 3, 2, 1. The large differences among species make temperature tolerance a useful aid in identification, but the origins of the differences among species are unknown.

Notizen: Members of the family Sarcocystidae, as defined by Frenkel, have had a complicated history, principally due to the existence of both coccidial and cystic stages. This formerly clandestine relationship resulted in dual or partial designations of nomenclature for individual species. The problem was further compounded by the obligatory heteroxeny of several of the genera, making it impossible to transmit the parasites from one individual to another of a single host. As a result, oocysts similar in appearance, though from hosts separated taxonomically up to the familial level, were sometimes considered to be identical. Discoveries within the last decade have generated much interest and some understanding. Current studies of these and other coccidia should emphasize complete cyclical transmissions with cognizance of potential heteroxeny with the production of tissue cysts in intermediate hosts.

Notizen: Book reviews in this article: Ecology and Parasitology. Alexander, M., ed. 1980. Advances in Microbial Ecology Smith, H. G. 1978. The Distribution and Ecology of Terrestrial Protozoa of Sub-Antarctic and Maritime Antarctic Islands Taylor, Angela E. R. & Muller, R., eds. 1980. Vaccines Against Parasites Kreier, Julius P., ed. 1980. Malaria New Textbook of Protozoology Farmer, John N. 1980. The Protozoa: Introduction to Protozoology Phytoflagellates and Serial Endosymbiosis Theory Cox, Elenor R., ed. Phytoflagellates Tappan, Helen. 1980. The Paleobiology of Plant Protists. Margulis, Lynn. 1981. Symbiosis in Cell Evolution: Life and Its Environment on the Early Earth. Intercellular Communication and Nuclear-Cytoplasmic Interactions O'Day, Danton H. & Horgen, Paul A., eds. 1981. Sexual Interactions in Eukaryotic Microbes Whitson, Gary L., ed. 1980. Nuclear-Cytoplasmic Interactions in the Cell Cycle. Invertebrate Texts Alexander, R. McNeill. 1979. The Invertebrates Barnes, Robert D. 1980. Invertebrate Zoology Engemann, Joseph G. & (the late) Hegner, Robert W. 1981 Invertebrate Zoology ATCC Catalogue of Strains Hatt, Harold D., ed. 1980. The American Type Culture Collection: Catalogue of Strains I.

Notizen: Polyamines are multiply amine-substituted straight-chain aliphatics; their content in different tissues may vary widely, and their functions are many. Their main routes of biosynthesis originate from ornithine and methionine. Polyamine content and biosynthesis in tryposomatid flagellates are reviewed concluding with emphasis on their possible role as critical drug targets in these parasitic protozoa so pathogenic for man in large areas of the world.

Notizen: During spring and autumn, the total number of amoebae and the number of Acanthamoeba species able to grow at 37°C were determined in six thermally polluted factory discharges and the surrounding surface waters. The isolated Acanthamoeba strains were studied for growth in axenic medium, cytopathic effect in Vero cell cultures, and virulence in mice. Although more amoebae were isolated in autumn, the number of Acanthamoeba species was lower than in spring, when the percent of pathogenic strains among the isolates was highest. Higher concentrations of amoebae were found in warm discharges, and more virulent strains occurred in thermal discharges than in surface waters.