ALBERT

Notes: The author has been involved in the manufacture of photogrammetric instruments for nearly 30 years. In particular, he was associated with the Thompson-Watts plotter and, at the present time, is concerned with the production of the CP1 and EMPD instruments which owe a great deal to his design and innovatory skills. This paper summarises his experiences and views of the production of photogrammetric equipment in England.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméPendant 30 ans l'auteur a participéà l'élaboration d'appareillages pour la photogrammétrie: en particulier les restituteurs Thompson–Watts; et maintenant les appareils CP1 et EMPD qui lui doivent beaucoup. Il condense ici l'expérience et les idées qu'il a dans ce domaine.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungDer Autor ist seit fast 30 Jahren an der Herstellung photogrammetrischer Auswertegeräte beteiligt. Insbesondere verbunden war er mit dem Thompson–Watts Plotter und befasst sich gegenwärtig mit der Fertigung der Geräte CP1 und EMPD, an denen er durch seine schöpferischen Fähigkeiten grossen Anteil hat. In dem Artikel werden seine Erfahrungen und Ansichten bei der Produktion photogrammetrischer Geräte in England zusammengefasst.

Notes: An application of photogrammetry in the measurement of palatal surface area is described. The accuracy of the photogrammetric method in such applications is also discussed.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméDétermination par photogrammétrie de l'aire du palais buccal; indications sur l'exactitude obtenue.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungDie Anwendung der Photogrammetrie zur Vermessung der Gaumen-oberfläche wird beschrieben und die Genauigkeit photogrammetrischer Verfahren bei solchen Messungen werden diskutiert.

Notes: A camera calibration method for object distances of 1 m to 4 m is described.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn décrit une méthode d'étalonnage de chambres de prise de vues pour des distances de prises de vues de 1 à 4 mètres.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungDiskussion eines Verfahrens zur Kammerkalibrierung für Aufnahmeentfernungen von 1 m bis 4 m.

Notes: Stereophotography with a pair of 35 mm cameras and stroboscopic illumination was used to record, reconstruct and measure the trajectories of falling hailstones under extremely adverse natural conditions. Since it was not possible either to fix or to measure precisely the camera positions and orientations, a method was devised to obtain both the three dimensional hailstone co-ordinates and the camera positions and orientations by making use of the otherwise redundant information contained in the stereo-photography.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn a utilisé deux cameras de 35 mm et un éclairage stroboscopique pour enregistrer en vue de leurs restitutions les trajectoires de grêlons; ceci n'a pu être réalisé que dans des conditions difficiles. Comme il n'était pas possible de stabiliser les cameras et de déterminer les coordonnées des points de station, on a mis au point une méthode spéciale.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungDie Stereophotographie mit einem Paar von 35 mm Kameras und stroboskopischer Beleuchtung wurde angewendet, um die Kurven fallender Hagelkörner unter extrem von den natürlichen abweichenden Bedingungen zu registrieren, rekonstruieren und zu vermessen. Da es nicht möglich war, die Kammerstandpunkte und -orientierungen zu fixieren oder exakt zu vermessen, wurde ein Verfahren abgeleitet, um sowohl die dreidimensionalen Koordinaten der Hagelkörner als auch die Kammerparameter durch Verwendung der durch die Stereophotos gelieferten redundanten Informationen zu erhalten.

Notes: The Ordnance Survey's approach to the revision of the 1: 2500 scale series is discussed, with particular emphasis on the variety of photogrammetric methods which are used. The special problems of re-casting existing maps onto the National Grid projection, without losing the value of the existing detail, are outlined whilst emphasising the need to complete the revision with maximum speed to an adequate accuracy for a minimum cost.〈section xml:id="abs1-2"〉〈title type="main"〉Résumé On expose les méthodes de l′ Ordnance Survey en matière de révision des levés au 1: 2500; on examine le problème de l'adaptation des levés existants au système cartographique national, sans qu'il y ait perte de richesse.〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Es wird ein Versuch des Ordnance Survey zur Laufendhaltung der Karte 1: 2500 beschrieben, wobei die verschiedenen photogrammetrischen Verfahren, die angewendet wurden, besonders betont werden. Die speziellen Probleme der Einpassung bestehender Karten in das Nationale Gitternetz ohne den Verlust der vorhandenen Details werden skizziert, wobei hervorgehoben wird, dass die Revision mit maximaler Geschwindigkeit ohne Genauigkeitsverlust bei minimalen Kosten durchgeführt werden muss.

Notes: This paper is concerned with a new technique (the terrestrial/photogrammetric (TP) technique) for the detection and compensation of systematic height errors in block aerial triangulation. The technique improves the height accuracy of such triangulation by reducing the original bridging distance, using new bands of corrected photogrammetric tie points as height control together with the original bands of the terrestrial (or ground) height control. A number of photogrammetric blocks with different characteristics and configurations have been tested in a comprehensive manner. The tests show that the TP technique gives consistent results over a wide range of circumstances and that it is a most effective, simple and inexpensive method for the compensation of systematic errors.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméCet article relate une technique nouvelle permettant de détecter et de compenser les erreurs altimétriques systématiques dans l'aérotriangulation par blocs: la technique terrestre/photogrammétrique (TP). Cette technique améliore la précision altimétrique de l'aérotriangulation en réduisant la distance de l'aérocheminement original, grâce à l'utilisation d'un canevas de points d'appuis altimétriques composés de points de liaison photogrammétriques corrigés, en supplément du canevas original de points d'appui altimétriques déterminés sur le terrain.On a essayé de manière approfondie un grand nombre de blocs dotés de caractéristiques et de configurations diverses. Les essais montrent que la technique TP fournit des résultats fiables dans un large éventail de circonstances et que c'est une méthode de compensation des erreurs systématiques efficace, simple et peu coûteuse.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungIm Artikel wird ein neues Verfahren behandelt (das terrestrisch-photogrammetrische Verfahren (TP)), das zur Aufdeckung und Kompensation system-atischer Höhenfehler in der Block triangulation dient. Es wird die Höhengenauigkeit durch Verkürzung der ursprünglichen Überbrückungsdistanz verbessert, indem neue Streifen korrigierter Verbindungspunkte als Höhenpasspunkte zusammen mit den ursprünglichen Reihen der terrestrischen Höhenpasspunkte verwendet werden. Eine Anzahl photogrammetrischer Blöcke unterschiedlicher Figur und Charakteristik wurde umfassend getestet. Die Tests zeigen, dass die TP-Methode konstante Ergebnisse für einen grossen Bereich van Möglichkeiten ergibt und dass es ein höchst effektives, einfaches und billiges Verfahren zur Eliminierung systematischer Fehler ist.

Notes: During June and July 1981, synthetic aperture radar imagery was acquired of selected sites in ten European countries as part of the European SAR 580 campaign. Evaluation of this imagery in the UK will be carried out by 18 approved experiments (out of 56 for Europe) when the processed data becomes available to investigators. To assist the evaluation process, a review is given of some recent research on applications of imaging radar in agricultural and urban areas. Research is described which considered the effects of terrain parameters and radar parameters on crop classification accuracy. The relative merits of a quantitative or a qualitative approach in classification of radar data are considered. Combined use of radar and Landsat data achieves a marked improvement in classification accuracy. The development of spatial filtering techniques may assist in the problem in urban areas resulting from the dependence of image tone on the relative alignment of ground features and radar look direction.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméPendant les mois dejuin et juillet 1981, on a, dans le cadre de la campagne européenne SAR 580, recueilli des données de radar imageur à synthèse d'ouverture sur des sites choisis dans une dizaine de pays d'Europe. Ces données seront évaluées au Royaume-Uni au moyen de 18 expériences ayant été acceptées (sur un total de 56 menées en Europe); ce travail commencera dès que les données une fois traitées seront distribuées aux chercheurs. Pour accompagner cette procédure d'evaluation, on fournit une analyse de quelques recherches récentes sur les applications de l'imagerie radar aux zones agricoles et urbaines.L'une de ces recherches prenait en compte les effets des paramètres liés au terrain sur l'exactitude de la classification des cultures. Les mérites réciproques des approches quantitatives et qualitatives dans la classification des données radar sont également examinés.Le recours à une combinaison de données radar et Landsat permet d'améliorer de manière significative l'exactitude de la classification. La mise en oeuvre des techniques de filtrage spatial peut aider à réduire, dans les zones urbaines, les conséquences néfastes sur la tonalité de l'image, d'objets au sol en alignement relatif avec la direction d'observation du radar.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungIm Juni und Juli 1981 erfolgten Radaraufnahmen mittels synthetischer Apertur von ausgewählten Gebieten in 10 europäischen Ländern als Teil der Europäischen SAR 580 Kampagne. Die Analyse dieser Aufzeichnungen wird im Vereinigten Königreich durch 18 (aus insgesamt 56 für Europa) bestätigte Experimente erfolgen, nachdem die Daten zur Verfügung stehen. Um den Analysenprozess zu unterstützen, wird ein Überblick über kürzliche Forschungen zu Radaraufzeichnungen in landwirtschaftlichen und städtischen Gebieten gegeben. Es werden auch Forschungen beschrieben, bei denen die Einflüsse von Geländeparametern auf die Genauigkeit der Ernteklassifizierung untersucht wurden. Der relative Wert eines quantitativen oder qualitativen Versuchs zur Klassifizierung von Radardaten wird abgeschätzt. Eine Kombination von Radarund Landsat-Daten ergibt eine merkliche Verbesserung bei Klassifizierungsgenauigkeit. Die Entwicklung von Verfahren der räumlichen Filterung kann von Wert bei städtischen Gebieten sein, weil es eine Abhängigkeit des Grauwertes von der relativen Ausdehnung von Geländecharakteristika und der Richtung der Radaraufnahme gibt.

Notes: Some aspects of the XYZBLC suite of programs for aerial triangulation are described. The Ordnance Survey Bute block of photography at a scale of 1: 24000 is computed by independent models using XYZBLC. Three of the strips in the block are treated as a test block and are computed with different configurations of control. Conclusions are drawn with regard to the usefulness of height control doublets and other dense control configurations.〈section xml:id="abs1-2"〉〈title type="main"〉Résumé Quelques aspects de l'ensemble XYZBLC de logiciels d'aérotriangulation sont décrits. Le bloc Bute de l'Ordnance Survey, composé de photographies à l'échelle du 1: 24000, a été calculé par modèles indépendants avec les logiciels XYZBLC. On a considéré trois des bandes du bloc comme formant un bloc d'essai et on les a calculées avec diverses combinaisons de canevas de points d'appui. On en tire des conclusions quant à l'utilité des doublets de points d'appui altimétriques et de diverses autres configurations denses de canevas d'appui. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Beschreibung einiger Aspekte des XYZBLC-Programmsystems zur Aero-triangulation. Ein Block des Ordnance Survey im Bildmassstab 1: 24000 wurde damit nach der Methode der unabhängigen Modelle berechnet. Drei der Streifen des Blocks wurden als Testblock behandelt und mit verschiedenen Passpunktanordnungen berechnet. Es werden Schlussfolgerungen in bezug auf die Nützlichkeit von Zwillingspunkten zur Höhenorientierung und andere dichte Passpunktanordnungen gezogen.

Notes: The wide availability of reconnaissance frame photography, together with the advantage of high image resolution that such photography provides and the extreme flight conditions under which it can be taken, means that it is of great interest to photogrammetrists. However, the geometry of the image is invariably distorted due to the mode of operation of the camera. In this paper, the effects of the focal plane shutter and apparent image motion compensation on the geometry of the photographs are considered.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméLe fait que la photographic de reconnaissance soil très répandue, conjointe-ment aux avantages que présente la grande résolution des images fournies par ces systèmes et les conditions extrêmes de vol dans lesquelles on peut les prendre, milite pour une prise en compte de lew intérêt par les photogrammètres. Toutefois la géométrie de ces images est systématiquement déformée par suite du mode de fonctionnement de la chambre. On traite dans cet article des effets de l'obturateur focal et de la compensation du filé de l'image sur la géométrie des photographies.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungDie grosse Verbreitung von Erkundungsfotos zusammen mit der grossen Auflösung solcher Fotos und den extremen Bedingungen unter denen sie auf-genommen wurden, lassen diese auch für den Photogrammeter interessant erscheinen. Die Geometrie dieser Bilder ist jedoch infolge der speziellen Kamera-funktion verzerrt. Im Artikel werden die Einflüsse des Schlitzverschlusses und des Bildwanderungsausgleichs auf die Bildgeometrie untersucht.

Notes: Book Reviewed in this article:AERIAL PHOTOGRAPHY. By G. S. Kumar.MANUAL OF PHOTOGRAMMETRY (Fourth Edition). Editor-in-Chief: C. C. Slama.

Notes: Microrelief mapping of the sea bed can only be carried out by photo-optical methods. It is shown that suitable equipment, bought off the shelf, can produce useful results. The paper describes equipment performance trials and a practical application in a study of large scale sea bed topography.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméLa cartographie du microrelief de fonds sous-marins ne peut être faite qu'à partir de photos. On montre, qu'avec un appareillage convenable on peut obtenir des résultats intéressants. On décrit les tests, ainsi qu'un travail pratique d'application à un levéà grande échelle de fonds sous-marin.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungDie kartographische Darstellung des Mikroreliefs des Meeresbodens kann nur auf photo-optischem Wege durchgeführt werden. Es wird gezeigt, dass mit einer geeigneten Ausrüstung günstige Ergebnisse erzielt werden können. Im Artikel werden Versuche zur Testung der Ausrüstung und eine praktische Anwendung zum Studium einer grossmassstäbigen Meerestopographie beschrieben.

Notes: The algorithm presented assumes a preliminary determination of the elements of inner orientation and bases its mathematical model on the collinearity condition, from which projective equations are derived. Linearisation of condition equations is based on Taylor's expansion, whilst the subsequent solution follows iteration cycles. The method aims to derive composite corrections to image coordinates, with the aid of test field data.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméL'auteur présente un algorithme oú l'on suppose déterminés au préalable les éléments d'orientation interne. La modélisation mathématique s'appuie sur les conditions de co-linéarité et sur les équations qui en résultent en projection. On linéarise les équations de conditions en utilisant un développement en série de Taylor, et l'on obtient la solution correspondante par itération. La méthode vise à apporter des corrections aux coordonnées images en utilisant les données d'un polygone d'essai.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungBei dem dargestellten Algorithmus wird die vorläufige Bestimmung der Elemente der inneren Orientierung angenommen, und das mathematische Modell basiert aufder Kollinearitätsgleichung, woraus perspektive Gleichungen abgeleitet werden. Die Linearisierung der Bedingungsgleichungen erfolgt durch Anwendung der Taylor-Reihe, was für die folgenden Berechnungen einen iterativen Prozess bedingt. Mit der Methode wird angestrebt, Bildkoordinaten mit Hilfe von Testfelddaten zu verbessern.

Notes: There is a growing interest in the potential of synthetic aperture radar (SAR) for mapping and for gathering intelligence for map revision. This paper first gives a simple guide to the characteristics of SAR and then describes a study carried out to investigate the geometric properties of the imagery and the information content which is of interest for topographic mapping and the production of large scale plans. The conclusions cautiously indicate a potential although better quality images are required and more information must be known about the optimum conditions which should obtain when the data are recorded.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn assiste à un intérét croissant envers le radar à ouverture synthétique (SAR) et ses possibilityés pour la cartographie et pour la collecte de renseignements utiles à la révision. Ce texte commence par donner un simple rappel des caractéristiques de ces radars pour décrire ensuite une étude effectuée sur le contenu informatif et les proprietyés géométriques de l'imagerie radar, qui intèresse la cartographie topographique et la confection de plans à grande échelle.Les conclusions font prudemment état d'une potentialité mais soulignent qu'il faudrait disposer d'images de meilleure qualityé et avoir davantage d'informations sur les conditions optimales à respecter lors de l'enregistrement des données.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungEs besteht zunehmendes Interesse an den Möglichkeiten von Radaraufnahmen mittels synthetischer Apertur (SAR) zur Kartenherstellung und Erfassung von Daten zur Laufendhaltung. Zunächst wird im Artikel eine einfache Einführung in die SAR-Charakteristika gegeben. Dann erfolgt eine Beschreibung eines Versuches zur Untersuchung der geometrischen Eigenschaften und des Informationsgehalts, der von Interesse für die Herstellung topographischer und grossmassstäbiger Karten ist. Vorsichtige Schlussfolgerungen ergeben Möglichkeiten zur Verwendung solcher Informationen, wobeijedoch eine bessere Bildqualität zu fordern ist. Auch müssen noch mehr Kenntnisse über die optimalen Bedingungen bezüglich der Datenregistrierung bestehen.

Notes: Landsat multispectral scanner (MSS) and return beam vidicon (RBV) image data in both analogue and digital formats were used to assess the performance of the MSS and RBV sensor systems, and to determine their potential for recording information associated with topographic or land use maps of selected Chinese study areas (Beijing, Tianjin and the Huang He elbow). MSS images permitted the detection of 40 per cent to 50 per cent of the features identified on maps of 1: 250000 scale and larger, whereas the higher resolution Landsat 3 RBV images provided 10 per cent to 20 per cent additional information. Completeness of information extracted from a colour cathode ray tube display exceeded that obtained from analogue single band black and white MSS images by only 5 per cent to 10 per cent. Only through major improvements in spatial resolution will it be possible to compile maps at scales of 1: 250000 and larger from satellite data. Significantly, it appears that instantaneous field of view values of 5 m to 10 m will be required to produce image data of sufficient resolution for topographic mapping or detailed thematic studies of the Asian environment.〈section xml:id="abs1-2"〉〈title type="main"〉Résumé On a utilisé les données de l'imagerie spatiale provenant du scanneur multispectral (MSS) et du tube vidicon à retour de faisceau (RBV) de Landsat, à la fois sous forme analogique et numérique, pour évaluer la performance des systèmes de capteurs MSS et RBV, et pour déterminer leur aptitude à contenir l'information figurant dans les cartes topographiques et les cartes d'occupation du sol, sur des polygones d'essais sélectionnés en Chine (Pekin, Tianjin, et le coude du Huan He). Les images MSS ont permis de détecter 40 à 50 pour cent des détails figurant sur les cartes à une échelle supérieure ou égale à 1: 250000, tandis que les images RBV à meilleure résolution de Landsat C fournissaient 10 à 20 pour cent d'informations supplémentaires. Le volume des informations extraites sur un écran cathodique de visualisation en couleurs n'a dépassé le volume obtenu à partir d'images d'une seule bande MSS en noir et blanc que de 5 à 10 pour cent seulement. Il semble que ce ne soit que par des améliorations importantes dans la résolution spatiale que l'on pourra tirer des données de satellites des cartes à des échelles supérieures ou égales à 1: 250000. Il apparait de manière significative qu'un champ instantané de prise de vues de 5 à 10 m (pixel) sera nécessaire pour obtenir des images ayant une résolution suffisante pour la cartographie topographique ou pour des études thématiques détaillées sur l'environnement asiatique.〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Verwendung von Landsat-aufzeichnungen, die mit Hilfe des multispektralen Scanners (MSS) und des Return Beam Vidicon (RBV) aufgenommen wurden und sowohl in analoger als auch digitaler Form vorlagen. um die Leistungsfähigkeit dieser Aufnahmesysteme zu ermitteln und die Möglichkeiten zur Gewinnung von Informationen zur Herstellung von topographischen oder Landnutzungskarten in ausgewählten chinesischen Versuchsgebieten (Beijing, Tianjin undder Huang He Bogen). MSS-Bilder gestatteten die Erkennung von 40 bis 50% der auf Karten im Massstab 1: 250 000 oder grösser identifizierten Objekte, während die RBV-Bilder von Landsat 3, die eine grössere Auflösung hatten, 10 bis 20% zusätzliche Informationen lieferten.Die Vollständigkeit der Information, die von einem Farbdisplay erhalten wurde, überstieg die von analogen einkanaligen schwarzweissen MSS-Bildern erhaltenen nur um 5 bis 10%. Nur durch wesentliche Verbesserungen der Objektauflösung wird es möglich sein, Karten 1: 250000 und grösser nach Satellitendaten herzustellen. Es wird offensichtlich eine Objecktauflösung von 5 bis 10m gefordert, um Bilddaten genügender Auflösung für die Herstellung topographischer Karten oder thematischer Studien des asiatischen Raums zu erzeugen.

Notes: . When a streptomycin-bleached mutant of Euglena gracilis strain Z was cultured in the dark at 33, 26, or 15°C, the content of paramylon was higher at lower growing temperature while that of wax esters was higher at higher temperature. Transfer of the cells grown at 33°C–15°C decreased the wax ester content while increasing the paramylon content; transfer in the reverse direction caused reverse changes. On incubation with labeled acetate, the cells grown at 33°C showed more distribution of radioactivity in wax esters than the cells grown at lower temperatures. Apparently the two energy-reserve substances have different physiological functions.

Notes: The sessiline peritrich Ellobiophrya conviva n. sp. is described from marine ectoprocts of the genus Bugula, the first report of an ellobiophryid on bryozoan hosts. The new species is distinguished from others of its genus by its different body proportions, size, host, and structure of the clasping holdfast (for which the new name cinctum is chosen). Ellobiophrya conviva has been found only on B. neritina and B. turrita and shows a marked seasonal cycle of abundance. The family Ellobiophryidae Chatton & Lwoff is revised on the basis of new information provided by E. conviva, with the single species of the genus Clausophrya removed to Ellobiophrya as E. oblida Naidenova & Zaika n. comb. The genus Caliperia Laird remains unchanged. The two genera of the revised family are distinguished from one another by differences in the structure of the cinctum. Hypotheses are advanced to explain the morphogenesis of the cinctum and the evolution of ellobiophryids from other peritrichs.

Notes: The spatial and seasonal distribution of Paramecium bursaria in two small Indiana ponds was studied using a sampling grid. Very small (5.0 ml) samples were taken so that the individual microhabitats could be studied. The results were evaluated in comparison to the data collected for the P. aurelia complex collected in the same manner and at the same sites. It was found that P. bursaria exist in a clumped distribution, but that the distribution was not very different from random. Paramecium bursaria also exist at the surface and at the mud-water interface. Temperature does not seem to play a statistically significant role in determining population size. The breeding system of P. bursaria is optimized for an outbreeding population of low density. In comparison, the species of the P. aurelia complex exist in a very clumped distribution, are found only at the mud-water interface, and are inbreeders. The evolutionary strategies of the two types of paramecia are discussed.

Notes: L'étude du caractère planctonique de différentes spores d'Actinomyxidies montre une complexité croissante dans leur adaptation au milieu aquatique. Au contact de l'eau, les trois cellules épéisporales de chaque spore se transforment en flotteurs de forme différente suivant les espèces. Ces flotteurs peuvent s'unir entre eux en un style équivelent à un quatrième flotteur ou associer diversement les huit spores issues d'un měme pansporocyste. C'est le cas dans le genre Synactinomyxon dont la diagnose est modifiée pour inclure une deuxième espèce S. Iongicauda n. sp. Un type nouveau est décrit chez lequel la preéence d'ancres à l'extrémité des cellules épisporales permet de maintenir efficacement réunies plusieurs dizaines de spores émises simultanément. Nous avons observé dans les genres Aurantiactinomyxon, Synactinomyxon, Echinactinomyxon l'emission du sporoplasme. II est libére en entier et capable de se déplacer dans l'eau pendant plus d'une heure grǎce à des mouvements amoeboïdes. Chez Aurantiactinomyxon eiseniellae les études ultrastructurales montrent que l'enveloppe du pansporocyste, d'une part, les épispores et les capsules polaires d'autre part sont réalisées à partir de cellules distinctes et profondément modifiées. Quant au sporoplasme, autrefois décrit comme un plasmode avec de nombreuses paires de noyaux, il contient, en fait, des ensembles identiques dont chacun est constitué de l'union d'un noyau satellite et d'une cellule uninucléée.〈section xml:id="abs1-2"〉〈title type="main"〉ABSTRACTThe study of the planktonic character of different Actinomyxidia spores reveals increasingly complex adaptations to an aquatic environment. On contact with water, the three episporal cells of each spore transform into floats, the forms of which differ according to species. These floats can join together so that a fourth type of float is formed, or they can unite in various ways the eight spores originating from the same pansporocyst. This is the case in the genus Synactinomyxon whose diagnosis is modified to include a second species S. Iongicauda n. sp. A new type is described in which the presence of anchors at the extremities of the episporal cells permits several dozen spores that have been emitted simultaneously to be kept together. We have observed the emission of the sporoplasm in the genera Aurantiactinomyxon, Synactinomyxon, and Echinactinomyxon. It is freed completely and for more than an hour is capable of changing its position in the water by amoeboid movements. In the case of Aurantiactinomyxon eiseniellae, ultrastructural studies show that the pansporocyst envelope on the one hand, and the epispores and polar capsules on the other hand, are formed from separate but profoundly modified cells. The sporoplasm, however, sometimes described as a plasmodium with numerous pairs of nuclei, contains, in fact, identical complexes, each consisting of a uninucleate cell united with a satellite nucleus.

Notes: Paramecia detect and accumulate in or disperse from some chemicals. Cells do this by changing frequency of turning and speed of swimming. There are at least two mechanisms by which cells respond: one dependent on ability to turn, one dependent on speed modulation. There are also two classes of chemicals: those that require the cells' ability to turn in order to cause accumulation and dispersal (type I), and those that apparently require only speed modulation (type II). Attractants of type I cause qualitatively similar changes in behavior to repellents of type II and the converse; therefore, assays are needed to distinguish between these two classes of chemicals, despite qualitatively similar behavior of some attractants and repellents. We examined two assays of paramecium chemoresponse, T-maze assay and well test, to understand how the T-maze distinguishes between attractants of type I and repellents of type II and why the well test does not.

Notes: The morphology of spore germination in Didymium nigripes was studied using scanning electron microscopy and Nomarski phase optics. First, the outer spore wall splits, revealing a fibrillar inner wall. Remnants of the inner wall continue to cover the newly emerged amoeba. A single nucleus and a prominent vacuole are visible throughout germination. Germination is more rapid in glucose-peptone-yeast extract than in phosphate buffer. Germination is completely inhibited at 4°C, and is very slow at 18°C. Germination is most rapid at 26°C; at 21°C or 32°C it is slightly slower. Germination is reversibly inhibited by 20 μ/ml cycloheximide, but not by 200 μ/ml 5-fluoro uracil or 200 μ/ml proflavin. It is completely inhibited by 10-3 M Na azide.

Notes: Crithidia fasciculata (Anopheles, Culex, and Nöller strains), C. hutneri, C. luciliae thermophila, and Herpetomonas samuelpessoai were grown in a defined medium with different values of osmolarity at different temperatures. C. fasciculata (all strains) grew best between 300 to 500 mOsm; H. samuelpessoai, 400–500 mOsm; and C. hutneri and C. luciliae thermophila, 500–800 mOsm. At higher temperatures better growth was obtained at the upper osmolarities.

Notes: Crypthecodinium cohnii, a small marine heterotrophic homothallic dinoflagellate, has diversified into a complex of morphologically very similar breeding groups (biological species or sibling species), some of which have become widely dispersed. Membership of two clones in the same sibling species is shown by their sexual compatibility as determined by genetic complementation in zygotes formed from motility mutants derived from the two stocks. Membership in different sibling species may be inferrec when motility mutants of one strain do not complement those of another. Fifty-six clones representing seaweed enrichments from *** geographic sites have been found to belong to 28 sibling species; 35 clones are members of seven wide-ranging biological species, and 21 are single representatives of 21 other breeding groups within the ranges of the others. Of 174 clonal isolates in our possession, 168 conform in size and shape to C. cohnii. Six others which have smaller cells and only one-fifth the standard DNA and chromosome number belong, we believe, to another species. The C. cohnii complex provides a unique opportunity for the study of evolutionary divergence and geographical dispersion of a dinoflagellate.

Notes: Until recently, pansporoblastic microsporidia that produce a variable and large number of sporoblasts from a sporont have been included in a single genus, namely Pleistophora Gurley, 1893. Ultrastructural studies have been used to determine whether the resemblance of these species is fundamental or superficial. The results indicated that the multisporous pansporoblastic forms belong to at least three genera and, thus, that Pleistophora is a “composite genus.” The term pansporoblast was originally used for stages in myxosporidian development. The term sporophorous vesicle adopted from Gurley is suggested for the spore-containing vesicle in the Microspora. Three species were studied: Pleistophora typicalis, the type-species; Pleistophora culicis, for which a new genus Vavraia has already been proposed; and Pleistophora simulii. P. typicalis and V. culicis have isolated nuclei throughout their development, and the sporophorous vesicle wall enveloping the sporoblasts is derived from amorphous secretions laid down during merogony external to the plasmalemma. Pleistophora and Vavraia are differentiated principally in terms of the structure of the sporophorous vesicle wall and mode of division of the sporogonial plasmodium. The nuclei of young sporonts of P. simulii are in diplokaryon arrangement and undergo meiosis to give haploid nuclei in the sporoblasts. The sporophorous vesicle wall is membranoid and is laid down external to the plasmalemma at the onset of sporogony. A new genus, Polydispyrenia n. g., is suggested for this species, the affinities of which are closer to the dimorphic species of microsporidia than to Pleistophora or Vavraia. The terms “merontogenetic sporophorous vesicle” and “sporontogenetic sporophorous vesicle” are used to distinguish between the two groups.

Notes: Plasmodium berghei infection was more severe in pregnant than in nonpregnant mice. Infection initiated on gestation day 7 resulted in rapidly increasing parasitemia and deaths of all pregnant mice within 12 days, while some nonpregnant mice survived until day 21 postinfection. When mice were infected on gestation day 12 or 14, a proportion of mice died before parturition; but some animals survived to deliver living pups. Reduced birthweights and increased spleen weight to body weight ratios were seen in pups from infected mice as compared with pups from uninfected animals. Histopathological abnormalities of placentae from infected animals included degeneration of the normal labyrinthine architecture and thickening of the trophobast separating maternal and fetal blood vessels.

Notes: Tetrahymena pyriformis strain WH-14 secreted large quantities of intracellular proteases into its culture medium during growth. Extracellular enzymes were purified to homogeneity from cell-free medium by ammonium sulfate precipitation, CM-Sephadex column chromatography, gel filtration, and DEAE-cellulose column chromatography. The DEAE-cellulose eluates were separated into four peaks (P-I, P-II, P-III, and P-IV), each of which exhibited a different specific activity toward azocasein and α-N-benzoyl-DL-arginine-ρ-nitroanilide (Bz-Arg-Nan). These four forms of the protease showed similarity in amino acid composition, molecular weight (21,000–24,000), and antigenic reactivity. They had pH optima at neutral range. P-I showed the highest specificity to azocasein whereas P-IV was most effective toward the synthetic substrates. The Km values for hydrolysis of Bz-Arg-Nan were 2.4, 1.6, 1.3, and 1.4 mM for P-I, P-II. P-III, and P-IV, respectively, and the corresponding Kcat/Km values were 5.0, 9.4, 28.5, and 114.3 S-1.M-1. These properties of secreted proteases were compared with those of intracellular proteases purified by the same procedure except for the initial Triton X-100 extraction. There were similarities in specific activity toward two substrates, molecular weight, Km, pH optima, and antigenic reactivity between the proteases from two sources, providing evidence that the intracellular proteases may be secreted into the extracellular medium without modification.

Notes: The separation of extracellular protozoan parasites from host cells based on a difference in surface charge has been described. However, with Trypanosoma cruzi no method exists for the isolation of pure parasite stages from heterogeneous mixtures. Studies on the electrophoresis of mixed stage populations confirm significant surface charge density differences exist among epimastigotes, trypomastigotes, and amastigotes. In ascending order of electronegativity, amastigotes have the lowest charge density, try-pomastigotes next, followed by epimastigotes. A technique has been developed for the separation of purified populations of parasites based on these charge differences using a continuous free-flow electrophoresis apparatus. The separated populations are morphologically intact and maintain their infectivity to mice. This separation method is applicable for preparative and analytical isolation of pure stages of T. cruzi for biochemical and immunological studies.

Notes: Cellular levels of protein and two acid hydrolases, acid phosphatase (EC 3.1.3.2) and acid proteinase, were followed during cyst differentiation, arbitrarily divided into five stages, in the ciliate Histriculus muscorum Kahl. Extracellular enzyme activities were also measured. Protein content decreased gradually during cyst differentiation. In mature cysts the protein content was ca. 60% that of stationary phase organisms. The activities of both acid hydrolases remained unchanged during stage 1 and then decreased gradually; acid proteinase decreased more rapidly. Both enzymes remained slightly active in the mature cysts. The acid proteinase activity of stage 1 was reduced by cycloheximide treatment at time zero, whereas the enzyme was no longer sensitive to the inhibitor when treated at 1.5 h (late stage 1) after the first wash with encysting medium. Acid phosphatase activity was insensitive to the inhibitor. Extracellular release of acid phosphatase increased linearly at least until stage 5, although the extracellular release of acid proteinase was not detected. Cycloheximide blocked the extracellular release of acid phosphatase after stage 1. These results suggest that de novo synthesis of acid proteinase occurs during stage 1 and that lysosomes may play an important role during early stages of cyst differentiation.

Notes: SYNOPSIS. Endosymbiotic algae from Paramecium bursaria when added to the culture medium are ingested by Chlorella-bearing P. bursaria at a rate of 2,000 algae/organism/day. That the ingested algae are digested and assimilated by the ciliates is suggested by the more rapid growth of Paramecium when algae are added to the medium (G= 40 hr with algae compared to 190 hr without). The digestion by the ciliates of exogenous algae contrasts with the survival of these algae under normal growth conditions. It is suggested that the protection of the endogenous algae is related to their location in peripheral perialgal vacuoles.

Notes: SYNOPSIS. Toxoplasma ranae sp. n. is described from the brain of a leopard frog, Rana pipiens, probably from Mexico. Its pseudocysts were 72(55-106) × 48(29-70) μm in fixed sections. They contained an average of ∼ 4,000 slightly curved elongate zoites measuring 4–5 × 0.5 μm, with a central, spherical, vesicular nucleus.

Notes: Book reviewed in this article:Pennycuick, C. J. 1974. Handy Matrices of Unit Conversion Factors for Biology and Mechanics.

Notes: SYNOPSIS. Egestion of carmine particle-containing food vacuoles from the cytoproct of Tetrahymena pyriformis has been analyzed by high-speed cinemicrography. The vacuole may enter into position in the cytoproct ∼ 7 sec before ejection, and forms a distinct bulge beyond the outline of the cell surface for over 2 sec prior to ejection. The ejection process itself requires 20–80 msec.

Notes: SYNOPSIS. Blood films were examined from 1477 birds of Taiwan (193 species, 49 families). Haemoproteus Kruse was by far the commonest parasite, with Leucocytozoon Danilewski a not very close second. It is probable that some of the Haemoproteus infections represented new species, and 1 occurring in the Bamboo Partridge (Bambusicola thoracica sonorivox Gould) seemed characteristic enough to justify recognition as such; the name Haemoproteus bambusicolae sp. n. is proposed for this organism. Malaria was found in 77 birds, the greatest number of infections occurring in the Bamboo Partridge. Most of them were caused by Plasmodium juxtanucleare Versiani & Gomes, a pathogen of chickens, but a number were due to an undetermined species of Plasmodium. The Bamboo Partridge may be a reservoir host of the former. A few other identified species (P. rouxi Sergent & Sergent, P. hexamerium Huff, P. tenue Laveran & Mesnil) were seen, as well as some unidentified ones. Plasmodium tenue was seen in Garrulax canorus taewanus Swinhoe, a babbler: until now it was known only from the Pekin Robin (Leiothrix luteus Scopoli), also a babbler, in which we have found it extremely common. Sixty-four microfilarial infections were identified; they were especially frequent in the Button Quail (Turnix suscitator rostrata Swinhoe).

Notes: SYNOPSIS. Short pulse-labeling of log phase Crithidia fasciculata cells with [3H]thymidine allowed the autoradiographic visualization of 2 sites of replication of kinetoplast DNA situated at the periphery of the networks and separated by 180°. Longer pulse-labeling led to the previously reported total peripheral labeling pattern. Pulse-labeled networks possess an intermediate density in ethidium bromide-CsCl equilibrium gradients between the densities characteristic of closed networks and open or linear DNA. Removal of ethidium bromide by several methods and treatment of intermediate band networks with RNase and pronase had no effect on the equilibrium rebanding pattern. Closed minicircles of Leishmania tarentolae are not labeled by a short pulse of intact cells with [3H]thymidine. A chase of ∼ 3–4 hr is required for the appearance of radioactivity in closed minicircles, a time delay which implies the existence of intermediate events between replication and eventual covalent closure of the minicircles.

Notes: SYNOPSIS. DNA synthesis during growth and differentiation in Naegleria gruberi strain NEG populations has been studied. Autoradiography of cells labeled with [3H]thymidine revealed that grains are concentrated over the nuclei in logarithmically growing populations of cells, whereas in differentiating cells, grains are scattered over the cytoplasm; i.e. no significant nuclear labeling is detectable. It was established by MAK chromatographic analysis that [3H]thymidine is incorporated into double-stranded DNA in Naegleria and that the actual amount of incorporation in the logarithmically growing populations of cells is 20 times greater than that in differentiating cells. These results suggest that nuclear DNA synthesis is reduced markedly soon after the initiation of differentiation, while cytoplasmic DNA synthesis continues. It was established from cell cycle analysis that the approximate intervals of G1, S, G2, and M phases were 180, 183, 90, and 28 min, respectively. Hence, the reduction in the nuclear DNA synthesis in differentiating cells is not due to the inhibition of initiation of DNA replication, but rather to the termination of the DNA replicating process. Thus DNA synthesis is curtailed in the presence of RNA and protein synthesis which are required for differentiation.

Notes: SYNOPSIS. The activity and sedimentation of acid phosphatase (APase), acid deoxyribonuclease (DNase), and acid ribonuclease (RNase) were investigated throughout growth and encystment in Acanthamoeba castellanii. The activities/mg protein of all 3 hydrolases are high in young cultures and decrease to constant levels in postlog cells. The RNase activity/ ameba decreases 50% during growth, whereas the activity/cell of both APase and DNase remains constant. The percent sedimentation at 20,000 g of all 3 enzymes gradually increases from about 40% in midlog to a plateau of 80% in postlog cells. During encystment, the sedimentation behavior of RNase differs from that of APase and DNase. Encystment is characterized by a differential decrease in the activity/cell of the 3 hydrolases, with RNase decreasing most rapidly and APase least rapidly. APase is unique in that a transient increase of its specific activity is noted during encystment, even though its activity/cell is decreasing.

Notes: SYNOPSIS. In cultures of Platymonas subcordiformis Hazen, grown in appropriate light-dark cycles, as many as 75% of the cells adhered to the surface of the glass culture vessel toward the end of the light period of each day. Cell division occurred primarily while the cells were attached. Subsequently, motile daughter cells were released into the growth medium by the rupture of the mother cell theca. The settling behavior appears to be an integral part of the life cycle being synchronized to the same extent as cell division.

Notes: SYNOPSIS. The coccidian parasite Eimeria gadi was found in the haddock, Melanogrammus aeglefinus, taken from the Nova Scotian fishing banks. The haddock infection rates ranged from a high of 58% on Emerald Bank to a low of 4% on Georges Bank, the average being 32%. There was no relationship between sex and degree or prevalence of infection. Although the probability of an occurrence of infection increased with size, small fish with heavy infections were observed. The degree of infection had no apparent effect on the condition factor (length/weight) of the fish. The infection rate reached a maximum in the fall of the year while the heaviest infections were observed in the spring. It is evident from the data that the infection is fatal.The parasite mass, appearing as a creamy viscous to a yellow semisolid material in the swimbladder, consisted of various parasite stages, fibrous and cellular debris, and lipid material. Some aspects of the sporocyst stage are described.No other gadoids from the Nova Scotian banks were found to be infected; however, a single specimen of the fourbeard rockling, Enchelyopus cimbrius, from St. John's, Newfoundland, was found to be heavily infected with E. gadi.

Notes: SYNOPSIS. Synthesis of RNA in the macronucleus and appearance of RNA in the cytoplasm were studied in heat synchronized Tetrahymena pyriformis GL and compared to those found under conditions of logarithmic growth (28 C) and during heat shocks (34 C).In macronuclei of logarithmically growing cells precursors were processed to 2 rRNA species (25S and 17S). In addition, another RNA (15S), more homogeneous than the RNA (8-15S) in the cytoplasm, was observed in the macronucleus. Both 17S and 25S rRNA species were found in the cytoplasm, 17S rRNA appearing more rapidly than 25S rRNA. Synthesis of rRNA was suppressed at 34 C in cells subjected to heat synchronization; 8-15S RNA synthesis appeared to be inhibited to a lesser extent.During the time preceding the first synchronized division, the synthesis of rRNAs in the macronucleus slowly recovered. Early in the cycle, almost no newly synthesized rRNAs were extracted. By 30 min after the last heat shock (EH), most of the RNA synthesized was not identified as rRNA. By 60 min after EH, the pattern of RNA synthesis had not returned to that observed in logarithmically growing cells.

Notes: SYNOPSIS. Cell-free preparations of Acanthamoeba castellanii trophozoites transfer glucose from UDP-[U-14C]glucose to a chloroform-soluble form. This radioactive material has been isolated by thin-layer chromatography; it contains an alkali-labile and an alkali-stable (unsaponifiable) component. Treatment of the enzymic product with 0.1 N KOH for 15 min at 0 C or 20 C releases radioactivity into the aqueous phase as glucose. During this treatment, 30–60% of the original glycolipid remains chloroform-soluble. It is considered to be an alkali-stable glycolipid because no further loss of radioactivity occurs during an additional 45-min of treatment with 0.1 N KOH. During incubation with 0.1 N HCI at 100 C glucose is released quantitatively from both the untreated glycolipid and the alkali-stable glycolipid with a half-time of 6 min. Glycolipid formation is inhibited by UDP and is reversible; extracts catalyze the formation of UDP-glucose from the alkali-stable glucolipid and UDP.The chemical and physical properties of the alkali-stable glycolipid are consistent with a glucosyl phosphoryl polyprenol structure. Extracts prepared from cysts catalyze the formation of glycolipids aiso, but the glucosyltransferase activity/cell decreases during the course of encystment. Radioactivity is incorporated into the fraction insoluble in chloroform-methanol-water (1:1:1:) during these incubations when UDP-[U-14C]glucose or [14C]glycolipid is the substrate.

Notes: SYNOPSIS. In populations of Euglena gracilis strain Z synchronized by cultivation on a repetitive light-dark cycle, chloroplasts undergo cyclic changes in structure. During most of the light period chloroplasts are relatively compact with closely appressed lamellae; during the dark (division) period the chloroplasts become quite distended. This change persists for at least one cycle even when the cells are left in continuous light, suggesting that the periodicity may be related more to the age of the cell than to a direct effect of light. In addition, the pyrenoid in synchronized cells has a transient existence, being present only in the first half of the light period.

Notes: SYNOPSIS. Although large hemoglobin inclusions are observed in intraerythrocytic Babesia microti parasites, they are absent from parasites freed of hamster red cells by immune lysis with antihamster erythsocyte serum. Babesia microti has no cytostome. This parasite, therefore, does not appear to feed by phagocytosis of large boluses of hemoglobin, as does Plasmodium. To determine whether Babesia can pinocytose protein, free parasites were fed ferritin in an in vitro system. Ferritin was taken up from the entire cell surface into narrow channels within 15 min at 37 C. Only merozoites, with their pellicular complex, failed to take up the protein. By 60 min, the ferritin was highly concentrated in many channels and vesicles, which formed interconnecting stacks. The ferritin-containing channels became associated with membrane whorls of the multimembranous structure. Membrane whorls were also observed in the process of extrusion in samples incubated for longer times. These events may represent steps in the digestion and excretion of the pinocytosed protein. Empty channels formed when Babesia was fed albumin. The diaminobenzidine reaction for hemoprotein was positive for the channels in both free and intraerythrocytic babesias. The staining reaction was completely inhibited by cyanide, but not at all by aminotriazole. These results further suggest that Babesia pinocytoses hemoglobin in vivo. Plasmodium lophurae parasites freed of red cells by immune lysis are surrounded by 2 membranes and apparently can ingest ferritin only through the cytostome. Extracellular cytostomal feeding involves both membranes, as it does in vivo. Ferritin was found in food vacuoles, some of which contained hemoglobin ingested before parasite isolation, connected to or near the cytostome. In both Plasmodium and Babesia low temperature inhibited ferritin uptake.

Notes: SYNOPSIS. During the course of infection in the rat, Trypanosoma lewisi produces 2 antigenic variants: the 1st represents the initial, reproducing population of cells; and the 2nd the nonreproducing, ablastin-inhibited adult population. The specificities of the agglutinins elicited by the variants were studied by adsorption and agglutination methods and the newer immunoelectroadsorption technic. It was found that the reproducing variant has a surface antigen that reacts with the agglutinin specific for the adult variant, but this antigen does not become immunogenic until transformation to the adult variant occurs. It was also found, with fractions of immune sera obtained by gel filtration, that the agglutinin specific for the reproducing variant is IgG and that specific for the adult variant, IgM. The antigenic variants of pathogenic and nonpathogenic trypanosomes are compared, and the roles of trypanocidal and ablastic antibodies in the induction of antigenic variation are discussed.

Notes: SYNOPSIS. Living Trypanosoma musculi bloodstream trypomastigotes were agglutinated specifically with concanavalin A (ConA), wheat germ agglutinin (WGA), soybean agglutinin (SBA), and fucose-binding protein (FBP). The agglutination with these lectins of living cells from which the coat was removed by trypsinization was the same as with intact trypanosomes. Glutaraldehyde or formalin fixation did not affect the results with regard to agglutination with WGA, SBA, and FBP, but lower agglutination with ConA was observed upon fixation. By using a dense iron-dextran marker many fewer ConA marker particles were localized at the fine structural level in the intact than in trypsin-treated trypanosomes. On the basis of the results obtained by agglutination and electron microscopy, it is likely that fixation cross-links intact surface-coat components associated with the ConA binding sites. It is evident from the studies in which lectins were employed that ligands containing α-D-mannose, N-acetylglucosamine, N-acetylgalactosamine, and α-L-fucose are randomly distributed in the outer surface of the pellicular and flagellar membranes of T. musculi trypomastigotes. Results obtained with α-amylase- and dextranase-treated trypanosomes suggested that lectin-binding sugar ligands in the cell surface were not directly associated with α-1,4 or repetitive α-1,6 glucan-bonded polysaccharide moieties. Similar conclusions can be drawn on the basis of neuraminidase treatment with regard to N-acetylated neuraminic acids.After thorough washing, intact, but not trypsin-treated trypomastigotes were agglutinated specifically with antisera against whole mouse serum and against mouse IgG. Evidently, adsorbed constituents of mouse serum are regular components of the T. musculi surface coat. After incubation in dilute whole mouse serum or in mouse IgG solutions, also the trypsinized cells were agglutinated by the 2 antisera. No such results were obtained with trypsinized cells incubated in serum-free buffers. It was concluded that mouse serum proteins were readily readsorbed on, and firmly bound to the trypsinized cells' surfaces. Specific agglutinations were obtained with trypsinized cells after incubation in dilute rat, rabbit, bovine, and human sera and in solutions of rat and rabbit IgG in reactions with the corresponding antisera. It seems, therefore, that the host serum proteins are adsorbed nonspecifically to the cell surface of trypsinized T. musculi bloodstream forms.When examined by electron microscopy, the intact trypomastigotes were covered by an ununiform, slightly granular, fibrillar extracellular coat, applied to the entire outer lamina of the pellicular and flagellar membranes. No indication of such a coat was noted in the trypsinized organisms. Flocculent surface coat-like matrix could, however, be discerned in cells which, after trypsinization, were incubated in various sera.

Notes: SYNOPSIS. Leptomonas pessoai from the reduviid hemipteron Zelus leucogrammus, was cloned. The original strain (ATCC 30252) and clones can differentiate from promastigote to opisthomastigote. Differentiation is faster at high temperature (37 C) and in a defined medium as compared with a complex medium. It is suggested that Leptomonas pessoai be designated Herpetomonas samuelpessoai.

Notes: Book reviewed in this article: Journal of Toxicology and Environmental Health. Vol. 1, no. 1, Sept. 1975. Hemisphere Publishing Corp.Maloine, S. A., ed. 1974. Diagnostique Immunologique des Parasitoses a Protozoaires et Helminthes.

Notes: SYNOPSIS. Haemogregarina bigemina was found in all Blennius pholis which exceeded 5.0 cm in length, but in none measuring less than 3.5 cm. No exoerythrocytic development was recorded. The first B. pholis eggs hatched in May while the first patent infections of H. bigemina occurred from September onward in metamorphosed fish. Consequently, if the life cycle of H. bigemina includes a vector, that organism is active between May and September at least. Circumstantial evidence indicates that the hematophagous isopod, Gnathia maxillaris and not leeches, could be a vector of H. bigemina. Developmental stages of sporozoa were found in a small number of the isopods which had fed on infected B. pholis but the parasites could not be identified as H. bigemina with certainty. Subcellular organization, typical of sporozoa, was recorded by electron microscopy of H. bigemina.

Notes: SYNOPSIS. Leptomonas pessoai promastigotes cultivated in a synthetic medium were agglutinated with concanavalin A (Con A). Agglutination was predominantly of the flagellar-flagellar type, and was inhibited with sucrose or α-methyl-D-mannoside.Cell surface polysaccharides and/or glycoproteins were demonstrated by several cytochemical methods at the fine-structural level. A Con A-horseradish peroxidase-diaminobenzidine (DAB) technic was used to detect Con A receptors in the pellicular membrane of the flagellar pocket region and in the flagellar membrane proper. Somewhat less of the Con A-DAB reaction product was observed in the pellicular membrane enclosing the rest of the cell.

Notes: SYNOPSIS. Phylogenetic relations are ultimately determined by homologous relationships, including both structural and functional data. Following the establishment of those relationships, the direction of evolutionary change must be determined using paleontologic, developmental, and especially morphocline, data. From that perspective the direction of subsequent development becomes clearer and the problems of origins become more explicit.Using the foregoing methodology it has been possible to identify plausibly monophyletic groups of animal protists or protozoa. Allowing for attendant difficulties, there nevertheless emerges certain fairly convincing generalities: (a) the predominantly pseudopodial forms, with a few minor exceptions, have direct origins from apochlorotic algae; (b) the predominantly kinetidal forms (zooflagellates and ciliates), though also derived originally from apochlorotic algae, give evidence of extended evolutionary development with the especially noteworthy emergence of a permanent ingestatory structure; (c) both groups have increased size, a tendency towards multinuclearity and polyploidy, cytoplasmic differentiations of various sorts, and complex life cycles.In terms of further evolution, namely the emergence of multicellular animals, the pseudopodial forms are almost certainly a dead end while the kinetidal forms are arguably the ancestors of at least 2 metazoan phyla.

Notes: SYNOPSIS. A clone of Cyclidium citrullus, adapted to growth at 18, 27, 37, 43, and 46 C had an optimum at 43 C, with 6.5 divisions/day. Transfer of cells previously grown at 43 or 46 C to 18 C resulted in death of most of the cells, transfer to 27 C increased the lag period, and transfer from 18 C to 37 or 46 C was followed faster division. All cells died at 48 C; some divided before death. At the temperatures employed maximum cell sizes (length and width) were achieved in the early log phase. At 43 C, however, the early log phase cells were smaller. Quantitative and qualitative differences in the free amino acids in the cells were found in ciliates grown at 18, 43, and 46 C; the highest amount/cell was found at 18 C, and the lowest at 43 C. High concentration of proline was noted only at 18 C.

Notes: SYNOPSIS. Additional information on host interactions with trypanosomatid membranes was obtained from studies of a monomorphic strain of Trypanosoma brucei harvested at peak parasitemia from intact and lethally irradiated rats. Pellets of trypanosomes were fixed briefly in glutaraldehyde and processed for thin section electron microscopy or freeze-cleave replicas. Observations of sectioned material facilitated orientation and comparison of details seen in replicas. Fracture faces of cell body and flagellar membranes as well as 3-dimensional views of the nuclear membrane were studied. Cell body membranes of 80% of the organisms from intact rats contained random arrays of intramembranous particles (IMP). Aggregated clusters of particles appeared on the fracture faces of 20% of the trypanosomes. Some of these membranes had nonrandomly distributed particles aligned in distinct rows on the outer fracture face of both cell body and flagellum. Many inner face fractures of the cell body membranes had a particle arrangement similar to the longitudinal alignment of cytoskeletal microtubules. No aggregated particle distribution was seen in membranes of trypanosomes harvested from lethally irradiated rats. Replicas of trypanosome pellets also had plasmanemes as a series of attached, empty, coated membrane vesicles. These structures were found in close association with, as well as widely separated from the parasites. The shedding of these vesicles and the variation of particles in cell body membranes are discussed in light of antibody-induced architectural and antigenic changes in surface properties of trypanosomatids.The convex face of the inner membrane of the nucleus also is covered with randomly arrayed particles. More IMP were observed on the inner than on the outer nuclear membranes. Images of nuclear pores were also seen. The importance of these structures in drug and developmental studies of trypanosomes is discussed.On fracture faces of the flagellar membrane there were miniature maculae adherentes, unique to the inner fracture face and occurring only at regions of membrane apposition between cell body and flagellum. Each cluster of particles exposed by the freeze-cleave method corresponds to an electron-dense plaque seen in thin section images. However, because of a unique fracture pattern, these plaques were not revealed on the apposing body membranes, as illustrated in thin sectioned organisms.

Notes: SYNOPSIS. Phytomonas davidi (Trypanosomatidae) originally discovered by Lafont in 1909 on the island of Mauritius was rediscovered in Euphorbia cyathophora in Florida. Successful cultures were established in diphasic medium consisting of duck blood agar and modified Phillips’medium as overlay. Optimal growth was obtained when Mansour's medium was used as overlay and poorest growth when Cowperthwaite's medium buffered at pH 5.0 was utilized for this purpose. Marked changes tending toward choanomastigotes rather than the elongate twisted promastigotes were observed in cultures.

Notes: SYNOPSIS. Past reports of Synophrya, the only apostome ciliate known to harm its host, indicated that it was restricted in its distribution and in the hosts it can infect. In recent collections of decapods from the off-shore waters of North Carolina and Georgia, 30% of all specimens were infected with Synophrya. Forty-four percent of all the species collected had individuals infected with Synophrya, and 63% of all the families collected contained species that had infected individuals. There is no obvious structural or phylogenetic relationship between these families that explain why they are infected. The presence of Synophrya may be related to salinity since decapods captured in estuaries were never infected and decapods captured close to shore were only rarely infected. The salinities of these waters range from 15–35%, but the salinity of the off-shore waters where the great majority of infected specimens was found ranges only from 35–36%.

Notes: Book reviewed in this article:Pirt, S. J. 1975. Principles of Microbe and Cell Cultivation.

Notes: SYNOPSIS. Plasmodium lophurae serine hydroxymethyltransferase (EC 2.1.2.1) was partially purified and characterized by (NH4)2SO4 fractionation and chromatography on Sephadex G-100. The enzyme, precipitated by 3.0–3.3 m (NH4)2SO4, had a molecular weight of 68,300 as estimated by exclusion chromatography on G-100. The pH optimum of the enzyme was 6.8–7.6 in sodium phosphate-citrate buffer. Citrate stabilized the enzyme during storage in phosphate buffer at 4 C. The Km was 4.3 × 10−3m for l-serine and 2.5 × 10−4m for tetrahydrofolate.

Notes: Book reviewed in this article:Cordero del Campillo, M. et al. 1975. Indice-Catalogo de Zooparasitos Ibéricos. I. Protozoos. II. Trematodos.

Notes: SYNOPSIS. Haemogregarina balli sp. n. is described from the blood and organs of the common snapping turtle Chelydra serpentina serpentina and from the gastric and intestinal ceca of the presumed invertebrate hosts, the leeches Placobdella parasitica and Placobdella ornata. In the peripheral blood of the turtle, male and female gametocytes and immature erythrocytic schizonts are found within erythrocytes. The maturation of erythrocytic schizonts containing 6–8 merozoites is recorded from liver imprints. Schizonts with 13–25 merozoites are found in various cells of the liver, lung and spleen. In the gastric ceca of the leeches the host erythrocytes are digested, releasing the gametocytes and immature erythrocytic schizonts. Immature erythrocytic schizonts degenerate. Association of the gametocytes occurs in the intestinal ceca. The microgametocyte apparently gives rise to 4 nonmotile microgametes, one of which fertilizes the macrogamete while the other remain as condensed, residual nuclei on the periphery of the developing oocyst. The oocyst increases in size with maturity. A mature oocyst produces 8 sporozoites from a single germinal center. Sporozoites liberated from the oocyst are found in the tissues of the leech. Transovarial transmission of the parasite does not occur in the turtle. Attempts at experimental transmission failed. Previously unfed (control) leeches were negative for the parasite. Haemogregarina balli is compared with other haemogregarines described from C. serpentina. Features of species of Haemogregarina and Hepatozoon as well as the taxonomy of these genera are discussed.

Notes: SYNOPSIS. In low viscosity media, Euglena gracilis strain Z responds to a sudden change in light intensity by a cessation of forward movement, followed by a reorientation of the locomotor flagellum which results in turning of the cell around the lateral axis (photophobic response). At a viscosity interface between low [∼ 1 cP (centipoise)] and high (4000 cP) media, the cells exhibit avoidance responses or become immobilized in the higher viscosity medium. Upon changing the light intensity, free swimming cells have photophobic responses, while immobilized ones undergo body contractions. For cells immersed in media of varying viscosity, the delay between light stimulation and body contraction (transduction time) is shortest at high viscosities. From 500 to 2000 cP, where the cells are capable of both movement and light-induced body contractions, there is a logarithmic dependence of the transduction time on the viscosity. The transduction time does not vary appreciably with the intensity of the primary light stimulus within a range of 0.14-1.13 kW/m2.

Notes: SYNOPSIS. Eight species representing 8 genera of gallinaceous birds were used: Alectoris graeca; Colinus virginianus; Coturnix coturnix; Gallus gallus; Meleagris gallopavo; Numidia meleagris; Pavo cristatus; Phasianus colchicus. Three-week-old birds were dosed with sporulated oocysts of Eimeria tenella Beltsville strain. At 4, 24, 48, 72, 96, 120, 144, and 168 hr after inoculation, 1-3 infected birds and uninoculated controls of each species were killed by cardiac exsanguination. Pieces of intestines were fixed and examined for stages of E. tenella as stained paraffin sections or indirect fluorescent antibody preparations. Oocyst counts were made in droppings collected for the first 6 days of the patent period. Sporozoites were found in the lamina propria of some birds of 5 species at 4 hr postinoculation, but no stages were found thereafter except in the breeds of G. gallus and A. graeca. At 144 and 168 hr postinoculation, a few macrogametes were found in the ceca of 2 A. graeca, but no oocysts were found in the feces. No statistical difference was found between the number of oocysts produced/bird in the breeds of G. gallus examined. It is evident from these observations that E. tenella did not complete its life cycle in several close phylogenetic relatives of G. gallus, even though in other studies this parasite was found to complete its life cycle in cell cultures derived from the same birds.

Notes: Book reviewed in this article:Faust, E. C., Beaver, P. C. & Jung, R. C. 1975. Animal Agents and Vectors of Human Disease.

Notes: Precursors of 2-aminobutanoic acid (2-ABA), found in the incubation medium of mixed rumen ciliate protozoa, were examined with washed or starved bacteria-free ciliates. Threonine and methionine strongly stimulated the formation of 2-ABA. Formation of 2-ABA by direct conversion of threonine and dethiomethylation of methionine was confirmed by radiotracer experiments with [U-14C]L-threonine and [carboxyl-14C] and [methyl-14C]L-methionine.

Notes: The effects of irreversible inhibition of protein synthesis by pactamycin in either infective forms of Trypanosoma cruzi or mammalian host cells on cellular invasion by this human pathogen were investigated. Treatment of bloodstream forms of T. cruzi with pactamycin markedly reduced their ability to bind either fibroblast-like cells of monkey origin or myoblasts of rat origin. The number of amastigote forms that could be established intracellularly was also significantly decreased with respect to control values obtained when mock-treated (medium alone) trypomastigotes were incubated with the cells. Pactamycin treatment also reduced the infectivity of T. cruzi trypomastigotes for mice as evidenced by both significantly reduced parasitemia levels and mortality rates when compared with those of control mice infected with mock-treated parasites. Inhibition of protein synthesis in the host cells neither prevented cell infection by untreated trypomastigotes nor altered the percentages of infected cells or the magnitude of the infection in vitro. These results indicate that protein synthesis is a requirement for cell invasion by T. cruzi and that the parasite can establish itself and replicate within cells relying on its own protein synthesis ability.

Notes: One hundred eighty-eight stocks of Paramecium primaurelia, P. biaurelia, P. tetraurelia, and P. octaurelia were grown axenically and tested for five esterases, visualized by starch gel electrophoresis, in a search for variant stocks. The five esterases can be distinguished on the bases of their substrate specificity, sensitivity to an inhibitor, and response to different growth conditions. This paper addresses the nature of the electrophoretic change in mobility of the variant stocks in order that species relationships can be more accurately assessed. Crosses carried out in all four species show that single genes determine the differences in mobility between variant and common subtypes. Extracts of variant stocks that gave similar patterns were run against each other, tested for their sensitivity to the inhibitor, and the pattern was compared to that found in extracts of stocks with variant and common subtypes in other species. The majority of the variants in P. primaurelia, P. tetraurelia, and P. octaurelia show an electrophoretic mobility characteristic of a common subtype, or a variant, in another species. The same proportion of variant subtypes as common subtypes have mobilities similar to esterase subtypes found in other species. Of the four species examined in this paper, P. tetraurelia and P. octaurelia appear to be most closely related on the basis of shared esterase subtypes. In P. biaurelia the mobilities of most of the variants are unique, as are the common esterase subtypes in this species. P. biaurelia stands out as having the greatest number of esterase subtypes, with very few of them homologous to subtypes found in other species. This observation supports the idea of greater diversification of stocks within P. biaurelia than for the other three species.

Notes: Glycogen phosphorylase and synthase activities were detected in the sonic lysate of rumen ciliates of the genus Entodinium. The ciliate phosphorylase had the following properties. The pH optimum was narrow and centered at pH 5.9. The activity was maximum at 30°C; above 40°C a rapid inactivation occurred. The Km value for glucose-1-phosphate (G-1-P) and for glycogen was 15 mM and 0.069% (w/v), respectively. NaF and ethylenediamine tetraacetic acid had no stimulative effect on the enzyme activity, though adenosine 3′,5′-monophosphate and theophylline activated it. NaHSO3 inhibited the enzyme activity at a concentration of 1 mM. The inhibition of glucose was noncompetitive for G-1-P. Glycolytic intermediates and nucleotides had a minor effect on phosphorylase activity. Glycogen synthase existed in two forms, glucose-6-phosphate dependent and independent forms: the proportion of the latter form increased with the decrease of reserve polysaccharide levels in the ciliates. Correlations between glycolytic enzyme activities included phosphorylase and synthase activities and reserve polysaccharide contents in the ciliates were determined, and a possible regulatory mechanism of polysaccharide synthesis and degradation was discussed.

Notes: The structure of the major protein of the pellicular membrane of Leishmania tropica was investigated. This protein is composed of two polypeptides, of ca. 50,000 d molecular weight, that were found to cross-react immunologically with the α and β subunits of pig brain tubulin. The polypeptides and pig brain tubulin subunits were partially digested with S. aureus V8 protease, and the peptides obtained analysed by SDS-polyacrylamide gel electrophoresis. A comparison of the patterns showed that the β subunits of Leishmania and pig tubulin have very similar primary structures, while the α subunits have evolved divergently. These experiments demonstrate that the major polypeptides found in the pellicular membrane of L. tropica are α and β subunits of tubulin. Immuno-electron microscopy indicates that the tubulin is located in the microtubules associated with the pellicular membrane of Leishmania. Arrays of microtubules were prepared by nonionic detergent treatment of the cells and observed by electron microscopy after negative staining. Optical diffraction reveals a 5 nm spacing between protofilaments in the microtubule and a 4 nm axial periodicity corresponding to the tubulin subunits. The pitch of the shallow left-hand three-start helix is 12°. A distance of 47 nm separates each microtubule from the next. These data show that the dimensions and supramolecular organization of the tubulin subunits in the microtubules are identical in the pellicular membrane of L. tropica and in mammalian brain.

Notes: Haemogregarina bigemina is redescribed from the blood of the marine fish Blennius pholis, and stages presumed to be those of the haemogregarine are recorded from the hematophagous praniza larva of the isopod Gnathia maxillaris. At College Rocks, Aberystwyth, Wales, the main study area, a high incidence of infection occurred in B. pholis. No exoerythrocytic stages were observed in these fish, nor was sexual dimorphism of the gametocyte evident. As in an earlier study, ecological evidence favored transmission by G. maxillaris rather than by leeches. Gametocytes, syzygy, oocysts, sporoblasts, and sporozoites were identified in the anterior hindgut of the isopod. The stages observed in G. maxillaris are compared with those of other haemogregarines described from the digestive tract of leeches. Mention is made of an intraleucocytic haemogregarine of another fish, Crenilabrus melops.

Notes: The nomenclature of three genera in the family Haemogregarinidae (Haemogregarina, Karyolysus, and Hepatozoon) has been reviewed and the following new names are introduced to replace homonyms or for previously unnamed species: Haemogregarina carlosi n. nom., in the erythrocytes of the lizard Lacerta ocellata; Haemogregarina tincae n. nom., in the stomach and intestine of the tench Tinca tinca; Hepatozoon insectivorae n. sp., in the leucocytes of the shrews Sorex araneus and Crocidura leucodon; Hepatozoon krampitzi n. sp., in the leucocytes of the vole Microtus oeconomus; Hepatozoon peromysci n. sp., in the leucocytes of the deermice Peromyscus boylii and P. truei gilberti; and Hepatozoon pallida (Pessoa et al., 1971) n. comb., in the erythrocytes of the snake Thamnodynastes pallidus nattereri.

Notes: Transmission and scanning electron microscopy of specimens of Paramecium multimicronucleatum treated with the Rio-Hortega silver-impregnation method as modified by Fernández-Galiano demonstrate that considerable deposition of silver occurs around the kinetosomes, especially at the level of the basal plate and also at the proximal end of the kinetosome. In addition, silver is heavily deposited within the kinetodesmal fibers, in the fibrous matrix that surrounds the postciliary and transverse microtubules, in the connective structures observed between the two kinetosomes of a pair and between the kinetodesmal fiber and the anterior kinetosome, and in the trichocysts. Differences and similarities in sites of deposit when other methods of silver impregnation are employed are discussed and the particular value of the present technique in studies of ciliate systematics and phytogeny is stressed.

Notes: . Various ions and treatments known to alter the availability of free Ca2+ were examined with respect to their effects on the cytopharyngeal pouch, a large prey receptacle found in the potentially carnivorous macrostomal form of Tetrahymena vorax. Addition of Ca2+, Ba2+, or Sr2+ induced the pouch to separate from the region of the cytostome, forming a large empty vacuole. Na+, alone, had no effect, but lowered the concentration of Ca2+ required to produce maximum vacuolar formation in populations of cells. Vacuolar induction was also initiated by the cation ionophore A23187 or by subjecting macrostomal cells to an electric current. In the presence of divalent cation chelators EDTA and EGTA, the cytopharyngeal pouch collapsed and was resorbed. Taken together, these results suggest that Ca2+ plays an important role during phagocytosis in this cell type.

Notes: Oocysts of Eimeria morainensis n. sp. are described from the golden-mantled ground squirrel, Spermophilus lateralis. in Northern Colorado. The oocysts of E. morainensis are double-walled and subspherical, 20.3 × 19.8 (18.7–26.2 × 17.5–21.2) μm; and the sporocysts are ellipsoid, 12.1 × 6.9 (8.7–13.7 × 6.2–8.7) μm. Oocyst residuum and micropyle are absent, but a polar granule is present. Sporocyst residuum and Stieda body are present. Differences in oocyst characteristics provide the basis for recognition of this new species of Eimeria.

Notes: Trichoduboscqia epeori Léger was found to parasitize nymphs of the mayfly Rhithrogena iridina Kolenati in southwest Germany for a new host record. It was studied by light and electron microscopy. The pansporoblast membrane is evaginated at several points, usually four, to produce long needle-like appendages 〉20 μm in length with a resilient inner core superficially resembling collagen, which is thought to maintain their orientation. It is suggested that the pansporoblast appendages may play a role in host infection. The structure and ultrastructure of developmental stages are recorded for the first time. Apart from the pansporoblast appendages, the ultrastructure of T. epeori conforms to the general pattern seen in many other pansporoblastic Microspora. Typically 16 spores are produced per pansporoblast but 32-spore pansporoblasts were also found, and the taxonomic significance of this is discussed.

Notes: Electron microscopy of the tomite of Conidophrys pitelkae confirms that Jankowski was correct in including the pilisuctorians in the Apostomatida. Like other apostome tomites, the tomite of Conidophrys possesses a rosette opening to the exterior, kinetodesmata made up of stacks of individual kinetodesmal fibrils, and canaliculi that are surrounded by dense inclusion bodies and open on the ventral surface. The fine structure of the trophont of Conidophrys, however, is quite unlike that of other apostome trophonts. The elaborate infraciliature of the tomite disappears immediately after it settles and reappears de novo on the trophont just before tomitogenesis. The cyst wall, which completely encloses the trophont and grows with it, attaches the ciliate to a seta on its, host, the shrimp Crangon crangon. The setae on which tomites settle vary greatly in size and shape, but each appears to have at its tip some digitiform cuticular projections that surmount a pore, which opens into the lumen of the seta. The trophont's only direct connection to its host is at the cytostome, a unique structure formed of delicate tubules that pass through the pore into the lumen of the seta. Ingestion is by micropinocytosis, and there are no visible food reserves.

Notes: Les colorations au protargol ainsi que la microscopie électronique á transmission et á balayage permettent de distinguer quatre parties dans I'organisation de Spirochona gemmipara: la collerette formée d'une entonnoir et d'une volute abritant la ciliature, le pseudatrium, et le cytostome; le cou contenant le cytopharynx, le systéme excréteur. et I'appareil cytoproctal; le corps renfle par les noyaux et les vacuoles digestives: et le pseudostyle allonge assurant la fixation au substrat. En majeure partie, le spirochone est limité par une pellicule non ciliée et dépourvue de cils; la pellicule comprend la membrane cellulaire, un épiplasme épais percé de nombreux pores et des triplets de microtubules (MT) sous-pelliculaires. Principalement située dans I'entonnoir, la ciliature somatiquc du spirochone est répartie en deux ensembles inégaux, le champ gauche et le champ droit. Les cinéties sont séparées par des crétes contenant les MT post-ciliaires disposés en une couche verticale; les MT sous-cinétiens sont nombreux, arrangés parallélement á la base des cinétosomes; ceux-lá présentent également une lame dense et des MT transverses, et une fibre cinétodesmale discrete. Un important réseau de faisceaux fibrillaires est disposé orthogonalement par rapport aux cinéties. La base de I'entonnoir est déprimée en une petite cavitéévasée, le pseudatrium; celui-lá conduit à un cytostome ouvert en permanence. Dépourvu de némadesmes, le cytopharynx est un tube cylindrique formé par une dizaine de rideaux microtubulaires; prés du cytostome, chaque rideau porte en plus quelques MT radiaires assimilés aux lamelles Z des Nassulida. Le phagoplasme est riche en tubules complexes et en vésicules de taille moyenne à contenu contrasté. Le champ X, peu organisé, comprend 10–30 cinétosomes situés à gauche du cytostome; il ne correspond certainement pas á la ciliature périorale droite de Chilodochona. Si cette difference se retrouve chez d'autres Chonotriches, il sera nécessaire de séparer taxonomiquement les espéces possédant une ciliature périorale de celles qui en sont dépourvues.〈section xml:id="abs1-2"〉〈title type="main"〉ABSTRACTIn the organization of Spirochona gemmipara, four parts can be demonstrated by protargol staining and also by scanning and transmission electron microscopy: the collar, composed of a funnel and a volute, which shelters the cilia, the pseudatrium, and the cytostome: the neck, which contains the cytopharynx, the excretory system, and the cytoproctal apparatus; the body, enlarged by the nuclei and the digestive vacuoles; and the elongated pseudostyle, which ensures attachment to the substrate. Most of the surface of the spirochone is covered by the pellicula devoid of cilia and alveoli; the pellicula comprises the cell membrane, a thick epiplasm perforated with numerous pores and subpellicular triplets of microtubules (MT). The somatic ciliature of the spirochone is located principally in the funnel and is divided into two unequal parts, the left and right fields. The kineties are separated from one another by ridges, each containing one layer of postciliary MT: numerous subkinetal MT run in a parallel direction under the kinetics; moreover, the kinetosomes show a transverse dense spur and MT, and a modest kinetodesmal fiber. A conspicuous net of fibrillar bundles runs orthogonally to the kineties. The base of the funnel forms a small splayed depression, the pseudatrium; the latter leads to a permanently open cytostome. The cytopharynx is a cylindrical tube devoid of nematodesmata but containing ca. 10 microtubular curtains, each bearing also some radial MT resembling the Z lamellae of the Nassulida. The phagoplasm contains many complex tubules and numerous middle-sized vesicles with an electron-dense content. The X field, which is not well organized and comprises 10–30 kinetosomes, lies on the left of the cytostome; it certainly does not correspond to the right perioral ciliature of Chilodochona. If this disparity is found again in other chonotrichs, it will be necessary to separate taxonomically the species that possess a perioral ciliature from those that do not.

Notes: Cells of the ciliate Tetrahymena pyriformis GL overproduce and accumulate massive quantities of the heme intermediate, protoporphyrin IX. Protoporphyrin is localized intracellularly in discrete membranous compartments. The amount of porphyrin stored in the cell changes dramatically as cells progress through the growth cycle. Porphyrin overproduction is stimulated by δ-aminolevulinic acid, but only during the mid-stationary phase. Overproduction of protoporphyrin IX apparently results from an increase, late in the growth cycle, of activities subsequent to δ-aminolevulinic acid synthetase. Feedback inhibition in the pathway by accumulated protoporphyrin IX does not occur. The presence of Co2+ completely inhibits accumulation of protoporphyrin IX in a manner reversed by δ-aminolevulinic acid. Sn4+ stimulates protoporphyrin IX accumulation in the culture.

Notes: SYNOPSIS. A video technic is described that permits a quantification of the degree of attraction of Trypanosoma cruzi trypomastigotes to vertebrate cells in vitro. Bovine embryo skeletal muscle cells (BESM), HeLa cells and Vero cells all attract a myotropic strain of T. cruzi trypomastigotes. BESM cells, however, are 2-fold more attractive to trypomastigotes than HeLa cells and 10-fold more attractive than Vero cells. Heat-inactivation of BESM cells abolishes their ability to respire and also to attract T. cruzi trypomastigotes. As there is no difference in the endogenous oxygen consumption between BESM, HeLa, and Vero cells, it is unlikely that differences in the attraction of trypomastigotes to the 3 cell types are due to variations in the magnitude of pO2 or pCO2 gradients in the milieu around the cells.

Notes: SYNOPSIS. Euglena gracilis strain Z has a motor response which results in orientation with respect to the polarization of a light stimulus. Cells swim preferentially in a direction perpendicular to the plane of polarization of the stimulus. If 2 polarized stimuli are given from opposite directions, the preferred direction is, under certain circumstances, at right angles to the directions of both stimuli. Euglena also preferentially assumes an orientation that is at right angles to the force of gravity. The relationships between these responses and phototactic movements oriented with respect to the direction of the stimulus are discussed.

Notes: SYNOPSIS. The behavior of Paramecium caudatum in small capillary glass tubes was investigated under various ionic conditions and at the various tube diameters. Along the inner walls of the tubes ciliates undergo regular spiral motion, which is completely different from natural spirallings or random walk-like movements observed usually in large vessels. The curvature calculated from the tracks of spiral motions was independent of the inner diameters of capillary tubes, but depend specifically on ionic conditions.A plausible law governing such regular spiral motions of Paramecium caudatum is proposed. A definite part of the anterior end of a ciliate seems to contact the curved surface of the inner wall of a capillary tube during the motion so that the organism receives a constant tactile stimulus, and the direction of motive force keeps a certain angle against the surface.