ALBERT

Notes: This paper gives a summary of the methods that have been used for independent model aerial triangulation. A modification of one of the methods is proposed and the paper concludes with a comparison of the independent model with the classical method of triangulation.

Notes: The camera is a further development of an existing type with greatly improved photogrammetric performance so that the photography can be used with first-order plotting machines. A new lens provides minimal distortion, high resolution and greatly improved marginal illumination. An entirely new shutter provides high speeds and efficiency. Laboratory results and preliminary survey trials indicate image quality and location standards of the same order as established existing cameras.

Notes: Book reviews in this article:INTERNATIONAL YEAR BOOK OF CARTOGRAPHY (Vol. IV, 1964). Editor, Eduard Imhof.JUBILEE VOLUME DEDICATED TO WILLEM SCHERMERHORN ON HIS SEVENTIETH ANNIVERSARY: ESSAYS ON THE DEVELOPMENT OF PHOTOGRAMMETRY. Published by I.T.C., Delft.

Notes: Book reviews in this article:THE CHESA PHOTOGRAMMETRIC EXPERIMENT (Technical Publication

Notes: A successful attempt has been made to produce design plans of large chemical plant using photogrammetric techniques, and involving the development and modification of cameras and plotting equipment. Photogrammetry has provided a solution to a problem which could not easily be solved by direct methods.

Notes: Book reviews in this article:PROCEEDINGS OF THE SECOND NATIONAL CONFERENCE OF SOUTH AFRICAN SURVEYORS, FEBRUARY 1964. Edited by G. H. Menzies et al.

Notes: Four authors review the activities of the seven Commissions of the I.S.P. at the Xth International Congress, Lisbon, 1964.

Notes: Rather than rely on laboratory calibration, test fields have been established in Sweden to enable photography from a tower or aircraft, and so simulate as nearly as possible actual operational conditions. Repeated experiments, followed by analysis of photography, and the application of statistical tests, have allowed the geometrical quality of the aerial photograph to be assessed, and systematic and irregular errors to be distinguished.

Notes: It does not seem to be widely recognised that the solution of the space resection problem from measurements made on a single photograph of three ground control points is not unique. There are, in general, four solutions, so that either the camera orientation must be approximately known (as is the case for near vertical photography) or extra control must be used to discriminate between these solutions. The iterative solution commonly used will only yield one solution, which will be correct if the photography is nearly vertical, but which is liable to be wrong in the general case. An explicit solution is therefore preferred since all solutions may be examined in the light of such extra control as is available. This paper gives a method for such a solution and shows how the discrimination should be used. The paper goes on to derive a method of adjusting the result to redundant control by least squares.

Notes: The salient features of a method of analytical triangulation operating directly on single photographs are described, and the close analogy with geodetic triangulation computation is demonstrated.Any combination of photographs, whether in stereo pairs, stereo triples, strips, sub-blocks or blocks, is handled by forming the set of observation equations for each individual photograph in turn, and then taking all these sets together and solving them simultaneously by the method of least squares.Special procedures for dealing with very large numbers of variables are discussed, and certain applications of the method are indicated.

Notes: A method of delineating the extent of floods has been devised involving the establishment of flood surfaces and the creation of photogrammetric digital terrain models. These two data sources are combined in a computer aided map production system and comparisons are drawn between the efficacy of different forms of terrain modelling in a floodplain environment.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn a mis au point, en vue de déterminer l'étendue d'innondations, une méthode numérique combinant les notions de surface innondable et de modèle numérique de terrain (MNT); on se pose le problème du choix du MNT dans un environnement de plaine innondable.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungAngabe eines Verfahrens zur Ableitung der Ausdehnung von Überschwemmungen, wobei die Flut-Oberfläche bestimmt und photogrammetrisch digitale Geländemodelle erzeugt werden. Diese beiden Datenquellen werden in einem rechnergestützten Kartiersystem kombiniert, und es werden Vergleiche bezüglich der Wirksamkeit verschiedener Verfahren der Geländemodellierung in Flussniederungen gezogen.

Notes: The rate of ingestion of cytoplasm from its prey ciliate by Podophrya collini shows a maximum at 18°C. The rate of ingestion is the same for all active tentacles during the feeding period. Calculation of the amount of cytoplasm ingested from rate measurement and from dimensional alterations of ciliate and suctorian during feeding indicates conformity to the hypothesis that the motive force for ingestion results from integrated activity of the total cell and not from autonomous activity of the tentacles alone. The estimated motive force approximates 0.2 atmosphere. Data is presented to indicate that energy to maintain this motive force is derived from the normal oxidative metabolism of the suctorian.

Notes: Hepatozoon procyonis, n. sp., is described from the raccoon Procyon lotor from southwestern Georgia. Mature gametocytes in monocytes in blood smears and schizocysts and developing gametocytes in sections of heart tissue were observed and described. A Hepatozoon was also found in the fox squirrel Sciurus niger.

Notes: In Paramecium there is no known correlation between the direction of electric current through the membrane and of ciliary beat. One reason is that the Ludloff phenomenon, an anodal shift in the limit of the area of reversal with increased current strength, has seemed contradictory to most other data. However, by assuming Paramecium to be a core conductor immersed in a volume conductor and by applying the laws of polarizing currents it is possible to explain all existing data on reversal of normal ciliary action, and also on activation of cilia in immobilized specimens by electrical current. It is assumed that a threshold degree of depolarization of the normal membrane potential or of current density causes reversal. The Ludloff phenomenon is caused by anodal progression of this degree of depolarization with increasing membranecurrent. If it is also assumed that an increase in the membrane potential of immobilized specimens causes activation in the normal direction, one can predict anodal activation, progression of reversal with decrement in velocity, time course of development of excitation, ancdal stimulation upon “break.” stimulation by linearly rising currents, relative refractory and supernormal periods, effect of angle of orientation, and effect of acetylcholine and antiacetylchoiine esterase. Assumption of a neuromotor system is not needed. However, if available data are interpreted in the manner commonly used for nerve it can be concluded that an active accommodative process exists and possibly also a local excitatory state. A recent “dipolar” theory of galvanotaxis is not acceptable because it does not include ciliary reversal.

Notes: The morphologic phenomena of the conjugation of Paramecium caudatum are analysed by transverse sectioning of couples at the level of the junction zone. This orientation allows exact determination of the adjacent surfaces (which strongly suggests the absence of a paroral cone) and their relation to the ciliary fields. The modifications of the outer pellicle are studied with the electron microscope. It is shown that cytoplasmic communications occur at the top of the ridges which limit the periciliary depressions. The kinetosomes remain apparently intact but cilia and trichocysts disappear. An active role by the latter organelles is suggested for the union of the two conjugants.

Notes: Resistance to sulfanilamide has persisted in a strain of Chilomonas Paramecium for 255 transfers (63 months) in a drug-free medium. In attempts to modify resistance, stocks derived from sulfonamide-resistant and normal strains have been acclimatized to and then maintained in media containing p-aminobenzoic acid at 5.0, 10.0, 15.0 and 20.0 mgJ100 ml. Each PABA-acclimatized strain was more susceptible to sulfanilamide than its parent stock. In other words, sulfanil-amide-resistant strains lost their resistance and normal strains became hypersensitive. One strain, adapted first to sulfanilamide, subsequently to PABA (15 mgJ100 ml) and again to sulfanilamide, showed a loss of and finally a restoration of sui-fonamide-resistance (but to a degree somewhat lower than the original level).

Notes: DL-serine, DL-methionine or DL-serine + DL-methionine in excess inhibited the growth of Tetrahymena pyriformis H. Excess serine was most inhibitory at high concentration of folic acid, whereas the effect of excess methionine or methionine + serine was most pronounced at low levels of folic acid. Inhibition due to excess serine was relieved by raising the level of methionine or by adding pyrimethamine to lower the effective folic acid level, and was intensified by adding Dl.-ethionine or by raising the level of folic acid. Similarly, inhibition due to excess methionine was relieved by supplying more serine or adding DL-ethionine (which reduced the amount of available methionine) and was intensified by adding pyrimethamine. Inhibition by excess methionine + serine was reversed by increasing threonine, provided there was ample guanine present. Low levels of guanine or the presence of 8-azaguanine prevented this reversal. Comparisons are made with the work of others.

Notes: Autogamy in Frontonia leucas is described for the first time. The process appears to occur at irregular intervals. From 7 to 10% of the individuals are affected. The beginning of autogamy is marked by a swelling of all the micronuclei which take part in the first two maturation divisions. The third division however affects only one of the second division products. Occasionally two or three may divide. A paroral cone is not prominent. But a small area close to the peristome is distinguishable as the region where the pronuclei fuse. The syn-karyon divides four times. Some of the division products disintegrate, after which 8 to 9 bodies are left which become differentiated into 4 to 5 macronuclear anlagen and 4 micro-nuclei. Mitotic division of the micronuclei results in their increase in number in the daughter individuals after metagamic divisions. Changes in the macronucleus during autogamy consist in its fragmentation and later absorption in the cytoplasm. There is some indirect evidence of a relationship between the dissolution of the old macronucleus and the development of the new.

Notes: An electron microscope study of Plasmodium lophurae maintained in vivo and in vitro provided information concerning the sequence of events during reproduction, and the role of the cytoplasm in this process.Contrary to the generally held opinion that nuclear fissions precede cytoplasmic division, it was found that the last nuclear fission takes place during advanced stages of cytoplasmic segmentation. This study also supplied evidence that in addition to repeated nuclear divisions, a number of changes occur in all major components of the cytoplasm. These changes are considered as preparatory for reproduction. The cytoplasm continues to be active during the formation of merozoites. At this stage a segregation of cytoplasmic components takes place resulting in the incorporation into the offspring of a condensed cytoplasm containing all the organelles. The watery part of the cytoplasm with the lipids and food vacuoles is withheld and at the end of reproduction forms the residual body, a separate structure bound by a membrane.

Notes: Ophryoglena hypertrophica is distinguished by its tomites and its pyriform theronts; by its elliptical and flattened macronucleus with 2 or 3 coupled micronuclei; by its large trophont; by its tomont covered with a thin mucous layer at the interior of which are formed 4 or 8 tomites closely bound one to another. Its physiological evolution is characteristic; the tomite when it comes out of the tomont undergoes a secondary encystment and then becomes the theront. Sometimes the tomite is rostrated and is not attracted by the tissues; the tomite undergoes as before a secondary encystment, but divides inside the cyst. This type also produces complete or partial particular palintomies and regularly forms resistant cysts.

Notes: Intraspecific chemotaxis between gametes was demonstrated in Chlamydomonas moewusii Gerloff var. rotunda nov. var. which was previously used as C. sp. 24 (Tsubo Y. 1957). a heterothallic isogamous species from Japan. The reaction is unidirectional; the “+” gametes are attracted by the “—” gametes or cell-free supernatant of medium in which the :“-” gametes were suspended. In a study with 4 other isogamous heterothallic Chlamydomonas — C. moewusii Gerloff, C. eugametos Moewus, C. reinhardi Dangeard, and C. morewusii Gerloff var. tenuichloris nov. var. — none of them revealed any intraspecific chemotactic behavior. However, as with the “—” gametes of C. moewusii var. rotunda, both mating types of C. moewusii, C. eugametos, and C. moewusii var. tenuichloris were interspecifically attracted by the supernatant of the “—” culture of C. moewusii var. rotunda. Only C. rein- hardi showed no chemotactic behavior in intra- or interspecific combinations.Although chemotaxis occurred in the above-mentioaed combinations, neither agglutination nor pairing ner zygete formation followed at all in the same combinations. The“;–” cells of C. moewusii var. rotunda killed by osmium vaper and then washed no longer produced the chemotactic agent, but did agglutinate with living “+” cells. Therefore, evidently, chemo-taxis is a separate step from agglutination and zygote-for-mation yet does not seem necessary in the mating of isoga-mous Chlamydomonas. Nonetheless, since this activity appears not in the vegetative but in the gametic stage, it seems to concern the sexual activity of the cells. In preliminary studies the chemotactic agent produced by C. moewusii var. rotunda was shown to be volatile.

Notes: A microsporidian infection in a laboratory clone of Hydra littoralis has been observed, and the parasite has been tentatively identified as a species of Plistophora. Infected hydra continue to bud and regenerate normally and show no significant physiological or morphological changes. Sexual crossing of infected and non-infected animals shows that the infection is transmitted by the ovum but not by the sperm. Continuous exposure of infected hydra to Fumidil B in solution resulted in the disappearance of all Plistophora spores after a five week period of treatment, and the clones of the treated animals have remained parasite-free for more than a year.

Notes: Patterns for free and protein amino acids and related substances were determined for Tetrahymena limacis and 7 strains of T. pyriformis from axenic stationary phase cultures grown at 25° C by means of 2-dimensional chromatography in a butanol-acetic acid and phenol solvent system with ninhydrin and other polychromatic indicators. A uniform protein amino acid (PAA) pattern was observed in all strains. There were 14 color spots indicating 19 amino acids (including cysteic acid), identified as follows: alanine, arginine, aspartic acid, cysteine/cystine, cysteic acid, glutamic acid, glycine, leucine/isoleucine/phenylalanine, lysine/histidine, proline, serine, threonine, tyrosine, valine/methionine.The following free amino acids and related substances (FAAs) were identified with 14 spots (several different from these for PAA patterns) found in all strains: alanine, arginine, asparagine, aspartic acid, glutamic acid, glutamine, glycine, leucine/isoleucine/phenylalanine, lysine histidine. proline, serine, threonine, tyrosine, valine/methionine. T. limacis and strains LI and Gf-J of T. pyriformis exhibited these only. Chromatograms of 5 strains of T. pyriformis (PR. F. L3 WH52, HS), however, also contained 1 to 4 spots representing certain of the following substances: Cysteic acid, cysteine/cystine, taurine, and the unknowns X1, X2, and X3, having Rf's of 0.33, 0.79, and 0.72 respectively in 4:1 phenol-H2O system Excepting for F and L3, which were similar, the T. pyriformis strains showed quite different distributional patterns of these substances at 25°C. Other deviations in the distribution of the 6 compounds were noted in the chromatograms of 10° and 35° cultures of WH52 and HS. These findings on FAAs and PAAs are tabulated, along with those of previous investigators, to furnish comparisons on 13 strains of Tetrahymena pyriformis, T. limacis and 9 other species of protozoa.

Notes: Three new species of Trypanosomatidae were isolated from three species of bugs: Leptomonas leptoglossi from Leptoglossus phyllopus, Crithidia acanthocephali from Acanthocephala femorata, and Blastocrithidia euschisti from Euschistus servus. All were cultured axenically and on avian embryo membranes. In addition to differences in morphology the three organisms displayed different growth rates in the chorio-allantoic fluids of duck and chick embryos incubated at 30°C. L. leptoglossi grew most abundantly. B. euschisti barely maintained itself while C. acanthocephali occupied an intermediate position.When the temperature of incubation was raised to 37°C, there was continued multiplication of L. leptoglossi and C. acanthocephali, but there was no growth of B. euschisti in either duck or chick embryos.It is suggested that the criteria of morphology, cultural characteristics in vitro and in vivo, plus physiological characters be used as future aids in classification of the Trypanosomatidae.

Notes: SYNOPSIS: Crithidia fasciculata was cultured in a modification of the nutrient medium described by Cowperthwaite in 1951. Carbon dioxide, lactic acid, succinic acid and ethyl alcohol were produced by the organisms during anaerobic conditions. Hexokinase, enolase, alcohol dehydrogenase and glucoses-phosphate dehydrogenase were demonstrated in ho-mogenates of the flagellates. Aldolase, phosphohexokinase and lactic acid dehydrogenase could not be demonstrated.

Notes: Application of fragmentation and thin-sectioning techniques to Tetrakymena pyriformis, Colpidium compiles and Glaucoma chattoni has permitted an analysis of the ultra-structure of their silverline and fibrillar systems. The classical silverline system consists of a mosaic of flat, membrane-bound blisters whose rims represent the sites of selective silver deposition. Cilia and protrichocysts emerge between adjacent blisters. I The pellicle consists of the membranes outlining the blisters, overlain by a continuous outer membrane that covers the whole cell and cilia. Fibrillar structures, which are not argentophilic, include: (1) tapering, striated kinetodesmal fibers arising singly from the kinetosomes, passing to the right and anteriad, and overlapping to form a loose bundle accompanying each kinety; (2) a longitudinal fibril band immediately beneath the pellicle at the right of each kinety, consisting of overlapping individual fibrils; (3) a transverse band of fibrils arising at the left side of each kinetosome and passing to the left under the pellicle; and (4) a set of postciliary fibrils arising at the right posterior edge of each kinetosome and passing posteriad under the pellicle. The fibrils of sets (2), (3), and (4) all are about 20 Mμ in diameter and appear tubular in cross-section; they are very unlike the heavier, solid kinetodesmal fibers. None of the fibril sets directly interconnect, although transverse and postciliary fibrils end in the vicinity of the longitudinal fibril band.

Notes: The structure of a cilium in Nyctotherus ovalis is that usually found: two single central filaments surrounded peripherally by nine double filaments; the whole is encased in a ciliary membrane continuous with the pellicle. The two central filaments end in a single enlarged bulb just above a septum, located at about the level of the pellicle, whereas the nine double filaments extend inward to form the cylindrical basal body, which is open at its inner end. Inside the basal body are granules àrranged in rows parallel to its sides. These granules may have significance in the origin of new basal bodies as well as in the outgrowth of new cilia. The latter may have been observed in a few instances. Parallel to the pellicle are two series of fibrils, one median and one inner, connecting adjacent basal bodies. Fibrils extend from the inner end of each basal body, these converge and extend deep into the ectoplasm, often becoming lost in a pattern of equilateral triangles, arranged to form hexagons. These features are clearly seen in the peristomial membranelles, where the basal bodies of the four rows of cilia are close together, separated from adjacent membranelles by a protoplasmic shelf and supported by a mass of fibrillar material comprising the peristomial ectoplasmic band. This broad band extends to the inner end of the peristome whence it returns along the opposite wall as a narrow mass of fibrillar ectoplasm without basal bodies. Peripherally the fibrils are condensed into fan-like bundles; internally they often form a network of equilateral triangles arranged to form hexagons, with corpuscles at the intersections. Trichite-like structures are also found in the peristomial groove and tube; these are connected to both the basal bodies and the fibrillar network.The functions, origin and development of this complex infraciliature during fission constitute one of the yet unsolved morphological problems in such complex ciliates.

Notes: SYNOPSIS. Thymidylate synthetase (E.C.2.1.1.45) has been demonstrated in unsporulated oocysts of Eimeria tenella. The properties of this enzyme have also been investigated in Tetrahymena pyriformis, as a protozoan model, and 7-day-old chick embryo, as a host model. The enzymes from E. tenella and chick embryo were inhibited by all concentrations of MnCl2 and MgCl2 tested. Tetrahymena pyriformis thymidylate synthetase was stimulated by low concentrations of both these cations but was inhibited by high concentrations. Subsequent data refer to chick embryo, E. tenella and T. pyriformis respectively: the apparent Km was 5.89 μM, 5.94 μM, and 0.53 M for the substrate dUMP: and 5.13 μM, 1.10 μM and 4.65 μM, respectively for the cofactor N5N10-methylenetetrahydrofolate. The pH optimum for the enzyme from both chick embryo and T. pyriformis was 8.0, with Tris-HCl buffer; activity of E. tenella thymidylate synthetase was still increasing at pH 8.2. The E. tenella enzyme was found to have a molecular weight of 4.6–4.9 × 105 daltons. The effects of nucleotides, inhibitors, and the omission of assay components on each enzyme are presented. Thymidylate synthetase from E. tenella is not greatly different from that of chick embryo, but does not resemble the enzyme from T. pyriformis. A case for using thymidylate synthetase as a chemotherapeutic target in the treatment of Eimeria infections remains. Indeed Eimeria may be considered as a model for infections caused by other protozoan parasites, such as Toxoplasma and Plasmodium, provided that suitable inhibitors can be found that are not toxic to the host.

Notes: SYNOPSIS. A protocol based on density differences between starved and fed cells and employing density gradient centrifugation has been devised to facilitate the isolation of auxotrophic mutants of cell lines derived from Tetrahymena thermophila strain B1868. First, a mass phenotype screening procedure was established whereby true auxotrophic mutants and slow-growing wild-type cells such as strain C* could readily be distinguished. Second, simulation experiments were performed in which wild-type cells starved first in non-nutritive buffer, then suspended in a defined medium lacking a single essential amino acid became significantly denser than the same cells when starved, then suspended in a complete defined medium. Finally, using the same protocol, a reconstruction experiment was carried out which resulted in effective separation of wild-type cells from cells of a tyrosine auxotroph. The overall procedure resulted in a 9-fold increase in the relative frequency of auxotrophic cells, while the density gradient centrifugation alone provided a 400-fold enrichment.

Notes: SYNOPSIS. Infectivity of Plasmodium gallinaceum (Brumpt) sporozoites isolated from midguts and salivary glands of experimentally infected Aedes fluviatilis (Lutz) was studied. The 2 populations were compared at 7, 8, and 9 days postisolation from mosquitoes, which were maintained at 27 C ± 1C and ∼75% relative humidity. Infectivity of the parasites was evaluated by the length of the prepatent period of the infection in 2-week-old chicks inoculated intramuscularly. Infection was caused by 7-day-old sporozoites from salivary glands, but not from midguts. Older sporozoites induced infection in all the inoculated chicks. The results suggested a somewhat higher infectivity of the 8- and 9-day salivary-gland parasites than of the oocyst sporozoites. However, unlike sporozoites from mammalian malaria, oocyst sporozoites from avian malaria were highly infective at this age.

Notes: SYNOPSIS. Sorogena stoianovitchae Bradbury & Olive, an epiphytic ciliate found in various parts of the world, has a trophic stage that feeds on members of the ciliate genus Colpoda. When grown in the presence of the food ciliate, it multiplies rapidly. When the cells become abundant they aggregate at the water surface on inserted plant fragments or floating pollen grains, the sides of culture dishes, or on floating films such as those deposited by bacteria or pollen grains. an aggregate mounds up and becomes ensheathed above the water level, after which the mass of cells called a sorogen rises aerially at the apex of a stalk deposited at its base. the tapering, noncellular stalk consists of a conspicuously furrowed sheath that encloses a mucilaginous matrix. At completion of stalk development the cells of the sorogen become encysted. the sorocysts are commonly discharged by fracturing of the drying sorus. Alternating light and dark conditions are required for sorocarp development.

Notes: SYNOPSIS. the antigenic types in populations of metacyclic trypanosomes of Trypanosoma brucei isolated from Glossina morsitans head-salivary gland trypanosome cultures and bloodstream forms in the early parasitemias produced from whole culture supernatant fluids containing metacyclic forms, were analyzed by the indirect fluorescent antibody test using clone-specific antisera. Metacyclic trypanosomes in cultures initiated with cloned bloodstream forms were heterogeneous with respect to their variable antigenic type (VAT). Trypanosomes comprising early parasitemias in immunosuppressed mice infected with metacyclics produced in cultures also had a range of VATs. Three of the VATs detected in the early parasitemias in mice have also been identified by other investigators in tsetse fly-transmitted populations of the same stock.

Notes: SYNOPSIS. A simple method is described for plating and cloning ciliates and other protozoa, based on a principle differing from that traditionally used for plating and cloning bacteria and other microorganisms. This procedure, referred to as the silicone-oil-plating-procedure (SOPP), involves vortexing small volumes of culture medium containing protozoa with larger volumes of a non-toxic silicone oil and plating the resulting unstable emulsion in small plastic petri plates. Discrete microdroplets of culture medium form containing protozoa entrapped and immobilized between the hydrophobic surfaces of the plastic petri dish and the oil. Protozoa, isolated by this method grow, divide, and multiply to form clones. the procedure may be used for plating and cloning protozoa in bacterized and axenic culture. Variations of the basic method may be applied to isolating protozoa from the wild, washing protozoa to remove microorganisms, screening for potential mutants, and for replica plating.

Notes: SYNOPSIS. Cyclic nucleotide phosphodiesterase [EC 3.1.4.17] was examined in Tetrahymena pyriformis strain NT-1. Enzymic activity was associated with the soluble and the particulate fractions, whereas most of the cyclic GMP phosphodiesterase activity was localized in the soluble fraction: the activities were optimal at pH 8.0–9.0. Although very low activities were detected in the absence of divalent cations, they were significantly increased by the addition of either Mg2+ or Mn2-. A kinetic analysis of the properties of the enzymes yielded 2 apparent KIII values ranging in concentration from 0.5 to 50 μM and from 0.1 to 62 μ M for cyclic AMP and GMP. respectively. A Ca2+-dependent activating factor for cyclic nucleotide phosphodiesterase was extracted from Tetrahymena cells, but this factor did not stimulate guanylate cyclase [EC 4.6.1.2] activity in this organism. On the other hand, Tetrahymena also contained a protein activator which stimulated guanylate cyclase in the presence of Ca2+, although this activator did not stimulate the phosphodiesterase. the results suggested that Tetrahymena might contain 2 types of Ca2+-dependent activators, one specific for phosphodiesterase and the other for guanylate cyclase.

Notes: SYNOPSIS. the cell size of Didinium nasutum was found to be dependent on the size of the Paramecium species available as prey. Didinium feeding on P. tetraurelia averaged 5.6 × 105μm3. the cell volume of Didinium increased with increasing prey size for the 5 prey species tested, to 9.1 × 105μm3 for Didinium feeding on P. caudatum. Didinium nearing a cell division ranged in size from 8.6 × 105μm3 on P. tetraurelia to 12.9 × 105μm3 on P. caudatum. the range in cell volume is such that Didinium feeding on P. caudatum are larger than the size at which Didinium divide when feeding on P. tetraurelia. This morphologic plasticity in cell volume allows Didinium to exploit a wide size range of Paramecium species as prey. It is proposed that the size of a Didinium may have profound effects on its ability to encounter and capture prey of different sizes.

Notes: RESUME. Chacun des 45–80 organelles adoraux de Bursaria truncatella O. F. Müller est constitué de 3 rangées de cinétosomes et l'aire buccale droite est couverte de nombreuses doubles rangées de cinétosomes. La stomatogenèse débute par la désorganisation et la résorption des organelles buccaux postérieurs. Puis, il y a désorganisation des rangées parorales de cinétosomes et multiplication des cinétosomes sur l'aire orale droite, en měme temps que sont rompues, selon une ligne oblique, un certain nombre de cinéties somatiques. La prolifération des cinétosomes aux extrémités des cinéties. de part et d'autre de la ligne de rupture, aboutit, d'une part, à la formation d'un champ anarchique qui est le primordium oral droit de l'opisthe, d'autre part, à la formation de nombreux doublets qui constituent chacun le primordium de chaque organelle adoral. Après la séparation des tomites, les cinétosomes de l'aire droite s'ordonnent en doubles rangées et les organelles adoraux se complètent par addition d'une 3ème rangée de cinétosomes. Les cinétosomes somatiques sont jumelés, reliés par 2 desmoses. Les fibres transverses postérieures et les fibres postciliaires forment de longs rubans de microtubules dirigés vers l'arrière et juxtaposés dans les crětes intercinétiennes. Les doubles rangées droites de cinétosomes buccaux sont assimilables à des stichodyades. Les organelles des cinétosomes adoraux portent des rideaux de fibres postciliaires convergents ou divergents. La rangée postérieure de chaque organelle est non ciliée. Par son type de stomatogenèse, par sa structure corticale, par l'ultrastructure des organelles adoraux, Bursaria appartient aux Colpodidea, ce qui suggère des remarques de plusieurs types.SYNOPSIS. In Bursaria truncatella O. F. Müller, each of the 45–80 adoral organelles is composed of 3 rows of kinetosomes, and the right buccal area is covered by many double rows of kinetosomes. Stomatogenesis begins by disorganization and disappearance of the posterior buccal organelles. Next, there is disorganization of the paroral rows of kinetosomes and multiplication of kinetosomes in the right oral area; at the same time, some somatic kineties are disrupted along an oblique line. Multiplication of kinetosomes at the extremities of the kineties, on both sides of the disruption, leads to the formation of an anarchic field which is the right oral primordium of the opisthe and the formation of doublets each of which constitutes an adoral organelle. After the separation of the tomites. the kinetosomes in the right buccal area position themselves, and the adoral organelles are completed by the addition of a 3rd row of kinetosomes. Somatic kineties are formed by successive pairs of ciliated kinetosomes united by 2 desmoses. the long posterior transverse ribbons and the postciliary ribbons extend posteriad, overlapping in the pellicular ridges. Oral rows of kinetosomes on the right can be compared with stichodyads. the adoral kinetosomes have convergent or divergent postciliary ribbons. the posterior row of kinetosomes in each organelle is not ciliated. By the type of stomatogenesis, the cortical ultrastructure, the ultrastructure adoral of its organelles, Bursaria belongs to the Colpodidea.

Notes: SYNOPSIS Free-living marine ciliates occur in the interstitial spaces of a wide vareity of filamentous and particulate substrata, on the surfaces of planar substrata, and in the plankton. In addition, they are found in association with a wide variety of plant and animal hosts. In this paper I review the progress during the past decade in understanding the distribution of marine ciliates, with particular emphasis on the relationship between ciliate biogeography and the species problem. It is concluded that as a general rule among marine ciliates, genera and species complexes are cosmopolitan. Specific locales may support a confusing array of sibling species or subspecific morphologic variants. Because the distributional processes and breeding biology of marine ciliates are only beginning to be understood, conventional ideas that marine ciliate species are cosmopolitan may require modification.

Notes: SYNOPSIS The subkingdom Protozoa now includes over 65,000 named species, of which over half are fossil and ∼ 10,000 are parasitic. Among living species, this includes ∼ 250 parasitic and 11,300 free-living sarcodines (of which ∼ 4,600 are foraminiferids); 1.800 parasitic and 5,100 free-living flagellates: ∼ 5,600 parasitic “Sporozoa” (including Apicomplexa, Microspora, Myxospora, and Aseetospora); and ∼ 2,500 parasitic and 4,700 free-living ciliates. There are undoubtedly thousands more still unmamed. Seven phyla of PROTOZOA are accepted in this classification—SARCOMASTIGOPHORA. LABYRINTHOMORPHA, APICOMPLEXA, MICROSPORA, ASCETOSPORA, MYXOSPORA, and CILIOPHORA. Diagnoses are given for these and for all higher taxa through suborders, and representative genera of each are named. the present scheme is a considerable revision of the Society's 1964 classification, which was prepared at a time when perhaps 48,000 species had been named. It has been necessitated by the acquisition of a great deal of new taxonomic information, much of it through electron microscopy. It is hoped that the present classification incorporates most of the major changes that will be made for some time. and that it will be used for many years by both protozoologists and non-protozoologists.

Notes: SYNOPSIS Leishmania donovani amastigote-to-promastigote transformation is inhibited by homogenates of infected hamster liver and spleen. This inhibitory activity is localized in the 100,000 g pellet fraction. Tests with lysates of adherent (macrophyages) and nonadherent (lymphocytes) spleen cells indicated that the inhibitory activity resided in the lymphocytes, specifically in the 100,000 g pellet fraction.

Notes: SYNOPSIS Antibodies induced in rabbits against Paramecium multimicronucleatum syngen 2 prevent sexually reactive cells from clumping, pairing, and forming cytoplasmic fusions. A biologic assay for the detection of these antibodies (designated blocking antibodies) is described. the blocking antibodies, unlike the immobilization antibodies, are produced against breis of sexually reactive cells and nonreactive cells of 2 types, nonstarved and immature. Isolated cilia from reactive cells of either mating type are weak immunogens for blocking antibodies. No correlation between the mating type specificity (III or IV) and these antibodies has been detected. Blocking antibodies can be absorbed with living cells, of which sexually reactive ones are the most effective absorbers, while immature ones are the least effective.

Notes: SYNOPSIS A method is described for the axenic mass cultivation of Paramecium tetraurelia strains 51s and 299s. the ciliate is grown in an enriched axenic medium developed by Soldo, Godoy & van Wagtendonk. Under continuous shaking on a rotary shaker, cultures were grown in one-liter Erlenmeyer flasks with 330 ml medium yield cell densities of 32,000 cell/ml and 20,000 cells/ml for strains 299s and 51s respectively. Doubling time is considerably shorter under these conditions than in the conventional static cultures. A 20-liter airlift bioreactor is described in detail which can be used successfully to otain up to 100 g wet weight of Paramecium in a single run; in this reactor the cell density reaches 38,000 cells/ml for strain 299s. and 23,000 cells/ml for 51s. This technic should facilitate the study of minor protein components of the ciliate.

Notes: SYNOPSIS The cadmium ion (Cd2+) was accumulated by Amoeba proteus in all cellular fractions, the highest level being associated with the cytosol fraction. On gel separation of the cytosol fraction, Cd-binding protein appeared in 2 peaks: one 〉45,000 MW (peak I) and the other 12,000 MW (peak II). Added cysteine increased the total Cd2+ taken up by the cells and resulted in disproportionate increase of Cd incorporated into the Cd-binding protein of peak II. the Cd-binding protein of peak II is analogous to the low-MW, Cdbinding proteins in Anacystis nidulans, Mytilus edulis, and to the metalloprotein of some vertebrates.

Notes: The foed vacuoles of Paramecium aurelia, when examined in the electron microscope, are seen to be surrounded by small secondary vacuoles 0.05 - 0.2 μ. in diameter. Similar small vacuoles also surround the deepest part of the buccal cavity. Young focd vacuoles, i.e. those containing well preserved bacteria, are encircled by a smooth. vacuolar membrane. In older food vacuoles the vacuolar membrane in a transverse section often appears more wavy with small gulfs and protuberances. It is suggested that the small surrounding vacuoles are formed by the vacuolar membrane of older vacuoles by means of a process similar to pinocytosis. There is no evidence, however, that formation of small surrounding vacuoles takes place by pinocytosis in young food vacuoles. Examination of the cytoplasmic membrane of the deepest parts of the buccal cavity shows a similar prccess of vacuole formation by pinocytosis.

Notes: Tritrichomonas foetus, Pentatrichomonas gallinarum, and nasal and fecal forms of Trichomonas suis grew well in NIH Thioglycollate Broth with 1% beef serum, and produced acid end-products. Succinic acid was the major acid produced by T. foetus P. gallinarum, and the nasal T. suis, accounting for over 50% of the total acid for each. The fecal T. suis produced more lactic than succinic acid; about 45% of the total acid was not accounted for. Pyruvic acid was found in small amounts in all cultures. The lactic/pyruvic ratio was about 2.5 for the two swine forms, and about 1.0 for the other two. The nasal form of T. suis produced much more total acid than the others.O2 uptake, CO2 production, H2 evolution, and anaerobic acid formation varied with age of organism. Respiratory activity was highest at 12 hours but varied considerably thereafter. The nature of the buffer used in manometric experiments also affected the results.Glucose, mannose, fructose and galactose most stimulated respiration. Disaccharides were slowly utilized (lactose and sucrose were not used by P. gallinarum). In a few cases lactate, pyruvate, formate, and malate stimulated O2 uptake.Evidence was obtained for hexokinase, phosphohexoisomer-ase, phosphofructokinase, aldolase, and glucose-6-phcsphate dehydrogenase in all 4 organisms. Phosphoglucomutase was demonstrated in T. foetus and the fecal T. suis. T. foetus and P. gallinarum showed evidence of phosphoglyceromutase and enolase. T. suis (fecal) and P. gallinarum had malic dehydrogenase, and P. gallinarum gave evidence of “malic enzyme” activity. Formic dehydrogenase activity was marked in all and presumptive evidence for a formic hydrogenlyase system was obtained for T. foetus and P. gallinarum.Study of reactions involving pyruvate and malate (with a possible linkage to a hexose monophosphate shunt) might perhaps provide a key to a better understanding of trichmonad metabolism.

Notes: Glaucoma chaitoni. A has been grown in a medium free from protein. Twelve amino acids, seven B-vita-mins, a purine and pyrimidine were essential. Long-chain unsaturated fatty acids and their triglycerides, synthetic phosphatides, and carbohydrates were stimulatory. Oleic acid- containing lipids were best. The significance of the phosphatide activity and the applicability of the results of this work to problems in tissue cell and bacterial cultivation are discussed.

Notes: Some conditions for optimum accumulation of vitamin B12 by resting Euglena gracilis cells were studied. Accumulation involves intracellular binding, as confirmed by disruption of the cells and differential centrifugation. At least 70% of the intracellular B12 was attached to sedimentable particles, apparently to the mitochondrial and cell wall-membrane fractions. The latter contains a heat-labile substance which rapidly binds B12.

Notes: Tritrichomonas foetus survives when frozen in the presence of 1 M glycerol after growth in cysteine-peptone-liver-maltose (CPLM) medium. In the present study, survival upon storage was better in a chest-type freezer at a constant −21°C than in an upright freezer from which were recorded cyclic temperature fluctuations between −23 and −25° or in a dry-ice chest with a nominal temperature of −72°. By the use of special thermocouples inside the freezing tubes, it was found that the temperature fluctuated between −22 and −24° in the chest-type freezer, between −19 and −30° in the upright freezer, but rising as high as -2° when the door was opened and samples were removed, and markedly in the dry-ice chest as the dry ice melted and was replaced, sometimes rising to as high as −27°. The poorer survival in the latter 2 freezers was considered due to temperature fluctuation.When equilibration with glycerol was carried out at room temperature, survival upon subsequent freezing was better following rapid equilibration (glycerol added all at once; equilibration time, 1 hour) than following slow equilibration (1/6 of the final amount of glycerol added each hour for 6 hr.; equilibration time, 7 hr.).Survival was extremely poor following either rapid or slow equilibration in the refrigerator (4°). Since T. foetus can grow indefinitely at 37° in the presence of 10% glycerol and since it is protected by glycerol when frozen, there is a critical zone near 4° in which glycerol appears to be toxic.Buffering the storage medium to pH's 6.3 to 7.1 with glycyl-glycine increased survival upon freezing, but buffering to the same pH's with triethanolamine had no significant effect upon survival, and buffering to pH's 7.1 to 7.5 with phosphates decreased survival upon freezing.

Notes: In three Patagonian cavies (Dolichotis Patagonia) which died in Dutch zoological gardens, coccidia were found. They were determined as Eimeria dolichotis (Morini Boero & Rodriguez, 1955). Cross-infection experiments with guinea-pigs exclude the identity with Eimenc cmvimt.

Notes: The effect of a series of phenylalanine- or tyro-sine-containing peptides and derivatives on the oxygen consumption of washed Tetrahymena performers W cells was determined. Peptides gave greater stimulation of oxygen uptake than phenylalanine or tyrosine alone. Intermediary reaction products of phenylalanine metabolism were not oxidized, nor were derivatives of phenylalanine in which the amino group was blocked. The action of several tyrosine or phenylalanine ant metabolites was determined. It was demonstrated that extra-cellular hydrolysis of glycyl-L-phenylalanine and alanyl-L-phenylalanine took place when these peptides were incubated with washed protozoa.

Notes: SVXOPSIS. Parasites belonging to the genus Cytamoeba have been found in amphibians from central and northern California. The infected animals and their numbers were (URODELA) Aneides flavipunctatus (2), A. lugubris (29), Batrachoseps a. atttnuatus (81). Dicamptodon ensatus (2), and (SALIENTIA) Rana b. boyli (1). The rates of infection varied between 0.6% and 29.3%, and the number of parasites per infected cell ranged from one to seven.Preparations stained with haematoxylin and Romanowsky dyes indicated several types of parasite: some were homogeneous, others possessed several dark staining granules and some possessed large, dark staining central bodies or peripheral dark staining rims. Parasites were seen in the erythrocytes, the plasma and, occasionally, in endothelial cells and monocytes. They were found in the peripheral and heart blood and in the blood of the liver, spleen, kidneys and lungs. Cell division was common in erythrocytes, and yielded daughter cells of identical size. In some cases, chains of 3 to 5 individuals were seen and, rarely, three bodies, in a cloverleaf configuration, were produced as the result of a single division. Following acid hydrolysis, methylene blue-stained parasites showed a peripheral ring of granules, and, in some, a few stained centrally located bodies.

Notes: The literature on the coccidia of the carnivorous mammals of the family Mustelidae has been reviewed. Three species of Isospora are described for the first time from the zoriile, Ictcnyx (Zorilla) capensis (Fam. Mustelidae). Two of these, I. hoogstraali sp. now, and 7. africana sp. nov are considered to be new species, while the third one, I. bigemina var. zorillae var. nov. is recognized as a new variety.

Notes: Electron micrographs of sections through the blepharoplast complex reveal it to be composed of four kineto-somes. In many of the sections the kinetosomes contain dense particles approximately 180-200 A in diameter. The costa is a striated fiber which extends posteriorly almost the entire length of the body. Its slender proximal portion appears to be attached to the base of the kinetosome of the recurrent flagellum. The parabolas fiber is similarly constructed, but is more slender than the costa. It is attached to the base of the kinetosome of an interiorly directed flagellum and subsequently proceeds posteriorly to the level of the nucleus. The costa and parabasal fiber probably serve as anchoring or supportive structures. The size of the costa may reflect its role as a supporting structure for the most highly differentiated locomotors organelle, the undulating membrane.

Notes: A survey of antigenic types, as revealed by immobilization reactions, among 78 strains of variety 1 of T. pyriformis grown in monoxenic cultures at 25°C discloses a minimum of six distinct classes. These are called the H serotypes, and are designated as types Ha, Hb, Hc, Hd, He and Hf. The terminal members of highly inbred series (Families A, A1, B, D, etc.) are of a single immunological class, but different inbred series show different serotypes. Early representatives of the inbred series show in contrast considerable serotypic variation. The distribution of serotypes is generally consistent with the genetic hypothesis developed in a parallel study, but new serotypes arise occasionally through some mechanism not yet adequately studied.

Notes: Two types of polymorphism, differing greatly in stability characteristics, have been recognized in Tetrahymena vorax strain V2. The basic life history involves three stages: a microstome, a macrostome, and a cyst. The appearance of each of these stages is dependent upon conditions of substrate availability, i.e., macrostomes persist in the presence of suitable ciliate prey, microstomes persist in the presence of bacteria or organic nutrient solutions, and cysts appear under conditions of starvation.Superimposed upon the basic life history is a second level of polymorphism: three markedly different types of sublines have been obtained from a single parental clone. No intermediate types have been observed. When grown under identical controlled conditions, the three types of sublines differ significantly in cell and nuclear size, meridian number, growth properties, competence to form cysts and macrostomes, and serotype. Each subline of a given type is subject to transformation into one or both of the other types. These transformations are usually spontaneous events with very low frequencies, although certain transformations may be induced. Once a transformation has occurred, the new phenotype is inherited by subsequent generations of cells for an indefinite period in a way which is independent of environmental influences. The available information suggests that the three types of sublines are not the result of gene mutations, but rather represent alternate epigenetic stable states of a single cellular system.

Notes: The flagellate Chlorogonium elongatum has been studied in the electron microscope by thin-sectioning techniques. The nucleus, limited by a porous membrane, contains a large nucleolus and some dense masses, probably of chromatin. When the medium is rich or the culture young, the chloroplast has few lamellae, and very few pyrenoids. Inversely, when the medium is poor or jthe culture old, the lamellae are abundant, appearing as piled discs or as a tortuous lamellar system. The pyrenoids are then numerous and are surrounded by starch grains. They are composed of an opaque, finely granular substance, and are never traversed by chloroplast lamellae. The stigma, within the chloroplast, is a circular or oval plate composed of a single tier of dense granulations. The cytoplasm contains mitochondria which are concentrated near the pellicle of the cell, an endoplasmic reticulum, an abundance of ribo-nucleoprotein particles or ribosomes, and a Golgi apparatus. These organelles resemble those observed in other protozoa. The two fiagella are encased in cylinders situated at the anterior end of the cell. At the base of the fiagella are the basal corpuscles or kinetosomes, which repose within a cupule. A dense granule which probably corresponds to the centrosome appears near this structure.

Notes: Colpoda cucullus forms two kinds of resting cysts: stable cysts which withstand freezing and need 24 hours for activation, and unstable cysts which do not survive freezing, but are activated within 3-4 hours. ImM 2,4-dinitrophenol has no effect on stable cysts, and increases the respiration rate of unstable cysts by 100%. 1 mM methylene blue increases oxygen consumption in both stable and unstable cysts, by 200% and 400% resp. The results suggest that the inhibition of metabolism is more complete in stable cysts. These differences are not correlated with nucleic acid level, as both kinds of cysts contain approximately equal amounts of RNA.

Notes: Total lipids of several protozoa were determined and found higher than in most other microorganisms. The lipid content in a phytoflagellate, Ochromonas malhamensis, could be increased by excess nicotinic acid or deficiency in nitrogen supply. Cell multiplication and lipid synthesis were unaffected by inhibitors of vitamin synthesis such as penicillamine, pan-toyltaurine, or pyridine-3-sulfonic acid, up to 100 mg%. The phytoflagellates, O. danica, O. malhamensis, Euglena gracilis, and the photosynthetic bacterium Chlorobium limkola contained large quantities of non-saponifiable lipids: ergesterol was identified as a major component of this lipid fraction. Sterols were not found in the bacteria, Streptococcus faecalis, Rhodopseudomonas palustris; the algae. Cyanidium calidarnm. Anacystis nidulans, and Porphyridium cruentum; and the protozoan Tetrahymena pyriformis.

Notes: Tetrahymena paravorax RP was cultured axenically in a medium of known chemical composition (within the limits of contemporary standards of chemical purity). In this medium, it required 12 amino acids, 6 B-complex vitamins, a purine, a pyrimidine, and inorganic salts. A sterol or sterol ester was necessary for optimal growth. Plant and animal 3 β-OH sterols with saturated and unsaturated ring systems, and with a variety of side chain structures, were active. Several methylated sterols suggested as intermediates in cholesterol synthesis were inhibitory.

Notes: Hexamastix dobelli n. sp. (Trichomonadidae) is described from the large intestine of the starred tortoise, Testu-do elegans Schoepff. This is the first species of Hexamastix to be reported from a chelonian. The organism is pyriform, oval, or round in shape. There are five anterior flagella, of which two are long and three short and a single recurrent flagellum, which equals the short anterior flagella in length. The axostyle is very slender and projects for some distance outside the body. The nucleus contains three to six granules and has no endosome. The pelta is crescent-shaped and the parabasal body is rod-like. Perinuclear granules are present in the anterior half of the body. The parasite is 6.0 to 16.5 μ long, 2.0 to 10.3 μ wide and the diameter of nucleus is 2.5 μ.

Notes: Seventy-nine adult birds in 8 species were examined at autopsy for the presence of Trypansoma avium. Films of thoracic blood were stained in Giemsa and later searched for trypanosomes. Marrow was removed from femora and humeri, mixed with Ringer's solution, and examined direct for living flagellates. Sixty-four birds (81%) showed positive marrows; 5 (6%) had positive bloods. In the 15 birds with negative marrows, only 2 had trypanosomes in the blood. These data emphasize the advantage of marrow over blood examination in determining the incidence of avian trypanosomiasis and point up the excellence of fresh marrow examination in such studies.

Notes: Eimeria leucopi n. sp. (Sporozoa) is described from oocysts in the feces of the deer mouse Peromyscus leu-copus (Rafinesque) taken in the vicinity of Durham, North Carolina. The oocysts are ellipsoidal, occasionally ovoid, and rarely round, 14-24 ± 14 - 21 μ, mean of 19.2 ± 16.8 μ. Length-width index 1.0 to 1.37, mean of 1.13. Micropyle absent. Oocyst wall composed of 2 layers. Clear residual bodies present. Sporocysts 11.5 - 14.0 ± 6.5 - 8.0 μ, mean 12 0 ± 6.8 μ Stieda body present. Minimum sporulation time about 74-hours, sporulation range about 54 hours. Prepatent period 5 or 6 days with a 6 day patent period. Although the intensity of infection was light in all naturally infected hosts, the incidence of infection ranged from 16.6 to 71.9%E. leucopi could not be transferred to the sympatric golden mouse P. nuttalli.

Notes: Five species of millipedes under investigation revealed the presence of six species of gregarines, five of which are new. A new method for the study of development of the gametocyst is described. A list of the millipedes and their gregarine parasites is given below:

Notes: Four species of Paramecium, P. calkinsi, P. mul-timicronucleatum, P. bursaria, and P. trichium, were treated in the following way. Counted numbers (100 or 200) were irradiated with X-rays in 2 ml air-tight Nylon syringes in steps of 50,000 r begining with this dosage and extending up to at least 450,000 r. For each experiment, the four different species were irradiated simultaneously each in one syringe. Survival and reproduction were then followed for at least 48 hours by expressing irradiated specimens from the syringes into spot plates. P. trichium was the most radiosensitive and recovery and reproduction occurred only after the lower dosages. P. calkinsi was the most radioresistant and showed relatively fast recovery and reproduction even after moderately high dosages. With certain high dosages, reproduction was blocked temporarily for 24-30 hours, after which there was not only recovery from irradiation but a gradually in creased reproductive rate. The greater the dosage, the slower the recovery to reproductive ability.

Notes: Thirty-five species of marine dinoflagellates are described and figured, including one new species, Gymnodinium chukwanii. These were collected by the author during the period February - March 1956. G. chukwanii has affinities to G. splendens and G. nelsoni and their group. The remainder of the paper is concerned with described species.

Notes: A brief summary of the literature exemplifying the indirect lines of evidence leading to the conclusion that -living ciliates conjugate in natural environments is followed by a description of the isolation of potential mates, conjugating pairs and recent exconjugants of Paramecium bur-saria from a pond in Westwood Village. Calif. The data suggest that natural populations of Paramecium pursaria pass through infrequent epidemics of conjugation.

Notes: Amicronucleate (strain W) and micronucleate (strain HAM 3) Tetrahymena pyriformis have been studied by light and electron microscopy. Numerous interphase and individually-sectioned organisms in division stages have been examined. In macronuclei of the amicronucleate organisms (strain W) the time of division is characterized by a rather marked chromatin condensation, by morphological changes in nucleoli, and by the presence of dense granules. In macro-nuclei of the micronucleus-possessing organisms (strain HAM 3) little alteration of the interphase morphology is observed at division. Mitochondrial changes and an increase in the amount and complexity of the endoplasmic reticulum are observed in division in the amicronucleate strain. These results show that macronuclear division is more complex than a simple “pinching-in-two” and that loss of the micronucleus may alter the mitotic events of the macronucleus.

Notes: Nitrogen in cell fractions of Paramecium aurelia varied according to the growth medium. Trichloroacetic acid-soluble fractions of cells were chromatographer. Adenine, adenosine, guanine, guanosine, hypoxanthine, aspartic acid, glutamic acid, histidine, lysine, proline, and phenylalanine were identified. Fyrimidines and xanthine, or their respective ribosides and ribotides, were not detected. Ammonia was released into the medium by both actively growing and “resting” cells. Culture fluids of “resting”cells also contained hypoxanthine and lesser amounts of adenine and guanine. Urea, uric acid, creatine, cretonne, and ailantoin were absent.Pyrimidine nitrogen seems excreted as dihydrouracil. The following enzymes were detected in homogenates and cell-free preparations: nucleotidases, nucleoside hydrolases, and cytidine deaminase. Urease, uricase, adenase, guanase, xanthine oxidase, adenosine deaminase, and 5′-adenylic acid deaminase were not present in this organism.Purine and pyrimidine incorporation into nucleic acids was investigated by the use of radioactive tracers. Guanosine gives rise to nucleic-acid guanine and adenine; adenosine was precursor to nucleic acid adenine only. Formate was incorporated into purines; glycine was not. P. aurelia can interconvert cytidine and uridine; both give rise to nucleic acid thymine. The methyl group of thymine may be derived from formate.

Notes: The slime mold Fuligo septica has been grown bacteria-free in a pure 1.5% agar and oats at a temperature of 25°C. The Plasmodium was also grown under water.

Notes: Books reviewed in this article:Larwood, G. & Rosen, B. R., eds. 1979. Biology and Systematics of Colonial Organisms.Hellebust, Johan A. & Craigie, J. S. eds. 1978. Handbook of Phycological Methods. Physiological and Biochemical Methods.

Notes: SYNOPSIS. Surface saccharides in 2 Trichomonas vaginalis strains, the moderately pathogenic, JH34A, and the mild, JH162A, were analyzed with the aid of plant lectins. Concanavalin A (Con A), wheat germ agglutinin (WGA), soybean agglutinin (SBA), castor bean agglutinin (CBA), and lectin from the garden pea (GPA) were employed in agglutination tests and in treatment of ultrathin sections for electron microscopy according to the horseradish peroxidase-3,3′-diaminobenzidine method. With Con A and WGA, small quantitative differences were noted between the 2 strains in the results of agglutination and in the reaction-product deposits observed by electron microscopy. Distribution of the binding sites for the 2 lectins was also somewhat different in the JH34A and JH162A trichomonads. In general, the reactions with the more pathogenic strain were slightly stronger. Although the reactions with SBA and CBA lectins were weaker than those with Con A or WGA, they provided the means for qualitative differentiation between the 2 trichomonad strains. SBA alone agglutinated the JH34A strain and formed demonstrable deposits on the cell surfaces. On the other hand, only CBA reacted with JH162A flagellates. The garden pea lectin failed to bind to the surface of either strain. On the basis of results obtained with the control preparations incubated in the presence of specific inhibitors, it was concluded that both strains had α-methyl-D-mannoside and/or α-methyl-D-mannoside-like as well as N-acetyl-D-glucosamine residues on their surfaces. In addition, JH34A strain had D-lactose-containing residues while JH162A trichomonads had residues with D-galactose. Neither strain appeared to possess residues containing N-acetyl-D-galactosamine.

Notes: SYNOPSIS. Centrifugation for 30–40 seconds at 8,000 g has been used to render monopodial specimens of the large free-living ameba. Chaos carolinensis. These monopodial amebae exhibit obvious torsional movements in the tail. In many cases the posterior ectoplasm assumes the form of a screw with helical ridges forming in place of the more common straight dorsal fins. This finding prompted a re-examination of normal polypodial C. carolinensis, and a majority of these were found also to exhibit torsional movement in the tail and in retracting pseudopodia. These movements suggest that the cytoskeleton of Chaos may have a helical component in its organization.

Notes: Books reviewed in this article:Levandowsky, M. & Hutner, S. H., eds. Biochemistry and Physiology of Protozoa.Raymont, John E. G. with J. D. Burton & K. R. Dyer. 1980. Plankton and Productivity in the Oceans. Vol. I. Phytoplankton.

Notes: Book reviewed in this article:Maramorosch, Karl & Hirumi, Hiroyuki, eds. 1979. Practical Tissue Culture Applications.

Notes: SYNOPSIS. Cysteine and ascorbic acid were previously shown to be required by Entamoeba histolytica trophozoites for attachment to glass, elongation, and ameboid movement as well as for short-term (12–24 h) survival in a balanced salt solution containing bovine serum albumin and a vitamin solution (Maintenance Medium 1). If the only function of cysteine and ascorbate was to decrease the redox potential, other reducing agents should be effective. However, the requirement for cysteine in the presence of ascorbic acid was highly specific. Equally effective were D- and L-cysteine; however, of many other compounds tested, only thioglycolic acid, ascorbic acid, or L-cystine (in decreasing order) were somewhat active. Under N2 atmosphere, cysteine and ascorbic acid were still required, although their concentrations could be halved. The ability to attach in the maintenance medium was irreversibly lost after only 5 min of cysteine-ascorbic acid deprivation; however, there was no decrease in viability when the amebae were transferred to growth medium within 30 min. Cysteine thiol groups in the medium were oxidized rapidly regardless of the concentration of ascorbic acid or the presence of amebae; however, ascorbic acid prolonged attachment of amebae.

Notes: SYNOPSIS. Low concentrations of chlorpromazine (∼0.01 mM) inhibit growth and nucleic acid synthesis in the ciliate Tetrahymena pyriformis. Brief exposure of the cells to, e.g. 0.018 mM chlorpromazine, had very little effect on 14CO2 production or on label incorporation into glycogen from [1-14C]glucetate, [6–14C]glucose, or [1-14C]leucine, but 17-h exposure of stationary phase cultures to this drug caused marked alterations in metabolism, including an almost complete loss of ability to decarboxylate L-[1-14C]leucine and L-[1-14C]tyrosine. It was shown that loss of ability to decarboxylate these amino acids results from loss of ability to transport them.