bluuebunny/crossref_metadata_2025 huggingface dataset:
A NEW CHLOROSARCINOPSIS FROM THE NEGEV DESERT
Authors: Friedmann I , Ocampo‐Paus Roseli
Published: April 2007

Chlorosarcinopsis negevensis n. sp. f. negevensis and Chi. negevensis f. ferruginea n. f. have been isolated in culture from a desert locality in the Negev. The organisms form regular 3‐dimensional cell packets. Pseudofilamentous groups or a gelatinous matrix are absent. Reserve material is an orange‐colored oil formed in quantities. In old cultures, palmelloid stages appear.

Reproduction is by zoospores, autospores, and isogametes. The sensitivity pattern of Chi. negevensis to inhibitory agents differs from that of the other species of the genus.
MATING TYPES OF CHLAMYDOMONAS FROM THE COLLECTION OF GILBERT M. SMITH
Authors: Hoshaw Robert W.
Published: April 2007

After the death of Dr. Gilbert M. Smith on July 11, 1959, the strains of Chlamydomonas maintained in his collection were sent to the Culture Collection of Algae at Indiana University. Axenic cultures of 29 strains were investigated to determine the nature of their sexual behavior. Mating types for 6 species (C. elliptica var. britannica, C. frankii, C. minutissima, C. moewusii f. microstigmata, C. reinhardtii, C. smithii) produced zygotes when agar cultures were harvested with sterile distilled water or low nitrogen medium and the complementary mating types for each species were mixed. Three species, C. moewusii f. microstigmata, C. reinhardtii, and C. smithii, produced sufficient zygotes to be of value in experimental work. C. smithii is an undescribed species interfertile with C. reinhardtii. The description of C. smithii will be published in a separate paper. Fourteen mating types of Chlamydomonas originally isolated and maintained by Smith are now maintained in the Culture Collection.
PHOTOINDUCTION AND PHOTOREVERSAL OF THE NOSTOCACEAN DEVELOPMENTAL CYCLE1
Authors: Lazaroff Norman
Published: April 2007

The developmental cycle of Nostoc muscorum, a nitrogen‐fixing blue‐green alga, is controlled by the spectral quality of illumination. Red light with peak activity at 650 mμ induces development of filaments from a nonfilamentous (aseriate) stage of the life cycle. Red‐light photoinduction is reversed by simultaneous or subsequent exposure to light from a broad band in the green region of the spectrum. Photo‐reversibility of the red‐light induction, by green light, decays very slowly, remaining at an appreciable level for over 24 hr after the primary stimulus.

Allophycocyanin is indicated to be the photoreceptor for red‐light induction. One or more phyco‐erythrins may operate as photoreceptors for reversal of induction.

The dosage response and wavelength dependence of developmental photocontrol in Nostoc muscorum A indicate that a nonphotosynthetic mechanism is involved in both developmental photoinduction and its photor ever sal.
HETEROTROPHY OF FOUR MARINE PHYTOPLANKTERS AT LOW SUBSTRATE CONCENTRATIONS1
Authors: Sloan P. R. , Strickland J. D. H.
Published: April 2007

Three pelagic marine phytoplankters, Coccolithus huxleyi, Skeletonema costatum, and Thalassiosira ro‐tula, and a facultative heterotroph, Cyclotella cryp‐tica, have been exposed to three organic substrates, viz, glucose, acetate, and glutamate, at low concentrations (organic carbon 0.25 mg/liter). Experiments were performed in the dark and light and the net assimilation of substrate was measured by using radiocarbon. The dark uptake of carbon dioxide was also determined, together with photosynthesis at near optimum light intensity. The expected heterotrophy was detected with Cyclotella cryptica. Thalassiosira rotula was found to assimilate glutamate at an appreciable rate. In all cases, however, the short‐term uptake of carbon dioxide in the dark was the greatest assimilation rate measured. Values are discussed in relation to their ecological significance and it is concluded that heterotrophic survival of these and probably most other algae in the open ocean xuould be impossible unless they were in contact with a high concentration of substrate in the form of particulate matter.
PARASITISM OF ASTERIONELLA FORMOSA HASS. BY A CHYTRID IN TWO LAKES OF THE RAWAH WILD AREA OF COLORADO1
Authors: Koob Derry D.
Published: April 2007

The populations of Asterionella formosa Hass. in two subalpine lakes in the Rawah Wild Area, Colorado, were composed of colonies of five distinct size classes based on frustule length. The spring bloom in these two lakes was dominated by cells of the Beta or Gamma population, whereas the fall pulse was dominated by cells of the Alpha and Beta, or Alpha populations. The Beta population was physiologically unique in that it was parasitized by the chytrid Rhizophidium planktonicum Canter. The development of the parasite population could not be correlated with the concentration or the growth phase of the host population. The occurrrence of parasitism did not noticeiceably affect the population growth patterns of the Asterionella populations.
A POPULATION OF STAURASTRUM FREEMANII FROM THE CENTRAL HIGHLANDS OF NEW GUINEA
Authors: Brook A. J. , Hine A. E.
Published: April 2007

An abundant gathering of the desmid Staurastrum freemanii has been collected from a pond located in the highlands of New Guinea. This material shows considerable polymorphism and contains a number of significant dichotypic forms. Examination of this material questions the validity of the varietal rank conferred by earlier investigators to many of the forms of this species. Consequently, a taxonomic revision of these varieties is proposed.
STUDIES ON THE BIOCHEMISTRY AND FINE STRUCTURE OF SILICA SHELL FORMATION IN DIATOMS. II. THE STRUCTURE OF THE CELL WALL OF NAVICULA PELLICULOSA (BRÉB.) HILSE
Authors: Reimann Bernhard E. F. , Leivin Joyce C. , Volcani Benjamin E.
Published: April 2007

The cell wall of the freshwater diatom Navicula pelliculosa (Bréb.) Hilse is composed of the silica shell and an organic skin which surrounds it. Isolated skins can be prepared by first removing the contents of the cell by mechanical shaking, followed by a posttreatment of these isolated cell walls with HF vapor to remove the silica shell. T h e skins can also be seen in sections, particularly well after the silica shell has been removed B y H. F; vapor.

The origin and morphological composition of the shin in N. pelliculosa are not yet completely ascertaincd. As parts of the cell wn11, both the silica shell and the skin are extracellularly located. The growth of the silica shell, however, occurs intracellularly inside a vesicle delimited by a triple‐layered membrane, the silicalemma. This membrane or secondary excreted organic material or both in various proportions may compose the skin.
ECOLOGY AND MORPHOLOGY OF TYDEMANIA EXPEDITIONS, A TROPICAL DEEP‐WATER SIPHONOUS GREEN ALGA1
Authors: Gilmartin Malvern
Published: April 2007

The morphological relationship between the glomeriferous and flabelloid aspects of Tydemania expeditionis, a rarely collected siphonous green algae, is presented and discussed in relation to the ecological niche it occupies and the phylogenic position of the genus within the Codiaceae. Using SCUBA techniques, the alga was observed and extensively collected at depths in the 40‐65‐m range. It is suggested that seasonal mean in situ light intensities exceeding 0.03 g cal/cm2/min inhibit the development of dense stands of the alga, and that Tydemania is a primitive member of the Codiaceae.
DEVELOPMENT OF THE SYMBIOSIS OF CONVOLUTA ROSCOFFENSIS GRAFF AND PLATYMONAS SP.1
Authors: Oschman James L.
Published: April 2007

The acoel flatworm Convoluta roscoffensis is infected by the alga Platymonas sp. The ova and young Convoluta do not contain algae, and each generation must be reinfected. The infecting algae undergo morphological alterations when within the worm. Flagella, theca, and eyespot are lost in that order. Flagellar basal bodies and striated rootlets remain. Loss of theca may be the result of a dissolution process, possibly the result of enzymes from the animal or from the algae. Upon loss of theca, the alga assumes an irregularly shaped form. Fingerlike processes of the algal cells penetrate between adjacent animal cells. This form is present in all but the earliest stages of infection, and may be a prerequisite for the establishment of a balanced photosynthetic mutualism.
CARBON DIOXIDE‐INDUCED DELAY OF CELLULAR DEVELOPMENT IN TWO CHLORELLA SPECIES1
Authors: Soeder Carl J. , Strotmann Heinrich , Galloxvay Raymond A.
Published: April 2007

Two species of Chlorella, C. fusca and C. vannielii, manifest delay in cell development in synchronous cultures when gassed with air enriched with 1.5% vol. C02 or higher. This effect is greater if the final developmental steps proceed in the light rather than in the dark. Despite this, as much as 5% vol. CO2 does not decrease the production of dry matter in continuous light. It is not unlikely that this action of CO2 is restricted to cases in which nitrate serves as the only N source.
SENSITIVITY OF MICROCYSTIS AERUGINOSA AND OTHER BLUE‐GREEN ALGAE AND ASSOCIATED BACTERIA TO SELECTED ANTIBIOTICS1
Authors: Vance B. Divain
Published: April 2007

Sensitivity of 5 blue‐green algae, especially Microcystis aeruginosa, and associated bacteria to 32 antibiotics was determined. A combination of neomycin and dihydrostrcptomycin was the most useful in inhibiting bacterial growth while allowing some algal growth. An axenic culture of M. aeruginosa maintainable for an extended time was not obtained. This and other studies indicate that a blue‐green chroococcalcan culture should not be reported to be bacteria‐free unless repeated rigorous tests for bacteria prove negative.
ANTIALGAL ACTIVITY OF SOME SIMPLE PHENOLS1
Authors: McLachlan J. , Craigie J. S.
Published: April 2007

The antialgal activity of a number of simple phenols was examined for their effect on the growth of 7 species of unicellular marine algae. The 3 knoiun algal phenols, 5‐bromo‐3,4‐dihydroxybenzaldehyde; 2,3‐dibromo‐4,5‐dihydroxybenzylalcohol, and 3,4‐dihy‐droxyphenylethylamine, were highly toxic as were other ortho dihydroxy compounds. Monohydroxy compounds were notably less toxic. Skeletonema costatum and Olisthodiscus sp. were the most sensitive organisms examined and Dunaliella tertiolecta was the most resistant. Possible ecological implications of these results are discussed.
LIGHT MICROSCOPE OBSERVATIONS ON CYTOLOGICAL MANIFESTATIONS OF NITRATE, PHOSPHATE, AND SILICATE DEFICIENCY IN FOUR MARINE CENTRIC DIATOMS
Authors: Holmes Robert W.
Published: April 2007

Cytological changes induced by nitrate or phosphate limitation were reproducible and readily visible by phase contrast microscopy in Coscinodiscus wailesii, Ditylum brightwellii, Rhizosolenia hebetata f. semi‐spina, Skeletonema costatum, and Stephanopyxis turris. These effects included changes in chromatophore number and shape, pyrenoid location, and mitochondrial abundance and appearance. In S. costatum, a diatom containing only 1 chromatophore, only nitrogen‐deficient cells could be recognized. Silicate deficiency prevented cell division almost entirely. When a few cells did divide in the presence of low silicate, abnormalities in valve structure occurred in some cells. Cytological differences with N and P deficiency may permit a rough assessment of the physiological condition of the same or similar species in natural diatom communities.
A CYTOCHEMICAL STUDY OF ACID PHOSPHATASE AND NUCLEASE ACTIVITY IN THE PLASTID OF CLOSTERIUM ACEROSUM1
Authors: Cook Philip W.
Published: April 2007

Acid phosphatase activity in Closterium acerosum has been studied using the Gomori and the azo dye procedures. A modification of the Gomori method was used for detecting the distribution of acid nucleases. The plastid is the major site of acid phosphatase activity luhich may be primarily within pyrenoids, between pyrenoids, or throughout the plastid. The Gomori procedure showed activity within the pyrenoids or in the central core of the plastid, whereas the azo dye method showed activity throughout with an occasional tendency to be localized near the ends. No other cytoplasmic activity was ob‐served but evidence for occasional activity in the nucleus is presented. Alkaline phosphatase could not be detected. Acid nuclease activity, which results in the degradation of DNA, RNA, and RNA‐Core, has been found in both the nucleus and the plastid. Plastid activity is heat labile, whereas nuclear activity is only slightly diminished after 5 min at 100 C. The results arc interpreted as indicating at least 2 acid phosphatases and 2 nucleases in C. acerosum. The findings are discussed with respect to the distribution of similar enzymes in other organisms.
NUTRITIONAL STUDIES OF THE EDIBLE SEAWEED PORPHYRA TENERA. II. NUTRITION OF CONCHOCELIS1
Authors: Iwasaki Hideo
Published: April 2007

The nutrition of the free‐living phase of Conchocelis of P. tenera was studied axenically. Conch‐ocelis preferred NO3, as nitrogen source. Urea and NH4 in low concentration, asparagine, and lysine were very good N sources. Several other amino acids were also utilized but growth was less abundant. Inorganic and organic phosphates were utilized; they were required at relatively low concentrations. Glycerophosphate gave excellent growth in a comparatively wide range of concentrations (0.1‐5 mg P %). The optimal Ca concentration was 10‐100 mg %. Needs for boron, manganese, zinc, strontium, rubidium, lithium, and iodine were demonstrated. The iodine effect was remarkable (peak growth with 1μg %); the effective concentration range was very narrow. Iron, cobalt, and bromine seemed to be adequately supplied as impurities of the macro‐nutrients. A modified artificial medium (ASP12I) for the Conchocelis phase is presented.
ULTRASTRUCTURAL STUDIES ON THE CYANELLES OF GLAUCOCYSTIS NOSTOCHINEARUM ITZIGSOHN1
Authors: Hall William T. , Claus George
Published: April 2007

Ultrastructural studies conducted on the intracellular symbiont of Glaucocystis nostochinearum Itz., a unicellular alga with a debated taxonomic position, have shown that the endosymbiont, although somewhat aberrant, is a blue‐green alga. Due possibly to its intracellular habitat, it lacks the characteristic cyanophycean double‐layered cell wall and the cells appear to be completely naked, bound only by a single plasma membrane. The protoplasm of the cell is differentiated into the lamellated chromatoplasm, which contains the photosynthetic pigments and polyphosphate granules, and a nonlamellar ccntroplasm, in which the nucleic material is dispersed. The usual cyanophycean organelles, as well as the different vacuoles and granules, with the exception of the formed bodies, are missing. Approximately 10% of the cells sliows a peculiar homogeneous area at one tip, the nature of which is unknown. Binary fission of the organism is mentioned. Since this cyanelle has not yet been classified, we name it Skujapelta nuda nov. gen., nov. sp.; and because of its structural peculiarities we find it necessary to create a new family for it, Skujapeltaceae in the order Chroococcales.
EFFECT OF LYSOZYME (MURAMIDASE) ON MARINE AND FRESHWATER BLUE‐GREEN ALGAE1
Authors: Fulco Lucia , Karfunkel P. , Aaronson S.
Published: April 2007

Marine blue‐green algae, Lyngbya Lagerheimii, Microcoleus chthonoplastes, Plectonema terebrans, Agmenellum quadruplicatum, and freshwater blue‐green algae, Anacystis nidulans, Anabaena variabilis, Nostoc muscorura, and Oscillatoria sp. treated with lysozyme (muramidase) formed spheroplasts but not protoplasts. The time needed for spheroplast induction varied with the species. Approximate internal osmotic pressures of the blue‐green algae were determined. Marine algae generally had a higher osmotic pressure than freshwater algae.
ON THE LIFE HISTORY OF MONOSTROMA FUSCUM (POSTELS ET RUPRECHT) WITTROCK1
Authors: Dube Maurice A.
Published: April 2007

Results of the study of Monostroma fuscum from Son Juan Island, Washington, fully support the separation of the species M. fuscum from Monostroma sensu Wittrock into a taxon including M. obscurum. It would appear from this and previous studies that the M. obscunim‐M. fuscum complex is clearly Ulvacean. The characteristics of the complex include (1) alternation of morphologically similar haploid and diploid generations; (2) production of biflagellate gametes and quadriflagellate zoospores; (3) a uniseriate form in early ontogeny; (4) thallus development progressing through a vesicular stage that, as a result of localized degenerative processes, opens at a size of less than I cm into a monostromatic blade; (5) cells elongated perpendicular to the plane of the thallus and with rotund‐truncate ends: (6) a single elongate plastid, thickened at the opposite poles of the cell and thinner in the equatorial region of the cell; (7) a thallus composed of cells with relatively inelastic walls; and (8) discrete discharge pores. The chromosome number of Monostroma fuscum is n =9. The first division of the zoosporangium nucleus is meiosis I.
POLYMORPHISM IN MASTOGLOIA1
Authors: Stoermer E. F.
Published: April 2007

Cells in a ‐wild population of a species belonging to the diatom germs Mastogloia may form frustules of 2 strikingly different morphologic types during their vegetative life cycle. Total conversion from coarsely structured morphologic form to a more finely structured form takes place during a single division; hence no inter gradations between the 2 forms are evident. Intact frustules with 1 valve of each type leave no reasonable doubt of the ability to make the change.
COMPARATIVE STUDIES ON ALDOLASE ACTIVITY IN MARINE PLANKTONIC ALGAE, AND THEIR EVOLUTIONARY SIGNIFICANCE1
Authors: Antia Naval J.
Published: April 2007

Fructose diphosphate aldolase activity was examined in acetone powders and cell‐free extracts of 15 photoautotrophically grown marine planktonic species belonging to 6 algal divisions as follows: Chlorophyta: Tetraselmis maculata, Dunaliella tertiolecta; Chrysophyta: Monochrysis lutheri, Isochrysis galbana, Prymnesium parvum, Coccolithus huxleyi; Bacillariophyta: Phaeodactylum tricornutum, Skeletonema costatum, Cyclotella nana; Cryptophyta: Cryptomonas sp., Rhodomonas lens, Hemiselmis virescens; Pyrrophyta: Amphidinium carteri; Cyanophyta: Anacystis marina, Agmenellum quadruplicatum. Indications of the types of aldolase (Rutter's classes) present in each alga were obtained from comparative studies of the effects of pH and of the following reagents on the activity: ethylenediamine tetraacetate, dithiothreitol, p‐chloromercuriphenyl sulfonate. Type I (higher plant‐animal type) aldolase only was indicated in the 2 chlorophytes, in I chrys‐ophyte (M. lutheri), and in 1 bacillariophyte (P. tricornutum), while the remaining algae appeared to contain either exclusively or principally Type II (bacterial‐fungal type) aldolase. The evolutionary implications of these findings are discussed.
TETRASPORA, CHLOROSACCUS, AND PHAEOSPHAERA, A UNIQUE EXAMPLE OF PARALLEL EVOLUTION IN THE ALGAE1
Authors: Rhodes Russell G. , Stofan Paul E.
Published: April 2007

The similarity among Tetraspora, Chlorosaccus, and Phaeosphaera, belonging to the Chlorophyceae, Xanlhophyceae, and, Chrysophyceae, adds to the concept of parallel evolution among algal classes. Not only are all 3 genera characterized by colonial organization, nonmotile vegetative cells embedded in a gelatinous matrix, but the genera are also found in the same habitat. Further, the characteristic pseudocilia of Tetraspora cells are also found in colonics of Phaeosphaera. Morphological features of pseudocilia of Tetraspora and the nature of papillae in Chlorosaccus are also presented.
PHYCOLOGY IN THE FIELD AND IN THE LABORATORY1
Authors: Pringsheim E. G.
Published: April 2007

Field and laboratory phycologists are still following different paths. This is regrettable because their labors supplement one another, and only by co‐operation can progress be achieved.
DISTRIBUTION OF TWO SPECIES OF LAMINARIA AS RELATED TO SOME ENVIRONMENTAL FACTORS1
Authors: Druehl Louis D.
Published: April 2007

The distributions of Laminaria saccharina and the long and short stipe forms of L. groenlandica about Vancouver Island were correlated with temperature, salinity, and water motion. The 2 forms of L. groenlandica were absent from areas of high temperature and low salinity. The long stipe form was restricted to areas of heavy surf and the short stipe form to areas of moderate surf. L. saccharina was absent from areas subjected to surf. These observations were subjected to laboratory and field tests involving gametophytes and sporophytes of both species. The distributions of the 2 forms of L. groenlandica can be explained on the basis of temperature and salinity distributions: both forms require low temperature and high salinity for survival. L. saccharina has a wide range of tolerance to temperature and salinity; surf appears to be the controlling agent.
SILICATE UPTAKE AND SILICA SHELL FORMATION BY SYNCHRONOUSLY DIVIDING CELLS OF THE DIATOM NAVICULA PELLICULOSA (BRÉB.) HILSE1,2,3
Authors: Busby William F. , Lewin Joyce
Published: April 2007

Cells of the freshwater diatom Navicula pelliculosa were induced to divide synchronously by the addition of excess silicate (20 mg Si/liter) to a culture which had been silicate‐starved for 14 hr. After a 3‐ to 4‐hr lag period, characterized by rapid silicate uptake (6.5 mg Si/liter/4 hr) and silica shell formation, the cell number then doubled in the succeeding 2‐3 hr.

This system promises to have significance in the study of silicon metabolism, transport phenomena, and silica deposition.
STUDIES IN SOME FOLIOSE RED ALGAE OF THE PACIFIC COAST. I. CRYPTONEMIACEXE1
Authors: Abbott Isabella A.
Published: April 2007

Pacific coast species of the red algae Halymenia and Cryptonemia are described Of the 8 previously reported species of Halymenia 3 (H. abyssicola Dawson, H. megaspore Dawson, H refugiensis Dawson) hive been placed in synonymy with other species. Halymenia hollenbergii from southern California is described as new; H cocinea is transferred from Schizymenia (and includes Aeodes gardneri Kylin) and H. templetonii is a transfer from Weeksia.

Five species of Cryptonemia are described; one of them, C. taylorii from the Revillagigedo Archipelago, as new. Wider distribution ranges are given for the remaining species, C. ovalifolia, C. obovata, C. bore alis and C. angustata. Keys to genera of the west coast Cryptonemiaceae and to the species of Halymenia and Crypronemia are provided.
FURTHER OBSERVATIONS ON GROWTH OF SINGLE CELLS OF COCCOID BLUE‐GREEN ALGAE
Authors: van Baalen Chase
Published: April 2007

Initiation of growth (lag) and subsequent growth to visible colonies was examined for single cells of several coccoid blue‐nreen algae under controlled incuba‐tion conditions. At 30 or 39 C, with tungsten or fluorescent illumination, organisms such as Agmenel‐lum quadruplicatum, strains PR‐6 and strain BG‐J, showed no evidence of lag associated with initiation of growth. The final colony count was within 20% of the expected number derived from cell counts and serial dilutions.

For Anacystis nidulnns, Tx 20, a new medium C, 10 with EDTA as chelator was developed. In this medium groiuth of single cells at 39 C was excellent with quantitative recovery and no evidence of lag. At 30 C, however, Tx 20 showed anomalous behavior, lag and nonquantitative cell recovery. This behavior at 30 C is not yet understood.
RHODOSORUS MARINUS GEITLER: A NEW ADDITION TO THE MARINE ALGAL FLORA OF THE WESTERN HEMISPHERE
Authors: Ott Franklyn D.
Published: April 2007

Rhodosorus marinus Geitler, previously known only from the Old World, is reported from material collected in the Florida Keys, thus taking its place with Chroothece richteriana Hansgirg in Wittrock and Nordstedt and Porphyridium cruentum (S. F. Gray) Nägeli as the third member of the Porphyridiales known for the marine algal flora of the Americas. Its apparent sensitivity to bright light, tolerance of high salinities, and possible confusion in identification, under certain conditions, with the red pigmented, coccoid, blue‐green algae, are noted.
FREEZE‐DRYING OF BLUE‐GREEN ALGAE FOR ELECTRON MICROSCOPE STUDIES1
Authors: Rogers Tom D. , Scholes Vernon E. , Schlichting Harold E.
Published: April 2007

Cultures of Anabaena cylindrica Lemm. and Eucapsis sp. were harvested, freeze‐dried, and prepared for electron microscope studies. A comparison of the freeze‐dried preparations was made with control specimens not freeze‐dried. Fixation and embedding were according to the Ryter and Kellenberger technique. The photosynthelic thylakoids of the freeze‐dried cells were more distinct and less distorted than those of the control cells. Freeze‐dried Eucapsis sp. cells exhibited a prominent mucous capsule, whereas in the nonfreeze‐dried, no such capsule could be discerned.
ARAGONITE IN HALIMED A AND TYDEMANIA (ORDER SIPHON ALES)12
Authors: McConnell Duncan , Colinvaux Llewellya Hillis
Published: April 2007

The mineral component of the marine green algal genus Halimeda is the orthorhombic calcium carbonate (aragonite); its presence appears to be a generic characteristic. Tydemania expeditionis also precipitates aragonite in contradistinction to species of the red alga Corallina wliich precipitate calcium carbonate of the hexagonal form (calcite). The analyses are based on x‐ray diffraction methods. Although other inorganic substances arc present, the amounts are minor and probably represent contaminants. Specimens that are to be studied for mineral components should not be stored in formalin.
OBSERVATIONS ON THE FINE STRUCTURE OF OEDOGONIUM. III. MICROTUBULAR ELEMENTS IN THE CHLOROPLASTS OF OE. CARDIACUM12
Authors: Hoffman Larry R.
Published: April 2007

The expansive, reticulate cliloroplasts of the filamentous green alga Oedogonium tardiacum were found to contain microtubular elements with an outside diameter of about 270 A. These microtubules have been examined in the chloroplast stroma of vegetative cells, zoospores, zoospore germlings, and eggs. They may occur singly or, more commonly, in groups or bundles of 2 to as many as 30. In longitudinal section these microtubules show a regular pattern of slightly oblique cross striations and the margins appear rough. They bear little structural resemblance to the more familiar and slightly smaller microtubules found in the cytoplasm external to the cliloroplasts. Their overall appearance suggests that each is constructed of 2 helically wound, ribbon‐like units that are approximately 155‐175 A broad and 45‐55 A thick. The 2 units of this proposed double helix appear to lie in juxtaposition at a pitch of 17‐27 deg. The dimensions of each unit, or helix, are such that it could conceivably be constructed of 3 filamentous subunits similar to those already described in the literature for other microtubular elements.
A NEW SPECIES OF NITELLA (CHARACEAE) BELONGING TO THE NITELLA FLEXILIS SPECIES GROUP IN NORTH AMERICA12
Authors: Tindall Donald R.
Published: April 2007

A new species of Nitella belonging to the N. flexilis species group is described. The neiu species shows definite relationships to N. flexilis, N. opaca, N. missouriensis, and N. mirabilis. Relationships of the new species to N. acuminata are also discussed.
THE OCCURRENCE AND SIGNIFICANCE OF ENDOSYMBIOTIC CHLOROPLASTS IN THE DIGESTIVE GLANDS OF HERBIVOROUS OPISTHOBRANCHS1
Authors: Taylor Dennis L.
Published: April 2007

Intact algal chloroplasts have been found in the digestive glands of 5 species of Opisthobranchia belonging to the order Saccoglossa. Preliminary studies on 3 of these confirm their endosymbiotic nature. It is suggested that the occurrence of these endosymbiotic organelles may be widespread among related species of Saccoglossa. Their independent functional existence supports the view that chloroplasts possess a system of nonchromosomal inheritance.
THE PIGMENTS OF THE ZOOXANTHELLAE SYMBIOTIC WITH THE INTERTIDALANEMONE, ANEMONIA SULCATA1
Authors: Taylor Dennis L.
Published: April 2007

The photo synthetic pigments of the zooxanthellae found in the endodermal tissues ofAnemonia sulcatahave been identified by column chromatography and spectrophotometry analysis. They appear to be identical with those found among free‐living species of Dinophyceae as well as the zooxanthellae of Pacific Madreporaria and Tridacnidae, and confirm the taxonomic relationship which tills symbiont has in common with these organisms.
SIMPLE CONDITIONS FOR GROWTH OF UNICELLULAR BLUE‐GREEN ALGAE ON PLATES1, 2
Authors: Allen Mary Mennes
Published: April 2007

The efficiencies of plating of 2 cultures of unicellular blue‐green algae, 1 coccoid and 1 rod‐shaped, were studied systematically. Reproducible colony growth and accurate viable counts are dependent on the use of a low agar concentration, and on the sterilization of the agar separately from the mineral components of the medium.
THE DEVELOPMENTAL MORPHOLOGY OF GONGROSIRA DEBARYANA1
Authors: Andrews Hollings T.
Published: April 2007

The development and asexual cycle of Gongrosira debaryana have been studied in unialgal culture. Zoospores may settle singly and develop a Pleurotham‐mon‐like thallus, or they may clump and so produce a thallus characteristic of Gongrosira. It is suggested that Borzi's Pleurothamnion papuasicum be considered a synonym of Gongrosira debaryana.
A UNIQUE COLONIAL MARINE CENTRIC DIATOM, COENOBIODISCUS MURIFORMIS GEN. ET SP. NOV.1
Authors: Loeblich Alfred R. , Wight William W. , Darley W. Marshall
Published: April 2007

A new colonial centric marine diatom, Coenobio‐discus muriformis gen. et sp. nov. (family Coscinodiscaceae) has been found in San Diego Bay, San Diego, California. The colony is composed of a single layer of 200‐530 cells linked girdle to girdle by a compartmentalized matrix. The colony has the shape of a slightly concavo‐convex disk approximately 400 μ. in diameter. Each cell is about 10 μ, in diameter and the valves have many structural features in common with those of Thalassiosira. The organic matrix contains 6‐11 partitions that radiate from each cell, forming a number of extracellular chambers. The organic matrix does not contain chitin or cellulose as a major constituent. Histochemical similarities are found with the capsular and tubular material of previously described diatoms. The colonies reproduce without passing through a unicellular vegetative stage.
THE LIFE HISTORY OF POLYSIPHONIA DENUDATA (DILLWYN) KÜTZING IN CULTURE1
Authors: Edwards Peter
Published: April 2007

The sequence of somatic phases in the life history of the red alga Polysiphonia denudata has been determined in unialgal culture, using supplemented seawater media. Tetraspores gave rise to sexual plants bearing either antheridia or carpogonia in 50 days. Fertilization occurred within 1 week and the fertilized carpogonium developed to produce the mature carposporophytic phase in approximately another week. Carpospores formed by the carposporophyte germinated to produce the tetrasporangium‐bearing phase, which released tetraspores in 44 days, thus completing the life history in 31/2% months. No deviations from this pattern have so far been observed.
THE EFFECT OF GROWTH ENVIRONMENT ON THE PHYSIOLOGY OF ALGAE: LIGHT INTENSITY12
Authors: Brown Thomas E. , Richardson Frances L.
Published: April 2007

Measurements were made of growth, pigmentation, photosynthesis, respiration, quinone Hill reaction, cell morphology, and structure as a function of growth light intensity for various algae. These processes showed varying degrees of dependency upon light intensity and are discussed with reference to algal classification. Eighteen algae, examples from 10 taxonomic divisions, were studied.
B12 SPECIFICITY OF MARINE CENTRIC DIATOMS1, 2
Authors: Guillard Robert R. L.
Published: April 2007

Twenty‐one species (23 isolates) of marine diatoms were examined for their capacity to utilize analogs of cyanocobalamin for growth at the ecologically significant concentration of 4 ng 1‐1. Yields due to the analogs were compared to those produced by B12. Responses of the various clones to the analogs were not all‐or‐none, but varied continuously; thus, assigning the clones to the conventional B12 specificity types is a convenient but arbitrary classification. The use of 10 and 1% levels of response is suggested for such classification.

At the 10% level of response, 11 clones had coliform, 4 lactobacillus, and 8 mammalian specificity patterns. At the 1% response level, 14 had coliform, 5 lactobacillus, and 4 mammalian specificities. All clones exceed the 10% response level on all benzimi‐dazole‐containine analogs tested. Few clones showed definite enough patterns of response to make them potentially useful for differential bioassay. The clones suggested are clone 675‐D (Bidclulphia sp.?), clone F;‐3 (Fragilaria sp.?), and the estuarine clone of Cyclotella nana (3H).
PHYSIOLOGICAL CHANGES OF SPONGIOCHLORIS TYPICA IN CULTURE12
Authors: McLean Robert J.
Published: April 2007

The physiological changes in the green alga Spongiochloris typica were followed in liquid and agar for 8 weeks. Agar cultures changed drastically in lipid content, pigment composition, and heat and desiccation resistance. Changes in liquid cultures were gradual and not as extreme as those of agar cultures. However, rate and extent of dry‐weight increments were similar in liquid and on agar. Liquid cultures are seemingly more stable in the physiological responses than are agar cultures where the environmental changes are conspicuous.
MORPHOLOGICAL VARIATION IN PTEROCLADIA PYRAMIDALE1
Authors: Stewart Joan G.
Published: April 2007

Seven Pacific species of Pterocladia and European collections of P. capillacea were examined. Ten morphological criteria were assessed in specimens of P. pyramiclale from 10 intertidal and subtidal populations in San Diego, California. The observations obtained from these populations were compared with descriptions and specimens of P. complanata from southern and Baja California; P. mexicana, P. robusta, P. okamurai, and P. okamurai f. densa from the Galapagos Islands and Baja California; and P. tenuis and P. densa from Japan. All these taxa were found conspecific with P. pyramidale. Pterocladia capillacea from Europe, using the same characters, was not distinct from the Pacific assemblage. These two taxa should be united under the name of Pterocladia capillacea (Gmelin) Bornet & Thuret (1876).

Pterocladia capillacea (= P. pyramidale) grows under varied conditions and exhibits various growth forms accordingly, in southern California. Variation between several forms seems related to the degree of exposure to light, temperature, and surf action; such forms are recognizable in herbarium collections from other parts of the world. Abundant fertile material occurs in southern California.
MORPHOLOGY AND REPRODUCTION OF THE RED ALGA ACROCHAETIUM PECTINATUM IN CULTURE12
Authors: West John A.
Published: April 2007

The life history of the marine red alga Acrochaetium pectinatum (Kylin) Hamel was studied in unialgal culture using supplemented natural seawater media. The tetrasporophytes are larger than the gametophytes, have a compact filamentous basal system, and produce monosporangia and tetrasporangia. Mono‐spores give rise to tetrasporophytes. Tetraspores develop into small gametophytes with unicellular bases. The gametophytes are heterothallic when small (usually less than 500 μ) but as some females become larger (2‐3 mm) they produce spermatangia as well as carpogonia. Gametophytes may bear mono‐sporangia in addition to carpogonia or spermatangia. These monospores give rise to gametophytes. Fertilization of the carpogonia has not been observed. The tetrasporophytes produce only monosporangia in day‐lengths of 12‐16 hr, but both tetrasporangia and monosporangia are formed in daylengths of 6–10 hr. Tetrasporangial production is reduced at 15 C compared with 10 C. Light intensity in the range of 5‐200 ft‐c (cool white fluorescent lighting) has no apparent influence on induction of tetrasporangia. Induction of tetrasporangia is not a photoperiodic response because their development is not inhibited by a brief light break in the middle of the dark period in short daylengths.

Plastid morphology, origin, and frequency of sporangia and vegetative branching are variable during the ontogeny, and consequently are somewhat unreliable as taxonomic criteria. Differences in basal systems between gametophytes and tetrasporophytes also indicate that this feature, which is used to distinguish major subgeneric groupings in Acrochaetium, may not be as useful as previously thought.
ELECTRON AND PHASE‐CONTRAST MICROSCOPY OF SEXUAL REPRODUCTION IN CHLAMYDOMONAS MOEWUSII1
Authors: Brown R. Malcolm , Johnson Sister Clement , Bold Harold C.
Published: April 2007

The sexual process of C. moewusii from gametic activation through germination of the zygote has been studied with phase‐contrast and electron microscopy. Long strands emerging from the gametic flagellar tips are the site of early flagellar attraction which is followed by union of compatible flagella within common flagellar sheaths. The gametic connecting strand is formed by coordinated elongation of the plasma papillae of a gametic pair and the penetration of the former through their wall papillae while the flagella are in intimate association. After the free‐swimming period, the gametic pairs aggregate in a second period of clumping. The connecting strand is abscised and extruded during plas‐mogamy as are the flagellar basal bodies. Evidence is presented which suggests union of the gametic plastids, and stages in karyogamy are illustrated. Formation of the wall layers, accumulation of starch and lipids, and changes in plastid organization in the maturing and germinating zygote are described as is the formation of the gonal walls.
DETECTION OF LIMITING OR SURPLUS NITROGEN IN ALGAE AND AQUATIC WEEDS1
Authors: Fitzgerald George P.
Published: April 2007

The rate of NH4+‐N absorption by algae and aquatic weeds in the dark has been shown to be 4‐5 times greater for plants which are N‐limited as compared to plants with sufficient available N. Eight species of green algae, 2 blue‐green algae, 2 diatoms, and 3 aquatic weeds were used to demonstrate the usefulness of the test in determining if available N was in surplus or limited supply in a particular environment. The test was shown not to differentiate between blue‐green algae capable of fixing N (4 species) from media with NO3‐N or without combined nitrogen. The factors influencing the results of NH4+‐N absorption tests have been investigated. In order to differentiate between plants with sufficient available N and those which are N limited, the rate of NH4+‐N absorption (0.1 mg N) over 1‐hr incubation in the dark by 10‐20 mg of algae or aquatic weed tissues is measured. The relatively simple analysis for NH4+‐N in the samples makes it very easy to follow the changing N nutrition of plants in cultures with a limited N supply or in the presence of possible N sources.
CULTURE AND HETEROTROPHY OF THE FRESHWATER DINOFLAGELLATE, PERIDINIUM CINCTUM FA. OVOPLANUM LINDEMAN1
Authors: Carefoot J. Russel
Published: April 2007

A defined minimal medium was developed for an axenic strain of Peridinium (Indiana Culture No. LB 1336). Thiamine, biotin, and vitamin B12 did not stimulate growth. Of 15 organic carbon sources tried in light, fructose, galactose, glucose, malate, malonate, and pyruvate enhanced growth but propionate retarded growth. In dark‐grown cultures only media with succinate permitted growth above the survival level. Stimulation of growth by organic carbon sources was markedly pH dependent.
THE BEHAVIOR OF OSCILLATORIA TEREBRIFORMIS IN HOT SPRINGS1
Authors: Castenholz Richard W.
Published: April 2007

Oscillatoria terebriformis, occurring from 54 to about 35 C in eastern Oregon hot springs, forms dense reddish‐brown surface mats which are held together by the interwoven nature of the trichomes and not by a gel‐like matrix, thus retaining the flexibility inherent in free trichome motility. The trichomes demonstrate gliding, flexional, and contractile movements. When the trichomes are interconnected, the mat contracts or retracts essentially as a unit in response to high light intensity (ca. 100 cm/hr) or supraoptimal temperature (ca. 2 cm/hr). Under lower light intensity and optimal temperature, the mat expands by the gliding movements of individual trichomes (1‐3 cm/hr). Probable positive and negative phototopotactic responses of trichomes to low and high light intensities, respectively, also influence the density of the surface mat. Thus, the population of Oscillatoria is able to adjust its position and density rapidly by migrations and contractions, remaining almost always within the full optimal temperature range and fairly well xuithin the optimal light conditions as well.
UPTAKE OF NITRATE AND NITRITE BY DITYLUM BRIGHTWELLII‐KINETICS AND MECHANISMS12
Authors: Eppley Richard W. , Coatsworth James L.
Published: April 2007

Ditylum brightwellii grown on NO2‐ as a nitrogen source took up and assimilated NO2‐ only in the light, apparently via a photosynthetic nitrite reductase. Assimilation was inhibited by dichlorophenyldimethylurea (DCMU), KCN, partially by 2,4 dinitrophenol, and by NO3‐. Kinetics of inhibition of NO2‐ assimilation by NO3‐ appeared to be “competitive.” D. brightwellii cells grown on NO2‐ took up NO3‐ in both light and dark and in both cases the uptake was inhibited by p‐chloromercuribenzoate, but not by DCMU, KCN, or by NO2‐. Most of the NO3‐ taken up in the dark was recovered unchanged from the cells. However only 40% of NO3‐ taken up in light was recovered from the cells and no NO2‐ was found. This suggests that a photosynthetic nitrate reduction mechanism was active in these cells. DCMU inhibited the light‐induced NO3‐ reduction. This mechanism of NO3‐ reduction is distinct from that involving NADH nitrate reductase in D. brightwellii since the concentration of the latter enzyme is very low in cells grown on NO2‐. Saturation kinetics were observed for NO2‐ and NO3‐ uptake. Half‐saturation concentrations (Ksvalues) were 4 and 2 μM, respectively. These values are compared with those obtained for NO2‐ and NO3‐ assimilation by other unicellular algae. The comparisons show lower Ksvalues in oceanic species compared with tide‐pool or freshwater algae and they support the idea that Ksvalues for NO3‐ assimilation may provide a key to understanding species succession when this is due to declining: nitrate concentrations in the sea.
SPORANGIA OF RALFSIA FUNGIFORMIS (GUNN.) SETCHELL ET GARDNER12
Authors: Edelstein T. , Chen L. , McLachlan J.
Published: April 2007

Unilocular and plurilocular sporangia of Ralfsia fungiformis are, for the first time, recorded for North America. The validity of certain types of structures, considered by some authors as plurilocular sporangia, is discussed.
SILICON METABOLISM IN DIATOMS. VI. SILICIC ACID UPTAKE BY A COLORLESS MARINE DIATOM, NITZSCHIA ALBA LEWIN AND LEWIN12
Authors: Lewin Joyce , Chen Ching‐hong
Published: April 2007

Cells of the colorless, heterotrophic diatom Nitzschia alba, after removal from the culture medium, were able to absorb silicic acid from a salt solution lacking carbon, nitrogen, and phosphorus. Silicic acid uptake continued for approximately 12 hr. At low cell densities (ca. 2.5×105 cells/ml), the cell number doubled under these conditions. At high cell densities (ca. 2 ×106 cells/ml) no cell division resulted.

When such cells were washed with a salt solution, their ability to absorb silicic acid was somewhat impaired. The degree of impairment became progressively more pronounced after subsequent washing treatments. A heat‐stable factor washed from the cells and present in the first “wash water” was able to restore completely the ability of washed cells to absorb silicic acid. The factor was not identified. Aspartic acid (5 ± 10‐4 M) or glutamine (5 ±10‐4 M) when added to the saline solution similarly promoted complete recovery. A t such concentrations, these substances had only a slight effect on unwashed cells. A solution of 5 ±10‐4 M Na glutamate (or aspartic acid plus glutamine) had an men more pronounced effect, and in addition promoted cell division or growth" of unwashed cells. Several other amino acids and other compounds tested were apparently without effect.
CULTURE STUDIES ON THE MARINE GREEN ALGA HALICYSTIS PARVULA‐DERBESIA TENUISSIMA. III. CONTROL OF GAMETE FORMATION BY AN ENDOGENOUS RHYTHM12
Authors: Page Joanna Ziegler , Sweeney Beatrice M.
Published: April 2007

Evidence is presented for an endogenous rhythm which controls gamete formation in the coenocytic gametophytic stage of the marine alga Derbesia tenuissima (De Notaris) Crouan fr. (Chlorophyceae), formerly known as Halicystis parvula. The rhythm is present under conditions of constant light and temperature, or in alternating light and darkness (LD 12 :12 or LD 8 : 8). Under controlled conditions in the laboratory, the basic period of this rhythm is 4‐5 days. The period is affected very little by temperature or light intensity. Gametangia may appear only at every other cycle of the underlying rhythm at approximately 8‐day intervals, or even every third cycle at intervals of about 12 days. The observation that the interval between the appearance of new gametangia does not vary continuously when light or temperature is varied but tends to be a multiple of 4 days is the strongest evidence available that a true endogenous rhythm with a period of about 4 days is present in Derbesia. Evidence is presented that circadian rhythmicity does not play a part in the timing of the initiation of gametangia in this organism.
STUDIES AT OYSTER BAY IN JAMAICA, WEST INDIES. IV. OBSERVATIONS ON THE MORPHOLOGY AND ASEXUAL CYCLE OFPYRODINIUM BAHAMENSEPLATE12
Authors: Buchanan R. J.
Published: April 2007

The morphology and asexual cycle of the luminescent armoured dinoflagellate, Pyrodinium bahamensePlate, were examinedin situandin vitro.Several previously unreported aspects of the cycle are described. Attempts to induce the formation of these alternate life stages by imposing new conditions were unsuccessful.
ULTRASTRUCTURE OF SPONGIOCHLORIS TYPICA DURING SENESCENCE12
Authors: McLean Robert J.
Published: April 2007

The ultrastructural changes which occurred during senescence in the stationary phase of growth of the unicellular green alga Spongiochloris typica were observed. The cell wall consists of a membrane like primary wall and an inner secondary wall which becomes progressively thickened with age of the culture. During senescence the lamellae become more compact within the chloroplast. The major feature of aging is the appearance of lipid bodies which eventually come to occupy a major portion of the cell lumen. The ultrastructural changes observed to occur during senescence are discussed in relation to physiological data.
REPRODUCTION IN ZONARIA FARLOWII. I. GAMETOGENESIS, SPOROGENESIS, AND EMBRYOLOGY1
Authors: Liddle Larry Brook
Published: April 2007

The brown alga Zonaria farlowii which exhibits an alternation of isomorphic generations has been found to be a particularly suitable organism for a comparative study of game to gene sis, sporogenesis, and embryonic development. The germinations of the zygote and spore have been compared and found to be similar. The development of the oogonium and sporangium has been studied with the light and electron microscopes, in an attempt to discern ontogcnetical similarities or differences. The timing and periodicity of oogenesis and sporogenesis were found to differ: oogonial development requires a lunar month from the time of its initiation to the time of egg release which occurs around the first quarter of the moon, whereas the sporangium does not follow this periodicity. The development of the spore embryos and zygotic embryos is essentially the same. It appears that the difference between the 2 phases of the life cycle exists only in the later stages of oogenesis and sporogenesis. These differences continue in the egg until fertilization, after which the zygote has the same cytoplasmic configuration as the spore. It is also notable that during release of the spore it must increase in size considerably since before germination begins it has attained the size of the egg.