bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE MORPHOLOGY AND FINE STRUCTURE OF CERATIUM HIRUNDINELLA (DINOPHYCEAE)1
Authors: Dodge John D. , Crawford Richard M. 
Published: August 2007

SUMMARYSome aspects of thecal morphology in Ceratium hirundinella are redescribed by means of scanning electron microscopy. The internal anatomy of the cell has been clearly revealed for the first time in serial sections examined by transmission electron microscopy. An unusual sulcus, termed the sulcul aperture, has been found to open into a large ventral chamber which extends toward the center of the cell. The 2 flagella are inserted at one side of the ventral chamber. The ultrastructure of the flagellar canals and root systems arc described in detail. A microtubular strand has been found to run from near the nucleus to near the flagellar bases but not to conned with either. The fine structure of the theca, trichocysts, nucleus, and chloroplasts is basically similar to that of other dinoflagellates. Food vacuoles are reported. These contain material thought to be undergoing digestion. It is suggested that the food particles enter the cell by way of the ventral chamber, which is lined only by membranes, unlike the rest of the cell, which is covered by thick plates. The new findings are discussed in relation to the earlier work on the species and to the fine structure of oilier dinoflagellates.
A NEW FRESHWATER CENTRIC DIATOM MICROSIPHONA POTAMOS GEN. ET SP. NOV.1
Authors: Weber Cornelius I. 
Published: August 2007

SUMMARYA new centric diatom, Microsiphona potamos gen. et sp. nov. (family Coscinodiscaceae), is described from the Little Miami River, Cincinnati, Ohio, where it occurred at cell densities ranging from 29 to 20,140/ml in surface grab samples during the period May 18–December 14, 1966, contributing an average of 11% and a maximum of 35% of the centric diatoms. This species has been observed in grab samples from rivers throughout the United States.The cells are 3–4 μ in diameter, 4–8 μ long, and contain 2 to several plate‐like chromatophores. They occur singly, or arc held together in short chains by the old girdle bands and by numerous apiculi that connect the opposing valves of adjacent daughter cells.
CULTURE STUDIES ON THURETELLOPSIS PEGGIANA KYLIN1
Authors: Richardson Norman , Dixon Peter S. 
Published: August 2007

SUMMARYInformation on the life history and development of Thuretellopsis peggiana Kylin (Cryptonemiales) has been obtained additional to that first given by Kylin in 1925. Culture studies showed the life history to consist of morphologically dissimilar gametangial and tetrasporangial phases. Examination of plants from, field material indicated carposporophyte development similar to that described by Kylin. Spermatangia were found in field‐collected material also bearing carpogonial branches. Monosporangia were observed on field and cultural material of gametangial plants and on tetrasporangial plants in culture. A crustose tetrasporangial phase arose in culture from germinating carpospores under a photoperiod of 16– hr and formed tetrasporangia under a photoperiod of 9–
image

hr. Germination of tetraspores yielded plants similar in morphology to gametangial plants collected in the field. The present study of the life history of T. peggiana and its crust, which has some similarity to Erythrodermis allenii, complements previous observations on the relationship between Halarachnion ligulatum and Cruoria rosea (Gigartinales). Observations on the arrangement of carpogonial and. auxiliary cell branches suggest the need for very close scrutiny of characters in cultured material.
GLAUCOSPHAERA VACUOLATA, ITS ULTRASTRUCTURE AND PHYSIOLOGY1,2
Authors: Richardson F. L. , Brown T. E. 
Published: August 2007

SUMMARY Glaucosphaera vacuolata was recently rediscovered, and isolated by Dr. Richard Starr of Indiana University Physiological and ultrastructural studies have been conducted on this cyanome and are reported for the first time. Glaucosphaera has been found to have low rates of photosynthesis, respiration, and Hill activity. Unusual features noted include the presence of R‐phycocyanin as the major accessory pigment, phycobilisomes, and eyeshot‐like structures in the cyanelles.
FREQUENT HETEROCYST GERMINATION IN THE BLUE‐GREEN ALGA GLOEOTRICHIA GHOSEI SINGH1
Authors: Singh R. N. , Tiwari D. N. 
Published: August 2007

SUMMARYA unique feature, frequent heterocyst germination, has been observed in a nonsporulating mutant clone (of spontaneous origin) of the blue‐green alga Gloeotrichia ghosei Singh. The controlling factor seems to be the presence of ammoniacal nitrogen in the medium. In addition, such a medium supports differentiation of successive crops of new heterocysts and their germination in the name medium and in the same algal culture. Contrary to previous observations with oilier blue‐green algae, ammoniacal nitrogen does not seem to inhibit heterocyst differentiation in this alga. Both the parent alga and its mutant clone grow poorly in a nitrogen‐free medium, which, although they are not completely free from bacteria, may indicate that they tire poor fixers or nonfixers. However, they form a large number of heterocysts under these conditions. The general conclusion is that the heterocysts of blue‐green algae show a multiplicity of structure and function. In the present case they have reproductive function leading to direct propagation of the alga.The bearing of these findings on the interrelationships of the genera Gloeotrichia and Rivularia has been discussed. It has been concluded that the distinction between them is purely artificial.
FIELD STUDIES ON THE GIANT KELP NEREOCYSTIS1,2
Authors: Nicholson Nancy L. 
Published: August 2007

SUMMARYAn intertidal population of Nereocystis luetkeana was investigated in the field, and techniques for measuring sporophyte growth were developed. Primary regions of growth in plants prior to reproductive maturity were located in the bases of the blades, upper stipe, and holdfast. After reproductive areas on blades appeared, growth was confined to 2 major regions: the blade bases and the junction between lower stipe and holdfast where new holdfast haptera were produced. Complete deblading halted growth at whatever stage the plants had attained at the time of the operation but did not kill the plants. Partial deblading resulted in low but measurable growth rates in the blade bases. The data presented suggest that the function of the blades is twofold: they bear reproductive structures in the mature plants and. they may provide, materials used, in rapidly growing regions.
THE EFFECTS OF LIGHT INTENSITY ON THE ULTRASTRUCTURE OF CHLOROGLOEA FRITSCHII MITRA GROWN AT HIGH TEMPERATURE1,2,3,4
Authors: Findley Davis L. , Walne Patricia L. , Holton Raymond W. 
Published: August 2007

SUMMARYThe effects of high and low light intensities on the ultrastructure of the large, single cells (designated as Stage IV cell types in the life cycle) of Chlorogloea fritschii grown at 45 C are described. The most noticeable difference between cells grown at 20–60 ft‐c and at 700 ft‐c is in the number and arrangement of the photosynthetic lamellae. In the former, the lamellae are in groups of 4–6 units, the component membranes of which are compact and, closely appressed. While the thylakoids are long, continuous, and frequently invaginated into the central cytoplasm to form concentric whorls, there is no evidence of swelling or separation to form vacuole‐like structures. In contrast, in cells grown at 700 ft‐c, the photosynthetic lamellae are fewer and fragmented, with the segments peripherally arranged dint frequently swollen and vesiculate. There are also differences in the, nature of the sheath, in the amount of cyanophycean starch, and in the cytoplasmic inclusions. At 20–60 ft‐c, the sheath, is extensive and. fibrillar; cyanophycean starch is abundant; and cytoplasmic inclusions (e.g., αand β‐granules) arc sparse. At 700 ft‐c the sheath is less extensive and frequently composed of short segments of fibrils and of particulate material; cyanophycean starch is sparse; and cytoplasmic inclusions are abundant.
MITOSIS, CYTOKINESIS, AND CELL ELONGATION IN THE DESMID, CLOSTERIUM LITTORALE1
Authors: Pickett‐Heaps Jeremy D. , Fowke Larry C. 
Published: August 2007

SUMMARYSome details of interphase cell structure are given. At prophase the nuclear envelope breaks down and the nucleolus disperses; very small doubled chromosomes generally form a precisely aligned, metaphase plate with normal spindle microtubules present; 2 plates of chromatids separate during anaphase, the spindle becoming invaded, by (mucilage) vesicles. Telophase nuclei arc initially very hard to discern, until they increase in volume. Microtubules collect at each pole, becoming increasingly focused on one small region containing fine granular malarial, the microtubule center (MC). The septum, an annular ingrowth, begins forming at prophase and partitions the cell by telophase. At no stage were microtubules involved in this initial cross‐wall formation.At telophase the spindle collapses and as the nuclei move back to the septum, increasing numbers of microtubules appear near this cross wall, all transversely aligned. An annular split deepens down the middle of the wall material in the septum, and the daughter cells begin to expand, stretching the new wall; the microtubules appearing near the septum now are transformed steadily into typical hooplike wall, microtubules, but strictly confined to the expanding wall (there are none near interphase cell walls). Meanwhile, the MC, has moved, to the side of the cell and begins migrating along one of the grooves in the chloroplast; a large number of parallel microtubules extends back to the nucleus, which becomes increasingly deformed as it begins to extend a long thin protrusion along these, microtubules. The MC keeps moving along the cell until it lodges in the cleavage developing in the chloroplast. Some microtubules extend still further up the cell, others appear in the chloroplast cleavage, but most en‐sheathe the nucleus which by now is moving along the cell as a cylindrical structure tightly fitting in the chloroplast groove. The nuclear membrane is then drawn up into the deepening chloroplast constriction, and when the chloroplast is finally cut in 2, the nucleus lakes up its interphase position between the 2 halves. While all this is occurring, the whole cytoplasm is expanding into the new semicell being created by growth of the wall originally derived from the septum. Thus the interphase cell symmetry is reestablished after mitosis. These results are discussed in terms of more general phenomena of cell division and morphogenesis.
DERMATITIS‐PRODUCING ALGA LYNGBYA MAJUSCULA GOMONT IN HAWAII. I. ISOLATION AND CHEMICAL CHARACTERIZATION OF THE TOXIC FACTOR1,2
Authors: Moikeha Sanae N. , Chu George W. , Berger Leslie R. 
Published: August 2007

SUMMARYThe toxic principle of dermatitis‐producing Lyngbya majuscula Gomont has been purified by extraction of dried alga with organic solvents followed by column and thin‐layer adsorption chromatography. The toxin is readily soluble in methanol, chloroform, acetone, diethyl ether, and ethanol; it is insoluble in water and slightly soluble in petroleum ether. Qualitative tests have shown no free alpha amino groups, phosphate, sugar, sterol, or quaternary amine. Sulfur and halogen are also absent. The infrared absorption spectrum indicates the presence of hydroxyl groups, CH, CC, and probably CN bonds. Ultraviolet irradiation results in a decrease in toxic activity as well as in bleaching of the pigment. The toxin is also inactivated by heat and by reduction or oxidation. A quantitative test for assay of toxicity has been developed with human amnion cells grown in tissue culture.
DERMATITIS‐PRODUCING ALGA LYNGBY A MAJUSCULA GOMONT IN HAWAII. II. BIOLOGICAL PROPERTIES OF THE TOXIC FACTOR1,2
Authors: Moikeha Sanae N. , Chu George W. 
Published: August 2007

SUMMARYThe course of the reaction produced by intracutaneous injection of the toxin of Lyngbya majuscula Gomont is that of a severe acute inflammatory reaction. No protective or sensitizing effect is induced by a previous exposure. The response from intravenous injection into a rat indicates that the toxin acts as a general cell toxin. The protozoan Tetrahymena pyriformis and rabbit erythrocytes are lysed by the toxic principle, which also possesses antibacterial activity. Of the organisms tested, Mycobacterium species are markedly inhibited, while Bacillus cereus, Gaffkya tetragena, and Sarcina lutea are slightly to moderately inhibited. Other components of the alga, which are steam distillable, have been found to have antibacterial activity but are not involved in the skin reaction.
GROWTH RATES OF ALGAE DETERMINED IN SITU USING AN IMMERSED MICROSCOPE1
Authors: Staley James T. 
Published: August 2007

SUMMARYA microscope was adapted for immersion in natural aquatic habitats to make direct observations of attaching microorganisms. Using this technique the growth of several types of algae was followed. The algae observed exhibited a diurnal growth pattern. Most of the size increase occurred during the daylight hours, whereas most cellular division occurred during the night. Growth rates determined by size measurements varied from 1.3 to 1.8 doublings per day.
SELECTIVE INHIBITION OF BLUE‐GREEN ALGAL GROWTH BY ETHIONINE AND OTHER AMINO ACID ANALOG1,2
Authors: Aaronson S. , Ardois G. 
Published: August 2007

SUMMARYSome metabolic analogs, including azaguanine, azathymine, azauracil, caffeine, 4‐azaleucine, dl‐ethionine, and dl‐p‐fluorophenylanlanine, were examined for their ability to repress the multiplication of algae from natural aquatic sources grown in defined or semidefined media. dl‐ethionine, dl‐p‐fluorophenylalanine, and 4‐azaleucine, in that order, inhibited the multiplication of blue‐green but not other algal groups. The purine and pyrimidine analogs were not inhibitory. In chemically defined axenic media, dl‐ethionine was about 100 times more inhibitory to the blue‐green algae Synechococcus cedrorum and Anabaena cylindrica than to the eucaryotic algae Ochromonas danica and Euglena gracilis. The ciliate Tetrahymena pyriformis was at least 100‐fold more resistant to ethionine than the algae. The unusual sensitivity of blue‐green algae to ethionine and other amino acid analogs represents an exceptional phylelic character and may be useful in the control of these algae when they become a nuisance. Amino acid analogs such as ethionine may also serve to remove blue‐green algae from cultures one may desire to render axenic.
ELECTROPHORETIC IDENTITY OF POLYPEPTIDES FROM THE NUCLEAR MEMBRANE OFANTHOPLEURA‐ASSOCIATED ZOOXANTHELLAE1
Authors: Franker Colin K. 
Published: August 2007

SUMMARYNonproliferating zooxanthellae fromAnthopleura elegantissimawere incubated with3H‐amino acids for 4–16 hr to uniformly label cell protein. Radioactive proteins from the nuclear membrane were extracted and solubilized for electrophoresis in polyacrylamide gels. Four major electrophoretic species of polypeptides were observed at pH 5.0, 7.0, and 9.0 in an SDS‐urea‐glutathione system. Their molecular weights were estimated to be 32,000, 44,000, 56,000, and 140,000 daltons. All 4 polypeptides are common to the outer as well as inner nuclear envelopes.
ULTRASTRUCTURE OF THE PYRENOID OFTREBOUXIAINRAMALINA MENZIESIITUCK.1,2
Authors: Fisher K. A. , Lang N. J. 
Published: August 2007

SUMMARYTrebouxiasp., the phycobiont of the lichenRamalina menziesiiTuck., was examined with the electron microscope. Its pyrenoid is characterized structurally as being permeated by interconnected vesiculate membrane systems associated with osmiophilic globules termed pyrenoglobuli. The variety of membrane structure associated with the pyrenoid has been documented with electron micrographs. A model based on serial sections was constructed to show the extent of vesiculation, to demonstrate that the pyrenoglobuli within the pyrenoid matrix are invariably adjacent to the thylakoid membranes within that, matrix, and to emphasize the recurrent thylakoid membrane to pyrenoglobuli relationship. A comparison of the glutaraldehyde‐osmium fixation image of the pyrenoglobuli and pyrenoid matrix with the permanganate fixation image has been included. The structure of the pyrenoid matrix in thin section was examined and appears essentially granular.
CONJUGATION IN THE DESMIDCLOSTERIUM LITTORALE1
Authors: Pickett‐Heaps Jeremy D. , Fowke Larry C. 
Published: August 2007

SUMMARYConjugation inClosteriumhas been studied using sectioned material prepared for light and electron microscopy. Prior to conjugation, cells become dense and accumulate lipid droplets. Conjugation commences in paired cells with the formation through a point of mutual contact of a circumferential strip of papilla wall material which is not necessarily centrally situated in each cell. Some microtubules are initially present, near this specialized wall which grows all around each cell but asymmetrically so that the area of papillae in contact increases and each papilla balloons out toward the other, kinking the semicells. Vesicles probably contribute material to this wall. Microtubules disappear from near the papilla as it expands; they are then often found around the older semicell wall immediately adjacent to the papilla. An enlarging vacuole is always formed in each papilla. Cytoplasmic shrinkage is first evident from an accumulation of mucilage between the plasmalemma and wall at the tip of each semicell; the terminal vacuoles collapse and disappear. During further shrinkage of the protoplast, alveolate structures are common on the plasmalemma, and the papilla wall material separating the protoplasts thins out and disappears. Meanwhile, a profound general change renders the cytoplasm far less osmiophilic and stainable for both light and electron microscopy, as it becomes relatively homogeneous and granular, revealing a considerable loss in minor cytoplasmic structures; grana in the chloroplasts become bloated. These changes are not considered processing artefacts, but may result from a breakdown of vegetative cell structures no longer needed for zygote formation. After fusion, the zygote protoplast tends to round up. Zygote maturation commences with deposition of a multilayered wall and shrinkage of the protoplast. Then the very thick zygote wall proper is slowly secreted; meanwhile, very considerable cytoplasmic condensation now renders the cell increasingly osmiophilic and dense until ultrastructural detail becomes totally obscured. Fairly consistent changes in the appearance and probably in the function of the golgi bodies were noted. The results are discussed in terms of the possible function of cell organelles and their role in the mechanics of conjugation.
LABORATORY STUDIES OF A GREEN NOCTILUCA FROM NEW GUINEA1,2
Authors: Sweeney Beatrice M. 
Published: August 2007

SUMMARYA strain of Noctiluca miliaris Suriray, containing in the vacuole a motile green flagellate, was collected off the north shore of New Guinea and maintained in culture in autoclaved seawater or an enriched seawater medium. In light, this green Noctiluca survived for at least a month and divided, without added food; while in darkness the symbiotic flagellate disappeared and the Noctiluca died within a few days, unless the food organism Dunaliella tertiolecta was present. Long‐continued growth in light required the presence of Dunaliella, since the symbiotic flagellate was gradually lost under all the culture conditions assayed.All green Noctiluca assayed were luminescent. The light emitted per cell varied with the nutritional state of the host, and was as bright as a Japanese strain without symbionts when the Noctiluca was feeding on Dunaliella. In the absence of Dunaliella, the light emitted per Noctiluca depended on the light intensity in which cultures were maintained. The luminescent flash followed the same time course as that of other strains of Noctiluca without symbionts. No circadian rhythm of luminescence was present.Observations on both the growth and luminescence show that the flagellate symbiont contributes to the nutrition of the green Noctiluca. The symbiosis, however, is unstable in culture.
A STUDY OF CALLITHAMNION LEJOLISEA FARL.1
Authors: Dixon Peter S. 
Published: August 2007

SUMMARYThe study of various aspects of the structure and development of Callithamnion lejolisea Farl. shows that this species is incorrectly referred to that genus. It is proposed that C. lejolisea should be, made the type species of a new genus, Ptilothamnionopsis. In addition, various other Pacific algae possibly referable to this genus are briefly considered.
IDENTIFICATION OF CHLORELLA STRAINS BY SEROLOGICAL TECHNIQUES1,2
Authors: Sanders Bob G. , Keller Edward C. , Wiley Kay L. 
Published: August 2007

SUMMARYThree strains of Chlorella were examined, by serological procedures for cellular antigenic differences. Antibodies produced in rabbits against, the 3 different Chlorella strains demonstrated the presence of antigens common to all 3 strains. Adsorbed antisera identified antigens specific for each, strain.
THE ULTRASTRUCTURE OF LICHENS. II.CLADONIA CRISTATELLA: THE LICHEN AND ITS ISOLATED SYMBIONTS1,2,3
Authors: Jacobs J. B. , Ahmadjian V. 
Published: August 2007

SUMMARYA Comparative Study Was Made Of The Fine Structure ofCladonia Cristatellaand its algal SymbiontTrebouxia Ericiin their lichenized and cultured (nonlichenized) states. Pyrenoglobuli were produced by the alga in the symbiotic and free conditions. Starch was formed during hydrated conditions. Pyrenoglobbuli migrated to the outer parts of the pyrenoid only during dry periods. Dictyosomes and eyespots were observed for the first time inTrebouxia. The pyrenoid divided by fragmentation. Ellipsoidal bodies were common in the hyphae of the lichenized fungus and absent in cultured hyphae, except for 1 colony which had been induced to form pycnidia. The ellipsoidal bodies were associated closely with the internal membrane system of the mycobiont. Haustoria seemed to penetrate the algal cells by enzymatic digestion. Intrahyphal hyphae were common.
NUTRITION OF PANDORINA MORUM1,2
Authors: Palmer Esther G. , Starr Richard C. 
Published: August 2007

SUMMARYA defined medium was developed for 3 strains of Pandorina morum. The strains tested required no vitamins or other organic compounds. The optimal initial pH was between 7.0 and 8.0. Various carbon sources were tested, and only glycolate and acetate appreciably stimulated growth. Mixotrophic growth in the light was stimulated by glycolate in all 3 strains, and by acetate in strains 880 and N76‐6. Only strain N76‐6 utilized acetate for heterotrophic growth in the dark. Thirty strains of P. morum of world‐wide distribution were surveyed for mixotrophic and heterotrophic growth with acetate. All were found to fit 1 of 3 classes with respect to acetate metabolism: (1) no effect in light or dark; (2) stimulation of growth in light only; (3) stimulation of growth in light and dark.