bluuebunny/crossref_metadata_2025 huggingface dataset:
In vitro Cultivation of Plasmodium elongatum in Duck Tissues*
Authors: WEISS MARGARET L. , MANWELL R. D.
Published: May 2007

SYNOPSIS.

Cultures of tissues from ducks infected with Plasmodium elongatum supported the growth and development of the parasites for 72 hours. Cultured parasites exhibited the same properties when reintroduced into the vertebrate host as did cells derived from similar sources upon direct transfer into a new bird. Parasites derived from acute infections led to patent infections after an incubation period of 7–8 days. Parasites derived from latent infections gave rise to infections becoming apparent after 11–15 days. Results of dilution experiments show that this lag period is not due to low numbers of parasites contained in tissues from latent infections. It is concluded that invaded cells may, after the acute stage of the infection, elaborate some hypothetical inhibitor which arrests multiplication of the parasite, while not interfering with its viability or virulence.
The Influences of Temperature on the Host‐Parasite Relationships of Several Species of Snakes Infected with Entamoeba invadens*
Authors: BARROW JAMES H. , STOCKTON JACK J.
Published: May 2007

SYNOPSIS.

Entamoeba invadens was studied in 8 species of snakes at temperatures of 13–14° and 25°C. Infected snakes of all species failed to show any gross pathology at 13°C, although amoebae were isolated from the snakes by culture. At the higher temperature all species showed pathological changes, most severe in Natrix, dekayi and red belly, and progressively less severe in the garter, milk, ribbon, ringneck and green snakes. For the last S species, the pathology in the liver and intestine was so characteristic as to provide an adequate basis for identification of the snake. Snakes infected at the lower temperature and later transferred to 25° showed the same pathological changes as those kept at 25° throughout. The possible effects of behavior patterns of snakes on pathogenicity of the amoebae are pointed out.
Two New Species of Flagellates Cultivated from Insects of the Genus Gerris*
Authors: WALLACE F. G. , CLARK TRUMAN B. , DYER MELVIN I. , COLLINS THOMAS
Published: May 2007

Two species of trypanosomatid flagellates: Critkidia flexonema from Gerris remigis at Ames, Iowa, and Leptomonas collosoma from Gerris dissortis at St. Paul, Minnesota, were isolated in pure culture and are described as new species. Blastocrithidia gerridis, which differs irorn bath of the new species in possessing an undulating membrane, failed to establish itself in culture.
Anaerobic Metabolism of Crithidia fasciculata*
Authors: SCHWARTZ JOYCE BLICHER
Published: May 2007

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.
Effect of Storage Temperature, Equilibration Time, and Buffers on Survival of Tritrichomonas foetus in the Presence of Glycerol at Freezing Temperatures*
Authors: FITZGERALD PAUL R. , LEVINE NORMAN D.
Published: May 2007

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.
A New Genus and two New Species of Ancistrocomid Ciliates (Holotricha: Thigmotricha) from Sabellid Polychaetes and from a Chiton
Authors: KOZLOFF EUGENE N.
Published: May 2007

Most of the thigmotrichous ciliates of the family Ancistrocomidae are parasites of gastropod and pelecypod mollusks. The only known exceptions are Hypocomella pho‐ronopsidis, from a phoronid, and some species of Hypocomella and Heterocinetopsis which parasitize the oligochaete Chaeto‐gaster limnaei as well as certain of the fresh‐water snails with which this worm is commensal. Two new species of marine ancistrocomids, found on the Pacific coast of Oregon, infect hosts belonging to groups from which ciliates of this type have not previously been reported. Hypocomella katharinae sp. Now is a parasite of the ctenidial epithelium of the chiton Katharina tunicata. Ignotocoma sabellarum gen. nov., sp. nov., is found on the peristomial cirri of two polychaete annelids of the family Sabellidae: Schizobranchia insignis and Eudistylia polymorpha. The genus Ignotocoma differs from previously described genera of ancistrocomids in having its ciliary system separated into two fields, each consisting of seven or eight rows, which are largely limited to weakly concave areas lying on opposite sides of a longitudinal ridge‐like eminence on the inferior surface.
Fine Structure of the Silverline and Fibrillar Systems of Three Tetrahymenid Ciliates*
Authors: PITELKA DOROTHY R.
Published: May 2007

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.
Genetics of Entamoeba histolytica: Initial Experiments*
Authors: ENTNER NATHAN
Published: May 2007

Six strains of Entamoeba histolytica were studied in an initial attempt to define some genetic characteristics. Sugar metabolism and drug sensitivity were the markers studied. The six strains showed little difference in characteristics and attempts to obtain mutations have been unsuccessful. The observed characeristics may be useful in helping to define the species.
Survival and Reproduction of Paramecium after X‐irradiation
Authors: WICHTERMAN RALPH
Published: May 2007

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.
New Species of Gregarines from Millipedes of Mysore State, India*
Authors: RODGI SHIVA S. , BALL GORDON H.
Published: May 2007

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:
Excystment Ability, Respiratory Metabolism, and Ribonucleic Acid Content in Two Types of Resting Cysts of Colpoda cucullus O. F. Miiller
Authors: PIGON A. , EDSTRÖM J. E.
Published: May 2007

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.
Some Amino Acid‐Folic Acid Interrelationships in Tetrahymena pyriformis
Authors: SINGER SAMUEL
Published: May 2007

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.
Color Sensitivity of the Amoeba Revisited*
Authors: HITCHCOCK LLOYD
Published: May 2007

SYXOPSIS. The duration of photic suppression of plasmosol movement was used as a measure of the sensitivity of Amoeba proteus to selected wavelengths of monochromatic stimulation. Radiant energy was equated across the wavelengths which ranged from 420 to 620 millimicrons. The data generally confirm previous findings but indicate that maximum sensitivity lies in the green (515 mμ) rather than the previously held blue (450‐490 mμ) region.
The Mechanism of Ciliary Movement. I. Ciliary Reversal and Activation by Electric Current; the Ludloff Phenomenon in Terms of Core and Volume Conductors.*
Authors: JAHN THEODORE LOUIS
Published: May 2007

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.
Polymorphism in Tetrahymena vorax*
Authors: WILLIAMS NORMAN E.
Published: May 2007

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.
Stomatogenesis and Formation of Cirri in Fragments of Oxytricha fallax Stein
Authors: HASHIMOTO KANEJI
Published: May 2007

Of fragments involving a partial removal of the original adoral zone of membranelles (AZM), the monomacro‐nucleate ones become reorganized monostomes resulting from a simple fusion of the remnant AZM to the oral primordium induced, and the binucleate ones become dividers by initiation of the oral primordium posteriorly from the posterior terminal of the remnant AZM. The cirral primordium in any fragment arises alongside its corresponding oral area. Weisz's idea of the dominance and inhibition of the original oral system extending over the oral primordium site is applicable in stomatogenesis of the present species. This application is found also in cirral formation.

In fragments from early stage dividers, a formed oral primordium is easily absorbed by influence of the intact original AZM. This event also occurs after complete removal of the AZM. Such results led to the hypothesis that the oral primordium in the normal divider may be formed under some stoma‐togenic activation of the AZM followed by escape from inhibition also arising from the same source. Irrevocable furrow formation and irreversibility of the oral primordium in stomatogenesis occur in later stages of division. Nevertheless division in these stages is blocked when certain operations are performed, forming monsters possessing the AZM of the opisthe translocated to the side opposite to that of the proter. In other monsters obtained from a fusion of the AZM of the proter to that of the opisthe, division occurs belatedly, prior to which secondary oral and cirral primordia are produced.
The Response of Poteriochromonas stipitata to Urethan and Related Compounds*
Authors: ISENBERG HENRY D. , BERKMAN JAMES I. , SUNDHEIM LILA H.
Published: May 2007

SYNOPSIS. The effect of urethan on Poteriochromonas stipitata has been studied. Several concentration‐dependent activities of the drug could be discerned. Low concentration increased cell yields; certain slightly higher ones resulted in complete cessation of growth. Further increase of urethan concentrations interfered with the respiration of the organism and still higher concentrations disrupted the cells.
Symbiodinium gen. nov. and Symbiodinium microadriaticum sp. nov., a Zooxanthella: Taxonomy, Life Cycle, and Morphology.*
Authors: FREUDENTHAL HUGO D.
Published: May 2007

SYNOPSIS. The life cycle of the zooxanthella of Cassiopeia sp., as determined by in vitro studies, includes a dominant vegetative autotrophic stage, a reproductive cyst producing autospores, aplanospores, or motile gymnodinioid zoospores, or possible gametes. The predominance of these stages is partially determined by environmental factors, e.g., photoperiodicity. As none of the existing genera of free‐living or parasitic algae are wholly applicable to this organism, a new genus, Symbiodinium, is proposed. The type species, S. microadriaticum, is described.
Electron Microscope Studies of Reproducing and Interkinetic Toxoplasma
Authors: GAVIN MARY ANN , WANKO THEODOR , JACOBS LEON
Published: May 2007

SYNOPSIS. The reproduction of Toxoplasma gondii has been investigated in osmium fixed and sedimented mouse peritoneal exudate. The material was obtained 9 days after intraperitoneal inoculation with the Beverley strain. Predominantly intracellular organisms were seen in various phases of multiplication and indicated the occurrence of three different modes of reproduction. One is a schizogonic cycle, whereby at least four progenies are delineated within a rosette‐shaped, multinucleated Toxoplasma cell. They subsequently separate to become individual parasites. The second mode is considered as a special type of schizogony that results in the production of only two merozoites within one parent cell. This process previously has been designated as endodyogeny. Finally, the observations suggest division by binary fission as a third type of reproduction.

From these results, it is possible to relate the genus Toxoplasma, previously regarded as a protozoon of uncertain classification, to the class Sporozoa.
Observations on the Life‐cycle of a New Race of Blepharisma undulans from India
Authors: SESHACHAR B. R. , BHANDARY A. VASANTHI
Published: May 2007

SYNOPSIS. A full account of the nuclear changes during binary fission and conjugation in a local race of Blepharisma is presented in this paper. The macronucleus consists of 2 nodes connected by a strand. Number of micronuclei varies from 6 to 18. During binary fission, condensation of macronucleus is followed by elongation and thinning of the middle region which finally breaks. Daughter nuclei later attain the typical vegetative form. Notably, during binary fission some micronuclei appear to complete their mitoses by the time the macronucleus attains the condensed form, while others lag behind and exhibit practically every stage of mitosis.

During conjugation, from 6 to 10 micronuclei undergo the first pregamic division, the same number through the second division, and two products of the second division take part in the third division. The rest degenerate. Division products of the nuclei in the paraoral region take part in synkaryon formation. The synkaryon undergoes either 2 or 3 divisions. In the former case, of the 4 products, 2 become the macronuclear anlagen, one the micronucleus and the fourth degenerates. In the latter case, of the 8 products, 3 to 4 become the macronuclear anlagen and the rest become micronuclei. Chromatin elimination has been observed during the division of the macronuclear anlage, followed by an extra metagamic fission of the cell.

Comparison with two other races from India and an American race indicates considerable diversity in the structure and behaviour of the nuclear apparatus in different races of Blepharisma undulans.
Exogenous Factors Affecting Respiration in Tetrahymena pyriformis*
Authors: McCASHLAND B. W. , KRONSCHNABEL J. M.
Published: May 2007

SYNOPSIS. Respiration of Tetrahymena pyriformis W, grown in Proteose peptone‐glucose medium, was determined by Warburg's direct and indirect methods. The Qo2 varied inversely with cell concentration under exogenous conditions (cells in conditioned medium, i.e., one which had supported growth) as determined by both methods, and under endogenous conditions (washed cells suspended in salts solution) when determined by the indirect method. Endogenous respiration, measured by the direct method, was low but independent of cell concentration.

Respiration, determined by the direct method, was little affected by lowered O2 availability, but varied directly with nutrient availability. The inhibitor, malonate, which also stimulates respiration at greater dilutions, inhibited respiration at 10−2M when present with low cell concentrations, but stimulated at high cell concentrations.

The reduced respiration at higher cell concentrations is thought less due to lack of O2 than to CO2 accumulation and competition for nutrients. Consideration of these variables is essential in comparing data from the literature.
The Plastid System of Normal and Bleached Euglena gracilis*
Authors: GIBOR AHARON , GRANICK S.
Published: May 2007

SYNOPSIS. The plastid system of “normal”Euglena gracilis strain Z was found to be extremely unstable. Under normal culture conditions in the light about 1 or 2% of the cells were found to have lost spontaneously the capacity to green on further culturing. Cells treated with streptomycin, heat or U.V. all lost the capacity to green on further culturing. Bleached cells whether appearing spontaneously or by induction with streptomycin, heat, or U.V. light, were all found to possess within them organelles which were identified as proplastids.

The proplastids of some “bleached” strains were capable of synthesizing porphyrins when grown in a standard culture medium. Others synthesized porphyrins only after the addition of delta‐aminolevulinic acid to their medium, while proplastids of still other strains could not synthesize porphyrins from this precursor. Normal cells when grown in total darkness were found to possess proplastids morphologically identical with those of the bleached strains. Upon exposure to light the proplastids enlarged and greened. In cells which grew under continuous light the plastid system appeared as an interconnected system of tubules. Cells maintained on a schedule of 12‐hour light and 12‐hour dark had plastids which were detached from each other.
Taxonomy of Genus Blepharisma with Special Reference to Blepharisma undulans
Authors: BHANDARY A. VASANTHI
Published: May 2007

SYNOPSIS. Three new species of Blepharisma are presented: B. seshachari sp. nov., B. intermedium sp. nov., and B. tropicum sp. nov. Two sub‐species of Suzuki are elevated to specific rank, B. undulans americanum to B. americanum and B. undulans japonicum Suzuki to B. japonicum Suzuki. Stein's taxa for the species Blepharisma undulans are considered to be diagnostic for that species.

Important features of morphology and life‐cycle of the above mentioned species are given. Discussion and position of the species Blepharisma undulans are presented and a proposal for the reorganization of the species is made. The possibility of a new key derived from a hypothesis of the phylogeny on an evolutionary basis of the genus is presented. This hypothesis has been extended to include ciliates like Stentor and Spirostomum and its implications discussed.
Epistylis helicostylum n. sp., a New Peritrichous Ciliate with an Allometric Stalk Formation
Authors: VAVRA JIRI
Published: May 2007

SYNOPSIS. A new peritrichous ciliate, Epistylis helicostylum n. sp. is described. It lives attached to the extremities of the ostracod Eucypris virens as its specific symphoriont. A spiral structure forming a protective theca for the colony of daughter animals is produced by the allometric growth of the outer sheath of the stalk. The whole process of its formation is described.
Evolutionary and Systematic Relationships in the Flagellate Order Trichomonadida Kirby*
Authors: HONIGBERG B. M.
Published: May 2007

SYNOPSIS. Discussion of the systematic relationships and of the evolutionary trends among the 4 families, Monocerco‐monadidae, Devescovinidae, Calonymphidae, and Trichomonadidae of the order Trichomonadida includes a consideration of 8 subfamilies, 3 of them new. The genera of Devescovinidae and Calonymphidae, all of which are limited in their distribution to lower termites, are not considered; those of Monocercomonadidae and Trichomonadidae are discussed in the light of the information pertaining to their structure, morphogenesis, distribution, and host‐parasite relationship. Diagnoses are given for 6 subfamilies and 14 genera belonging to the latter two families, which are diagnosed also. Type genera are designated for each family and subfamily that is discussed, and type species are designated for each of the 14 genera. A complete synonymy is presented for each type species. Two new species, one of Monocercomonas and another of Tritrichomonas are named and diagnosed.

The paper includes a key to all the families and subfamilies of the order and to the genera of Monocercomonadidae and Trichomonadidae.
Regeneration Rate of Blepharisma with Special Reference to the Effect of Temperature*
Authors: GIESE ARTHUR C. , McCAW BARBARA
Published: May 2007

SYNOPSIS. The regeneration of three species of Blepharisma—americanum, undulans and japonicum (grown in conslant yellow light in a constant‐temperature room at 25d̀C) from specimens of which the hypostome had been removed, was studied under a variety of conditions. The reliability of the methods was checked by an extensive series of experiments with B. americanum and B. japonicum under normal conditions. The time of regeneration of 50% of the individuals was taken as a convenient means for comparing action of various agents. No diurnal rhythm of rate of regeneration was observed. Regeneration is readily affected by the state of nutrition of the cells, starved ones regenerating more slowly than well‐fed ones. Regeneration is accelerated by maintaining the cells at 30d̀ but retarded at 35d̀. Even brief exposures to 40d̀ may retard regeneration. Regeneration is slowed by maintenance at temperatures below 25d̀, and stopped at 10d̀. Cut Blepharisma placed at 5d̀ lose pigment in a “shock” reaction and many die. The injury is more marked in lettuce medium than in balanced salt solution. Between 13 and 30d̀ the rate of regeneration increases with rise in temperature, the Q10′s for the ranges 13 to 18d̀, 18 to 25d̀ and 25 to 30d̀ being, respectively, 6.92, 3.93 and 1.56. The effect of temperature upon division of Blepharisma was found to be similarly sensitive to temperature, the Q10's for the ranges 13 to 18d̀, 18 to 25d̀ and 25 to 30d̀ being 3.87, 2.92 and 1.59, respectively. High and low temperature limits for division were also found to be similar to those for regeneration. Preliminary evidence indicates some degree of thermal adaptation in Blepharisma to both higher and lower temperatures than those usually tolerated. The studies indicate a general similarity in sensitivity of regeneration and division to environmental influences in the various races of the species studied, with some individual variations.
The Mode of Action of Certain 3‐ and 5‐Nitropyridines and Pyrimidines. IV. Development of Drug‐Resistance by Trichomonas vaginalis.
Authors: MICHAELS RHODA M. , TREICK RONALD W.
Published: May 2007

SYNOPSIS. Certain 5‐nitropyridines and pyrimidines are growth inhibitory to Trichomonas vaginalis in vitro. Populations were made resistant either to 2‐amino‐5‐nitropyrimidine, or 2‐amino‐5‐nitropyridine, or 2‐hydroxy‐5‐nitropyridine, by growth in gradually increasing concentrations of one of these inhibitors. After resistance was maximal, clonal lines were established. The development of resistance to any one of these inhibitors was accompanied by resistance to the other two. Since cross‐resistance was complete, these inhibitors act at the same locus. This in vitro resistance persisted in vivo.

Resistance was accompanied by an increase in the generation time and a decrease in the maximal obtainable population. These growth parameters were unique for each resistant clone. The growth of the clone made resistant to 2‐amino‐5‐nitropyridine was the closest to the normal clone. Its metabolic capacity, as measured by conventional Warburg techniques, was less than half of the parent strain and anaerobically was the same as had been previously found for non‐resistant cells which had been grown for 3 hr with inhibitor. The mechanisms of killing by the inhibitor and the development of drug resistance are the same. The inhibitor kills the cells by holding them in an early metabolic sequence. Some of them succeed in growing by using this metabolic sequence and reinforcing it with an alternate aerobic route.
A Wilt of Coffea liberica in Surinam and its Association with a Flagellate, Phytomonas leptovasorum Stahel
Authors: VERMEULEN H.
Published: May 2007

SYNOPSIS. A description is given of a disease of Coffea liberica Bull ex Hiern. occurring in Surinam, British Guiana and, according to previous investigations by Stahel, also in Brazil, San Salvador, and Colombia. The symptoms and spreading of the disease are described and its relation to a fungus disease of coffee with very similar wilting symptoms. Special attention has been paid to the concurrence of the observed flagellate Phytomonas leptovasorum Stahel and the multiple division of the phloem vessels on account of the scepticism with which Stahel's discovery of the flagellates in sieve tubes of wilting coffee trees was met by other research workers.

Moreover a short description is given of experiments to transmit the disease to healthy coffee trees by grafting, with special reference to the successful root grafting. Furthermore it could be ascertained that no viruses or nematodes are involved as pathogens. The possible relation between the disease and insects is still unsettled; observations of flagellates in the midgut of certain bugs, found on the roots of coffee trees, seem to indicate that the vector of the phloem necrosis disease is a Hemipteran insect.

Although no final proof of the pathogenicity of the flagellate can be given, secondary indications support the theory that the flagellate Phytomonas leptovasorum is the cause of the phloem necrosis disease of Coffea liberica in Surinam.
On a New Collar Ciliate of a Gribble: Lobochona prorates n. sp. on Limnoria tripunctata
Authors: MOHR JOHN LUTHER , LeVEQUE JEAN ANTHONY , MATSUDO HITOSHI
Published: May 2007

SYNOPSIS. Lobochona prorates n. sp., a collar cliate (CHONOTRICHIDA) ectocommensal on the pleopodal bristles of Limnoria tripunctata, is described. Lobochona prorates differs from the previously described chonotrichidan ectocommensal of the gribble, Lobochona limnoriae Dons on Limnoria lignorum (Rathke), in the outlines of the body and of the marginal lappets of the collar. The genus Lobochona Dons and the species Lobochona limnoriae Dons are redescribed.
Development of EDTA Media for the Rapid Growth of Chlamydomonas mundana
Authors: MACIASR F. M. , EPPLEY R. W.
Published: May 2007

SYNOPSIS. An empirical method is used to determine mixtures of the chelating agent, EDTA (ethylenediamine tetraacetate), and trace metals which allow maximum growth rates of Chlamydomonas mundana under optimum environmental conditions. In this method which resembles an immunological titration one trace metal (Ca, Fe, Mn or Zn), in increasing concentrations, is used to “saturate” a standard amount of EDTA. Other required trace metals are added in a range of minimum concentrations. Extent of growth with each mixture is evaluated after 24 hours of incubation. Mixtures allowing greatest growth are then used to evaluate growth rate. Media with manganese as the EDTA‐saturating trace metal allow most rapid growth rates equivalent to 11.0 doublings per day. Magnesium as the EDTA‐saturating metal does not allow growth, suggesting that Mg does not displace other required trace metals from EDTA‐complex. Since the mixtures allowing maximum growth rate are “underchelated” it appears that the free metals rather than the metal‐chelate complexes are utilized by the alga in rapid growth.
An Electron Microscope Study of the Amoebo‐flagellate, Naegleria gruberi (Schardinger). I. The Amoeboid and Flagellate Stages*
Authors: SCHUSTER FREDERICK
Published: May 2007

SYNOPSIS. Axenic and monobacterial cultures were utilized to study the ultrastructure of the amoeboid and flagellate stages in the life‐cycle of Naegleria gruberi. The cytoplasm of the amoeboid stage is poor in electron‐dense components; a loosely organized endoplasmic reticulum is present. The absence of cytoplasmic inclusions in the ectoplasm is the only detectable difference between it and the endoplasm. The nucleus of Naegleria is typically vesicular. The mitochondria are of the type commonly found in protozoa. Food and contractile vacuoles are described. No Golgi apparatus has been found.

The general ultrastructure of the flagellate resembles that of the amoeba. The kinetic apparatus consists of flagella and their associated kinetosomes, a “spur” made up of isodiametric fibrils (14 mμ in diameter) attaching to the base of the kinetosome, a cross‐striated rhizoplast, and thin‐walled fibrils (22 mμ in diameter) with a center of attachment in the kinetosomal complex.

Neither centrioles nor kinetosomes have been found in the amoeba. Complex arrangements of endoplasmic reticulum have been seen in the cytoplasm of transforming individuals which may be points of origin of the kinetosomes and/or flagella. The nuclei in metamorphosing individuals frequently show unusual plasticity.

Some speculations on possible orgins and affinities of Naegleria are included.
Electron‐Microscopic Demonstration of Plastids in Polytoma*
Authors: LANG NORMA J.
Published: May 2007

SYNOPSIS. The subcortical network identified as a leucoplast in Polytoma by some light microscopists actually consists of a system of branching mitochondria. A starch‐bearing plastid which may also contain stigma granules occurs beneath the mitochondrial layer. Tubular profiles in the plastid similar to those seen in a Chlamydomonas mutant may be significant to the hypothesis of the origin of Polytoma from a Chlamydomonas‐like organism by step‐wise loss of chlorophyll‐synthesizing ability. The basal bodies of the two typical flagella are connected by an additional broad fibril which arches across the anterior papilla.
Electron Microscopy of the Longitudinal Fibrillar Bundle and the Contractile Fibrillar System in Spirostomum ambiguum
Authors: YAGIU RYOZO , SHIGENAKA YOSHINOBU
Published: May 2007

SYNOPSIS. A study of the ‘longitudinal fibrillar bundle’ (LFB) and the ‘contractile fibrillar system’ (CFS) of a large protozoan ciliate, Spirostomum ambiguum, has been performed by means of an electron microscope. A system of sub‐pellicular fibrils has been newly found and its function is discussed. Each LFB runs parallel with a longitudinal row of ciliary bases. It seems to be identical with the so‐called kinetodesma. It is composed of tubular fibrils arranged in layered sheets, each of which contains 13 to 35 fibrils with the same diameter as the intra‐ciliary fibrils and has a close connection to each of the ciliary bases. The CFS lies on a transitional plane between ectoplasm and endoplasm of the organism and forms a cobweb‐like system of myofibrils as a whole. It stands in an intimate relationship with a characteristic vacuolar system. In a peristomial field, the fibrous structures are interrupted and somewhat thickened. A sub‐pellicular system is composed of minute fibrils 20 to 26 mμ in diameter. The fibrils run parallel with each other in an antero‐posterior direction, immediately beneath the inner pellicular membrane.
Influence of Enzymes on Germination of Sporocysts Of the Gregarine Pyxinia crystalligera Frenzel*
Authors: KOZLOFF EUGENE N. , BROWN HAROLD E.
Published: May 2007

SYNOPSIS. Sporocysts of P. crystalligera readily germinate to permit escape of their sporozoites when placed in an infusion of the contents and the tissue of the midgut of the beetle host, Dermestes vulpinus. To determine the type of digestive enzyme required for germination to take place, sporocysts were exposed in hanging drops to 0.25% (w/v) concentrations of commercial preparations of trypsin and lipase in a saline solution. Sodium taurocholate was used in combination with certain of the enzyme preparations.

Up to 99% of the sporocysts exposed to trypsin 1:300 and to a relatively crude preparation of lipase (containing some trypsin) germinated within three hours. A refined preparation of trypsin (2 × crystallized, salt‐free) induced up to 65% of the sporocysts to germinate within three hours. Refined lipase (50μl CO2/mg/30 min.) had no germinating effect upon sporocysts, either by itself or in combination with sodium taurocholate. In mixtures, crystallized trypsin seemed definitely to be inhibited by sodium taurocholate, and perhaps was inhibited also by refined lipase.

The fact that trypsin is effective in causing germination to take place suggests that the germination of sporocysts in the digestive tract of D. vulpinus depends upon a proteolytic enzyme. Unlike trypsin, which was more active in solutions adjusted to an initial pH of 7.0 and 8.0 (especially the latter, in the case of crystallized trypsin) than in those of pH 6.0, this enzyme was more effective in inducing germination at pH values of 6.0 and 7.0.
Genomic Exclusion in Tetrahymena: Genetic Basis*
Authors: ALLEN SALLY LYMAN
Published: May 2007

SYNOPSIS. Genomic exclusion is an aberration that occurs during conjugation in variety 1 of Tetrahymena pyriformis. Instead of containing markers from both parents, the out cross pairs are either homozygous for all the genes of one parent (unilateral genomic exclusion); or, some of the pairs are homozygous for the genes of one parent and other pairs are homozygous for the genes of the other parent (bilateral genomic exclusion). This phenomenon was first demonstrated in the C strain: some stocks evoke unilateral genomic exclusion; others, bilateral genomic exclusion. C*, inbred for 5 generations, was used to explore this phenomenon in some detail since unilateral genomic exclusion of C genes occurs in almost all pairs in outcrosses of C*. In a mating of C*, both exconjugants are recovered, both are dipioid and similar in phenotype. Using morphological markers, C* can be shown to participate in the mating; therefore, C* does not induce illegitimate matings of the normal mate. When the normal mate is heterozygous for alleles (HA/HD) not present in C*, 3 classes of offspring (HA/HA, HA/HD and HD/HD) are produced in a 1:2:1 ratio. These observations indicate that 2 meiotic products of the normal mate unite to form the syn carya. The genetic ratios obtained in 1 and 2 factor crosses limit the possible cytogenetic bases for genomic exclusion. They suggest that 1 of the 4 haploid nuclei replicates and the replica fuses randomly with any 1 of the 4 nuclei. The 2 schemes of nuclear behavior (single fertilization, double fertilization) that would satisfy these requirements have not yet been resolved.
Adaptations in Growth and Division inEuglenaEffected by Energy Supply*
Authors: COOK J. R.
Published: May 2007

SYNOPSIS.Euglena gracilis(strain Z) was grown auto‐trophically at different light intensities, saturating or limiting for cell division. Adaptation to culture at each light intensity was gauged from division rate, mass, protein, photosynthetic pigments, nucleic acids, volume, paramylum, lipids, respiration, and photosynthesis. Illumination above 1200 foot‐, candles was saturating for all aspects of cell growth; the highest intensity examined (3,000 ft‐c) slightly inhibited cell division. Intensities between 400 and 1200 ft‐c were saturating for all except photosynthesis and paramylum accumulation. Intensities less than about 200 ft‐c became limiting for all fractions except protein, which remained constant over the range 120–3000 ft‐c, dropping, however, at 65 ft‐c. Concentration of photosynthetic pigments increased as light intensity decreased.

Absolute synthetic rates were estimated for the individualEuglenacell for the measured cell constituents. While most followed a predictable pattern, increasing with light intensity to saturating levels, the synthetic rates for the pigments went through maxima at 190 ft‐c. Since fixed carbon in limiting light is so apportioned that protein is synthesized to the exclusion of paramylum, one concludes that the energy requirements for cell growth (measured as protein synthesis), and to a lesser extent cell division, have a higher priority than do those activities concerned more directly with maintenance.
The Transmission of Haemoproteus sp. of English Wood‐pigeons by Ornithomyia avicularia
Authors: BAKER J. R.
Published: May 2007

SYNOPSIS. Haemoproteus sp. (probably a subspecies of H., columbae Kruse, 1890) of Columba p. palumbus L. in England produces sporozoites in the salivary glands of Ornithomyia avicularia L. and has been transmitted by the bite of this insect. The parasite has also been isolated from naturallyinfected O. avicularia. Observations on experimentally‐infected birds have shown that the macrogametocytes reach their full size in six days, and the microgametocytes in five. The taxonomy of the genus is briefly discussed.
The Suppression of Mineralization in a Coccolithophorid By an Inhibitor of Carbonic Anhydrase*
Authors: ISENBERG HENRY D. , LAVINE LEROY S. , WEISSFELLNER HEINRICH
Published: May 2007

SYNOPSIS. The carbonic anhydrase inhibitor 2‐acetylamino‐1,3,4‐thiadiazole‐5‐sulfonamide‐sodium prevents mineralization in the coccolithophorid Hymenomonas sp. in concentrations which still permit the growth of organisms.
Protozoa as Toxicological Tools*
Authors: Hutner S. H.
Published: May 2007

At the age of 50 a Puka‐Pukan retires from manual labor and becomes one of the members of The Company, spending hi; evenings shooting popguns or playing checkers, and his nights in ordering the young fry about. He never again has to go fishing, to gather coconuts, or to do any other work.

When the malos [young men] bring in their fish they are given to the fathers, who divide them after picking out the choice bits for themselves… To be sure, many of the fathers spend a day or two at fishing now and then, but this is not required of them and they do it only to pass the time… (22).
A Revised Classification of the Phylum Protozoa*
Authors: Honigberg B. M. , Balamuth W. , Bovee E. C. , Corliss J. O. , Gojdics M. , Hall R. P. , Kudo R. R. , Levine N. D. , Lobblich A. R. , Weiser J. , Wenrich D. H.
Published: May 2007

SYNOPSIS. A classification of the phylum Protozoa at supra‐familial levels is given with definitions or descriptions of all of the involved taxa, some 140 in number. The scheme represents the result of the cooperative efforts of an international group of specialists and consultants who have‘been studying the overall problem for the past several years. Innovations of a nomenclatural nature have been held to a minimum, aside from the use of a system of uniform endings, but several major shifts of taxonomic significance have been introduced at all levels treated, including the subphyla. These revisions are explained in appropriately placed footnotes.
The Fine Structure of Leishmania donovani and the Role of the Kinetoplast in the Leishmania‐Leptomonad Transformation*
Authors: RUDZINSKA MARIA A. , D'ALESANDRO PHILIP A. , TRAGER WILLIAM
Published: May 2007

SYNOPSIS. An electron microscope study of Leishmania donovani revealed major differences between the intracellular leishmanial and the extracellular leptomonad stages. Parasites were also removed from infected hamster spleen, inoculated into cultures, and examined at intervals during incubation in order to follow changes during the transformation from one stage to the other. Prominent changes are evident primarily in the kinetoplast and the nucleoli after several hours of cultivation when the parasite is in an intermediate stage of transition. The kinetoplast, a composite organelk containing DNA and cristae mitochondriales, is a regular, sausage‐like structure in the leishmanial stage, but becomes irregular and enlarges extensively after a few hours in vitro, developing branches that are mitochondrial in nature and which, very likely, become new mitochondria. In the nucleus, significant nucleolar changes occur. The two homogeneous nucleoli characteristic of the leishmanial stage merge during transformation into one which is larger, less compact, and composed of small centrally located granules about 100 Å in diameter and larger particles over 200 Å in diameter at the periphery. These transformations of the kinetoplast and nucleolus are undoubtedly expressions of adaptive changes in the metabolic pattern of an intracellular parasite transferred to a markedly different extracellular environment of much lower temperature.

It was also found that the leishmanial stage of the parasite has two unit membranes which extend over the flagellum and the flagellar pocket; the intermediate stage and the leptomonad have only a single membrane. Furthermore, some leishmanias in spleen cells were found to be covered by a capsule‐like structure formed by the deposition of fine granular material between the two unit membranes. Since two to four organisms were occasionally found within such capsules, it is possible that encapsulation is a preparatory step for reproduction.
Induced Division Synchrony in Tetrahymena vorax*
Authors: WILLIAMS NORMAN E.
Published: May 2007

SYNOPSIS. Temperature‐cycling of the type used with T. pyriformis was applied to cultures of Tetrahymena vorax Tur in attempts to induce synchronous cell division. The best temperature‐cycling treatment found produced division indexes of 40% (T. pyriformis yields 85%). The age‐dependent thermal sensitivity of untreated T. pyriformis which is often cited as an explanation for its response to temperature‐cycling has been demonstrated in T. vorax. However, a difference was noted which may explain the different degrees of synchrony obtained. It is suggested that the fission‐delay distributions obtained with T. pyriformis can be explained on the basis of an hypothesis in which all cells behave uniformly. In T. vorax, in contrast, the delay distributions suggest that the thermal sensitivity pattern is not the same in all cells.