bluuebunny/crossref_metadata_2025 huggingface dataset:
The Fine Structure of Trypanosoma congolense in Its Bloodstream Phase
Authors: VICKERMAN KEITH
Published: May 2007

SYNOPSIS. The fine structure of 2 isolates of Trypanosoma congolense maintained in laboratory rodents has been studied from thin sections of osmium‐ and aldehyde‐fixed flagellates. The pellicular complex, nucleus, and flagellar apparatus are all similar to those of other African trypanosomes. Aberrant intracellular differentiation of the flagellum is occasionally found.

As in bloodstream forms of other salivarian trypanosomes the single mitochondrion forms an irregular canal running from one end of the body to the other, with a shallow bowl‐shaped expansion forming a capsule for the fibrous kinetoplast (mitochondrial DNA). A connexion between the mitochondrial envelope of the kinetoplast and the basal body of the flagellum is not evident, and sometimes the flagellum base is not even apposed to the kinetoplast but lies behind it. Tubular cristae are present in the mitochondrial canal and, by light microscopy, this structure gives a positive reaction for NAD diaphorase suggesting at least some activity in electron transport, even tho at this stage in its life cycle respiration is doubtfully sensitive to cyanide and cytochrome pigments are in all probability absent.

The region of the cytoplasm between the nucleus and the flagellar pocket has all the trappings associated with secretory cells in higher animals, or with the secretion of surface structures in phytoflagellates. just behind the nucleus a limb of granular reticulum subtends a Colgi stack of flattened saccules with attendant vesicles. Close to the distal pole of the Golgi complex is a network of smooth‐membraned cisternae, termed here the agranular or secretory reticulum, which undergoes localized swelling with the accumulation of a secretory product to form large spherical sacs or vacuoles. These network‐linked vacuoles probably correspond to the post nuclear vacuole complex visible by light microscopy. From its apparent secretory function this complex is regarded here as being possibly an extension or derivative of the Golgi complex, the smooth‐membraned tubules lying alongside the 2 structures possibly representing a link between them.

By analogy with phytoflagellates and the secretory cells of higher animals, it is suggested that the secretion is transported for discharge into the flagellar pocket by way of multivesicular bodies and smooth‐walled tubules or vesicles. Spiny pits in the wall of the flagellar pocket, and similar‐sized vesicles in the nearby cytoplasm, could be stages in either exocytosis of secretion or endocytosis (pinocytosis). It is tentatively suggested that the secretion may be the material from which the surface coat is formed.

Neither a cytostome nor a contractile vacuole has been observed in T. congolense.
Toxoplasmosis in Cold‐Blooded Hosts*
Authors: STONE W. B. , MANWELL R. D.
Published: May 2007

SYNOPSIS. The existence of naturally acquired toxoplasmosis in cold‐blooded animals, tho sometimes claimed, has always been regarded as extremely doubtful, and tests of susceptibility to experimental infection have usually given negative results. Using a strain of human origin (RH), we attempted infection of 7 species of reptiles (red‐eared turtle Pseudemys scripta elegans, horned toad Phrynosoma cornutum, coal skink Eumeces anthrospinus, blue spiny lizard Sceloporus cyanogenys, chamaeleon Anolis carolinensis carolinensis, spectacled caiman Caiman sclerops, iguana Iguana iguani), and 3 species of amphibia, (American toad Bufo americanus, leopard frog Rana pipiens pipiens, newt Diemectylus viridescens viridescens). The horned toads, chamaeleons, and toads were kept both at room temperature and 37 C, and the skinks only at 37 C; other species were kept only at room temperature. Inoculation was by intrapcritoneal injection of parasitecontaining ascitic fluid from infected mice. Results were measured by the finding of parasites microscopically and by infection of mice. In toads, infection persisted 7 days: in red‐eared turtles, chamaeleons and the blue spiny lizard 7‐8 days; skinks had a fulminating infection which was fatal in a week or less. Actual reproduction of parasites occurred in both homed toads and skinks kept at 37 C, showing that there was true infection and not simply survival of organisms. These results suggest that natural infections could occur under suitable environmental conditions in horned toads and some other species of lizards.
Inhibition of Ochromonas Respiration by Hypocholesteremic Compounds and its Annulment by Unsaturated Fatty Acids
Authors: AARONSON S. , ROZE U. , KEANE M. , ZAHALSKY A. C.
Published: May 2007

SYNOPSIS. Eleven of 14 hypocholesteremic drugs inhibited aerobic respiration of the phytoflagellate Ochromonas danica. Lecithin and unsaturated fatty acids annulled the inhibition of respiration by triparanol. Saturated fatty acids, squalene, cholesterol and a mixture of amino acids, purines, and water‐soluble vitamins were inactive. Unsaturated fatty acids only annul the triparanol inhibition if preincubated or added simultaneously with triparanol. Evidence is presented suggesting that triparanol and oleic acid form a complex or micelle; presumably in this form the triparanol no longer inhibits aerobic respiration.
An Apparent Carbohydrate‐Amino Acid Interaction in Tetrahymena pyriformis
Authors: REYNOLDS HOWARD
Published: May 2007

SYNOPSIS. Experiments were designed to examine the nature of the response of Tetrahymena pyriformis to inhibitory levels of L‐serine when growing in defined media with carbohydrate as mono‐, or polysaccharide. Growth curves indicated that, when a polysaccharide is being utilized, inhibition by serine affects at least 2 different loci. At one locus, inhibition causes a marked increase in the growth lag, at the other a significant decrease in the maximum rate of growth. Since the inhibition was completely reversible by glucose supplementation, it is evident that the initial inhibition, expressed as increased lag time, is specifically related to uptake or metabolism of the polysaccharide, i.e., it precedes glucose in the metabolic sequence. The inhibition expressed as decreased rate of maximum growth appears to be due to interference at some stage in the glycolytic pathway. The results suggest that in metabolizing a polysaccharide, T. pyriformis utilizes 2 mechanisms simultaneously. One involves phagocytic ingestion of molecular dextrin followed by phosphorylytic cleavage whereby the energy of the glycosidic bond is utilized to form glucose‐1‐phosphate. The 2nd mechanism depends upon elaboration of extracellular hydrolytic enzymes to cleave the polysaccharide to glucose, which enters the glycolytic pathway via glucose‐6‐phosphate in the usual manner.
Light and Electron Microscope Observations on Nosema nelsoni Sprague, 1950 (Microsporida, Nosematidae) with Particular Reference to its Golgi Complex*
Authors: SPRAGUE VICTOR , VERNICK SANFORD H.
Published: May 2007

SYNOPSIS. A species of Nosema in the muscles of the North American white shrimp, generally known as Penaeus setiferus but also known as P. fluviatilis, appears identical with type specimens of N. nelsoni Sprague, 1950, in P. aztecus. Its Golgi apparatus, as seen in the sporoblast, is a complex system of cisternae, small vesicles and expanded sacs which plays a major role in spore morphogenesis. It transforms directly into the polaroplast complex, certain membranous investments of the polar filament, the polar sac and perhaps part of the posterior vacuolar system. Probably the polar sac contains the polar cap. The PAS‐positive material in both the cap and the filament may be a component of the Golgi complex. This new concept of the Golgi complex supplements our earlier view of spore morphogenesis according to which the polar filament is of nuclear origin. It also reconciles the idea with Vávra's identification of Golgi vesicles associated with the developing polar filament.
Gamma Irradiation of Stentor polymorphus
Authors: PREECE ALAN W.
Published: May 2007

SYNOPSIS. Stentor polymorphus was irradiated with 60Co gamma rays at 525 rads/minute to examine the effect on survival, cell division, oral membranellar frequency and oxygen uptake. Both survival and cell division were studied on single cells. The LD50 is 285 kilorads but cell division is inhibited below this dose; 110 kilorads doubles the 1st post‐irradiation division interval, and a delay of 240 hours occurs at the maximum tolerated dose of 310 kilorads. Conjugating cells are more sensitive, with an LD50 of approximately 40 kilorads.

The frequency of cilia in the membranellar band, measured stroboscopically, is reduced by 30% after 14.5 kilorads, and stopped by higher doses. Recovery has a similar time scale to recovery of fission. A Clarke electrode was used to measure changes in oxygen uptake after irradiation. Depressions of up to 50% were found. Recovery followed a similar pattern to that of ciliary activity and cell division.
The Form and Function of the Cytostome‐Cytopharynx of the Culture Forms of the Elasmobranch Haemoflagellate Trypanosoma raiae Laveran & Mesnil
Authors: PRESTON T. M.
Published: May 2007

SYNOPSIS. In the culture forms of the elasmobranch trypanosome Trypanosoma raiae is found a prominent cytopharyngeal complex. This consists of a group of 5 or 6 microtubules associated with a deep invagination of the cell membrane which arises from a cytostome near the opening of the flagellar pocket. This structure is a constant feature of the various epimastigote and trypomastigote forms that this flagellate has in culture. Replication of the cytopharyngeal apparatus is completed before cytokinesis.

Experiments using ferritin as an electron dense tracer show that endocytosis occurs from the blind ending of the cytopharynx both in the exponential and stationary phases of growth in vitro. Ferritin is transported from the cytopharynx by endocytotic vesicles to large, membrane‐bound vacuoles in the posterior region of the cell. Ultrastructural location of non‐specific acid phosphatase within these digestive vacuoles and also within the Golgi apparatus is reported.

Coated vesicles found in association with the flagellar pocket are another route of uptake of ferritin by T. raiae.
Apparent Indispensability of Bacteria in Foraminiferan Nutrition
Authors: MULLER WILLIAM A. , LEE JOHN J.
Published: May 2007

SYNOPSIS. Bacteria were required for the sustained reproduction of 4 species of foraminifera in gnotobiotic culture. None of the species of algae tested, singly or in combination, supported continuous reproduction of the foraminifera in bacteria‐free gnotobiotic culture. It is inferred that bacteria have some nutritional factor required by the foraminifera that is either unavailable or unavailable in sufficient quantity in an exclusively algal diet.

Gnotobiotic clones of Quinqueloculina lata, Spiroloculina hyalina, Rosalina leei, and Allogromia laticollaris were established on bacteria + algae (usually 1 or 2 species). In balanced gnotobiotic cultures neither light nor foraminiferan density (organisms/ml) were limiting. As cultures aged, pH shifted and limited growth. When waste products were removed by washing, reproductive rates were higher.
The Nutrition of Paramecium aurelia, Stock 299
Authors: SOLDO A. T. , VAN WAGTENDONK W. J.
Published: May 2007

SYNOPSIS. Paramecium aurelia, stock 299 (symbiote‐free) was cultivated in a synthetic medium consisting of amino acids, vitamins, purine and pyrimidine derivatives, fatty acids, stigmasterol, sodium acetate and salts. The medium supported the continued growth of this stock in serial subculture. Populations up to 17,000 organisms/ml were obtained in 9 or 10 days in the medium supplemented with a phospholipid. Synthetic 1‐oleoyl‐2‐stearoyl‐dl‐phosphatidyl serine, phosphatidyl ethanolamine, phosphatidyl inositol, phosphatidyl serine and cephalin were comparable in growth‐promoting activity. The nutritional need for each of the components of the medium was examined. The following were determined to be essential nutrilites for P. aurelia: arginine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, threonine, tryptophan, tyrosine, valine, folic acid, nicotinamide, calcium pantothenate, pyridoxal, riboflavin, thiamine, DL‐6‐thioctic acid, guanosine, uridine (or cytidine), oleic acid, stigmasterol, calcium and magnesium. Serine replaced glycine for growth in the presence of thymidine. In the absence of thymidine, comparatively high levels of folic acid were required for optimal growth. Sodium acetate did not replace DL‐6‐thioctic acid. Populations were reduced in the absence of the non‐essential amino acids, alanine, asparagine, aspartic acid and glutamic acid. These were restored to optimal levels by the addition of sodium acetate to the medium. Pyruvate was about as effective as acetate in this respect; glucose and certain other carbohydrates were not.
Structure of a Nonpathogenic Histomonad from the Cecum of Galliform Birds and Revision of the Trichomonad Family Monocercomonadidae Kirby*
Authors: HONIGBERG B. M. , KULDOVAÁ JELENA
Published: May 2007

SYNOPSIS. The nonpathogenic flagellate from the cecum of fowl, hitherto known as Histomonas wenrichi Lund, is an actively ameboid organism equipped with 4 flagella. Three of the flagella, subequal in length, are applied to one another for a short distance anterior to their origin in the kinetosomal complex and typically terminate in knob‐like expansions; the 4th flagellum originates independently of the others and ends in a fine filament. A short, wide pelta is joined to the anterior part of the broad, spatulate axostylar capitulum applied to the left‐ventral surface of the ellipsoidal, spheroidal, or ovoidal nucleus. Posterior to the nucleus the capitulum narrows into a slender axostylar trunk, which does not project beyond the body surface. The parabasal body, associated with a long, stout parabasal filament, is dorsal and to the right of the nucleus. On the basis of the flagellar number, the parasite is placed in a new genus Parahistomonas. A new subfamily, Protrichomonadinae, is created within the appropriately emended trichomonad family Monocercomonadidae for Parahistomonas wenrichi (Lund) comb. nov. as well as for Histomonas meleagridis (Smith) and Protrichomonas legeri (Alexeieff).
An Analysis of the Formation of Ciliary Primordia in the Hypotrich Ciliate Urostyla weissei*
Authors: JERKA‐DZIADOSZ MARIA , FRANKEL JOSEPH
Published: May 2007

SYNOPSIS. The protargol technic was used in a study of the development of oral, cirral, and dorsal primordia of Urostyla weissei fixed during division, reorganization, and regeneration following transection at different levels. While the course of development is similar in all situations, differences were observed in the way in which some primordia are initiaily formed. The primordium of the new AZM always appears posterior to the old AZM. It develops into an entire new membranellar band in dividing cells and in opimers (posterior fragments from equatorial transections), while it eventually joins with a portion of the old AZM in reorganizers, promers (anterior fragments from equatorial transections) and “large opimers” (cells whose anterior tip has been cut off). The UM‐primordium of proters is derived from disaggregation of the kinetosomes of the 2 old UM's, that of opisthes and opimers is formed “de novo” to the right of the AZM‐primordium, while the UM‐primordium of reorganizers, promers, and “large opimers” is of composite origin, partly “de novo” and partly from the old UM's. The UM primordium differentiates into the new UM's and the 1st frontal cirrus. The primordia of the remaining frontal, ventral, transversal (F‐V‐T) and marginal cirri originate as “streaks” of cilia, most of which are derived from re‐alignment of the constituent cilia of certain pre‐existing cirri. New cirri differendiate from the streaks, and replace the remaining old cirri. The streaks are formed similarly in all developmental situations, except for the 1st 3 F‐V‐T streaks. In proters, reorganizers, and promers, these originate from the posterior 3 frontal cirri, while in opisthes and opimers they are formed “de novo” to the right of the UM‐primordium. In the “large opimers” these streaks are formed “de novo” behind the 1st 3 frontal cirri, in spite of the continued presence of these cirri at the anterior tip of the fragments. The site of formation of these streaks thus appears to be determined by an anteriorposterior gradient, rather than by any preformed cortical structure.

The new dorsal bristle rows I to III develop from the proliferation of portions of the old rows, while rows IV and V originate from short kineties formed “de novo” on the right margin. New caudal cirri differentiate at the posterior ends of the new rows I to III.

The numbers of ventral cirral rows and transversal cirri are variable; these variations are correlated, and related to variations in numbers of developing streaks.

A survey of hypotrich developmental patterns revealed extensive parallels, especially in the sites of appearance of primordia. The primordium site appears to be a more constant feature of cortical development than is the “source” of ciliary units. It is concluded that sites of primordia are determined by cellular gradients, with competent preformed structures being utilized if they are appropriately positioned within these gradients.
Etude Cytologique, Systématique et Pathologique d'Ichtyobodo necator (Henneguy, 1883) Pinto, 1928 (Zooflagelle)
Authors: JOYON LOUIS , LOM JIRI
Published: May 2007

SYNOPSIS. The free form of Ichtyobodo necator is typically quadrangular, with rounded corners, and flattened dorso‐ventrally. Its dorsal surface is strongly convex and its ventral surface somewhat concave. A longitudinal groove traverses the posterior 2/3 of the ventral surface near its right margin. The part of the organism anterior to the groove is rather thick; that containing the depression thins out progressively toward the posterior end. Most of the organelles are in the major part of the cytoplasm to the left of the groove. Anteriorly this depression continues into a rather short canal. Two (4 in predivision stages) flagella originate near the anterior end of the canal, from which they run posteriorly. The cytostome is also near the anterior part of the canal. The cytostome, canal, and cell membrane are reinforced by microtubules. The chondriome, undoubtedly represented by a single very elongated mitochondrion, contains numerous dilated areas rich in deoxyribonucleic acid.

The fixed form of the flagellate is highly modified. Its anterior part becomes attached to the host cell by forming a plate. A type of sucking organelle that contains the cytostome forms from the plate and penetrates the host cell.

I. necator belongs in the family Bodonidae.

RESUME La forme libre d'Ichtyobodo necator est quadrangulaire avec des angles arrondis, et présente un aplatissement dorsoventral. Sa surface dorsale est fortement convexe et sa surface ventrale légèrement concave. Une gouttiére longitudinale traverse les 2/3 postérieurs de la face ventrale sur le bord droit. La région cellulaire antérieure à, la gouttiére est plus épaisse que celle qui contient la dépression et s'amincit progressivement vers la partie terminale. La plupart des organites cellulaires occupent la partie gauche de la cellule. Dans la région antérieure la gouttiére se prolonge par un canal assez court. Deux (quatre dans les stades de prédivision) flagelles partent de ce canal et se dirigent vers la région postérieure. Le cytostome est également localisé près de la région antérieure du canal. Le cytostome, le canal et la membrane cellulaire sont jouxtés de microtubules. Le chondriome, sans doute représenté par une seule mitochondrie très allongée, présente de nombreuses dilatations riches en acide désoxyribonucléique.

La forme fixée du flagellé est très modifiée. Sa partie antérieure adhère à la cellule hǒte par l'intermédiaire d'un plateau. Une sorte de suçoir, qui contient le cytostome, se forme à partir de ce plateau et pénètre dans la cellule hǒte.

Ichtyobodo necator appartient à la famille des Bodonidae.
Intranuclear Virus‐like Bodies in the Amoeboflagellate Naegleria gruberi*
Authors: SCHUSTER FREDERICK L.
Published: May 2007

SYNOPSIS. Intranuclear virus‐like bodies were seen in cultures of the EG strain of Naegleria gruberi from soil. Introduction of these virus‐like particles into cultures seemed to coincide with use of chicken embryo extract as a supplement in culture media used to maintain axenic amoebae in the laboratory; the appearance of the virus‐like units is triggered by transfer of axenic lines of N. gruberi EG into monobacterial culture medium. The particles, ∼ 100 nm in diameter, are mainly restricted to the nucleus of the cell. Passage of particles from the nucleoplasm into the cytoplasm is suggested by theit association with tubular projections from the nuclear membrane, and particles have been seen in the cytoplasm of the amoebae. The virus‐like bodies resemble reovirus.
Autogamy in Allogromia laticollaris (Foraminifera)
Authors: LEE JOHN J. , McENERY MARIE E.
Published: May 2007

SYNOPSIS.The life cycles of 2 strains ofAllogromia laticollaris(CSH and TPA) raised on experimentally restricted diets have been studied. Cloned cultures of the strains differed in nutritional requirements for continuous reproduction. The TPA strain was more fecund. Both strains have a basically apogamic (asexual) life cycle; only occasionally were gamonts (sexually reproducing individuals) produced. They were autogamous (self‐fertilizing) and fusion of the gametes took place within the parental test.

We found in CSH clones a regular alternation of vesicularly nucleated and compactly multinucleated diploid generations. The details of the life cycle of either strain are not known well enough to be able to construct life cycle diagrams more meaningful than that of Arnold. The 2 strains studied differ in cytologic and nuclear detail from each other and from the strain studied by Arnold.
Brooklynella hostilis n. g., n. sp., a Pathogenic Cyrtophorine Ciliate in Marine Fishes*
Authors: LOM JIRI , NIGRELLI ROSS F.
Published: May 2007

SYNOPSIS. Brooklynella hostilis is a new genus and new species of highly lethal Chilodonella‐like parasite in the gills of marine fishes. It differs from other dysteriid ciliates by a combination of these features: 1) posterior‐ventral adhesive apparatus consisting of a single glandular organelle that lacks a distinct discharging canal or podite; 2) the kinetosomes cover the entire ventral surface, except the left posterior portion of the body; the outer right kinety is divided into 2 segments; the middle postoral kinetyues as a row of kinetosomes without cilia around the glandular organelle; 3) there are never more than 9 nematodesmata; and 4), there are numerous small micronuclei. The lesions caused by the infection vary from a mild inflammatory reaction to extreme tissue damage resulting in severe hemorrhages, desquamation, and fusion of the gill lamellae.
Nosema algerae n. sp. (Cnidospora, Microsporida) a Pathogen in a Laboratory Colony of Anopheles stephensi Liston (Diptera, Culicidae)
Authors: VAVRA JIRI , UNDEEN ALBERT H.
Published: May 2007

SYNOPSIS. A new microsporidan, Nosema algerae n. sp., was found in a laboratory colony of Anopheles stephensi. The microsporidan infects a variety of tissues of both larvae and adults and is highly pathogenic for its host. The structure and life cycle of the microsporidan under the light and electron microscope is described and its relationship to other Nosema species infecting mosquitoes is discussed.
Helicosporidium parasiticum Keilin Infection in the Caterpillar of a Hepialid Moth in Argentina
Authors: WEISER JAROSLAV
Published: May 2007

SYNOPSIS A case of infection by Helicosporidium parasiticum Keilin, 1921, in a hepialid caterpillar from Argentina is described. The pathogen produces deep proliferation starting from a cuticular callus, with numerous cysts occluded by multiple fibrous layers of connective tissue. Other cysts encapsulated in layers of lymphocytes and cysts in the lobes of the fat body are present in different parts of the body. Centers of melanization occur in most cysts. The pathway of infection, the reaction of the host and some structural features of the parasite are typical for fungus infections. Transfer of the genus Helicosporidium from Protozoa to primitive Ascomycetes, Saccharomycetaceae, is proposed.
Eimeria reedi sp. n. and E. chobotari sp. n. (Protozoa: Eimeriidae) from Heteromyid Rodents
Authors: ERNST JOHN V. , OAKS EMILY C. , SAMPSON J. ROBERT
Published: May 2007

SYNOPSISThe oocysts of 2 new species ofEimeriaare described from heteromyid rodents. The subspherical to ellipsoidal cocysts ofEimeria reedifromPerognathus formosusaveraged 22.6 by 20.8 μ. An ellipsoidal polar granule was present. The oocyst residuum was a single globule about 8 μ in diameter. The ovoid sporocysts averaged 10.9 by 7.7 μ and had a residuum of 6‐12 granules. A Stieda body and substiedal body were present in the sporocysts.Eimeria chobotarioocysts, fromDipodomys merriamiandD. microps, were ellipsoidal to ovoid and averaged 47.7 by 35.2 μ. No polar granule was seen. The large oocyst residuum consisted of several granules of various sizes. The ovoid sporocysts averaged 15.8 by 11.3 μ and had a residuum of many small granules. A Stieda body and substiedal body were present in the sporocysts.
Pneumocystis carinii Delanoë, its Ultrastructure and Ultrastructural Affinities*
Authors: VAVRA J. , KUCERA K.
Published: May 2007

SYNOPSIS The fine structure of Pneumocystis carinii Delanoë is described in detail and is compared to the fine structure of protozoa and fungi. Pneumocystis does not have ultrastructural affinities to Protozoa but rather to fungi. Specifically, the process of intracystic body formation in the cyst is similar to the formation of ascospores inside a yeast ascus. The significance of the structural similarity between Pneumocystis and fungi is discussed. It is concluded from the ultrastructural evidence that Pneumocystis may indeed be a yeast or have a yeast‐like stage in its life cycle. However, Pneumocystis is not completely similar to any fungus whose ultrastructure has been described so far. Perhaps its particular structure may be an adaptation to the parasitic way of life in mammalian lungs. It should be cultivated in order to be sure of its exact taxonomic position.
The Fine Structure of Some Developmental Stages of Mattesia grandis McLaughlin (Sporozoa, Neogregarinida), a Parasite of the Boll Weevil Anthonomus grandis Boheman
Authors: VAVRA JIRI , McLAUGHLIN ROY E.
Published: May 2007

SYNOPSIS Sporozoites, macronuclear schizonts, merozoites and gamonts of Mattesia grandis were examined by electron microscopy. A conoidal complex, consisting of conoid, polar rings and subpellicular microtubules was present in all of these stages. The conoidal complex was similar in structure to the same organelle of other Sporozoa. The conoidal complex in mono‐ to quadrinucleate macronuclear schizonts is transformed into an organelle similar to the mucron of some eugregarines.

This mucron consists of a specialized area of the cell membrane from which fine fibers extend into a large vacuole situated directly beneath the cell membrane. The top part of the vacuole is encircled by 2 ring‐like structures formed by the dilatation of the original apical rings. The vacuole of the mucron contains many anastomosing protrusions of the cytoplasm, suggesting a nutritional role. The mucron disappears when the schizont reaches the multinucleate state. Later the merozoites bud from the surface of the schizont as in the coccidia. Each merozoite again has a conoidal complex, which persists thru the gamont stage and usually serves as the point of contact between 2 gamonts during their pairing.

The presence of a conoidal complex thru a major portion of the life cycle, its transformation into a mucron and the mode of formation of merozoites indicate that the Neogregarinida combine the fine structure characters of both the Eugregarinida and the Eucoccida, thereby suggesting a phylogenetic relationship between these sporozoans, with the neogregarines as a link between eugregarines and coccidia.
The Ultrastructure of Brood Pouch Formation in Tokophrya infusionum
Authors: MILLECCHIA LYNDELL L. , RUDZINSKA MARIA A.
Published: May 2007

SYNOPSIS Asexual reproduction in Tokophrya infusionum is by internal budding, whereby a ciliated, motile embryo is formed inside the sessile, non‐ciliated parent in a specialized structure, the brood pouch. The process of embryogenesis and brood pouch formation was studied with the electron microscope using synchronized cultures. Reproduction begins with invagination of the pellicle and plasma membrane in the apical region of the adult. Early invagination is characterized by the presence of numerous microtubules beneath the plasma membrane or epiplasmic layer of the invaginating membranes. These microtubules apparently are important in formation of the brood pouch for colchicine blocks embryogenesis during the early stages. When the embryo is completed, it is ejected from the brood pouch thru the birth pore, an opening which is the site of the initial invagination and is present thruout embryogenesis. Theories of brood pouch formation are reviewed and discussed in light of the present investigation.
Lysine Uptake in Cultured Trypanosoma cruzi: Interactions of Competitive Inhibitors*
Authors: HAMPTON JAMES R.
Published: May 2007

SYNOPSIS Three sites are involved in lysine transport in Trypanosoma cruzi, as inferred from interactions of inhibitory neutral amino acids. Phenylalanine and tyrosine inhibit one site; proline and the straight‐chain amino acids, alanine, methionine and cysteine inhibit another; and glycine and the branched‐chain valine, leucine, and isoleucine inhibit a 3rd. The curved rather than straight line obtained with a Lineweaver‐Burk plot of uptake rates presumably results from the functioning of qualitatively different transport sites. Blocking every site but one results in the linear double‐reciprocal plot characteristic of adsorption kinetics. The partial competitiveness of most of the inhibitions appears to denote qualitatively different sites for lysine transport and the reaction of the inhibitor with more than one site. Since most of the inhibitions were partially competitive, the specificities of the 3 lysine transport sites must overlap considerably.
Life Cycles of Leucocytozoon dubreuili Mathis and Leger, 1911 and L. fringillinarum Woodcock, 1910 (Haemosporidia: Leucocytozoidae)*
Authors: KHAN RASUL A. , FALLIS A. M.
Published: May 2007

SYNOPSIS The development of Leucocytozoon dubreuili and L. fringillinarum was studied on successive days in simuliid and avian hosts. Sporogony of both parasites is completed in at least 5 species of sylvatic Simuliidae in a minimum of 4‐5 days at 21 C. The pattern of development of the 2 species is similar but the size of the oocysts and the number of sporozoites differ. Sporozoites of L. dubreuili and L. fringillinarum were injected into uninfected robins (Turdus m. migratorius) and grackles (Quiscalus quiscula versicolor), respectively. Hepatic biopsies were performed on some of the injected birds. These and others were killed at intervals following inoculation and their tissues examined to detect stages of schizogony. Blood and macerated tissues from birds injected with sporozoites were transferred to uninfected birds to determine whether asexual stages would develop in the latter as a result of the inoculations.

The 1st asexual cycle of L. dubreuili is completed in hepatic parenchymal cells in a minimum of 84 hr. Merozoites produced by the hepatic schizonts apparently follow one of 3 courses: invade hepatic parenchymal cells to initiate another cycle; penetrate blood cells and become gametocytes; penetrate tubular cells of the kidneys and grow into renal schizonts.

The minimum prepatent period in infections with L. fringillinarum is 76 hr. The 1st asexual cycle occurs in hepatic parenchymal cells and in tubular cells of the kidney. A schizogonic cycle is completed in a minimum of 72 hr in the former and 96 hr in the kidney. Merozoites from the primary hepatic schizonts apparently give rise to (a) gametocytes; (b) secondary hepatic schizonts; (c) renal schizonts. Thus the schizogonic cycles of L. dubreuili and L. fringillinarum differ from each other and from those of L. simondi in ducks.
Helical Nature of the Ciliary Beat of Paramecium multimicronucleatum*
Authors: KUŹICKI LESZEK , JAHN THEODORE L. , FONSECA JAMS R.
Published: May 2007

SYNOPSIS. Phase and interference cinemicrographs of cilia of Paramecium multimicronucleatum, immersed 3–24 hours in 1.0% methyl cellulose, revealed that 1) in swimming Paramecium the cilia beat with a traveling helical wave from base to tip rather than with the back and forth movement usually assumed, 2) during ciliary reversal the cilia merely change direction, but continue to beat with a traveling helical wave, and 3) in stationary Paramecium the beat is conicoidal. The traveling wave appears as an undulatory wave about 1 1/4 wave lengths long in both surface and profile views, and therefore must be helical. Envelope of the wave is cylindrical except near the base. Observations were confirmed in media without methyl cellulose by means of high speed cinemicrography, up to 4000 frames/sec.

The back and forth movement, as described in all textbooks and monographs, is based mostly on 1) analogy to the abfrontal cilia (cirri) of Mytilus, which do beat with a back and forth movement, and 2) conclusions drawn from fixed preparations which do not represent what actually happens in a living animal.

In a stationary Paramecium the envelope of the beat is conicoidal as seen in profile, but probably is a spiral wave, i.e., similar to a helix but increasing in diameter from base to tip. This change in wave form could be caused by the increase in resistance of the water in a stationary organism over one that is moving.

Cilia and flagella (also ciliates and flagellates) are usually distinguished on the basis of wave form, but the present observations, together with previous data on flagella, show that such distinctions are untenable.
The Effect of Acetate on Euglena gracilis var. bacillaris as a Function of Environmental Conditions
Authors: BATES ROBERT C. , HURLBERT RONALD E.
Published: May 2007

SYNOPSIS. Acetate, a widely used substrate for the growth of Euglena gracilis var. bacillaris, becomes lethal to these organisms at pH's below 5.0. The kinetics, as well as the extent of acetate‐induced death, depend upon both the hydrogen ion and acetate concentrations. Formic, propionic, butyric, and fluoroacetic acids also kill E. gracilis at low pH's, whereas fumaric, malic, succinic and pyruvic acids do not under these conditions.

It is suggested that death is caused by a lowering of the intra‐cellular pH, due to the release of hydrogen ion brought into the cell by freely penetrating undissociated acetate molecules.
The Effects of Colchicine and Colcemid on Oral Differentiation in Stentor coeruleus*†
Authors: HAIGHT JOHN M. , BURCHILL BROWER R.
Published: May 2007

SYNOPSIS. Oral regeneration, oral reorganization and cell division in the ciliate Stentor coeruleus can be temporarily blocked at any stage of development by exposure to colchicine. The implications of this observation, presented as an assumption that colchicine exerts its effects by specifically preventing the formation of microtubular elements in the cells, suggest that microtubules are essentially involved in many aspects of these complicated processes of cellular differentiation.
The Incorporation of Phenylalanine and Uridine in Tetrahymena: A Pressure Study1
Authors: LOWE‐JINDE LOUISE , ZIMMERMAN ARTHUR M.
Published: May 2007

SYNOPSIS. The action of pressure was studied on the incorporation of labelled phenylalanine and uridine, and on the synthesis of water‐soluble proteins in heat‐synchronized Tetrahymena pyriformis. Incorporation of [14C] phenylalanine and [3H] uridine into TCA insoluble fractions was markedly decreased in pressuretreated Tetrahymena. Moreover, the incorporation was dependent upon the age of the cells. Water‐soluble protein synthesis was unaffected. These results appear consistent with the proposal that pressure‐induced division‐delays occur by inhibiting the accumulation of “division proteins” which are essential for cell division.
Two Marine Species of Flabellula (Amoebida, Mayorellidae)*
Authors: PAGE FREDERICK C.
Published: May 2007

SYNOPSIS. Two species of amoebae identified as Flabellula citata Schaeffer, 1926, and F. calkinsi (Hogue, 1914) were isolated from saltwater habitats on the Maine coast. Both species showed the locomotive form and behavior of the genus Flabellula emend. Bovee, 1965. Both showed a mitotic pattern distinct from that of the genus Vannella Bovee, 1965, supporting Bovee's subdivision of Schaeffer's genus Flabellula. Preparations of F. calkinsi had an unusually high proportion of cells with 2 or more nuclei. F. calkinsi is a voracious cannibal. Neither F. citata nor F. calkinsi formed cysts in culture. Both species could be cultivated on media made with highly dilute sea water, but neither survived in a medium equivalent to a freshwater medium.
Changes in Structure of Phytomonas elmassiani in Experimental Infections of Apocynaceae, a Presumably Foreign Plant Host
Authors: McGHEE R. BARCLAY , HANSON W. L.
Published: May 2007

SYNOPSIS. Allamanda nereifolia and Plumeria rubra, plants belonging to the family Apocynaceae were infected experimentally with the trypanosomatid flagellate, Phytomonas elmassiani. In these presumably exotic hosts, P. elmassiani, ordinarily infecting plants belonging to the family Asclepiadaceae, underwent marked structural changes. The presence of numerous choanomastigote like organisms along with a certain proportion of promastigotes and amastigotes, would, under ordinary circumstances, result in classification of the infecting organisms as Crithidia. Obviously, the change in environment from Asclepiadaceae to the closely related Apocynaceae, exerts a profound influence on structure of the organism.
Holotrich Ciliates from the Stomach ofHippopotamus amphibius, with Descriptions of Two New Genera and Four New Species
Authors: THURSTON JUNE P. , GRAIN JEAN
Published: May 2007

SYNOPSIS.Holotrich ciliates from the stomach contents ofHippopotamus amphibiusare described, including details of their infraciliature. They are placed in 4 families: subclass Holotrichia, order Gymnostomatida, suborder Rhabdophorina, family Buetschliidae:Blepharozoum binucleatumn.sp.,Cucurbella vivaxn.g., n.sp.; order Trichostomatida, family Plagiopylidae:Paraplagiopyla kibokon.g., n.sp.; family Paraisotrichidae:Paraisotricha minutaHsiung, 1930; family Blepharocorythidae:Charonina hippopotamin.sp.

Paraisotricha minutaappears identical to the form found in the cecum and colon of the horse;Blepharozoum binucleatum, Cucurbella vivaxandCharonina hippopotamialso approach species found in the digestive tract of Equidae. By contrast,Paraplagiopyla kibokoresembles species that are free‐living or are commensal in the digestive tract of Echinodermata.
The Mechanism of Onset of the Stationary Phase inEuglena gracilisGrown with 10 mM Succinate: Intracellular pH Values*
Authors: VOTTA JOHN J. , JAHN THEODORE L. , LEVEDAHL BLAINE H.
Published: May 2007

SYNOPSIS.WhenEuglena graciliswere grown with 10mM succinate at pH 3.5 the extracellular pH averaged 3.62 and the cultures had produced 6 × 105cells/ml when the stationary phase began. Oxygen consumption values reached a maximum of 30 μliters/106cells/hr. Total protein and dry weights per cell remained constant during the logarithmic phase and began to decline when the late logarithmic phase was reached. Added succinate caused the cultures in stationary phase to commence logarithmic growth once more. Onset of the stationary phase in cultures grown at pH 3.5 was due to depletion of succinate.

When cultures were grown at pH 6.9 the extracellular pH averaged 7.62 and the cultures produced 3 × 105cells/ml when the stationary phase began. Oxygen consumption values reached a maximum of 20 μliters/106cells/hr during the logarithmic phase. The decline in total protein and dry weights per cell began at the beginning of the logarithmic phase and continued into the stationary phase of growth. Cultures grown at pH 3.5 should produce a larger number of cells/ml than cultures grown at pH 6.9 if the cells are responding to the unionized moiety of succinate and not the ionized moiety. At pH 3.5 83% of the succinate is unionized, whereas at pH 6.9 0.20% of the succinate is unionized. The onset of the stationary phase in cultures grown at pH 3.5 and pH 6.9 is due to lack of an adequate amount of extracellular unionized succinate.

Intracellular pH values were determined in cultures grown at pH 6.9 using the weak acid DMO (5.5‐dimethyl‐2,4‐oxazolidinedione). As the extracellular pH increased from 6.90 to 7.62, the intracellular pH increased from 5.89 to 6.89. As the extracellular pH increased from 7.62 to 8.44, the intracellular pH increased from 6.89 to 7.50.
Fine Structure of the Mastigont System in Tritrichomonas foetus (Riedmüller)*
Authors: HONIGBERG B. M. , MATTERN CARL F. T. , DANIEL WENDELL A.
Published: May 2007

SYNOPSIS. Tritrichomonas foetus shares many fine‐structural features with the previously described genera of the subfamily Trichomonadinae. These include the arrangement and structure of the kinetosomes, of most rootlet filaments, including the sigmoid filaments of kinetosome #2, as well as those of the parabasal apparatus and of the pelta‐axostyle complex. On the other hand, this species, and presumably all other Tritrichomonas augusta‐type flagellates, differ from Trichomonadinae in certain important details. Among the features which T. foetus does not share with Trichomonadinae are the fine structure of the costa and of the undulating membrane, as well as several organelles not found in the latter subfamily. The costal base of Trichomonadinae is replaced in T. foetus and other Tritrichomonadinae by a comb‐like structure, extending between the costa and the infrakinetosomal body. The suprakinetosomal body, connected to kinetosome #2 in the region of attachment of the sigmoid filaments, and the infrakinetosomal body, which appears to contribute to the proximal marginal lamella, are organelles evidently restricted to Tritrichomonadinae. The undulating membrane consists of 2 parts. The proximal part is a fold‐like differentiation of the dorsal body surface, the dorsal part of which contains the proximal marginal lamella. The distal part of the undulating membrane, with no obvious physical connection to the fold, encloses the distal marginal lamella in its ventral, and the microtubules of the recurrent flagellum in its dorsal area. The organelle of T. foetus which by its size, certain structural characteristics, and relationship with the undulating membrane and some organelles, including the paracostal granules, is analogous to the costa of Trichomonadinae and of Trichomitopsis termopsidis (subfamily Tritrichomonadinae), conforms in the structure of its periodic cross‐striations to that of the parabasal filaments of the latter organisms; its origin corresponds closely to that of parabasal filament 2 of Trichomonadinae.
Eimeria callosciuri n. sp. (Protozoa: Eimeriidae) from Prevost's Squirrel Callosciurus prevostii Demarest, 1822 in Malaysia*
Authors: COLLEY FREDRICK C.
Published: May 2007

SYNOPSIS. Eimeria callosciuri n. sp. is described from Prevost's squirrel Callosciurus prevostii in Malaysia. Its oocysts are 24–31 by 20–2μ with a mean of 21.9 by 28.4μ. Schizogonic and gametogonic stages develop in the tips of the villi of the small intestine, above the nuclei of the host epithelial cells. It is the first species of Eimeria described from the rodent tribe Callosciurini.
Oral Regeneration in the Ciliate Stentor coeruleus: A Scanning and Transmission Electron Optical Study
Authors: PAULIN JEROME J. , BUSSEY JOHN
Published: May 2007

SYNOPSIS. Elaboration of ciliated feeding organelles in the protozoon Stentor coeruleus was reinvestigated for the first time by scanning electron microscopy which gives the most realistic 3‐dimensional images. Parallel transmission EM studies of synchronized regenerating stentors gave further ultrastructural details of stomatogenesis, while also confirming the expectation that in the structure of its kineties this now classical experimental object does not differ from other species of Stentor previously studied.

Within 2 hr after the stimulus to regeneration, several generations of new kinetosomes for the oral primordium are produced, first in association with kinetosomes of kineties at the restricted primordium site. These kinetosomes rapidly sprout membranellar cilia as well as subpellicular microtubules but are still randomly oriented (anarchic field). The forming membranellar band increases from its center‐line to both sides while it grows in length. Young cilia are blunt‐ended.

Recession of the early anlage occurs without rupture of the pellicle; soon apparent is the clear border stripe of unknown function along the right side of the membranellar band.

Instantaneous fixation of beating cilia in early primordia revealed random beating, with coordination and presumably membranellar organization not yet attained. In late anlagen there are 2 types of metachronal rhythm: transversely from cilium to cilium across any given membranelle, as well as the easily observable serial beating of membranelles along the entire band. A single file of cilia leads the subsequent cytostomal invagination. The posterior end of the membranellar band then follows to line the cytopharynx.
Sequential Coccolith Morphogenesis in Hymenomonas carterae
Authors: OUTKA D. E. , WILLIAMS D. C.
Published: May 2007

SYNOPSIS. A careful re‐examination with refined technics of the ultrastructure of the formation of calcified scales (coccoliths) in the marine unicellular alga Hymenomonas carterae has yielded new and more detailed information about the structure and morphogenesis of these unique and complex Golgi‐elaborated organelles. The coccolith rim is formed from 2 distinct, alternating, anvil‐shaped elements, 13–16 each, fitted together with a “right‐handed” asymmetry. The coccolith is assembled in Golgi cisternae from 2 precursors, a single, scale‐like base and multiple granular elements called coccolithosomes. The association of scales and coccolithosomes and subsequent development to the mature coccolith occur in a characteristic sequential fashion within what is one of the better examples of a polarized Golgi. Morphogenesis involves a special cisternal membrane association with the base of the coccolith, the contribution of granular material by coccolithosomes to form the outer rim matrix, and the subsequent filling of the area enclosed by the matrix with an electron‐dense material, presumably CaCO3. A “microenvironment” model system for species specific shape‐determination of calcified elements is proposed.
Some Ecologic Factors Influencing Eimeria mccordocki Honess, 1941 in White‐Tailed Deer Odocoileus virginianus (Zimmermann)1
Authors: SAMUEL W. M. , TRAINER D. O.
Published: May 2007

SYNOPSIS. A study of coccidiasis of white‐tailed deer from the Welder Refuge in south Texas was conducted from 1964 to 1968. Thirteen percent of 374 deer were infected with low numbers of Eimeria mccordocki, the only coccidium found commonly. Percentage of infection and numbers of coccidia were highest for young deer, for deer collected in winter, and for deer collected in plant communities with “sparse” vegetation. Immunity, environmental change, intensive and concentrated grazing behavior by deer in open areas are presented as factors contributing to the findings.