bluuebunny/crossref_metadata_2025 huggingface dataset:
The Mastigont System of Trichomonas gallinae (Rivolta) as Revealed by Electron Microscopy
Authors: MATTERN CARL F. T. , HONIGBERG B. M. , DANIEL WENDELL A.
Published: May 2007

SYNOPSIS. The fine structure of Trichomonas gallinae has been examined by electron microscopy and correlated with previous light microscope observations. A composite diagram of the flagellate, derived from both types of examination, is presented. Details of relationships of various mastigont organelles are documented by electron micrographs.

The extent of the pelta and its connection to the capitulum of the axostyle have been determined.

Four types of kinetosome rootlets have been described. One consists of superficial “filaments” radiating from each of the 9 triplet microtubules of kinetosomes #1, #2 and #3. A 2nd type of rootlet structure is represented by single comma‐shaped filaments emerging clockwise from kinetosomes #1 and #3. The filament from kinetosome #1 has a periodic structure similar to that of the marginal lamella with which it is believed to connect. A 3rd type of rootlet emerges from kinetosome #2 as a sheet of about 9 filaments which traverse a sigmoid course and terminate on the inner surface of the microtubules of the pelta near the peltar‐axostylar junction. The 4th set of structures consists of the costa and parabasal filaments. These structures have major periodicities of similar dimension but have readily differentiable repeating units. The costa appears to originate at the kinetosome of the recurrent flagellum, but its origin is also contiguous with that of parabasal filament 2 which has some continuity with kinetosomes #2 and #3. Parabasal filament 1, on the other hand, arises solely from or near kinetosome #2.

Occasional observations of a costa and a parabasal filament in juxtaposition over a great part of their length has led to the suggestion that the parabasal filament may play a role in the development of the costa.

Periodic and filamentous structures have been observed in paraxostylar and paracostal granules and in nearby cytoplasm. Their possible role in providing substance for the developing axostyle and the costa is discussed.

The results are discussed in the light of available information pertaining to structure of various trichomonad species as revealed by light and electron microscopy.
Comparative Immunology of Selected Wild Types, Varieties and Mutants of Chlamydomonas*
Authors: BROWN R. MALCOLM , WALNE PATRICIA L.
Published: May 2007

SYNOPSIS. Rabbit antisera to strains of different mating types of Chlamydomonas moewusii and to one strain of C. eugametos were tested against strains of C. reinhardti, C. eugametos, and C. moewussi, and against strains of 2 varieties and 6 mutant types of C. moewusii. Technics of double diffusion, absorption, and immunoelectrophoresis revealed marked serological differences between the sexually incompatible, distinct genetic species C. moewusii and C. reinhardti. Less distinct serological differences were resolved between C. moewusii and the so‐called “species”C. eugametos, which is sexually compatible with the former, thus reconfirming the conspecificity between the 2 strains as suggested by Gowans. Marked serological differences were noted between C. moewusii and 2 of its varieties (C. moewusii var. tenuichloris and C. moewusii var. rotunda) which constitute 2 additional genetic species because of sexual incompatibility between themselves and with C. moewusii. Wild types and certain mutants of C. moewusii were compared serologically and could be distinguished on this basis. Strains of different mating types as well as certain mutant strains (e.g., paralyzed flagella, flagella‐less, twins and monsters) could be differentiated serologically altho differences were often very subtle. Some antigens were common to organisms tested.
A Comparative Study of Mitosis in Amoebae and Plasmodia of the True Slime Mold Didymium nigripes
Authors: KERR SYLVIA JOANN
Published: May 2007

SYNOPSIS. Studies comparing mitosis in amoebae and plasmodia of the true slime mold Didymium nigripes reveal that at the time of differentiation pronounced changes occur in the mitotic process. Not only does the amount of time required for division of the 2 stages differ, but plasmodial mitosis is characterized by persistence of the nuclear membrane and the apparent lack of centrioles. The origin of multinucleate plasmodia from uninucleate cells which have already undergone cytoplasmic differentiation is described. Division time in a population of amoebae becomes more uniform after those cells which are destined to form plasmodia have differentiated.

The observations and data presented indicated that differences in mitotic behavior also occur between amoebae of 3 stocks with differences in plasmodial structure and behavior. Comparison of mitosis in the plasmodia of these 3 stocks revealed no significant differences.
Differentiation of Trypanosoma cruzi in Culture*
Authors: CASTELLANI OLGA , RIBEIRO L. V. , FERNANDES J. F.
Published: May 2007

SYNOPSIS. A medium containing sodium and potassium chloride, phosphate buffer, glucose, calf serum, hemoglobin and lactalbumin hydrolysate permits some growth and differentiation of crithidiae into the metacyclic forms of Trypanosoma cruzi. The addition of ox liver infusion greatly enhances the growth promoting properties of this medium while making it very poor as far as differentiation is concerned. With dog heart infusion instead of ox liver, the medium is still good for growth but not much better for differentiation. If, however, the pH of the dog heart infusion medium is lowered from 7.2 to 6.7, it continues to be good for growth and becomes excellent for differentiation.

Other factors were studied that stimulate or repress the rate of differentiation, such as preincubation at certain levels of temperature and the size and age of inocula.
Growth and Colony Formation of the Phytoflagellate Prymnesium parvum Carter on Solid Media
Authors: PADAN ETANA , GINZBURG DALIA , SHILO MOSHE
Published: May 2007

SYNOPSIS. Colonies of Prymnesium parvum from single cells were obtained in an atmosphere of high humidity, in soft‐agar overlayers on solid medium. Light intensity above 60 foot candles at the surface of the agar plates inhibited colonial development. Such colonies were used to obtain pure lines of the phytoflagellate.

A method for direct demonstration of hemolysin formation on agar plates was developed. The occurrence of hemolytic activity by P. parvum colonies was light‐dependent.
Mutation of the Euglena Chloroplast System: The Mechanism of Bleaching by Nitrosoguanidine and Related Compounds
Authors: McCALLA D. R.
Published: May 2007

SYNOPSIS. I have examined the possibility that compounds like nitrosoguanidine bleach Euglena by serving as sources of diazomethane or other active compounds. Since exposure of Euglena gracilis Z to sufficient diazomethane to kill over 99% of the cells does not cause any significant bleaching (i.e., permanent loss of chloroplastforming ability) in the survivors, diazomethane is not the active bleaching agent. The possibility that other breakdown products of nitrosoguanidine bleach Euglena is ruled out by 2 observations. First, solutions of these bleaching agents rapidly lose their activity when they stand in the light. Second, while N‐methyl‐N‐nitroso‐p‐toluenesulfonamide does not decompose in the dark at pH 6.8, it effectively bleaches Euglena under these conditions. I conclude that the basis for selective bleaching is to be sought in the properties of nitrosoguanidine and its analogs rather than in their breakdown products.
Crithidia mellificae n. sp. an Acidophilic Trypanosomatid of the Honey Bee Apis mellifera
Authors: LANGRIDGE D. F. , McGHEE R. BARCLAY
Published: May 2007

SYNOPSIS. Crithidia mellificae n. sp. is described from the honey bee Apis mellifera in apiaries of Victoria, Australia. Organisms were isolated and cultured in a modified NNN medium with Cowper‐thwaite's medium as an overlay. In contrast to other isolates of Crithidia, C. mellificae grows best at a pH between 4.5 and 5.5 with optimum near pH 5. In Cowperthwaite's medium alone, buffered at pH 4.5–5.5, the organism will survive apparently indefinite passages. The organism has so far as known, no pathologic effects in the hymenopteran host.
Taxonomic Criteria for Limax Amoebae, with Descriptions of 3 New Species of Hartmannella and 3 of Vahlkampfia*
Authors: PAGE FREDERICK C.
Published: May 2007

SYNOPSIS. Seven species of limax amoebae were isolated into clonal, monoxenic cultures with Aerobacter aerogenes from material collected from freshwater habitats. Studies were made of their trophic structure, nuclear division, cyst structure, some aspects of cytochemistry, and other characteristics. Six new species are described: Vahlkampfia inornata, V. avara, V. jugosa, Hartmannella limacoides, H. vermiformis, and H. exundans. The well‐known species Naegleria gruberi (Schardinger, 1899) is re‐described on the basis of 8 strains; its flagellated phase was found to be biflagellate, with rare exceptions.

A correlation exists between the manner of locomotion and the pattern of nuclear division in the limax amoebae in the family Vahlkampfiidae and those in the genus Hartmannella.

Trophic amoebae of all species had a PAS‐positive surface layer, altho results with H. vermiformis and H. exundans were less definite than with other species. All species except H. limacoides formed cysts in culture. The cyst walls of all cyst‐forming species were strongly PAS‐positive, but results of the zinc chloroiodide test for cellulose were negative with the method used.

The genus Hartmannella Alexeieff, 1912, is re‐defined to include those species which assume a simple, monopodial limax‐like form during locomotion and have nuclear division similar to that of metazoan cells and to distinguish it from the genus Acanthamoeba Volkonsky, 1931.
Eimeria balphaen. sp. from the Ord Kangaroo RatDipodomys ordii*
Authors: ERNST JOHN V. , CHOBOTAR BILL , ANDERSON LARRY C.
Published: May 2007

SYNOPSIS.Eimeria balphaen. sp. is described from the Ord kangaroo ratDipodomys ordii.The sporulated oocysts are broadly ellipsoidal to ovoid, averaging 16.7 by 14.3 μ. A single, large, homogenous body represents the oocyst residuum. A polar granule is present. There is no micropyle. The ovoid sporocysts average 8.7 by 5.9 μ. The sporocyst residuum is composed of 7–14 round, clear granules. This species ofEimeriawas found in 1 of 82D. ordiiin northwestern Utah.
The Process of Chamber Formation in the Foraminifer Rosalina floridana (Cushman)
Authors: ANGELL ROBERT W.
Published: May 2007

SYNOPSIS. The foraminifer Rosalina floridana builds a chambered, calcareous test which is periodically enlarged by the addition of new chambers. R. floridana begins to form a chamber by constructing an algal growth cyst which covers the dorsal side of the animal and is cemented to the substrate. The pseudopods that build the cyst coalesce to form a cytoplasmic template or anlage on which the chamber walls will be secreted. Electron micrographs reveal the anlage cytoplasm to be a “froth” of nearly empty vesicles which contain mitochondria, fibrillar material, and electron dense granules. The organic lining of the new chamber is secreted on the anlage by pseudopods extending thru it. After the organic lining is completed, cytoplasm from within the test flows into the forming chamber and forces the anlage cytoplasm out thru the new aperture. This “frothy” anlage cytoplasm forms a sheath over the dorsal surface of the test; while it is in place, a layer of calcite is deposited on the walls of the new chamber and over the rest of the test. When calcification is completed, the sheath breaks up and is incorporated into newly formed pseudopods as the foraminifer gradually moves out of the growth cyst and begins normal feeding.

The production of vesiculated cytoplasm in normal pseudopods and in the anlage is viewed as a method of greatly increasing cytoplasmic volume with a resultant very small loss in cytoplasmic mass. In the anlage during the production of the organic lining the vesiculated cytoplasm apparently acts only as a support for the membranes being secreted by the pseudopods and presumably does not take part in the secretory process. This same cytoplasm forms the sheath that is present during calcification. The view is advanced that, altho the sheath could be active during calcification with the mitochondria within the vesicles actively transporting calcium to sites of crystal growth, its more probable function is to form a partition between the parts to be calcified and the environment. The foraminifer could then secrete CaCO3 from pooled reserves in the cytoplasm into the area between the sheath and the chamber membranes. The basal membrane is considered the nucleating agent during calcification and is responsible for the ordering of the crystals so their C axes are perpendicular to the surface of the chamber.
An Intra‐Axonal Protozoon in the Spinal Cord of the Toad Bufo arenarum (Hensel)
Authors: STENSAAS LARRY J. , STENSAAS SUZANNE S. , SOTELO J. ROBERTO
Published: May 2007

SYNOPSIS. A protozoon was found in myelinated axons of the spinal cord and brain of the toad, Bufo arenarum. Examination with the light microscope using Giemsa, Feulgen, PAS and methylene blue technics revealed a primary cell as large as 30 μ in diameter and containing up to 80 nuclei. Electron micrographs showed that the protozoon ranged from 2 μ to 30 μ in diameter and that larger specimens contained numerous secondary cells (2 μ) in addition to multiple nuclei. A few specimens were found in which the secondary cells had long processes with microtubules. Multiple nuclei together with secondary cells suggest that it may be a schizont form of a sporozoon.

The protozoon was found most frequently in axons of the perimedullary plexus just beneath the pia. These axons are without degenerative changes, are up to 3 times the diameter of the largest normal myelinated fibers. The myelin appears normal altho there are fewer laminae than in myelin of other large nerve fibers. The protozoon apparently causes axonal swelling but does not block the fibers completely.

Light microscopic attempts to locate similar forms or other stages in the life cycle by examining blood, skin lesions, spleen, liver, small intestine, dorsal and ventral roots, or sensory ganglia were unsuccessful.

Examination of spinal cords which had been mechanically severed excluded the possibility of confusing the protozoa with multinucleated macrophages. Altho observations do not prove their mode of entrance to the nervous system, the preponderance of protozoa in the peripherally located perimedullary plexus suggests that the path may be by way of the cerebrospinal fluid or along the endoneurium.
Gonyaulax monilata: Population Growth and Development of Toxicity in Cultures
Authors: ALDRICH DAVID V. , RAY SAMMY M. , WILSON WILLIAM B.
Published: May 2007

SYNOPSIS. The development of three 8‐liter and four 12‐liter cultures of the photosynthetic dinoflagellate Gonyaulax monilata was followed for 4 months. Weekly estimates were made of population levels of this chain‐forming flagellate, along with incidence of cells in chains and toxicity to fish. Guppies (Lebistes reticulatus) were used to assay toxicity. Populations reached a peak when cultures were 3–5 weeks old, declined during weeks 6–10, and tended to stabilize thereafter thru the 17th (final week). The percentage of cells in chains was related to the slope of the population curve; rapidly increasing populations had the highest proportion of long chains, suggesting that incidence of chains is an index of the growth phase in G. monilata. Peak toxicity was not reached until culture populations had been steadily declining for a month, indicating that most toxin is released by autolysis. The reproducibility of culture population and toxicity levels recommend the methods used for future studies.
Fine Structures Associated with Nutrition of the Intracellular Parasite Eimeria auburnensis*
Authors: HAMMOND DATUS M. , SCHOLTYSECK ERICH , CHOBOTAR BILL
Published: May 2007

SYNOPSIS. In the nearly mature macrogametes of Eimeria auburnensis, the cell membrane is a unit membrane, with underlying and overlying osmiophilic layers usually present. Cup‐shaped micropores were occasionally seen. Smaller, V‐shaped invaginations were also found in considerable numbers at the surface. At the deepest point, these invaginations were bounded only by a unit membrane. Immediately adjacent to this point, vesicles with homogenous electron‐pale contents bounded by a similar unit membrane, were frequently seen. Pinocytosis evidently occurs at the site of these invaginations. Numerous folds of the host cell membrane bordering the vacuole in which the parasite lay extended about 0.1–0.7 μ into the vacuole. These “intravacuolar folds” varied in depth and number in different specimens. In some, the majority of folds had apparently become disconnected from the host cell membrane. A highly developed smooth endoplasmic reticulum occurred in the adjacent host cell cytoplasm. The intravacuolar folds may assist in transfer of nutrients, including membrane material, from the host cell to the parasite. The evidence indicates that in this species of Eimeria nutrients are taken into the parasite primarily as fluids by pinocytosis and possibly other processes.
Re‐Definition of the Genus Acanthamoeba with Descriptions of Three Species
Authors: PAGE FREDERICK C.
Published: May 2007

SYNOPSIS. Ten strains of Acanthamoeba from freshwater habitats were isolated in clonal cultures. Studies were made of trophic structure, nuclear division, cyst structure, some aspects of cytochemistry, and other characteristics. One strain was identified as A. castellanii (Douglas, 1930), one as A. astronyxis (Ray and Hayes, 1954), and 8 as A. polyphaga (Puschkarew, 1913). Strains of Acanthamoeba isolated by other workers were also examined comparatively.

The pattern of nuclear division in all strains resembled that in metazoan cells, with the exception that centrioles were never found. Trophic amoebae had a PAS‐positive surface outline. Cyst walls were strongly PAS‐positive and also gave a positive test for cellulose with zinc chloroiodide.

The genus Acanthamoeba Volkonsky, 1931 is re‐defined, being distinguished from Hartmannella Alexeieff, 1912, emend. Volkonsky, chiefly by the formation of tapering, hyaline pseudopods (acanthopodia) and by a cyst made up of an ectocyst and a polyhedral or stellate endocyst, with excystment by removal of opercula. Other characteristics found in all strains include a distinctive food cup, the presence of many small refractile globules in the cytoplasm of trophic amoebae, and a cyst wall containing cellulose. The degree of spindle convergence, employed by Volkonsky as a generic criterion, was unusable.

Differential diagnoses based principally on cyst structure are offered for A. castellanii, A. astronyxis, and A. polyphaga. The strain previously called Mayorella palestinensis Reich, 1933 is a distinct species of Acanthamoeba.
A New Method for Collecting Sessile Ciliates in Plastic Petri Dishes With Tight‐Fitting Lids
Authors: SPOON D. M. , BURBANCK W. D.
Published: May 2007

SYNOPSIS. Large numbers of sessile ciliates were successfully collected in plastic petri dishes with tight‐fitting lids, transported in the water‐filled dishes without disturbance. Each species within the transparent dishes was identified with a dissecting microscope and the position on the dish surface of each sessile individual was located and recorded on graph paper for further quantitative comparisons. This method was used for numerous experiments on the ecology and behavior of sessile ciliates and their responses to toxins.
The Use of Sessile Ciliates Collected in Plastic Petri Dishes for Rapid Assessment Of Water Pollution
Authors: BURBANCK W. D. , SPOON D. M.
Published: May 2007

SYNOPSIS. Species of sessile Stentor, Vorticella and colonial peritrichs were collected in boxtype plastic petri dishes. Thru a hole in the wall of the dish, various concentrations of mercuric chloride, a standard bactericidal agent, were introduced. Following a 3‐hour exposure to the toxicant, the death of the sessile ciliates followed a set pattern with a clearcut toxicity threshold of 0.1–0.5 parts per million with an LD 50 of about 0.25 ppm. Furthermore, the sessile ciliates were not dislodged when the natural pond water in the dish was poured out and replaced with water from other sources. Various responses were elicited by 4‐hour exposure to 4 changes of environment. By this procedure, the protozoan community was subjected to new sets of conditions. Such a technic could serve as a method of detecting and assessing water pollution.
Electron Microscopic Localization of Exogenous Ferritin within Vacuoles of Giardia muris*
Authors: BOCKMAN DALE E. , WINBORN WILLIAM B.
Published: May 2007

SYNOPSIS. Trophozoites of Giardia muris parasitic in hamsters were fixed in situ at intervals of 1–3 hr after injection of horse ferritin into the small intestinal lumen. Concentrations of ferritin molecules are localized within vacuoles beneath the plasmalemma along the dorsal and ventral surfaces of Giardia. Limiting membranes of these vacuoles are identical with the plasmalemma. It is suggested that the vacuoles function in sequestration of molecules from the intestinal lumen by invagination of the cell membrane.
Eimeria eumoposn. sp. from a Colombian BatEumops trumbulli*
Authors: MARINKELLE C. J.
Published: May 2007

SYNOPSIS.Eimeria eumoposn. sp. (Coccidiida, Eimeriidae) from a Colombian batEumops trumbulli(Chiroptera, Molossidae) is described. This is the first recorded coccidium in a bat from the western hemisphere, and the sixth bat coccidium species described to date. The unsporulated oocysts in the bat feces are 30.9–24.0 by 28.9–23.2 μ (near 28.8 × 26.1 μ). Their outstanding feature is the pronounced pitting of the thick brownish oocyst wall.
The Fine Structure of Trophozoites and Gametocytes in Plasmodium coatneyi*
Authors: RUDZINSKA MARIA A. , TRAGER W.
Published: May 2007

SYNOPSIS. An electron microscope study of Plasmodium coatneyi in the rhesus monkey supplied information on the fine structure of trophozoites, gametocytes and of the host cell. The trophozoites resemble other mammalian malaria parasites. They do not have typical protozoan mitochondria, but instead a concentric double‐membraned organelle, which, it is assumed, performs mitochondrial functions. They feed on the host cell by pinocytosis, engulfing droplets of erythrocytes thru invaginations of the plasma membranes at any region of the cell or thru the cytostome. Digestion of hemoglobin takes place in small vesicles pinched off from the food vacuole proper.

Gametocytes can be clearly distinguished into macro‐ and microgametocytes. Macrogametocytes are covered by 2 plasma membranes, the inner one appearing thicker in some places. The cytoplasm is filled with Palade's particles and has numerous vesicles of endoplasmic reticulum and toxonemes. In microgametocytes most of the inner membrane is thickened, the cytoplasm has few Palade's particles and vesicles of the endoplasmic reticulum and does not have toxonemes.

Erythrocytes with trophozoites are irregularly scallop‐shaped and have elevated points with knob‐like protrusions covered by a double membrane. If these protrusions are sticky they might be in part responsible for clumping and arresting the schizonts and segmenters in the capillaries. The host cell contains numerous Maurer's clefts which in some instances are continuous with the membranes of the parasite suggesting that they might originate from them.
The Fine Structure of the Mature Gametes of Haemoproteus columbae Kruse*
Authors: BRADBURY PHYLLIS CLARKE , TRAGER WILLIAM
Published: May 2007

SYNOPSIS. The filiform microgamete of Haemoproteus columbae consists of an elongate double‐walled nucleus paralleled by 2 axonemes embedded in a homogeneous matrix. At one end of the gamete, the axonemes are sharply flexed back on themselves, but no conventional kinetosome has been recognized. No mitochondria have been seen. Single‐walled vesicles occur in the matrix, and the entire gamete is surrounded by a single membrane.

The large round macrogamete has a conspicuous central nucleus with its outer membrane drawn out into anastomosing evaginations which extend to the periphery of the cell. A moderately electron dense material fills the space between the 2 nuclear membranes and the lumina of the evaginations. Nucleolar material may occur in scattered masses within the nucleus. One or 2 axonemes appear to arise endogenously next to the nuclear membrane.

The cytoplasm is filled with ribosomes and perhaps glycogen granules. Typical protozoan mitochondria and vesicles containing pigment retained from the erythrocytic stage are found in the peripheral cytoplasm. Accumulations of dense‐walled vesicles occur in the cytoplasm in conjunction with evaginations of the nuclear membrane. Amid these vesicles triple‐ringed discs resembling the cytostomes of merozoites are frequently seen.

Several distinct layers of dense material surround the micro‐gamete.
The Free Amino Acid Levels of Pelomyxa carolinensis, Amoeba dubia and Proteus*
Authors: FRIZ CARL T.
Published: May 2007

SYNOPSIS. The free amino acid extracts of 3 species of the free‐living amoebae, Pelomyxa carolinensis, Amoeba dubia and A. proteus, were studied. Both the free amino acid patterns and levels in each species were different. Altho it appears that the free amino acid patterns were not altered by culture routines or starvation, the free amino acid levels were altered by these factors. The possibility of using free amino acid levels as a criterion for recognizing genetic differences is discussed.
Observations on the Type Specimen ofEntamoeba serpentisCunha and Fonseca, 1917
Authors: GHOSH TARA N.
Published: May 2007

SYNOPSIS.The type specimen ofEntamoeba serpentisCunha and Fonseca, 1917 was studied. Description of the cysts of this species, hitherto unreported, shows that this species resembles the “histolytica” type, producing 4‐nucleate mature cysts; their measurements fall within the size range occupied in part byE. invadens.
Nature of the Nitrogen Compounds Supporting Phototrophic Growth of the Marine Cryptomonad Hemiselmis virescens*
Authors: ANTIA N. J. , CHORNEY V.
Published: May 2007

SYNOPSIS. Previous claims of a specific amino add‐nitrogen requirement for growth of Hemiselmis virescens have been disproved. The photosynthetic cryptomonad grows well on ammonium ion (at subtoxic concentrations) as sole N‐source but cannot utilize nitrate‐or nitrite‐N. Although the organism utilizes glycine efficiently, other amino acids are poor N‐sources, and only L‐glutamine, L‐cysteine, L‐cystine, and L‐tryptophan gave evidence of limited growth. Glycine peptides, derivatives (sarcosine, hippuric acid), and homologous relatives (β‐alanine, taurine) gave no growth. Among other amino compounds tested, only D‐glucosamine and D‐galactosamine supported some growth. Urea and some of its derivatives (alloxan, parabanic acid) were efficiently utilized, while other derivatives (biuret, guanidine, hydantoin, hydantoic acid, allantoin, creatinine) failed to support growth. All purines tested (adenine, hypoxanthine, xanthine, guanine, uric acid) gave moderate to good growth, while the pyrimidines cytosine, uracil, thymine were not utilized. No dark growth was obtained from any of the compounds supporting phototrophic growth. The capacity for efficient utilization of glycine, urea, and some of the purines may have ecologic significance.
Some Recent Advances in Our Understanding of Parasitic Protozoa*†
Authors: HONIGBERG B. M.
Published: May 2007

SYNOPSIS. Striking progress in our understanding of parasitic protozoa has been achieved thru the employment of advanced electron‐microscopic, biochemical, immunologic, and cultivation methods. Some recent information gathered by means of these methods on trichomonad and trypanosomatid flagellates as well as on eimeriidian and plasmodiid haemosporiidian Sporozoa is discussed. It is emphasized that the parasitic protozoa when studied by the presently available sophisticated methods in the context of being parasites, not merely cells maintained on refined media, can aid us greatly in illuminating the highly complex functional aspects of host‐parasite interactions.
Studies on Meiotic Division in Coccidial and Malarial Parasites
Authors: CANNING ELIZABETH U. , ANWAR M.
Published: May 2007

SYNOPSIS. Oocysts of Eimeria tenella and E. maxima, incubated in colcemid after removal from the host gut, were better preserved after fixation with acetic alcohol than oocysts fixed directly. Colcemid may delay hardening of the oocyst but does not interfere with meiosis. During meiosis the nucleolus disappears and 10 rod‐like chromosomes are formed by condensation of filamentous, beaded chromosomes, which appear in prophase. Two granules which appear on the nuclear membrane at the end of prophase are interpreted as centrioles. The 10 chromosomes align themselves in 2 rows of 5 parallel with, rather than transverse to, the elongate meiotic spindle. After stretching across the spindle as beaded filaments during migration to the poles, the chromosomes condense as a cluster of 5 rods at each pole. Reduction is thus effected in a single phase without duplication of chromosomes or centromeres.

During meiosis in P. gallinaceum oocysts paired, Y‐shaped and paired dot‐like chromosomes appear among the pigment granules. No duplication is evident.
Fine Structure of Schizonts and Merozoites of Eimeria nieschulzi*
Authors: COLLEY FREDERICK C.
Published: May 2007

SYNOPSIS. Schizonts of E. nieschulzi lie in a vacuole within the host cell. After nuclear division the cell membrane invaginates forming merozoites. Differentiation of the pellicle and other organelles occurs while merozoites are still attached to the schizont cytoplasm. Merozoites have a pellicle thickened at the anterior end to form a polar ring. Radiating posteriorly from the ring, directly beneath the pellicle, are about 25 microtubules. Within the polar ring is a dense conoid. Extending posteriorly from within the conoid is a paired organelle. The paired organelle varies in size and shape in each generation of merozoites. Numerous toxonemes occupy the anterior half of the merozoites. Two paranuclear bodies are present in 1st generation merozoites. One or 2 granular bodies were seen in the anterior end of 2nd generation merozoites. In 3rd generation merozoites 6 or more granular bodies were seen anterior to the nucleus.

Each merozoite has a single nucleus containing diffuse chromatin material. Elongate mitochondria and glycogen granules are present. The vacuole surrounding mature merozoites contains residual cytoplasm of the schizont and some granular material. Microvilli project into the vacuole from the host cell membrane.
Encystment and Excystment of the Heterotrichous Ciliate Blepharisma stoltei Isquith*
Authors: REPAK ARTHUR J.
Published: May 2007

SYNOPSIS. The structure and cytochemistry of encystment and excystment of Blepharisma stoltei Isquith are described.

The encystment process may be subdivided into 4 stages: (i) in the precystic stage the buccal apparatus overlaps about the posterior, (ii) in early encystment, the buccal apparatus is resorbed and an ectocyst is secreted, (iii) an interwall space, endocyst, and plug are secreted during late encystment, and (iv) the resting cyst stage typically has disc‐like structures on the ectocyst, and a vacuole in the macronucleus.

In excystment, 6 distinct stages may be defined: (i) partial kineties are formed in early excystment, (ii) permanent kineties give rise to anlagen of the buccal apparatus during stomatogenesis, (iii) the organism elongates and reforms the vegetative shape in late excystment, (iv) some cysts then divide, (v) the redeveloped organism is liberated thru the plug pore, and (vi) the postcystic stage resembles the vegetative form except for its size and lack of pigmentation.

Cortical structures, extracellular membranes, and the macronuclear membrane are composed of protein‐lipids. Unbound protein and RNA are found in the cytoplasm thruout the cystic cycle. DNA is present only in the nuclei. Polysaccharides, 1st found in the cytoplasm, are shifted to the plug in encystment. The plug material disappears during excystment, while PAS positive granules appear in the cytoplasm.
Effects of Acetaldehyde on Growth and Biosynthesis in an Algal Flagellate Polytomella caeca*
Authors: WISE DONALD L.
Published: May 2007

SYNOPSIS. Eight mM acetaldehyde prevented growth of Polytomella caeca in acetate medium and differentially changed the labeling by acetate‐2‐14C of chromatographically separated RNA hydrolysate products. Four mM acetaldehyde also prevented growth in acetate medium unless uridine, thymidine, guanosine, uracil, thymine or quanine were present; then growth was delayed by 2 or 4 days. Orotidine, orotic acid, dihydroortic acid, cytosine, cytidine, adenosine and adenine had no effect on growth in acetate medium containing 4 mM acetaldehyde. One mM acetaldehyde promoted growth in acetate medium and also could serve as a sole carbon source. One mM propionaldehyde, but not butyraldehyde, was also an adequate carbon source. Four mM acetaldehyde, as a sole carbon source, supported growth only when uridine was present.
Light and Electron Microscope Study of a New Species of Glugea (Microsporida, Nosematidae) in the 4‐Spined Stickleback Apeltes quadracus*
Authors: SPRAGUE VICTOR , VERNICK SANFORD H.
Published: May 2007

SYNOPSIS. Cell hypertrophy tumors (xenomas) associated with Glugea weissenbergi n. sp. frequently occur under the peritoneum (parietal or visceral) of Apeltes quadracus (Mitchell) near Solomons Island, Maryland. The microsporidan is similar to the type species, G. anomala (Moniez, 1887) Gurley, 1893, but has larger spores. Its fine structure corresponds with the basic pattern revealed by other authors in various species of Nosematidae. A concept of spore morphogenesis, in which the polar filament primordium is 1/2 of the nuclear isthmus present during division of the sporont, is elaborated and its implications discussed. The membrane systems of the Glugea and host cell components appear to be continuous with one another, this being an indication that the membranes are all furnished by the host cell. Lacking mitochondria and (apparently) a Golgi apparatus, Glugea is, when considered apart from the membrane system which is common to it and the host cell, a very simple organism, consisting of very little besides the genome. The simplicity of the Glugea, its very high degree of structural and physiological integration with the host cell, and the transformative development of the host cell all suggest an analogy with certain viruses.
Trypanosoma pifanoi n. sp. from Colombian Bats*
Authors: MARINKELLE C. J. , DUARTE R.
Published: May 2007

SYNOPSIS. A new large trypanosome was found in the blood of 19 Artibeus lituratus and 2 Phyllostomus hastatus bats. The monomorphic trypanosome resembles Trypanosoma megadermae in some respects, but differs from it in that it is larger and has a short flagellum, both extremities are very tapered, the kinetoplast is very close to a small nucleus and there is a greater distance between the kinetoplast and the posterior extremity of the body. In diphasic blood‐agar cultures there is a great variety of odd multiplication forms not described from other trypanosome cultures, but some simulate T. cruzi. This trypanosome is not capable of infecting mice, tissue culture cells, Carollia perspicillata bats, or triatomids, but is able to infect A. lituratus bats. Culture forms of the trypanosome inoculated intra‐coelomically are pathogenic for several species of triatomids, and multiply in the hemolymph of Rhodnius prolizus, often producing forms similar to crithidiae of T. rangeli. Culture forms of the trypanosome seem to have common antigens with T. cruzi. This new species is described as Trypanosoma pifanoi.
Two New Species of Hartmannella Amebae Infecting Freshwater Mollusks
Authors: RICHARDS CHARLES S.
Published: May 2007

SYNOPSIS. Two new species of small amebae, Hartmannella biparia n. sp. and Hartmannella quadriparia n. sp., were 1st observed in the freshwater mollusks Bulinus globosus and Biomphalaria pallida, respectively. The amebae multiplied in cytoplasmic vacuoles in host cells, particularly in foci in the mantle collar, foot, and intestinal wall. Both amebae had functional contractile vacuoles while within host cells. H. biparia emerged from intracytoplasmic vacuoles in pairs, H. quadriparia in fours, suggesting characteristic reproductive stages.

H. biparia had limax‐type motility by smooth lobopodia, was 22 μ long; with vesicular nucleus 3 μ and central endosome 1.5 μ, multiplied by binary fission and formed spherical, smooth‐walled cysts 11 μ in diameter. H. quadriparia had limax‐type motility by lobopodia with fine, acute projections; was 10 μ long, with vesicular nucleus 2 μ and central endosome 0.75 μ, multiplied and formed spherical, smooth‐walled cysts 5 μ in diameter. Neither species multiplied in cysts outside the host.

H. biparia was found infecting 12 species and experimentally transferred to 4 more species of freshwater snails; H. quadriparia was found in one species and experimentally transferred to 6 other species.
Observations on the Fine Structure of the “Cyst Stage” of Besnoitia jellisoni
Authors: SHEFFIELD HARLEY G.
Published: May 2007

SYNOPSIS. Light and electron microscope studies of the “cyst” of Besnoitia jellisoni indicate that it consists of an extracellular wall, a large, sometimes multinucleate, host cell, and an intracellular vacuole containing the parasites. The “cyst” wall has fine fibrils and small dense granules embedded in an election‐lucid matrix. The wall may be formed from a secretion of the enclosed host cell. The plasma membrane of the host cell is very irregular, being modified into microvillar or pseudopodial extensions. Small vesicles and invaginations of the plasma membrane indicate mioropinocytosis. The one to several large lobular nuclei lie in a thick area of cytoplasm which is filled with rough endoplasmic reticulum and many mitochondria with lamellar cristae. The parasite‐containing vacuole is limited by a vacuolar membrane which has many blebs suggesting a transfer of materials into the vacuole.

The “cyst” organisms are crescentic or piriform and are enclosed by a pellicle consisting of outer and inner membranes. Twenty‐two subpellicular fibrils extend longitudinally adjacent to the inner membrane from the anterior polar ring to a posterior ring. A micropyle is situated laterally in the pelliole near the level of the nucleus. A conold and several associated paired organelles are present at the anterior end. Microuemes, more abundant in older organisms, are also present in the anterior portion of the parasite. A Golgi apparatus lies adjacent and anterior to the nucleus. One or more mitochondria with saccular cristae, ovoid glycogen bodies, free ribosomes and occasional vacuoles are also present. Organisms within the “cyst” multiply by endodyogeny.
Growth of Tetrahymena in Carbohydate‐Free High‐Glutamate Media
Authors: COX DUDLEY , FRANK OSCAR , HUTNER S. H. , BAKER HERMAN
Published: May 2007

SYNOPSIS. In chemically defined media, pH 6.4–6.8, supplementation with glycerol permitted growth equal to that with a carbohydrate supplement. In a pH 5.4 medium described in detail, containing L‐glutamic acid 0.25%, supplementation with L‐serine (essential for this strain), especially when further supplemented with proline, likewise permitted growth nearly equal to that with carbohydrate. These results are discussed in relation to the question of which components of peptone act as substrates and the resemblances of the Tetrahymena pattern of substrate utilization to that of metazoa.
Ribonucleoprotein‐Containing Vesicles in Cysts of Naegleria gruberi*
Authors: SCHUSTER FREDERICK L. , SVIHLA GEORGE
Published: May 2007

SYNOPSIS. Ultraviolet microscopy and electron microscope autoradiography were used to study ribonucleoprotein in cysts of Naegleria gruberi. The absorption maximum for cysts is at 265 nm with little detectable absorption occurring at 295 nm. Pre‐cystic trophozoites absorb less strongly than the cysts at 265 mm. Acridine orange staining indicated concentrations of ribose nucleic acid or ribonucleoprotein in the cytoplasm of young cysts. The dye stained discrete vesicles in the cytoplasm.

Tritiated uridine and tritiated proline were used to follow changes in RN‐protein at encystment. Label was incorporated into vesicles filled with ribosome‐like particles. These are presumably the sites of acridine orange staining. Relatively little label was associated with the cyst cytoplasmic matrix; most of the silver grains lay over the nucleus and cytoplasmic organelles. The vesicles are believed to represent autophagosomal‐type vacuoles with the contents derived from breakdown of organelles such as mitochondria. The path of label into the vesicles is via lysis of labeled cytoplasmic organelles.

The RN‐protein vesicles of Naegleria gruberi cysts are compared to the chromatoid bodies of Entamoeba invadens. It is concluded that, tho differences in detail are present, the role of the structures in the cysts is probably the same. They are a ready source of amino acids and ribosomes in a dedifferentiated or pool state to be used for synthetic reactions that accompany resumption of trophic existence.
Electron Microscope Study of the Everted Polar Filament of Glugea weissenbergi (Microsporida, Nosematidae)*
Authors: ERICKSON B. W. , VERNICK SANFORD H. , SPRAGUE VICTOR
Published: May 2007

SYNOPSIS. The everted polar filament, shadowed with chromium and observed with an electron microscope, terminated in either a cup‐shaped or a saccate enlargement on which was an electron‐dense and raised object. The cup is interpreted as either a portion of a sac or a sac with one side invaginated. The raised object may be the germ. The observations support West's opinion that the internally coiled filament terminates in a sac containing the germ. They are consistent with a similar hypothesis of Sprague and Vernick which postulates further that the terminal sac on the filament, the nuclear vesicle and the posterior vacuole of the spore are identical.
Large‐Scale Temperature‐Induced Synchrony of Cell Division in Euglena gracilis*
Authors: NEAL W. K. , FUNKHOUSER E. A. , PRICE C. A.
Published: May 2007

SYNOPSIS. Temperature‐induced patterns of synchronous cell division and cell size were obtained with Euglena gracilis. The alga was cultured in a glutamate‐sucrose medium in 6‐liter quantities. Synchrony was induced by non‐lethal shifts of temperature between 14.5 and 28.5 C. Three liters of cells containing 2 × 106 cells/ml were harvested in each 24‐hour cycle.
Microtubular Structures in Macronuclei of Synchronously Dividing Tetrahymena pyriformis
Authors: FALK HEINZ , WUNDERLICH FRANK , FRANKE WERNER W.
Published: May 2007

SYNOPSIS. When heat‐synchronized cultures of Tetrahymena pyriformis, amicronucleate strain GL, were examined by electron microscopy, intramacronuclear microtubules were observed in dividing cells. These tubules have a diameter of 180–230 A and occur either singly or packed together in bundles. They are predominantly associated with outpocketings and invaginations of the nucleus. Sections as well as negatively stained preparations of isolated macronuclear envelopes indicate that the microtubules are inserted at the inner nuclear membrane.

The findings suggest that microtubules of the spindle type participate in the process of macronuclear division.
Light Synchronization of an Endogenous Circadian Rhythm of Cell Division in Tetrahymena*
Authors: WILLE JOHN J. , EHRET CHARLES F.
Published: May 2007

SYNOPSIS. Synchronization of cell division in axenic cultures of the free‐living ciliated eukaryote Tetrahymena pyriformis (W) may be achieved equally as well by a sudden increase in irradiance, DD→LL (switch‐up), or by a sudden decrease in irradiance, LL→DD (switch‐down), provided that the irradiance transition occurs after a critical time in the late ultradian exponential growth phase. Circadian division indices (∼24 hrs) are associated with infradian generation times (GT>>24 hrs).
Spores of Thelohania in Adult Female Anopheles: Development and Transovarial Transmission, and Redescriptions of T. legeri Hesse and T. obesa Kudo
Authors: HAZARD E. I. , WEISER J.
Published: May 2007

SYNOPSIS. Two distinctly different types of spores were found in Anopheles mosquitoes infected with Thelohania. One type, found in larvae, is commonly known to protozoologists and was used in the original descriptions of Thelohania legeri Hesse and T. obesa Kudo. The 2nd type, which is cylindrical and unlike any Thelohania spores previously described, is associated with the transovarial cycle of these Microsporida in the adult. Spores of the 2nd type, which were previously described as Microsporida of the genus Nosema, develop in the blood cells of females. Spores similar to but obviously of another species than the ones found in these Anopheles females were also found in Aedes cantans (Meigen) and Culex salinarius Coquillett females. These cylindrical spores were associated with Thelohania infections in the larvae of these mosquitoes. The cylindrical spores have distinct taxonomic characters which when used with the structural characters of stages in the larvae aid in the differentiation of the 2 species. Descriptions of these stages in the 2 Thelohania species are presented with a brief discussion of the transovarial development of the parasites in the female bost.
Observations on the Ultrastructure of the Buccal Apparatus in Thigmotrich Ciliates and their Bearing on Thigmotrich‐Peritrich Affinities*
Authors: LOM JIRI , CORLISS JOHN O. , NOIROT‐TIMOTHÉE CÉCILE
Published: May 2007

SYNOPSIS. In the first use of electron microscopy in a comparative investigation of ciliates belonging to the order Thigmotrichida, ultrastructural data were collected on ciliary organelles of the buccal area. Species studied included members of the genera Ancistrum and Boveria. Analysis of the findings suggest close affinities between thigmotrich and peritrich ciliates. Further comparison with studies on hymenostome (sensu lato) ciliates supportes the hypothesis of a common ancestral stock in the phylogenetic history of all 3 of these groups. Structures very likely homologous in species of hymenostomes, thigmotrichs, and peritrichs include: the undulating membrane, the polykineties, the oral ribs, the filamentous reticulum, and a small field of barren kinetosomes.