Double-layered Wall Research Articles

Tyzzeria parvula (Kotlan, 1933) Klimes, 1963 (Apicomplexa: Eimeriidae) in the greylag goose (Anser anser Linnaeus, 1758) in southeastern Brazil

Tyzzeria parvula from the greylag goose (Anser anser) is described in Southeastern Brazil. Oocysts are spherical to subspherical ranging from 12.4-180 to 10.7-15.9 microm (15.4 X 13.4 microm), shape index 1.15, with a double layered wall 0.4 to 0.7 microm thick (n=20), outer smooth and colorless, inner pale greenish. Micropyle is absent, but oocyst residuum is present containing numerous granules and spherules. Surrounded by residuum there are eight sporozoites having one end round and other fine and slightly curved.

The Modified Misgav-Ladach versus the Pfannenstiel-Kerr Technique for Cesarean Section: A Randomized Trial

Suturing the uterine wall after cesarean section, begun in the late 19th century, markedly lowered the mortality risk from operative delivery. Pfannenstiel, in 1897, proposed making a curved transverse suprapubic incision in the abdominal skin, and Kerr, in 1926, first described the transverse lower-segment incision accompanied by double-layer uterine wall sutures and peritoneal closure. In 1972, Joel-Cohen described a transverse skin incision made 5 cm above the pubic symphysis along with blunt dissection of the abdominal wall. Subsequently, single-layer suturing of the uterus and not closing the peritoneum were introduced. These innovations and subsequent changes are termed the modified Misgav-Ladach (MML) technique after the major hospital contributing to their development. The investigators planned a prospective, randomized study of 162 patients having transverse lower-uterine-segment cesarean section, 88 of them with the MML technique and 74 by the Pfannenstiel-Kerr method. After making a Pfannenstiel skin incision, the subcutaneous tissue is opened upward in the midline to reach the rectus sheath above the point of insertion of the pyramidalis muscles. The subcutaneous tissue is extended and the rectus muscles separated digitally. The parietal peritoneum is opened at the level of the upper intermuscular space, also digitally. A transverse lower-segment incision 2 to 3 cm in length then is made involving both the peritoneum and myometrium. After dissecting the remaining uterine fibers and opening the fetal membranes, the incision is extended laterally by blunt dissection, and the fetus and placenta are extracted. The uterine fundus may be removed from the abdominal cavity if necessary to aid suturing. The uterine incision is closed by one-layer suturing. The visceral and parietal peritoneum are not sutured. Finally, the rectus sheath is sutured, as is the subcutaneous tissue if it is deeper than 2 cm. There were no significant differences between the two surgical groups in maternal age or weight, gestational age, parity, previous cesarean section, frequency of a nonreassuring fetal sate, or maternal/fetal conditions that contraindicate vaginal delivery. No patient had intraoperative complications or postpartum endometritis, but one woman in the MML group who was taking heparin had serious postoperative bleeding. The MML technique took significantly less time than the Pfannenstiel-Kerr approach. Women in the MML group tended to have less febrile morbidity, but there were no important group differences in analgesic needs, return of bowel function, by the second day, or wound complications. These observations suggest that the MML technique will prove more cost-effective than earlier techniques of cesarean delivery, in part because of a shorter operating time and a lesser need for suture material. Using the more recently developed approach does not appear to compromise the immediate condition of the mother or infant.

Behaviour of ventilated double layer external wall briquettes under earthquake loading

Ventilated double layer briquette is used as external walls in the construction of classical as well as modern buildings that are built in regions having climates with high temperatures or rainy and windy seasons. In this construction technique, the external layer which acts as shield against rain, wind and solar rays, and internal layer are laid separately and then interconnected to each other with steel ties. The aim of using such briquettes in the construction of external walls is to obtain ventilated double layer wall by just laying single layer of briquettes. The staggering of vertical joints provides better bond and added structural strength. The hollow cores should be directly above one another so that they can be filled with additional thermal insulation materials as the wall constructed, if required. In this paper, the earthquake response of two walls, one built using the new briquette produced from normal concrete mortar and the other constructed using the proposed briquette made out of lightweight pumice concrete mortar are studied. It was found that the wall produced using lightweight pumice concrete mortar behaves better under earthquake loads and it has higher energy absorption capacity than the other.

Effects of media composition on submerged culture spores of the entomopathogenic fungus, Metarhizium anisopliae var. acridum, Part 1: Comparison of cell wall characteristics and drying stability among three spore types

Metarhizium anisopliae var. acridum (IMI 330189) can produce at least three spore types in vitro; blastospores, submerged conidia, and aerial conidia, as defined by culturing conditions, sporogenesis, and spore morphology. This study compares morphological characteristics (dimensions and cell wall structure), chemical properties of cell wall surfaces (charge, hydrophobicity, and lectin binding), and performance (germination rate and drying stability) among these three spore types. Submerged conidia and aerial conidia both possessed thick, double-layered cell walls, with hydrophobic regions on their surfaces. However, in contrast to aerial conidia, submerged conidia have: (1) a greater affinity for the lectin concanavalin-A; (2) more anionic net surface charge; and (3) a less distinct outer rodlet layer. Blastospores were longer and more variable in length than both submerged conidia and aerial conidia, and had thinner single-layered cell walls that lacked an outer rodlet layer. Also, blastospores had a greater affinity than either conidia type for the lectin, wheat germ agglutinin. Blastaspores lacked hydrophobic regions on their surface, and had a lower anionic net surface charge than submerged conidia. In culture, blastospores germinated the fastest followed by submerged conidia, and then aerial conidia. Survival of submerged conidia and aerial conidia were similar after drying on silica gel, and was greater than that for blastospores. We provide corroborating information for differentiating spore types previously based on method of production, sporogenesis, and appearance of spores. These physical characteristics may have practical application for predicting spore-performance characteristics relevant to production and efficacy of mycoinsecticides.

Isospora automoli, a new coccidian parasite (Apicomplexa: Eimeriidae) from the buff-throated foliage-gleaner Automolus ochrolaemus and the olive-backed foliage-gleaner A. infuscatus from South America.

A new species of isosporan parasite is described from the faecal contents of the buff-throated foliage-gleaner Automolus ochrolaemus and the olive-backed foliage-gleaner A. infuscatus collected in the rainforests of eastern Ecuador. Sporulated oöcysts are subspherical to ovoidal, 23.4 x 21.3 (18-28 x 17-24) microns, colourless, with a smooth, double-layered wall with the inner layer darker and thinner; the shape-index (length/width) is 1.1 (1-1.22). Oöcysts contain one polar granule, but lack a micropyle and an oöcyst residuum. Sporocysts are ovoidal, 15.4 x 9.9 (14-17 x 8-11) microns, with a smooth single-layered wall and a small nipple-like Stieda body attached to a small, inconspicuous, acentric substieda body. Sporozoites are vermiform with one prominent posterior, refractile body (c. 4 x 5 microns), and a centrally located nucleus of equal size. Sporozoites are randomly arranged in the sporocysts with a subspherical sporocyst residuum composed of coarse granules.

Description of Pythonella scleruri n. sp. (Apicomplexa: Eimeriidae) from a brazilian bird rufous-breasted-leaftosser Sclerurus scansor, 1835 (Passeriformes: Furnariidae).

Coccidian oocysts containing 16 sporocysts with 4 sporozoites in each were observed in a faecal sample from Sclerurus scansor collected in the Itatiaia National Park, southeastern region of Brazil. The oocysts are characterized by ellipsoidal shape measuring 42.5 x 32.8 mm, with smooth, thick double-layered wall of a greenish-orange colour. An oocyst residuum of numerous scattered granules among the sporocysts in sporulated ones; 16 round sporocysts, averaging 10.5 x 10 mm each containing four elongated sporozoites; presence of residuum; absence of Stieda body. The presently described coccidian, recorded for the first time in birds, is a new species named P. scleruri.

Excystment of the oligotrich ciliate Strombidium conicum

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 09:149-156 (1995) - DOI: https://doi.org/10.3354/ame009149 Excystment of the oligotrich ciliate Strombidium conicum Kim YO, Taniguchi A Cysts of an oligotrich ciliate were isolated from sediment samples collected in Onagawa Bay on the northeastern Pacific coast of Japan and incubated under laboratory culture conditions. Successful excystment occurred regularly and the excysted cells were identified as Strombidium conicum. The cyst of S. conicum has a papulifères form and is enveloped by a double-layered wall, rigid inner and membranous outer layers. The excysted cells showed a distinctive conical shape with well-developed trichites and a ventral kinety restricted to the posterior end. The effects on excystment of temperature, light intensity, oxygen concentration, bacteria, and storage in the dark and at cold temperatures are reported. Among these variables, temperature is likely to be the principal factor controlling excystment. Cyst . Excystment . Planktonic ciliate . Strombidium conicum Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 09, No. 2. Publication date: August 31, 1995 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 1995 Inter-Research.

New high-efficiency sound suppressor

The switch shop at the Muromsk Switch Factory employs a technology in which the the surface of a stock rail and a switch rail are heated by an HF current and exposed to a jet of compressed air. The noise generated by these operation exceeds health standards by 12-22 dB. Working with specialists from the Zhukov Central Aerohydrodynamic Institute, a sound suppressor that was compact, efficient, and easy to use was developed for the process. The suppressor is a rectangular, dual chamber device of the active type. The direction of the air jet is changed three times and is directed outward at the end of the operation. The double-layer walls of the suppressor are made of ultrathin basalt fibers with sound absorbing compartments welded over the inlet and outlet of the suppressor. The total noise reduction achieved with the suppressor in tests was 14-18 dBA. The noise reduction increased to 18-22 dBA for high frequencies.

Optimization of viscoelastic compliant walls for transition delay

The potential of wall compliance for delaying boundary-layer transition through the attenuation of TollmienSchlichting waves (TSW) has been recognized in many previous theoretical studies. The present paper seeks to determine the best transition-delaying performance possible using compliant walls made from viscoelastic materials for marine applications. The wall may take the form of either a homogeneous slab of material or a thin, stiff upper layer resting on a thick, soft substrate, the latter type holding the most promise in the practical use of compliant walls. To determine the growth rates of the TSW, a highly efficient means of solving the coupled Orr-Sommerfeld/compliant-wall eigenproblem is presented. Using spectral methods, the eigenproblem is cast in a matrix form which can then be solved using an SIMD parallel computer. What prevents the use of very soft compliant walls to suppress TSW completely is the existence of hydroelastic instabilities in the wall/flow system, namely traveling-wave flutter (TWF) and divergence. Efficient methods are also presented for the evaluation of these wall-based instabilities. A thorough investigation of the effects of the wall configuration and its material properties is carried out. Both single- and double-layer walls are optimized over the full range of wall parameters. It is shown that the best performance of single- and double-layer viscoelastic walls, respectively yield 2.5- and 5-fold delays of transition when compared with a rigid wall. These factors have been achieved using the conservative value of n = 1 in the en calculations.

A Bright-Field and Scanning Electron Microscopic Study of the Development ofPuccinia ZoysiaeonZoysiaSpecies andPaederia Scandens

The development of the heteroecious, macrocyclic rust Puccinia zoysiae on zoysiagrasses (Zoysia spp.) and Paederia scandens was studied using bright-field and scanning electron microscopy. This fungus grows intercellularly through the mesophyll of the zoysiagrass leaf, invading parenchyma cells, and forming haustoria. However, its growth is restricted by the vascular bundles and the bulliform cells, which the fungus does not penetrate. As a consequence, longitudinal lesions are formed, predominantly on the adaxial leaf surface. Soon after the onset of infection, paraphyses and echinulate urediniospores are produced, and are rapidly exposed due to rupture of the epidermis. Teliospores form later, first within the uredinia, and subsequently in telia which appear on both leaf surfaces. These spores are two-celled, persistent, and pedicellate. They germinated after two months of suspension in water at 4 C, followed by exposure to a saturated atmosphere for 24 hours. Germination begins with the emergence of a basidium (promycelium) from either or both cells of the teliospore. This is followed by the formation of septa and sterigmata from which basidiospores arise. These spores infect leaves of P. scandens, producing inconspicuous, intercellular spermogonia. Aecia form intercellularly and eventually erupt through the lower leaf surface. The aecial peridium has an unusual double-layered wall, the inner wall of which consists of non-viable aeciospores. Aeciospores are verrucose and are produced in basipetal succession.

A Bright-Field and Scanning Electron Microscopic Study of the Development of Puccinia zoysiae on Zoysia Species and Paederia scandens

The development of the heteroecious, macrocyclic rust Puccinia zoysiae on zoysiagrasses (Zoysia spp.) and Paederia scandens was studied using bright-field and scanning electron microscopy. This fungus grows intercellularly through the mesophyll of the zoysiagrass leaf, invading parenchyma cells, and forming haustoria. However, its growth is restricted by the vascular bundles and the bulliform cells, which the fungus does not penetrate. As a consequence, longitudinal lesions are formed, predominantly on the adaxial leaf surface. Soon after the onset of infection, paraphyses and echinulate urediniospores are produced, and are rapidly exposed due to rupture of the epidermis. Teliospores form later, first within the uredinia, and subsequently in telia which appear on both leaf surfaces. These spores are two-celled, persistent, and pedicellate. They germinated after two months of suspension in water at 4 C, followed by exposure to a saturated atmosphere for 24 hours. Germination begins with the emergence of a basidium (promycelium) from either or both cells of the teliospore. This is followed by the formation of septa and sterigmata from which basidiospores arise. These spores infect leaves of P. scandens, producing inconspicuous, intercellular spermogonia. Aecia form intercellularly and eventually erupt through the lower leaf surface. The aecial peridium has an unusual double-layered wall, the inner wall of which consists of non-viable aeciospores. Aeciospores are verrucose and are produced in basipetal succession.

Eimeria palumbi, a New Coccidian Parasite (Apicomplexa: Eimeriidae) from the Galapagos Dove (Zenaida galapagoensis)

Eimeria palumbi is a new coccidian parasite described from one of eight (12.5%) adult Galapagos doves (Zenaida galapagoensis) living on Genovesa Island in the Galapagos Archipelago. Oocysts of the new species are ovoid to ellipsoid, 24.2 x 21.7 (2722 x 24-19) ,im, colorless, with a smooth, double-layered wall; shape index (length/width) is 1.16 (1.05-1.21). A micropyle and polar granules are absent, but an oocyst residuum is present, composed of several irregularly shaped granules loosely held together. Sporocysts are ellipsoid, 15.3 x 8.1 (17-15 x 8-8.5) ,Am with a smooth, single-layered wall and a protruding, nipple-like Stieda body and no apparent substieda body; shape index is 1.89 (2.12-1.76). Sporozoites lie head-to-tail in the sporocysts, each with one large refractile body near one end and the sporocyst residuum composed of scattered nonuniform granules covering the midregion of the sporocyst. No other parasites were found in the fecal contents. The Galapagos dove (Zenaida galapagoensis) is found on all of the major islands and many of the smaller islands in the Galapagos Archipelago. It represents the only endemic columbiform species in the archipelago (Harris, 1974). The present study describes a new coccidian parasite found in Galapagos doves captured on Genovesa Island. Genovesa Island, also called Tower Island, is the northeastern-most island in the archipelago. It is located 35 km north of the equator, approximately 90 km northeast of Santa Cruz Island and 45 km due east of Marchena Island. Genovesa Island is an uninhabited, generally arid island of about 14 km2 and is composed of basaltic lava flows covered with a growth of Opuntia spp. and low trees and shrubs (Jackson, 1985; White et al., 1986). MATERIALS AND METHODS During an ecological expedition in March and April 1987, fecal samples from eight Galapagos doves were collected. Procedures for preserving fecal material and for processing and measuring oocysts were as described earlier (McQuistion & Wilson, 1989). All measurements are in micrometers (,um) with size ranges in parentheses following the means. Oocysts were between 60 and 90 days old when examined and measured. I I am indebted to Dr. P. R. Grant, Princeton University, Princeton, New Jersey for collecting the fecal samples and identifying the birds. I thank the officials of the Charles Darwin Foundation, The Galapagos National Park, the Charles Darwin Research Station, and the Government of Ecuador for permission to conduct the study. I also thank Millikin University for awarding me a grant to fund the project. TRANS. AM. MICROSC. Soc., 110(2): 178-181. 1991. ? Copyright, 1991, by the American Microscopical Society, Inc. This content downloaded from 157.55.39.136 on Tue, 05 Jul 2016 04:17:26 UTC All use subject to http://about.jstor.org/terms VOL. 110, NO. 2, APRIL 1991

Host-parasite relationships of Ascogregarina chagasi (eugregarinorida, aseptatorina, lecudinidae) in Luzomyia longipalpis (Diptera: Psychodidae)

The life cycle of Ascogregarina chagasi in larvae and in adult female Lutzomyia longipalpis was studied by light and electron microscopy. Sporozoites and young gamonts were attached to the epithelial lining of the larval midgut via an osmiophilic contact zone. The mucron of young gamonts was bordered by an invaginated pellicular fold, and an electron-opaque vesicular structure was observed adjacent to it. Sporozoites possessed an apical complex and were bound by a double membrane with underlying subpellicular microtubules. The gamont pellicle was uniformly corrugated and consisted of two cortical membranes and a plasma membrane. Mature gamonts and gametocysts were found in the posterior ectoperitrophic space of third and fourth instar larval midguts and in the haemocoel of adult flies. Gametocysts in adult females adhered to the genital accessory glands, where they were encased in electron-dense capsules secreted by the fly through haemocyte-mediated humoral immune reactions. Oocytes were spindle-shaped and bound by a double-layered wall with a discernible polar plug at each end. Sporulation was endogenous, occurring within gametocysts in the midguts of larvae or the accessory glands of adult females. FITC-phalloidine staining of all stages of A. chagasi except mature gametocysts produced bright fluorescence, indicating the presence of a diffuse, actin-like protein in the cytoplasm.

The delay of transition of a laminar boundary layer over compliant wall

In a previous paper[1], a method has been developed to study the stability characteristics of laminar boundary layers over compliant walls. In this paper, the effect of double layered compliant wall and Kramer type compliant wall on delaying the transition is investigated, and it is shown that there does exist the possibility to delay the transition by applying such compliant walls.

Morphological changes in putrefactive anaerobe 3679 (Clostridium sporogenes) induced by sorbate, hydrochloric acid, and nitrite.

Putrefactive anaerobe 3679 (Clostridium sporogenes), a gram-positive bacterium, was examined by light and electron microscopy during normal growth and in a medium containing sorbate (50 mM, pH 6.5), hydrochloric acid (pH of medium adjusted from 7 to 5 with HCl), or nitrite (1 mM, pH 7). During the early exponential growth phase, untreated cells were filamentous and nonseptate, but became septate later and divided when the culture entered the stationary phase. Untreated short and filamentous cells had a double-layered cell wall. Sorbate-treated cells were usually filamentous and nonseptate, but with distorted shapes characterized by numerous bends and bulges. Septation, when present, resulted in minicells. The inner cell wall appeared to be thickened and the outer wall was absent in many areas. Acid-treated cells were similar to sorbate-treated cells but contained septa. Considerable cellular debris was present in the suspension. Nitrite-treated cells were also filamentous, bent, and bulged but the cell wall appeared normal. Considerable cellular debris was also present in suspensions of nitrite-treated cells. Changes in morphology are discussed in relation to possible mechanisms of cell growth regulation and the inhibitory action of sorbate, acid, and nitrite.

Clostridium thermosulfurogenes sp. nov., a New Thermophile that Produces Elemental Sulphur from Thiosulphate

A new Clostridium species is described that was isolated from a thermal, volcanic, algal-bacterial community via selective enrichment procedures with pectin as energy source. Clostridium thermosulfurogenes sp. nov. deposits elemental sulphur on the cell surface and in the culture medium from thiosulphate transformation. This species stained Gram-negative, but electron micrographs revealed a double-layered wall without the presence of an outer membranous layer. Thin sections displayed numerous internal membranes and sulphur granules were not discernible. The organism was motile and formed distinctly swollen sporangia with terminal, white-refractile, spherical spores. The temperature range for growth was >35 °C and <75 °C, the pH range was between 4·0 and 7·5. The DNA base composition was 32·6 ± 0·04 mol% guanosine plus cytosine. Fermentable carbohydrates included pectin, starch, xylose, glucose, mannose, cellobiose, maltose, arabinose and sucrose. The doubling time on glucose or pectin was about 2 h. The production of ethanol, H2/CO2, acetate and lactate accounted for a balanced fermentation of glucose, whereas methanol and isopropanol were also produced during pectin fermentation. The taxonomic relationships of C. thermosulfurogenes to other thermophilic Clostridia and its biological role in a thermal microbial community are discussed.

Observations on the ultrastructure of microtubules.

After a specific time of glutaraldehyde-acrolein fixation, microtubule walls appear to be composed of single 6.5–7.5 nm diameter osmiophilic subunits. Variations in the duration of glutaraldehyde-acrolein and also glutaraldehyde-osmium fixation reveal a two layered wall containing osmiophilic subunits, 4.0–4.5 nm in diameter, arranged radially, in tandem. The double-layered wall is demonstrated by microdensitometer traces. These observations are discussed in relation to previously proposed models of microtubule substructure.

Properties of bacteriophage PM2: A lipid-containing bacterial virus

Procedures are described for the isolation in pure form of the bacterial virus PM2. This virus isolated from seawater is shown to contain lipids by its sensitivity to ethyl ether and by chemical analysis of the purified virus. The virus has a buoyant density in CsCl of 1.28 g cm −3 and a sedimentation constant in 1 M NaCl of 230 S; it contains 14% by weight of DNA and a minimum of 10% by weight of lipids. Phosphatidylethanolamine is the main lipid present in weight percent. The virus is disrupted in 0.05% Sarkosyl or sodium dodecyl sulfate. Analysis in acrylamide gel electrophoresis indicates the presence in the virus of at least two proteins, probably lipoproteins since they can be stained with Black Sudan. The virus appears to be a polyhedral object 60 mμ in diameter; the coat seems to have an unusual structure, in that an apparent double-layered wall can be observed in the electron microscope.

Properties of a D-quinovosamine-producing Achromobacter.

The bacterial mucopolysaccharide of a Gram-negative bacterium, Georgetown strain COC-21, includes a hexosamine component, D-quinovosamine. The bacterium has been identified and classified as Achromobacter georgiopolitanum n. sp. and a description of the organism is given. The overall deoxyribonucleic acid base composition, determined by buoyant density measurements in cesium chloride, is 41 moles %. Electron micrographs of ultrathin sections reveal a double-layered cell wall structure typical of the Gram-negative bacteria.

Studies on Coprozoic Ciliates

This paper contains a revision of the morphology and classification of three species of holotrichous ciliates, Lembus pusillus, Cyclidium glaucoma and Uronema nigricans (=Uronema marina Dujardin, 1841=Cryptochilum nigricans Maupas, 1883=U. marina et U. marinum auctorum, pro parte), together with various observations on their biology. The revised data on these species are summarised in the diagnoses preceding their description.The close resemblance between U. nigricans and the other species described has led to its transfer from the family Chiliferidae to the family Pleuronemidae.Cyst formation in L. pusillus is described for the first time. The cysts, when fully formed, are provided with a double-layered wall, to which the body of the ciliate is more or less closely adherent. When preserved in dry condition, the cysts retain the same structure and are able to hatch after several months. Excystation is brought about by active rupture of the cyst-wall on the part of the ciliate. The primary cyst does not, however, afford adequate protection to the ciliate in a fluid medium. After remaining in the latter about three weeks, the animal secretes a cyst of the second order, in which it remains viable some time longer, but if left in the fluid, the ciliate ultimately dies, gradually breaking up into a number of granules.In order to establish the relationship of the marine and fresh-water forms of the same species, experiments on their acclimatisation to the opposite environment were conducted. The fresh-water U. nigricans adapted itself to pure sea water within 12 days and developed for 12 months in this medium, in which it is still being maintained. The marine U. nigricans was gradually transferred to fresh water, in which it was kept for 60 days. Observations on the morphological changes undergone by this ciliate in the course of acclimatisation show that the fresh-water forms living in sea water gradually acquire the habitus of the marine ones, and that the latter undergo the reverse change in fresh water. The characters distinguishing the two strains of U. nigricans being insignificant and transitory, the two forms are regarded as constituting a single species.The fresh-water L. pusillus required eight days for acclimatisation to sea water, in which it was maintained for 163 days without exhibiting any morphological changes.Attempts to acclimatise the fresh-water C. glaucoma to pure sea water failed, but in 50 per cent, sea water it grew for 130 days. The morphological and biological differences between the fresh-water and marine strains of C. glaucoma are probably sufficient for them to be regarded as sub-species or races.Experiments were conducted on the cultivation of these ciliates in faecal matter from normal and diseased human subjects, and varying widely in consistency. Tests on the influence of the reaction of the medium upon the growth of the ciliates showed that they prefer a slightly alkaline medium (pH 7·4–8·0), but are able to tolerate an increase of alkalinity up to pH 9·0–10·0, whilst the acidification of the medium beyond pH 5·0 inhibits their growth.As regards the facility with which these ciliates grew in faecal cultures, Lembus occupied the first place, having developed in the majority (64 per cent.) of samples of pure (i.e. undiluted) faeces, and in all those slightly diluted with water. The second place belongs to Uronema, which grew in all the diluted specimens and in one undiluted, whereas Cyclidium was unable to grow in pure faeces, but developed in about half of the diluted samples. All these ciliates were successfully cultivated in suspensions of human and animal faeces.The coprozoic habits of the ciliates in question are compared with the records for “Uronema caudatum,” comprising a number of ciliates described by some authors as human intestinal parasites. It is shown that the conditions under which these ciliates were observed indicate that they were coprozoic forms that had contaminated the material examined. Though described under the name “U. caudatum” these ciliates represent at least two distinct genera, those recorded by Martini being similar to Cyclidium or Uronema, the ones described by Yakimoff et al. probably representing Lembus pusillus.The last-named ciliarte having been originally found in a sample of canine faeces, experiments were carried out with the view of ascertaining its origin. It was demonstrated that the ciliate was unable to withstand incubation at 37°C. for 24 hours, and, when fed to mice in the form of cysts, did not survive the passage through their intestine. These facts indicate that the faeces in which Lembus was found must have been contaminated by this ciliate from outside.