ALBERT

Notes: The paper traces the history of the Wild series of rectifiers, paying particular attention to the mechanical solutions of the Newton and Scheimpflug conditions.

Notes: Land systems are patterns of landscape recognised on aerial photographs and mapped to define areas of similar terrain with a similar environment. Breaks of slope often form the major boundaries both between and within land systems. They can be usefully mapped from aerial photographs even if their significance can only be deduced after ground investigation. Many of the characteristics of land systems can be appreciated from aerial photographs and measurements made on the photographs can improve their quantitative description.

Notes: A method of slotted templet triangulation is described in which the authors have used photographs printed on a stable base as the templets. The advantages, disadvantages and possibilities of the method are discussed.

Notes: The paper gives, for a large number of cases, numerical errors due to using approximate, first-order, formulae for correcting x-parallaxes for tilt. The figures show that the errors are considerably smaller than might be expected. It is also shown that the root mean square of the four tilts of a pair of pictures is a reliable measure from which the effect of tilt on heights can be estimated with some confidence.

Notes: Research work is being undertaken by the Department of Orthodontics at Addenbrooke's Hospital, Cambridge, which involves studying the growth of children's faces in three dimensions. In evaluating the morphology of soft tissues, the advantages offered by photogrammetry have been recognised and this paper describes how the technique has been put into practice at the hospital where a stereometric instrument, equally suitable for use as a camera or as a projection plotter, has been constructed.

Notes: After a brief review of the history of the orthophoto mapping process and its methods, the paper describes the automatic production of orthophotographs in the BS-Stereomat. Technical details, especially of the electronics of the instrument, are given. The range of applications of an orthophoto is discussed, as well as the method's limitations.

Notes: Equipment manufactured in connexion with the special applications of photogrammetry has developed from very early designs, often with remarkably few changes. The first section of the paper traces this evolution up to the present time.Architectural photogrammetry has been, since Meydenbauer, one of the most important of these special applications and the second part describes some recent work of this type in England and Jordan.

Notes: The problem of incorporating airborne auxiliary data into an aerial triangulation block adjustment is considered. The conclusion is reached that this problem can be most readily solved by the use of a fully rigorous adjustment method. The first order adjustment equations for all types of airborne auxiliary control are developed and the method of incorporating these equations into the block solution is demonstrated. The general computing problems of the aerial triangulation block adjustment are briefly discussed and a method outlined for the incorporation of tie strips, at any angle across the block, into the adjustment without unduly increasing the storage requirements for the solution. The problem of correctly weighting the different types of available data is discussed. The paper concludes with a demonstration of the improved accuracy possible if precise aerial triangulation data are combined with apparently crude absolute airborne data.

Notes: The author explains one of the chief problems, the composition of a survey aircraft navigation system, facing Commission I of the International Society for Photogrammetry. The tasks to be accomplished by such a system are outlined, and some of the alternative equipment available to carry out the various aspects of this work are discussed.

Notes: It is well known that there exists a “danger cylinder” for space resection, analogous to the “danger circle” in the plane, on which the resection is unstable. This paper shows how the existence of this surface may be detected and draws attention to the way in which the instability differs from that in the plane.

Notes: This paper discusses a simple method of computing independent strips under certain reasonable approximations. It is shown that, if the method is regarded as if it were computation by polynomials, the order of the polynomial is decided by the nature of the control provided and not by the number of controlled models. This conclusion should throw some light on the vexed (and perennial) problem of the choice of orders for polynomials.

Notes: An attempt is made to review the factors affecting the use of colour photography in photogrammetry and photo-interpretation. Examples of current practice and results of comparative tests are quoted, as well as the advantages and deficiencies of the various materials available.

Notes: During the summer of 1965, colour, false colour, infra-red and panchromatic photography was flown of the Breidamerkur Glacier area in south-east Iceland. Subsequent comparative interpretation studies of the film types have indicated that colour photography is superior for the interpretation of glacierized† areas. This is attributed to brightness qualities and a continuous colour tone range, which, in this instance, closely matched visual representation of ground objects.The false colour film, due to the striking tonal qualities of vegetation and moisture, is considered best for studies involving the delimitation of these features. Panchromatic film appears to be satisfactory for general interpretation work, particularly where the utmost in definition is called for. The infra-red film, because of the dark tones produced by gravels and the subsequent high contrasts between ice and gravel debris on the ice surface, is considered a poor choice for the interpretation of glacierized areas.

Notes: This paper gives convenient formulae for numerical relative orientation for use with instruments in which the Y-parallax may be accurately measured.

Notes: SYNOPSIS. In cultures of Trypanosoma conorhini the authors have detected “cyst-like bodies” (CLBs) that, in the initial phase, have the appearance of 2 or more overgrown crithidiae fused together; after disorganization of the internal structure of the parent flagellates and division of their organelles, new crithidiae are formed within the CLB. The wall of the CLB consists of an irregularly thick layer of cytoplasm surrounded by the periplast of the parent flagellates and a true cystic membrane is not evident. The daughter crithidiae eventually escape from the CLB leaving the periplast and other residues of the parent flagellates. It is suggested that this represents a method of reproduction entirely different from binary or multiple fission, that is probably common to other trypanosomes of the Section STERCORARIA, and that it may provide for genetic exchange even if it is not a true sexual process.

Notes: SYNOPSIS. During conjugation of Kahlia the micronuclei divide 3 times before synkaryon formation and 2 times thereafter. The 1st division is heterotypic, as in other ciliates, in that it is characterized by the parachute stage. Following this stage, 24 to 26 bivalents and 4 to 8 univalents appear in the micronuclear area. When the bivalents move to organize the metaphase plate, the univalents lag behind and fail to reach the equatorial region at the same time. Due to this irregular behavior of the univalents there is no distinct metaphase in the first meiotic division. A few meiotic irregularities including the breakdown of the spindle apparatus have been observed. During the breakdown of the spindle apparatus the chromosomes fuse into irregular bodies which resemble the chromosome aggregates observed during the somatic divisions. Generally 1, and rarely more, of the products of the 1st division enter the 2nd division. The spindles of this division are oriented parallel to the long axis of the cell, and 1 of the daughter nuclei reaches the partition membrane separating the conjugants. This nucleus alone undergoes the 3rd division, resulting in the formation of gametic nuclei. Reciprocal exchange and fusion of the gametic nuclei result in the synkaryon formation. The synkaryon divides twice in rapid succession resulting in 4 daughter nuclei; 1 of them degenerates and 2 condense and become functional micronuclei. The chromosomes of the remaining daughter nucleus resemble in size and number the bivalents of the 1st meiotic division. They become polytenic and then reproduce to give rise to the polyploid macronucleus. The development of the macronucleus has been traced from a single diploid set of chromosomes and no evidence has been found for the formation of genetic “subnuclei.” During the early stages of the development of the macronuclear anlage, somatic pairing forces keep the homologs together, while in the later stages these forces cease to exert influence. While these changes are in progress the old macronucleus; breaks up into small irregular polymorphic bodies which are scattered throughout in the cytoplasm. The exconjugants usually encyst and the cysts are not favorable for detailed cytologic study.

Notes: SYNOPSIS. In young first generation schizonts of E. bovis, the nuclei appeared to have a random distribution. In calves killed 8 days after inoculation some of the schizonts had the nuclei arranged in a single layer at the periphery, with a few infoldings of this layer into the interior. In further development, such ingrowths of the nuclear layer resulted in the formation of compartments of varying size. In schizonts of calves killed 12 days after inoculation spherical or ellipsoidal bodies (blastophores), about 5–20 μ in diameter with a single peripheral layer of nuclei were formed. Merozoites developed as radial outgrowths from the blastophores, leaving residual bodies of variable size, which later disappeared. The response of the host cell to the presence of the schizont was characterized by marked growth of both the nucleus and cytoplasm. The nucleolus became greatly enlarged, and the chromatin was distributed in relatively fine granules. In the host cell cytoplasm, 2 concentric layers were observed; the inner was more dense than the outer. After growth of the schizont was completed its host cell was stretched into a thin covering layer about 1 μ thick. In some schizonts, the host cell disintegrated, and the schizont was then invaded by eosinophils, macrophages and other cells, which eventually destroyed the merozoites.

Notes: SYNOPSIS. Blood smears from 133 Rio Grande wild turkeys Meleagridis gallopavo intermedia live-trapped in the Welder Wildlife Refuge in south Texas, were examined for blood parasites. All of the 63 immature turkeys and 63% of the 70 adult turkeys were infected with Haemoproteus meleagridis. The infections were light, half the cases having less than 5 infected cells per 10,000 red blood cells. Infection with H. meleagridis caused significant enlargement of the host RBC. Other parasites specifically searched for but not found were Leucocytozoon, Trypanosoma, Plasmodium and microfilariae.

Notes: SYNOPSIS. The fine structure of the tomite stage of Hyalophysa chattoni was examined with particular attention to its kinetal apparatus.The pellicle, thick and dense compared with that of other ciliates, is formed of three layers. The inner layer is composed of short fibrils oriented perpendicular to the surface.The cytoplasm around the oral passage and beneath falciform field 8 is crowded with dense inclusion bodies of unknown function. Dorsal to the oral passage is the rosette, a disc-shaped organelle subdivided by septa in the form of incomplete radii about a central chamber containing a tuft of cilia. The septa are composed of 3 membranes enclosing a fine layer of cytoplasm. At their inner ends 20 mμ fibers run dorsally and ventrally. Dense clumps of fibrous material line the luminal surface of the septa.Rows of fusiform trichocysts parallel the kineties. The trichocysts are composed of a finely periodic, moderately electron-dense material surrounded by 20 mμ fibrils oriented along the long axis of the trichocyst. Between and below the kinetosomes and the rows of trichocysts are electron-dense vesicles 300 mμ in diameter and bounded by a loose membrane. The large “trichocysts,” the “gros trichocystes” of Chatton and Lwoff, whose appearance heralds the beginnings of trichocystogenesis, prove to be canaliculi opening to the surface.Four separate ciliary membrane systems—the oral ciliature (XYZ), falciform field 8, falciform field 9, and the ogival field—are located on the ventral surface of the tomite. Each differs from the others and from the somatic kineties in the fibrillar organization around its kinetosomes.In the somatic kineties the kinetodesmos is a dense, periodic fiber which is formed of stacks of up to 18 subfibers, each arising from the base of a kinetosome. The kinetosomes are short (300 mμ) and contain dense central granules. In some kineties, alternating between the kinetosomes, are elliptical kinetosome-like structures which do not bear cilia and perhaps provide a reservoir of kinetosomes for future growth of the kinety.

Notes: SYNOPSIS. The life cycle of the true slime mold Physarum polycephalum includes 2 vegetative stages: the multinucleate coenocytic plasmodium and the uninucleate amoeba. A clone of amoebae established from a single spore does not normally yield plasmodia. Plasmodia are formed when amoebae from particular clones are mixed; thus plasmodium formation is said to be controlled by a ‘mating-type’ system.Previous work by the author with a sample of P. polycephalum derived from a single source revealed that 2 mating types were present and were determined by a pair of alleles at 1 locus. The present paper reveals the presence of 2 more mating types in a sample of P. polycephalum derived from a different source and provides evidence that these are determined by 2 alleles at the same locus as the other 2.Evidence for the presence of other inherited factors affecting plasmodium formation, the mode of action of these factors and possible explanations for the occurrence of plasmodia in single-spore cultures are also discussed.

Notes: SYNOPSIS. Transection and regeneration of Blepharisma intermedium initiate complex macronuclear activity and micronuclear division. Reversible condensation of the macronucleus is achieved by contraction which involves primary and secondary coiling. Primary coiling, evident in vegetative cells, is enhanced by pronounced constriction of the macronuclear extremities during regeneration. Secondary coiling is restricted to the period of contraction and is initiated at the ends of the mauonucleus. Condensation terminates the coiling processes and gives rise to an amorphous structure. Re-elongation of the macronucleus is not followed immediately by coiling. Micronuclear division begins early in regeneration, but the peak of visible activity is not reached until the 3rd through 5th hours.

Notes: SYNOPSIS. Lipids in aging cultures of Tetrakymena pyriformis were extracted at various times after inoculation, purified, and weighed or chromatographed on thin layers of silica gel. The total cellular lipid increased throughout logarithmic and early stationary phases but decreased sharply after 72 hr. The amount of one lipid class, probably the triglycerides, followed the same trends. It may be a cellular reserve.

Notes: SYNOPSIS. Rearing of cockroaches without sporozoan parasites of the Malpighian tubules permitted the 1st experimental infections reported for these organisms as well as study of the intracellular early stages of infection. Infectivity tests show that the route of invasion is peroral rather than transovarian; that fresh spores obtained from either the Malpighian tubules or the hindgut are infective; that fresh spores held in aqueous suspension for 36 hr are not infective; that all ages and both sexes of cockroaches are susceptible, although older cockroaches are more readily infected experimentally; that a single peroral dose of a few hundred spores is sufficient to produce infection; that the earliest signs of progressive infection in the Malpighian tubules appear 15 days after ingestion of spores; and that the infection, spread mainly by schizogony, is well established by 23 days. Spores are acid-fast. The PAS-positive spore membrane is not dissolved by 20-min treatment with hot KOH, but tests for chitin were inconclusive. The life history of the parasite is described. “Encapsulation” of the parasite has been observed. Electron microscope studies, the first reported for the class Haplosporea, show similarities of the cytoplasmic structure of this haplosporidian with that of some members of the sporozoan class Telosporea, though no specialized structures were seen. Finding of intracellular stages together with failure of interspecific infection attempts suggest that the microorganism should be placed in the genus Nephridiophaga Ivanic, 1937 with the specific name blattellae Crawley, 1905.

Notes: SYNOPSIS. A centrifugation procedure for removing Tetrahymena from mass cultures is described. This method offers the following advantages: (a) inexpensive apparatus, (b) the short period of time required for harvesting large numbers of cells, (c) lack of cellular damage, (d) the ability to obtain proven dilution with regard to the culture fluid, (e) nearly quantitative recovery of the cells, and (f) the ease of assembling and disassembling the apparatus for cleaning.

Notes: SYNOPSIS. Monocercomonas molae from the hindgut of the sunfish Mola mola is described. The host was taken from southern California coastal waters in October, 1964. The body of the flagellate is 8.0 × 10.7 microns. A single basal granule complex gives rise to 4 flagella, one of which is recurrent. The axostyle is relatively stout, with argentophilic granules, and possesses a periaxostylar ring. The capitulum of the axostyle continues into the sickle-shaped pelta, and the parabasal body is rod-shaped or lobed and roughly triangular in cross-section.

Notes: SYNOPSIS. The complete life history of a homothallic, dioecious strain of Volvox aureus was studied in axenic culture. Asexual reproduction occurs by repeated division of specialized reproductive cells (gonidia), inversion of the resultant mass of cells to form daughter colonies, and subsequent morphologic differentiation of new gonidia in these daughters. Male colonies lack gonidia; however, the posterior 2/3 of the cells in a colony function as male initials each of which enlarges, divides, and undergoes rudimentary inversion to form a packet of 32 biflagellate sperm. Evidence was presented for the homology of eggs and undivided gonidia. The penetration of young vegetative colonies by sperm and the subsequent formation of apparent zygotes in these colonies was described and figured. Zygote germination, including division and inversion of the germling, was described; the cytological nature of the zygote divisions was not determined.A substance, MIS, in filtrates of sexual cultures induced differentiation of male colonies; a bioassay for it was perfected. Bioassay colonies show a differential susceptibility to male induction by MIS which is a function of the particular stage of development; colonies 48 hr after release from parentals are optimally susceptible. MIS was reasonably stable to heat, non-dialyzable, and Sephadex gel filtration indicated a molecular weight 〉 200,000. MIS activity is destroyed by trypsin and pronase but is unaffected by chymotrypsin. MIS was successfully concentrated ∼37-fold by the Carbowax method. The patterns of differentiation in other species of Volvox are described and possibilities discussed for studies of cellular differentiation in the genus as a whole.

Notes: SYNOPSIS. Haemogregarina faiyumensis n. sp., a parasite of toads, Bufo regularis, in Faiyuni Province, Egypt, U.A.R., is described. In a survey of 689 toads from various localities in Cairo, Giza and Faiyurn provinces, only 3 out of 13 toads from Kom O Shim near Faiyum were infected. This species, known only by blood forms (most probably gametocytes) of two different staining reactions, is 13-17 μ long and 4-5 μ wide, with an average of 15.5 × 4.5 μ. The nucleus is typically subcircular and 3-5 × 3–5 μ, with an average of 4.5 × 3.9 μ.

Notes: SYNOPSIS. Haemogregarina boueti França, 1910, was found to be the commonest blood parasite in the common toad, Bufo regularis Reuss, in Egypt. The rate of infection was about 30% (of 689 toads examined).In properly fixed blood films, the parasites were almost exclusively intraerythrocytic. Most characteristic was the encapsulated “elongate” form averaging 22.3 by 6 μ with a more-or-less central nucleus and a pointed, slightly bent, posterior end. Infected red cells were conspicuously hypertrophied and their nuclei were markedly displaced and frequently broken into 2-4 parts.Young and growing blood forms as well as two types of hepatic schizonts are described for the first time.Schizonts of the first type develop in hepatic cells, are 28–30 μ in diameter and produce numerous elongate oval merozoites about 8 × 2.2 μ radially arranged around a residual body about 10 μ in diameter.Schizonts of the second type start their growth in erythrocytes but later complete their development as free bodies in the liver sinusoids. When mature, they are 32–35 μ in diameter and produce a larger number of thin merozoites about 8 × 1.5 μ, surrounding a larger residual body about 19 μ in diameter.

Notes: SYNOPSIS. Haemogregarina pestanae França, 1910, is apparently rare in Egypt, having been found in 1 toad Bufo regularis Reuss out of 689 examined. Capsulated capped, young thin, and young and advanced broad forms were present in the peripheral blood. Schizogony occurred in the liver. Two types of schizonts were present—macroschizonts producing 150 or more elongate oval merozoites surrounding a large residual body, and microschizonts producing 60 or less banana-shaped merozoites often radiating from a small, eccentric residual body.Merozoites of the first type developed into a large broad form representing early schizonts of the second type. The latter developed into thin young intraerythrocytic forms and apparently later into encapsulated capped gametocytes. H. pestanae, H. aegyptia and H. tunisiensis all occur in toads (Bufo regularis for the first two, and B. mauritanicus for the third), and produce characteristic encapsulated looped gametocytes in peripheral blood. The capsules contain dark-staining material condensed into a single well-developed cap in H. aegyptia and 1 or 2 much smaller caps in H. pestanae; this material is scattered regularly around the parasite in H. tunisiensis. The capsule of H. pestanae is more or less cylindrical along most of its length, more slender and slightly shorter than the regularly oval capsule of H. tunisiensis or the spindle- or egg-shaped capsule of H. aegyptia.

Notes: SYNOPSIS. Spathidium spathula irradiated with 0 to 55 kr of × rays showed one or more of the following kinds of behavior: (1) Death of an undivided cell (primary death); (2) death of a descendant of an irradiated cell (secondary death); (3) permanent injury including one or more of the following: low daily division rate, excessive macronuclear enlargement, total loss of micronuclei, cytostome replication, heavy pigmentation, and decreased motility; (4) temporary division retardation for 1 to 2 days followed by apparent complete recovery; and (5) no apparent injury. The first 3 kinds of behavior increased with increasing dosage from 15 to 25 to 55 kr. At 6 kr only the last 2 categories were observed. The LD50 for 8 days was 46 kr for both primary and secondary death, or 60 kr for primary death alone.Micronuclear number varied greatly following irradiation in lines showing either permanent or temporary injury. Two different responses occurred: (1) The micronuclear number averaged about twice the normal number of 20 with a large range (0 to 360) 1 day after exposure. The number gradually decreased during the next 2 days; (2) some cells lost all micronuclei following irradiation, the incidence increasing with dose. At 55 kr complete loss of micronuclei occurred in 96% of the surviving lines.

Notes: SYNOPSIS. Exchange of cytoplasm in Tetrahymena pyriformis, syngen 1, has been demonstrated by growing cells of 1 mating type in medium supplemented with H3-uridine or H3-histidine, washing, mixing with cells of an unlabeled, starved mating type, sampling conjugants at different times, and preparing autoradiographs. It was found that cytoplasmic interchange begins soon after the mates unite, and has become extensive before the end of the 1st prezygotic prophase (micronuclear crescent stage). When the RNA in one mating type had been labeled with H3-uridine, the activity was distributed almost evenly between the mates by late stages of conjugation. These results are consistent with electron micrographs of this syngen showing small pores in the attachment region of the mates, and many free ribosomes in the cytoplasm (8,11). By contrast, when protein in one mating type had been labeled with H3-histidine, these cells at late conjugation remained about twice as active as their originally unlabeled mates, presumably because of the physical characteristics of some structures which incorporated the amino acid (for example, cilia and membranes of the cell surface; cytoplasmic bodies, such as mitochondria, larger than the pores). That the radioactivity in the originally unlabeled cells came from their mates and not from the environment is indicated by the continued presence of inactive non-conjugants after 1 and 2 days in the mating type mixtures. Other cells which did acquire small amounts of active cytoplasm probably had engaged in abortive conjugation, separating from labeled mates before forming and exchanging pronuclei.

Notes: SYNOPSIS. A major difference in heme content was found between leishmanias and leptomonads of Leishmania donovani. When tested with a fluorescence method for heme, leishmanias gave a negative response whereas leptomonads fluoresced brightly. Studies on the terminal respiration of L. tarentolae leptomonads by absorption spectra assay and respiratory inhibitors indicated the presence of cytochromes. Lactic dehydrogenase could not be detected in the leptomonad stage nor could it be found in any other hemoflagellate culture form tested.

Notes: SYNOPSIS. The fine structure of various stages in the life cycle of Theileria parva is described. The appearance of the parasites suggests that there may be a double macroschizogony cycle. Micromerozoites are produced by a process of budding off from the body, known in light microscopy preparations as the residual body.

Notes: SYNOPSIS. A pure strain of Eimeria debliecki (University of Illinois strain A) established from a single oocyst was used to determine the endogenous cycle. Young parasite-free pigs 2 weeks to 3 months old were used throughout the study.The endogenous cycle was found to take place in the small intestine where the parasites were located in the distal portion of the striated simple columnar epithelial cells of the villi. The first generation schizonts were found in only the jejunum (15% of small intestine). The second generation schizonts and gametes occurred in the jejunum and ileum (70% of small intestine), a slight posterior progression occurring with each stage. The entire cycle required 6.5 days.The schizogonous cycle comprised 2 generations. The first generation schizonts required 2.5 days to reach maturity, measured 8-12 μ, contained 16 merozoites measuring 12-15 μ and had a polar residual mass. The second generation schizonts required 2 days to reach maturity, measured 13-16 μ, contained 32 rotund merozoites measuring 6–8 μ, and had only a few granules of residual material.Gametogony took place in 1.5 days. The macrogametes measured 12-16 μ, and the microgametocytes measured 9-14 μ with microgametes measuring 5–6 μ.

Notes: SYNOPSIS. Trypanosomatid-free plants of the family Asclepiadaceae identified as Asclepias syriaca, A. curassavica, A. incarnata, Stephanotis floribunda, Seutera maritima, Amphistelma scoparia and plants of the family Euphorbiaceae identified as Euphorbia tirucalli, E. trigona, and Pedilanthus tithymaloides were exposed to the bite of the bug, Oncopeltus fasciatus, infected with Phytomonas elmassiani, a flagellate which occurs naturally in A. syriaca and O. fasciatus. Two weeks subsequent to exposure to laboratory-infected oncopeltids all the experimental Asclepiadaceae were infected. The mean length of the protozoa varied depending on the host plant. The flagellates in A. syriaca, A. curassavica, and A. incarnata were shorter than those in S. floribunda, S. maritima, and A. scoparia.None of the Euphorbiaceae became infected.

Notes: SYNOPSIS. The mechanism of Prymnesium parvum ichthyotoxicity was studied in immersed minnows (Gambusia affinis) in the presence of various synergists (especially polyamines and invert soaps) and under varying conditions of pH and salinity. The effect of immersion in toxin-synergist solution on permeability of gill tissues to trypan blue and to radioactive substances, e.g., I125 and radio-iodinated albumin, was established. Fish sensitivity to various toxic substances was increased after immersion for short periods in suitable toxinsynergist solutions. This sensitivity, as well as the increased permeability of gill tissue, was transient and disappeared when fish were stored in tap water for several hours after the toxin-synergist treatment. Good correlation was found between the conditions (synergist quality and concentration, pH, salinity) leading to P. parvum ichthyotoxicity and conditions instrumental in increased gill permeability and toxin sensitivity. The primary site of damage is concluded to be the gill membrane.

Notes: SYNOPSIS. Tetratrichomonas gallinarum was found in the blood of 3 chickens experimentally infected with Borrelia anserina. The blood infection was successfully reproduced in healthy chickens and was accompanied by evidence that the trichomonads multiplied in the blood, ingested red blood cells, and were themselves phagocytized by leucocytes. T. gallinarum was maintained in serial passage in chicken embryos as well as in the usual trichomonad culture media.

Notes: SYNOPSIS. Schwartz identified a protozoan, parasite of the marine fish Leiostomus xanthurus as a haplosporidian belonging to genus Ichthyosporidium Caullery and Mesnil, 1905. Now, a coiled polar filament in the spore of that organism has been clearly recognized in certain PAS preparations which were used in the original study. The parasite is, therefore, a microsporidian rather than a haplosporidian. The generic characters of this and other protozoans still in genus Ichthyosporidium need further study.

Notes: SYNOPSIS. Suspensions of whole, killed ciliates were diffused against rabbit antisera for the respective strains to observe cross precipitation. The strains fell into the following groups: I. GL, H, ChS, GP, Aq, L-I, L-II, L-2, and V1; II. W, L-3, Gl-R, and V2; III. PR and F; and IV. BF and Lava. T. vorax strains V1 and V2 each resembled certain T. pyriformis strains more closely than they resembled each other. The same grouping of strains emerged in comparing antigenic suspensions and in comparing antisera and was confirmed by comparing absorption properties of antigens from the different strains.

Notes: SYNOPSIS. Two hundred and fifty-nine specimens of the sea urchins Echinometra lucunter (201), Diadema antillarum (52), Tripneustes ventricosus (5) and Eucidaris tribuloides (1), collected on the littoral of the Federal District of Venezuela, were examined for intestinal ciliates.Iron hematoxylin and silver-impregnation staining technics permitted determination of eight of the nine ciliates found: Anophrys aglycus, A. elongata, Cohnilembus caeci, Biggaria bermudensis, B. echinometris, Cyclidium rhabdotectum, Metopus circumlabens and M. rotundus. An unidentified species of Euplotes was also found.

Notes: SYNOPSIS. The firm union of the shells of adult Gromia oviformis in plastogamous pairs is followed by gametogenesis and fertilization with the production of distinctive fusiform zygotes that undergo further transformation into amoebulae initially having hyaline radiate pseudopodia. The amoebulae emerge from the parental shells and probably initiate the asexual phase of the life cycle.

Notes: SYNOPSIS. The establishment of Eimeria acervulina sporozoites in the duodenal glands of Lieberkühn of the chicken is described. Sporozoites were found to enter the tips of the villi and pass into the lamina propria, or core, of the villus. Within the lamina propria, sporozoites were engulfed by macrophages and taken to the glandular epithelium.Data are presented which indicate that macrophages serve as a defense against infection as well as a mode of transportation.

Notes: SYNOPSIS. Electron microscope observations of a strain of Labyrinthula indicate that the spindle cells glide within a collapsible slime tube rather than on top of it. These slimeways are clearly extracellular, partly covered with membranes, and consist of an amorphous matrix encrusted with many small vesicular elements.

Notes: SYNOPSIS. Thirty-one stocks of a marine ciliate, Euplotes minuta Yocom, collected from different localities, can be grouped in seven mating types. True pairs are formed only in mixtures of stocks belonging to different mating types. No selfing pairs or intraclonal conjugation have ever been observed. Synclonal inheritance of mating types is the rule, although about 10% of pairs show clonal inheritance. The latter can be explained by assuming syncaryon formation through cytogamy or through caryogamy of pronuclei derived from different products of meiosis. Mating type determination is due to 7 alleles at the single locus mt. There is complete dominance among the 7 alleles which can be orderly seriated, as shown in Table 3, according to their dominance relationship. The 5 stocks, and only these 5, of mating type VII have the autogamy trait. The mortality rate in F1 and F2 is very low–a maximum of 10%; however, the F2'S obtained by autogamy from F1 progenies in which mating type VII is involved have a very high mortality rate. The two facts (high mortality rate in F2 and strict association of autogamy trait with mating type VII in natural populations) have been considered as evidences of a probable isolation mechanism existing between mating type VII and the other 6 mating types. Thus, the 7 mating types have been assigned to the same syngen only tentatively.

Notes: SYNOPSIS. Sporozoites of Lankesterella hylae were found in 12 of 13 green tree frogs (Hyla caerulea) from Gin Gin, Queensland. The intraerythrocytic sporozoites had two pale-staining vacuoles at the poles of the nucleus and frequently a dome-like protuberance on the concavity of the crescentic protozoon.Motility was observed in free but not intracellular sporozoites in fresh blood. Locomotion was of a gliding nature, though in addition parasites flexed and extended, and a peristaltic constriction passed backwards along the body of two. One parasite entered and emerged from a red cell, the erythrocyte playing a passive role.All stages of sporogony were observed in liver smears from a debilitated frog. In araldite sections of the small intestine of another frog, parasites were found in the vacuoles within unidentified cells in the lamina propria, thus suggesting that the parasite's point of entry is possibly the alimentary tract.

Notes: SYNOPSIS. Some of the serotypes in Paramecium caudatum are described in this paper. Immobilization antigens of P. caudatum have been obtained by extracting paramecia in a dilute salt solution containing 15% alcohol. Immobilization antigen F from stock 162 has been isolated and has a sedimentation coefficient of 9.3 Svedbergs, diffusion coefficient of 2.3 × 10-7 cm/sec, and molecular weight of approximately 340,000.

Notes: SYNOPSIS. Two species of Isospora are described from Chloris chloris with the additional hosts Passer domesticus and Fringilla coelebs. I. lacazei Labbé has spherical oocysts measuring 16.6 to 30.0 μ; the oocyst wall is colorless and smooth, consisting of a thick layer and, in the majority of oocysts, an inner thin membrane. Stages of the life cycle in the epithelial cells of the duodenum are described. The internal stages consist of first and late generation schizonts which produce merozoites without any residual body, spindle-shaped microgametes and macrogametes without obvious “plastic granules.” The oocysts of I. chloridis sp. n. have colorless, smooth surfaced walls of one thick layer. They are ellipsoidal, measuring 17.2-33.2 μ× 16.6-30.0 μ. The internal stages of this species infect the epithelial cells of the small intestine in the same region as I. lacazei. They produce 2 generations of schizonts, consisting of merozoites and a residuum; microgametes are comma-shaped and macrogametes have obvious “plastic granules.”

Notes: SYNOPSIS. Blood and tissue smears from 156 yellow-billed magpies showed infection with hematozoa in 154 (99%). Leucocytozoon berestneffi was found in 149 (96%), Haemoproteus picae in 40 (26%), Plasmodium relictum, in 32 (21%), Trypanosoma sp. in 3 (2%), and microfilariae in 42 (27%). Fifty-two birds were infected with two genera of parasites, 27 with 3, and 4 with 4. Leucocytozoon, Plasmodium and microfilariae showed a higher incidence in tissue than in blood smears.

Notes: SYNOPSIS. Monolayers of cells of coverslips were produced by culturing known numbers of trypsinized chick cells in growth medium (solution 199 plus 20% calf serum) at 37 C for 2 days. The fluid was then replaced with maintenance medium (solution 199 plus 5% calf serum) containing various known numbers of T. cruzi and the preparations were incubated at 33 C for 5 days; fresh maintenance medium was substituted on the 2nd or 3rd day. The inocula of parasites were obtained from T. cruzi-cell cultures, supplemented with 2% sterile NNN overlay, or from NNN cultures.The numbers of extracellular parasites, proportions of infected cells, and percentage distribution of infected cells relative to the number of intracellular leishmanial bodies were determined on days 2 or 3 and 5 of parasite cultivation in many experiments. Analyses of the data gave the following results. Extracellular parasites increased 2- to 14-fold during the first 2 or 3 days, depending upon the source and size of the inocula, and 10- to 20-fold during the last 2 or 3 days. Cell infection continued throughout incubation at daily rates of 1.4-4.5%; 8-22% of the cells became infected during the 5 days of incubation. Intracellular growth was reflected most clearly by increases in the proportion of cells having 〉10 leishmanial bodies. This increase was about 5% daily during the last 2 or 3 days of incubation.A useful test procedure for assessing the antiparasitic action and chick embryo cell toxicity of drugs is illustrated by data obtained with furazolidone and tris (p-aminophenyl)carbonium chloride.

Notes: SYNOPSIS. Tetrahymena pyriformis strains E, A-136 31C and IMT II survived freezing in 10% dimethylsulfoxide when the temperature was lowered to freezing at 4.5 C/min. Survival was then obtained for at least 128 days by lowering the temperature rapidly to 95°C. Of the 3 strains, T. pyriformis IMT II was most resistant to the effects of freezing. Its volume averaged about half that of either of the other strains and may have contributed to the differences in survival. In addition to differences among strains, a medium relatively low in the concentration of nutrients, a culture nearing peak population, and a rate of cooling of 4.5 C/min, all gave best survival. Paramecium aurelia regained motility after being frozen in 6 to 7.5% dimethylsulfoxide for as long as 7 days at either –27 or –196 C, but cultures were obtained only after storage for 20 min at –27 C. A concentration of 6 to 7.5% dimethyl-sulfoxide, cooling at 4.5 C/min, and culture media containing Aerobacter aerogenes or composed of a commercially available composition were all required for survival of P. aurelia.

Notes: SYNOPSIS. Microstome →macrostome transformation in Tetrahymena vorax was induced by suspending microstomes in a transforming principle, stomatin, released by a potential prey, T. pyriformis. It was found that 70–90% of the microstomes formed macrostomes within 7 hours following suspension in this transforming principle. Macrostome formation occurred by the process of oral replacement. This process involved resorption of the microstome oral apparatus and its replacement with a larger (macrostome) one, which arose from an anarchic field that formed behind the resorbing oral area. Ninety-five percent of those microstomes which were destined to form macrostomes were in some stage of oral replacement 195 minutes after their suspension in stomatin. Several commercially produced products were tested over a wide range of concentrations to determine their ability to act as an inducer of macrostomes. Only 2, Trypticase and Bactocasitone, had any activity, and it was too small to be considered really effective. An attempt was also made to destroy the activity of stomatin by using enzymes. RNAse was effective but only in very high concentrations, so it was suggested that this activity might be related to the destruction of RNA within the transforming cell and not related to hydrolysis of stomatin. None of the other enzymes tested had any effect in reducing the activity of stomatin.

Notes: SYNOPSIS. A developmental sequence is proposed for the haplosporidan Minchinia nelsoni Haskin, Stauber and Mackin, 1966, based on study of oyster infections over the past 5 years in Chesapeake Bay. Uninucleate stages develop by nuclear division into multinucleate plasmodia which proliferate in the tissues by plasmotomy. Relatively small plasmodia containing what are considered to be gametic nuclei originate by unequal plasmotomy of large plasmodia. These have been interpreted to aggregate and fuse to form large plasmodia which contain prozygotes. Pairing and fusion of nuclei occur within each plasmodium to produce zygote nuclei (synkaryons) which undergo division, possibly meiotic, to form sporonts. Sporoblasts differentiate into spores with the development of spore walls and opercula. Cystoid plasmodia develop during times of unfavorable conditions. An anomalous but common sequence involving sexuality and mitosis is described, and the occurrence of various life cycle stages within the host thruout the year is discussed.

Notes: SYNOPSIS. Many of the sub-pellicular and infraciliary structures in protozoa have proved difficult to study with standard thin-sectioning technics. When these structures are viewed in isolated and fragmented form, many of the thin-sectioning difficulties are circumvented. Langmuir-trough isolation followed by critical-point drying, as well as thin sectioning, were used in this study to determine the patterns of sub-pellicular microtubules and fibrils interconnecting kinetosomes of membranelles and cirri of Euplotes eurystomus. The fibrillar network in the bases of these ciliary organelles is presented in some detail and apparent variations in pattern are noted. Functional aspects of some of the structures are discussed. With special preparation nearly whole Euplotes may be obtained for study in the electron microscope. Fused cilia were frequently obtained and their ultrastructure was studied.

Notes: SYNOPSIS. A technic is described for the quantitative assay of paramylum content of euglenoid flagellates. The method relies on the alkaline solubility of paramylum followed by treatment with the anthrone reagent. The intensity of the color developed by paramylum is about 14% greater than that developed by an equivalent amount of glucose. The method is sensitive down to about 10 μg.

Notes: 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.

Notes: SYNOPSIS. The pigments synthesized by Astasia ocellata include α- and ε-carotene, 4-keto-β-carotene (echinenone), and 4,4′-diketo-β-carotene (canthaxanthin); 4-keto-α-carotene, accounting for about half the pigment in the cells, was tentatively identified; a strongly adsorbed keto-carotenoid, accounting for 25% of the pigments and bearing some similarities to astacin, polytomaxanthin and phoenicoxanthin, was also found.

Notes: SYNOPSIS. Blepharisma intermedium was cultured axenically. The organisms were freed of contaminating microorganisms by serial washing in a sterile salt solution. The major nutrients in the various media were: Freshly killed or lyophilized and autoclaved bacteria (Pseudomonas ovalis), yeast extract prepared from Fleischmann's baking yeast or Fleischmann's yeast autolysate, lettuce infusion or stigmasterol, 6 B-vitamins, and phosphate buffer at 2 times 10−3 M. The cultures were kept in the dark at 25 C. Altho the 1st division after transfer into fresh media was delayed, B. intermedium divided in approximately 32 hours thereafter in most of these media.

Notes: SYNOPSIS. The effects of temperatures of 12–18 C on cell division and oral primordium development were investigated in cultures of synchronized Tetrahymena pyriformis GL-C. If exposures to 12 or 15 C were initiated prior to a “transition point,” long delays of cell division were generated. After this transition point, cell division could no longer be substantially delayed by exposure to low temperature. The time of the transition point was somewhat earlier with 15 C than with 12 C treatments. At temperatures higher than 15 C long delays of cell division were not generated regardless of time of treatment.The effects of low temperature on oral morphogenesis were strongly dependent on the stage which was affected. (i) The further development of cells initially in the “anarchic field” stage (stage 1) was immediately blocked at both 12 and 15 C. (ii) Cells initially in the stages of incipient membranelle differentiation (stages 2 and 3) continued to develop at both 12 and 15 C, and formed oral primordia in which all 3 membranelles were clearly differentiated (stage 4). The subsequent progress of these stage 4 primordia depended on the temperature: at 12 C virtually all were resorbed (and cell division was blocked); at 15 C only about 1/3 were resorbed, while the remaining 2/3 completed their development (with the concomitant completion of cell division). (iii) Cells initially in intermediate stages of membranelle differentiation (early stage 4) developed to some extent at 12 C, and then underwent resorpton of oral primordia and blockage of cell division; at 15 C such cells completed their development and division normally. (iv) Cells in which the membranelles and undulating membrane were complete or nearly so (stage 5 and very late stage 4) at the time of the beginning of the cold treatment subsequently finished their development and went thru cell division, even at temperatures as low as 5 C.These results indicate that in addition to a “stabilization point” which occurs shortly before the completion of membranelle development, there is an earlier change in the primordium at the time of the onset of membranelle development, which renders development much less sensitive to direct interference by low temperature.

Notes: SYNOPSIS. Excysted sporozoites of Eimeria meleagrimitis, E. necatrix, E. acervulina, and E. gallopavonis were inoculated into monolayer cell cultures of bovine, ovine, porcine, and human kidney. E. meleagrimitis developed only in bovine embryonic kidney. Mature schizonts were found in the 11th, 16th, and 20th serial passages, but only immature schizonts were in the 4th and 6th passages. E. necatrix developed to mature schizonts in the 3rd, 4th, 6th, 11th, 16th, and 20th passages of bovine kidney and also to immature schizonts in the 175th and 189th passages of PK-15 (cell line porcine kidney). Schizonts, however, did not develop in the 140th and 145th passages of CCI-33 (cloned PK-15). Neither E. meleagrimitis nor E. necatrix developed in the primary, 1st or 2nd passages of bovine embryonic kidney, primary porcine kidney, 45th and 52nd passages of a human embryonic kidney cell line, or in the primary, 5th and 18th passages of ovine kidney. Eimeria acervulina and E. gallopavonis did not develop in any of the cultures. E. meleagrimitis and E. necatrix probably completed only one asexual generation in culture. The structure of mature schizonts of both species differed greatly from those in the natural host. Schizonts of E. meleagrimitis present at 48 hours were small (13–18 by 12–14 μ) and contained only 12–28 merozoites that were 3.2–3.8 μ long. At 48 hours, E. necatrix schizonts were 15–18 μ in diameter or less and contained only 15–20 merozoites (2.0–3.5 μ long); at 96 hours they were 50–70 by 10–35μ and contained either hundreds of small merozoites (2.0–3.5 μ long) or a lesser number of larger merozoites (9–11 μ).

Notes: SYNOPSIS. In heavily endemic collecting sites in Panamá and Colón Provinces, Republic of Panama, 14.7% of Ameiva ameiva and 8.5% of Basiliscus basiliscus were injected with Besnoitia darlingi. Single infected specimens of A. leptophrys and A. festiva were also taken, these being new host species records for this parasite. Infections were found only in the older lizards.Initially, virulence of the lizard parasites for white mice was low but increased with successive mouse passages. Concomitantly, the cyst-forming capacity of the strain diminished with successive mouse passages. No relation between initial virulence of the lizard parasites for mice and subsequent virulence after 16 or 17 mouse passages was recorded.The original description of B. panamensis (a synonym of B. darlingi) is emended on the basis of extensive material to include cyst diameters of 200–500 μ; also, the liver, mesentery, and tunica propria of the testis occasionally contain cysts. Cysts are frequently macroscopic and on the surface of organs so that they can be seen on casual inspection. B. sauriana Garnham, 1966 is a synonym of B. darlingi.

Notes: SYNOPSIS. An electron microscope study of microgametocytes and macrogametes of Eimeria nieschulzi Dieben, 1924 revealed that they lie within vacuoles bounded by a host unit membrane. The vacuole surrounding the microgametocyte contains granular material. The vacuole around the macrogamete is narrower and contains vesicles and membranes. Micropores were seen on the surface of the plasma membrane of microgametocytes and macrogametes. Microtubules were seen in macrogametes. Young microgametocytes and macrogametes have a similar cytoplasmic matrix, mitochondria and nuclei. Glycogen granules apparently develop around vacuoles in both microgametocytes and macrogametes. Glycogen granules were also seen along the margins of parallel bundles of fibers in microgametocytes. As nuclei of the microgametocyte divide, they move to the periphery of the parasite. Three basal bodies, each with 9 fibers in triplet form, develop in association with each nucleus. Microgametes have 2 free flagella and a central short, attached flagellum. Basal granules lie along the outer fibers of the central flagellum. Each microgamete has an elongate mitochondrion in close contact with the nucleus. In macrogametes wall-forming bodies develop in lacunae in the cytoplasm. Smaller dark bodies with areas of low density were also seen. Wall-forming bodies and dark bodies move to the periphery of mature macrogametes.

Notes: 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.

Notes: SYNOPSIS. Sexual reproduction of up to 50% of the cells from 9 cultures of Stentor coeruleus was observed repeatedly for several months. Photomicrographs were taken of mating pairs, and a number of new observations were made, including the ability of well fed cells (containing food vacuoles) to conjugate, the ability of a high percentage of cells (approaching 50%) in a culture to mate at one time, a more detailed description of the region of cell attachment as viewed from the frontal fields of the partner cells, and the ability of one partner to twist off and leave its oral area attached to the other member of the pair.

Notes: SYNOPSIS. Comparison of RNA molecules between certain protozoa using the technic of nucleic acid hybridisation revealed that there are complementary sequences for ribosomal RNA molecules in the genomes of such cells. Furthermore the genes for ribosomal RNA have been conserved during evolution in this group of organisms. On the other hand, RNA molecules from these protozoa which can be considered to be “messengers” show little in the way of sequence relationships. By utilising the technic of hybridisation it was found that Oxytricha can compete effectively against Paramecium ribosomal RNA for Tetrahymena DNA but the ribosomal RNA sequences of the latter could not compete completely against Paramecium ribosomal RNA for Oxytricha DNA. The result is interpreted to show that different ribosomal sequences were hybridising with each of the DNA samples from Tetrahymena and Oxytricha. A general interpretation of this result in terms of ribosome evolution is presented.

Notes: SYNOPSIS. Strains of Tetrahymena pyriformis, including amicronucleate strain GL and representatives of 9 syngens, have been examined to determine the patterns whereby cortical features vary with numbers of ciliary meridians. The characteristics scored were the positions of the contractile vacuole pores (CVP's), the extent of the area within which CVP's develop, the incidence of supernumerary CVP's, and the number of postoral meridians. Intrasyngenic comparisons were possible in 6 syngens and permitted an assessment of intrasyngenic variation for these characteristics. Only the CVP positions appear to be reasonably constant within syngens in the strains examined. On the basis of this criterion the syngens can be arrayed in an approximate order of 1, 3, 7, 6, 8, 9, 2, 5, GL and 4; the angle formed between the central axis, the stomatogenic meridian and the CVP's is most acute in syngen 1.

Notes: SYNOPSIS. The bionomics of Labyrinthula Cienkowski and the validity of the family Labyrinthulidae Haeckel are reviewed. The structure, physiology (including nutrition), locomotion, ecology, and possible pathogenicity for eel-grass (Zostera marina L.) are discussed. The uniqueness of its gliding motility along slime tracks, lack of phagotrophy, and poorly understood congregation tendencies emphasize the present taxonomic isolation of the group. Further interest attaches to some species because of their steroid requirements.

Notes: SYNOPSIS. Sporozoites of L. simondi were maintained in a viable state for 7 months in liquid nitrogen. Comparison of parasite development initiated with fresh and frozen sporozoites showed a delay in development of each stage studied. Comparisons of prepatency, first elongate gametocytes, peak density of round and elongate forms, anemia and disappearance of megaloschizonts were made. In each phase there was a delay of 2–3 days in ducks infected with frozen sporozoites.

Notes: 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.

Notes: SYNOPSIS. Parauronema virginianum n. g., n. sp., a marine hymenostome ciliate is described from the Virginia coast. Structural studies were made on specimens treated with the Chatton-Lwoff silver impregnation technic and on animals observed with the phase microscope. Particular attention was given to the buccal ciliature and its importance to generic assignment in the order Hymenostomatida.

Notes: 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.

Notes: SYNOPSIS. Structure and morphogenesis, and cytochemical data on Cochlodinium heterolobatum, a new species of unarmored dinoflagellate, were derived from living and fixed material from culture. C. heterolobatum is characterized by the torsion of the girdle which descends in a left-hand spiral 1.8 turns; the sulcus having a torsion of 0.8 turn; a sulcus loop in the epicone; a tongue-shaped lobe in the right hypocone; nucleus in the epicone; and a stigma in the left epicone. Trichocysts and behavior of the nucleus during typical and atypical divisions are described in cells from cultures of different ages. A small form with the specific characters was found. Intracellular bacteria were seen and their growth followed in individuals from cultures of different ages. A possible relationship between those bacteria and the accumulation of metabolites inside old cells is discussed.

Notes: 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.

Notes: SYNOPSIS. From characteristics of binary fission, conjugation, size and number of micronuclei, body size and incidence of giantism, a Blepharisma isolate hitherto called B. undulans is classified as B. dawsoni sp. nov. Binary fission in B. wardsi differs from fission in B. dawsoni in that the strand connecting the macronuclear nodes is severed; in B. dawsoni the strand persists.

Notes: SYNOPSIS. Experiments with mixtures of latex-tagged cultures of amoebae of strains, species and genera of the Dictyosteliaceae indicate little specificity in engulfment. This is in sharp contrast to the decided specificity for compatibility in completion of morphogenesis in the same organisms. Lack of specificity in engulfment is considered additional evidence favoring engulfment as a normal feeding activity rather than a process associated with syngamy in the cellular slime molds.

Notes: SYNOPSIS. Eimeria colchici sp. n. is described from English pheasants Phasianus colchicus. It has cocysts measuring 19–33.5 (27.4) by 13–21 (16.7) μ, having both micropyle and polar granule. The large 1st and 2nd generation schizonts occur in the glands of the small intestine, 3rd generation schizonts occur deep in the glands of the ceca, and gametocytes occur in the epithelial cells of the ceca. The prepatent period is 6 days. In young pheasants the parasite causes coccidiosis characterized by formation of white cores in the ceca. Mortality is high in experimental infections. Zoalene (0.0125%) in the feed almost completely suppressed the infection; Amprolium (0.0125%) also gave good control, but sulfaquinoxaline (0.0125%) was not so effective. Sulfaquinoxaline, Saquadil and Sulfamezathine in the drinking water controlled mortality, but treatment had to be applied early to avoid weight losses.

Notes: SYNOPSIS. Monolayer primary and secondary cultures of embryonic bovine kidney, spleen, intestinal and testicle cells, and secondary cultures of embryonic bovine thymus, maintained in lactalbumin hydrolysate, Earle's balanced salt solution and ovine serum were observed for a maximum of 21 days after inoculation of E. bovis sporozoites. The sporozoites entered the cells in all of these cultures but underwent development only in primary cultures of kidney and intestinal cells and in secondary cultures of kidney, spleen, thymus, intestinal, and testicle cells. In acellular media, the sporozoites retained motility no longer than 21 hr. In the cell cultures, free motile sporozoites were seen for as long as 18 days after inoculation. Sporozoites entered cells anterior end first; the process of penetration required a few seconds to about a minute. Sporozoites were also observed leaving host cells. Intracellular sporozoites were first seen 3 min after inoculation; they were observed at various intervals up to 18 days after inoculation. In transformation of sporozoites into trophozoites a marked change in size and appearance of the nucleus took place before the change in shape of the body occurred. Trophozoites were first found 7 days after inoculation, multinucleate schizonts after 8 days, and schizonts with merozoites after 14 days. Schizonts containing merozoites were seen only in kidney, spleen, and thymus cells. The mature schizonts were smaller and represented a much lower proportion of the total number than in comparable stages of infections in calves. Schizonts with many nuclei occurred in intestinal cells; the most advanced stage seen in testicle cells was the binucleate schizont. Nuclear and cytoplasmic changes were observed in the infected cells.

Notes: SYNOPSIS. Peritoneal macrophages from hamsters were monolayered on coverslips in Leighton tubes. Twenty-four hours later these were transferred to a perfusion chamber. Leptomonads were added with fresh medium and the infection process observed with the aid of phase contrast. In the perfusion chamber free-swimming leptomonads attached to the macrophage by the tip of their flagella. Shortly after this initial attachment the macrophage extended a narrow pseudopodium around the flagellum which eventually reached and enveloped the body of the parasite. Upon complete envelopment the pseudopod containing the leptomonad was retracted into the central body of the macrophage. When first seen in the granular endoplasm of the macrophage, most of the leptomonads appeared to be surrounded by vacuoles. In most cases these vacuoles disappeared in a few minutes making it difficult to distinguish the parasite from the host cell cytoplasm.Leptomonads also were added directly to Leighton tube cultures, and the coverslips with the adherent macrophages and parasites were removed, fixed and stained periodically during the infection process. In these preparations most of the parasites were in clumps in the vicinity of macrophages. Details of the ingestion of the clumps could not be seen, but occasionally a single organism was seen with its flagellum and part of its body enclosed by an extended pseudopod. Most of the intracellular leptomonads were in large vacuoles. Forms intermediate between elongate leptomonads and LD bodies were surrounded by smaller vacuole-like spaces. The halo-like vacuoles most frequently seen around LD bodies may have been fixation artifacts. Under favorable conditions the leptomonads transformed to LD bodies in 1–4 hours, but it was 48 hours before a population increase could be found.

Notes: SYNOPSIS. Coccidia-free beagle puppies were experimentally infected with a cloned culture of Isospora rivolta oocysts. The endogenous stages were found in the posterior 1/2 of the small intestine, and rarely in the cecum and colon. Maximum numbers of all stages occurred just anterior to the ileocecal valve. Endogenous stages were found in the distal third of the villi, predominantly parasitizing subepithelial cells of the lamina propria; however, stages were occasionally present in epithelial cells. The number of asexual generations could not be determined from their structure, but evidence based on oocyst production suggested that there were at least 2 asexual generations. The schizonts were 17–24 by 12–25 μ and contained 4–24 merozoites, the most common number being 4 or 8. Schizonts with mature merozoites were found as early as 72 hr, but were present in maximum numbers at 96 hr. Merozoites had slender curved bodies and were 10.5–13.4 by 2.3–3.0 μ. Mature gamonts were found by 144 hr. Mature microgametocytes were 13.4 by 8.7 μ and contained 50–70 microgametes. Microgametes had slightly curved tapering bodies (5.8–6.4 by 0.6 μ) with 2 posteriorly directed flagella 11–14 μ long. Mature macrogametes had reticular cytoplasm and a uniformly large nucleus and nucleolus.The prepatent period was 142–146 hr. The patent period was 13–23 days with an average of 19 days.

Notes: 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.

Notes: SYNOPSIS. Optimal growth of the colorless flagellate, Astasia longa, in terms of generation time occurred at 25–30 C. Above and below this interval, generation time increased. In contrast, length of the lag phase was constant over a wide temperature range, 18–32 C. At 13 C dry weight of Astasia was 15% greater than at 28.5. Alcohol-ether soluble material accounted for 72% of the dry weight increase at 13, while RNA and protein contents of the cells were the same at both temperatures. Rates of synthesis of dry weight, RNA, protein and lipid per μl oxygen consumed were all reduced at 13 C; however, lipid synthesis was the least affected. Cell division in Astasia was synchronized repetitively by cold (13–15 C) and warm (28.5 C) temperature cycles. Under best conditions, cell division began immediately at the onset of the warm period. Cellular preparations for cytokinesis apparently were at least partially completed in the cold, and raising the temperature released a block to cell division.

Notes: SYNOPSIS. Isolated rumen protozoan species (Entodinium) were incubated in vitro with starch, antibiotics and Na214CO3. 14C-carbonate was incorporated into amino acids of the Entodinium protein. Arginine, aspartic acid, alanine, and glutamic acid had the highest specific activities. Carbonate was incorporated into the TCA-soluble fraction, into cell polysaccharides, and into ether and acetone extracts of TCA-precipitates.