ALBERT

Notes: This paper gives a summary of the methods that have been used for independent model aerial triangulation. A modification of one of the methods is proposed and the paper concludes with a comparison of the independent model with the classical method of triangulation.

Notes: The camera is a further development of an existing type with greatly improved photogrammetric performance so that the photography can be used with first-order plotting machines. A new lens provides minimal distortion, high resolution and greatly improved marginal illumination. An entirely new shutter provides high speeds and efficiency. Laboratory results and preliminary survey trials indicate image quality and location standards of the same order as established existing cameras.

Notes: Book reviews in this article:INTERNATIONAL YEAR BOOK OF CARTOGRAPHY (Vol. IV, 1964). Editor, Eduard Imhof.JUBILEE VOLUME DEDICATED TO WILLEM SCHERMERHORN ON HIS SEVENTIETH ANNIVERSARY: ESSAYS ON THE DEVELOPMENT OF PHOTOGRAMMETRY. Published by I.T.C., Delft.

Notes: A successful attempt has been made to produce design plans of large chemical plant using photogrammetric techniques, and involving the development and modification of cameras and plotting equipment. Photogrammetry has provided a solution to a problem which could not easily be solved by direct methods.

Notes: Book reviews in this article:PROCEEDINGS OF THE SECOND NATIONAL CONFERENCE OF SOUTH AFRICAN SURVEYORS, FEBRUARY 1964. Edited by G. H. Menzies et al.

Notes: Four authors review the activities of the seven Commissions of the I.S.P. at the Xth International Congress, Lisbon, 1964.

Notes: Rather than rely on laboratory calibration, test fields have been established in Sweden to enable photography from a tower or aircraft, and so simulate as nearly as possible actual operational conditions. Repeated experiments, followed by analysis of photography, and the application of statistical tests, have allowed the geometrical quality of the aerial photograph to be assessed, and systematic and irregular errors to be distinguished.

Notes: It does not seem to be widely recognised that the solution of the space resection problem from measurements made on a single photograph of three ground control points is not unique. There are, in general, four solutions, so that either the camera orientation must be approximately known (as is the case for near vertical photography) or extra control must be used to discriminate between these solutions. The iterative solution commonly used will only yield one solution, which will be correct if the photography is nearly vertical, but which is liable to be wrong in the general case. An explicit solution is therefore preferred since all solutions may be examined in the light of such extra control as is available. This paper gives a method for such a solution and shows how the discrimination should be used. The paper goes on to derive a method of adjusting the result to redundant control by least squares.

Notes: SYNOPSIS. Silver impregnation techniques were used to study the silverline system of three species in the genus Spirostomum. It was concluded that for those species studied in the general area of Washington, D.C., the average numbers of ciliary meridians in S. teres, S. minus and S. ambiguum are 18, 24 and 46 respectively. Seventy-six % of the measurements in S. teres and S. ambiguum and 84% of the measurements in S. minus deviate from the mean by less than 1 standard deviation.

Notes: SYNOPSIS. Blepharisma seculum sp. nov. is described as a small-sized blepharisma with a compact, spheroid macronucleus and a distinct curvature of the body anteriorly. A comparison of this form with other species of the genus Blepharisma subgenus (Compactum) is given.

Notes: SYNOPSIS. Lymphotropha tribolii gen. nov., sp. nov. (Neogregarinida, Schizocystidae) is described from the haemocoele of Tribolium castaneum (Herbst) (Coleoptera, Tenebrionidae). The trophozoites are large, ovoid and uninucleate with distinct longitudinal striae. Schizogony occurs in one type of cycle only, each schizont giving rise to up to 8 merozoites. Gametocytes are uninucleate when they associate. Up to 16 oocysts each with 8 sporozoites are formed in each gametocyst. The oocysts are lemon-shaped, and sporozoites emerge from the poles.The parasite causes considerable mortality in young larvae, though its pathogenicity is probably inferior to that of Farinocystis tribolii Weiser.

Notes: SYNOPSIS. Sarcocystis garnhami n. sp. is described from an opossum, Didelphis marsupialis. Its distinguishing characters are the spiny cyst wall, 6–8 μ thick, and the size of the spores, 5.3–6.9 μ in length and 1.3–1.9 μ in breadth. Sarcocystis darlingi, Brumpt 1913 is considered Besnoitia darlingi (Brumpt, 1913) n. comb.

Notes: SYNOPSIS. An epizoic suctorian from Gulf of Maine coastal waters, designated as Paracineta sp., is described. Morphological measurements are given for 23 small, medium, and large specimens. Mean length was 200 μ and average cell body diameter 39 μ. Of 21 copepod species and 19 zooplankton groups examined, only copepods of the genus Metridia showed any Paracineta attached. Suctorian occurrence was, with a single exception, limited to adult copepods, with the larger females showing the heaviest incidence. Differences in areal occurrence were observed with greatest incidence of Paracineta on M. lucens in the eastern and central Gulf, and lowest numbers in the western area. This differential occurrence is accredited to an apparent cold water affinity of the suctorian. It is suggested that Paracineta could be carried into the Gulf during periodic intrusions of cool Nova Scotian water, reaching the western area in the southwesterly flowing Gulf of Maine eddy system. No significant differences in vertical distribution were found in Paracineta incidence on Metridia among the depths sampled (0, 10, 30, and 60 m). No harmful effect of Paracineta on Metridia was evident.

Notes: SYNOPSIS. The intralymphocytic stages of Theileria parva, T. lawrencei and T. annulata have been cultivated for several months in tissue cultures of bovine lymphocytes associated with baby hamster kidney cells. In established cultures the theilerial particles multiplied at about the same rate as the host cells, the percentage of infected cells and the mean number of parasite particles per cell remaining nearly constant.During mitotic division of the host cell the theilerial body becomes closely associated with the spindle fibres and is pulled apart and distributed to both daughter cells in late anaphase. The single theilerial particles (chromatin) within the theilerial body divide by binary fission; their division is not synchronous with that of the host cell.

Notes: SYNOPSIS. A sulfolipid, isolated from the phytoflagellate, Ochromonas danica, and from its medium, constitutes over 50% of the sulfur of the cells. It is bound to protein and excreted by the phytoflagellate. When the S35-labeled sulfolipid was placed in the medium it was incorporated by the cells without cleavage of the sulfate group. Thus it passes back and forth between the growth medium and the cells.The sulfolipid has been found in O. danica, O. malhamensis, Tetrahymena pyriformis, Chlamydomonas sp., Pseudomonas sp. (sea water bacterium). It was identified in the culture medium of O. danica, O. malhamensis, Chlorella pyrenoidosa, and Streptomyces griseus. Preliminary evidence was obtained for its presence in the growth medium of white clover and sorghum.

Notes: SYNOPSIS. The normal cycle of asexual reproduction in Euplotes eurystomus was subjected to a detailed morphological study using whole-mounted and sectioned material prepared by the method of silver impregnation. The cycle was arbitrarily divided into 7 stages (numbered 0–6) characterized by nuclear and cortical events. Particular attention was focused on the development of the oral primordium (OP), and the production of new kinetal cilia (or “dorsal bristles”).The OP is interpreted as originating from an invagination or infolding of the parental cortex, followed by considerable in situ growth and differentiation beneath the cell surface. It is suggested that differentiation beneath the parental cell surface may in some way facilitate morphogenesis of other cortical structures without necessitating dedifferentiation of the parent's buccal apparatus. During stage 6, the division constriction plays an important morphogenetic role in shaping the opisthe's buccal apparatus.During stage 4, a zone of ciliary increase (ZCI) appears in the central portion of each kinety. New kinetal cilia arise as semi-circular clusters of 1 to 9 kinetosomes flanking each old basal structure; the latter persist until the new organelles are well established. An analysis of total kinetal cilia in animals during stages 0 to 3 indicates that, while ciliary number varies according to animal size, there is no increase in cilia prior to formation of the ZCI.Several aspects of the asexual cycle in Euplotes seem to bear importantly on the more general problem of ciliate morphogenesis. The pattern or gradient concept might be useful in the analysis of factors determining primordial sites, although later development of the primordium into a specific organelle or organelle system is probably controlled by autonomous epigenetic processes that are somewhat independent of the parental cortical pattern. The hypothesis of kinetosome continuity cannot account for the origin of primordial fields in cortical regions remote from pre-existing kinetosomes, as observed in Euplotes. The initiation of morphogenetic activity on the cortex is closely correlated with, and may be causally related to, the appearance of replication bands in the macronucleus. The known metabolic significance of these bands, particularly the release of nuclear RNA, lends support to this suggestion.

Notes: SYNOPSIS. Experiments were performed to ascertain the effect of heat and cold on oral and micronuclear development in synchronized Tetrahymena pyriformis WH-6. The developing oral primordium becomes insensitive to cold sometime during stage 2. Cold shocks cause the reversion of many stage 2 primordia to stage 1. Cells so affected are set back in division. The delayed division is always asynchronous. When heat shocks are applied prior to late stage 4, the developing primordium will regress. High temperature shocks applied at later stages permit continued development. However, when the cell begins to cleave at the high temperature, division is frequently arrested and the new oral areas regress. Subsequent cell separation is greatly delayed and asynchronous.Heat and cold affect the micronucleus in the same way. Both agents prolong the arrest of mitosis brought about by the synchronizing treatment. A temperature shock is ineffective if applied after there is a space completely separating the chromosome groups, so that mitosis is completed in the presence of the agent. Bimicronucleate chains result in those cases in which division is arrested by heat shocks.It is suggested that the different phases of sensitivity to heat and cold may reflect different types of syntheses necessary for development of the oral primordium. Division arrest and subsequent oral replacement might possibly be related to high temperature induced changes in the physical state of the ciliate cortex.

Notes: SYNOPSIS. The free amino acids of E. invadens and 4 strains of E. histolytica cultured in the CLG medium have been identified by thin layer chromatography. The chromatogram patterns of 3 strains grown for 72 hr at 37°C (103, K-9 and 200) were nearly identical. Amino acids detected on chromatograms according to Rf values, relative positions on chromatogram plates, and identifying colors using a polychromatic ninhydrin spray were: leucine/isoleucine, tyrosine, valine, alanine, glycine, glutamic acid, lysine/ornithine, histidine, proline, plus very small amounts of arginine and possibly serine, aspartic acid and citrulline/glutamine. Cysteic acid may also be present. The same amino acids were detected on chromatograms using comparable extracts of strain Laredo and E. invadens grown for 6 days at room temperature. However, the patterns were different in that serine, glycine, threonine and especially alanine were present in greater abundance in these latter 2 cell types.These chromatogram patterns were compared with similar analyses of strains Laredo and 200 grown in the modified Shaffer-Frye medium of Reeves.Similar analyses are reported on the basic ingredients of the CLG medium, including the cells and protoplasts of the Bacteroides, the non-multiplying bacterial associate employed in the CLG medium. The chromatogram patterns of the Bacteroides, protoplasts and medium were decidedly different from those of the amebae, thus indicating that adequate separation of bacteria, amebae and medium was accomplished.Analyses of the culture filtrates of all cells analyzed revealed a possible difference between the Laredo strain and the other strains of E. histolytica (103, K-9 and 200) in amino acid utilization. Similar differences were observed between the Laredo strain and E. invadens.

Notes: SYNOPSIS. Colligocineta furax gen. nov., sp. nov., parasitizes the epithelial cells of the peristomial cirri of the sabellid polychaete Laonome kröyeri Malmgren. The material studied was dredged in West Sound of Orcas Island, San Juan Archipelago, Washington. In general, the pattern of ciliation of Colligocineta resembles that of Hypocomella and Heterocinetopsis. However, of the ten kineties which constitute the ciliary system, two from the extreme right side appear to be continuous with two from the left side. During division, the posterior part of the ciliary field is conferred upon the opisthe, and in the proter all of the ten kineties are for a time completely separate.

Notes: SYNOPSIS. Myxosoma cartilaginis n. sp. is described from the cartilage of Lepomis macrochirus (bluegill), L. cyanellus (green sunfish) and Micropterus salmoides (largemouth black bass). The development of the parasite is described from naturally infected fish which were held in spore-free water after infection. The sporoplasm invades cartilage, and becomes a multi-nucleate trophozoite which forms pansporoblasts, each of which produces 2 to 4 spores. The first spores appear in 7 weeks.The histopathology in the above fish consists at first of little cellular reaction, but after 4 to 5 months epithelioid granulomas appear around some of the spore masses. Cartilage liquefaction is present around the parasites for at least 5 weeks. Eosinophilic globules are present in cartilage cells adjacent to the lesions. Diffuse infiltration of the spores from the lesions is described.Of 24 chemicals tested for polar filament extrusion, potassium hydroxide gave the best results.An illustrated synopsis of the Myxosoma of North American fishes is given. Included is some additional information and illustrations of M. hoffmani Meglitsch, 1963. Also included is a table showing the hosts, site of infection, geographic location, spore and polar capsule sizes.

Notes: SYNOPSIS. Two species of hysterocinetids occur in the alimentary tract of Drilocrius breymanni, an aquatic oligochaete collected in Departamento del Valle, Colombia. The suckers of both species are unusual for their complexity. In Craticuloscuta escobari gen. nov., sp. nov., the sucker is a shallow oval concavity with longitudinal and transverse supporting elements. About one-fifth of the area of the sucker, in its posterior portion, is ciliated, but argyrophilic punctations, which probably represent kinetosomes, are distributed in a regular pattern over most of its surface. In Epicharocotyle kyburzi gen. nov., sp. nov., the oval major portion of the sucker is deep, and continuous with a short trough which extends posteriorly and bends toward the left. Veil-like flanges, bordered by a fringe of thick, inactive cilia, arise from the margins of the sucker on either side. In the region of the trough, the flanges may overlap in such a way that the trough is almost completely covered. The trough and a small area of the major portion of the sucker anterior to it are ciliated. However, argyrophilic punctations which probably represent kinetosomes are distributed over most of the surface of the sucker. The pattern of longitudinal and transverse supporting elements found in the sucker itself extends into the flanges. In both Craticuloscuta and Epicharocotyle, the arrangement of the adoral and buccal ciliary organelles is essentially like that in Hysterocineta, Ptychostomum, and other ciliates of the family Hysterocinetidae.

Notes: SYNOPSIS. Various protozoa and lower metazoa were exposed to filtrates of Staphylococcus aureus B (formerly called Type S-6) (2) and non-enterotoxigenic filtrates of staphylococci to study the toxicity of staphylococcal enterotoxin to these organisms. No reaction specific for enterotoxin was observed either in those culture filtrates from toxin-producing strains or in solutions of purified enterotoxin. Non-specific reactions were obtained with various growth media and a “potassium inhibited” filtrate containing 0.5% K2HPO4.

Notes: SYNOPSIS. The effect of hexamethonium chloride, an acetyl-choline competitor, on the ciliary and myonemal systems of Spirostomum intermedium and S. ambiguum was investigated. Although the drug caused immobilization of the cilia, severe cell damage often ensued indicating an unspecific action. The general reaction was usually more severe and the ciliary inhibition less in S. ambiguum than in S. intermedium. It is postulated that the general reaction is the result of either membrane depolarization or binding of hexamethonium at the surface. Fed animals were more susceptible to drug action than starved ones. Raising the external potassium level did not affect the drug action.

Notes: SYNOPSIS. A morphological study on the ectoplasm and the proboscis in the ciliate Didinium nasutum, has been performed by means of an electron microscope. The ectoplasm and the endoplasm of Didinium are separated by a fibrous layer. In addition to the ciliary apparatus and the filament system, the ectoplasm is characterized by having ectoplasmic vacuoles enclosing cross-striated bodies and by having small rods surrounding the ciliary basal body.The filament system is composed of 4 types of tubular filaments: primary filaments originating from the basal body, secondary ones coursing longitudinally along the cell periphery, tertiary ones going down in cylindrical arrays from the periphery of the proboscis into the endoplasm, and finally kinetosomal ones from the base of the basal body into the endoplasm through the newly found pore of the fibrous layer.The fine morphology of the trichites in the proboscis is elucidated three-dimensionally and illustrated schematically. Moreover, the correlation among the small rod, ectoplasmic vacuole and trichite is discussed.

Notes: SYNOPSIS. Animals arising spontaneously in a culture of Paramecium aurelia, variety 4, strain 51.8s, swam about three times as rapidly as normal 51.8s, 51.7s or 29.8 animals. When the 51-fast animals were mixed with 51.8 or 29.8 paramecia, a random sampling of swimming rates showed a bimodal distribution. The faster rate of 51-fast animals was maintained under such deleterious conditions as 48-hour starvation. “Fastness” or “slowness” could not be selected for in vegetative clones. The 51-fast paramecia would not mate with 51.7, 51.8 or 29.8 animals, although fission rate, serotype and general appearance indicated that 51-fast probably arose from strain 51.8.

Notes: SYNOPSIS. Silver stains of the free-swimming sessiline peritrich Opisthonecta henneguyi reveal the adoral infraciliature as the bases of two membranes, a haplokinety and a polykinety, which diverge at the buccal overture and spiral down the infundibulum to end at the cytostome. A second polykinety parallels the adoral polykinety in the oral half of the infundibulum, and the two form a peniculus. The haplokinety appears as a single row of kinetosomes, the adoral polykinety as a series of transverse rows of three kinetosomes. The peniculus is six kinetosomes in width.The electron microscope shows that the haplokinety is a double row of staggered kinetosomes. Only the external row bears cilia. The polykinety is a complex ciliary membrane, three kinetosomes wide. The three kinetosomes are connected with one another by fibrous bundles passing beneath them. They are linked orally and apically into longitudinal rows of thick, zig-zag, fibrous connections. The kinetosomes of the internal longitudinal row are attached by a dense fiber to a strand of fibrous material interrupted at regular intervals by dense nodes.A section of the wall of the infundibulum is thrown up into longitudinal folds with tubular fibrils running parallel to the folds. These structures, the crests, appear to continue into the cytopharynx. Beneath and around the adoral and infundibular infraciliature and the crests is a fibrous matrix with dense nodes, resembling the reticulated infundibular fiber described by Faureé-Fremiet.The trochal band in silver stains appears as short diagonal rows of kinetosomes. The electron microscope shows 5 to 7 kinetosomes per diagonal row. The kinetosomes of the diagonal rows are linked to thick dense rods which originate just above the trochal band and continue antapically past the kinetosomes for a distance of 10 to 15 μ. The kinetosomes are joined to one another by fibrous strands and each is also connected by a dense fiber to the diagonal rod to its left. Running below the kinetosomes and at right angles to the rods is a system of striated fibers.At the aboral end of the body, a ring, 2 μ in diameter, of argentophilic granules is shown by the electron microscope to be a small circle of kinetosomes. Sessile stages have not been reported for Opisthonecta. The aboral ring is probably a vestigial or non-functioning scopula.The argyrome is represented by circular striae around the body. Each stria bears argentophilic dots on either its apical or its antapical side. Electron microscopy reveals that these dots are pores in the cuticle. The striae themselves may be points of adhesion between the inner cuticle and the outer cuticle, or ridges of cytoplasm between flattened alveoli of the inner cuticle. A dense fiber runs below and parallel to each stria. Opisthonecta shows at least three different kinds of ciliary membranes. Some speculations are offered on the taxonomic affinities of peritrichs based on their infraciliature.

Notes: SYNOPSIS. Haplosporidium mytilovum Field, 1924, a sporozoan (?) parasite in the ova of the mussel Mytilus edulis L., is found to be morphologically similar to, and deemed to be congeneric with, the type species of genus Chytridiopsis Schneider, C. socius S., 1884, in beetles. It is compared also with the only other reported species of Chytridiopsis in a mollusc, C. ovicola Léger and Hollande, 1917, in ova of the European oyster, Ostrea edulis L. These two parasites in ova of bivalve molluscs are much alike but, since they seem to have some slight morphological differences, it would be premature to conclude that they belong to the same species. Chytridiopsis, a genus of uncertain affinities, has been considered by various authors to be related to the Chytridiales, the Haplosporida, the Mycetozoa or the Microsporida. New evidence favors the hypothesis that it is microsporidian in nature, although proof in the form of a clearly demonstrated polar filament has not yet been produced.

Notes: SYNOPSIS. Leptomonas costoris n. sp. is described from Gerris comatus. It differs from other species of Leptomonas in the structure of the reservoir which has ultramicroscopic thickenings in its wall, matched by corresponding thickenings in the adjacent flagellar membrane. The one or two diagonal lines seen in the reservoirs of Giemsa-stained specimens are thought to be manifestations of these ultramicroscopic fibrils. The reservoir structure suggests a close relationship between this species and Cryptobia, (family Bodonidae) in which somewhat similar structures have been described. Blastocrithidia veliae is redescribed and differentiated from B. gerridis.

Notes: SYNOPSIS. Glucose-6-phosphate dehydrogenase activity and the level of reduced glutathione were assayed in host-parasite interactions in which the malaria parasites preferentially invade: 1. mature erythrocytes (Plasmodium lophurae in the duck) and 2. reticulocytes (P. berghei in the mouse). Assay for glucose-6-phosphate dehydrogenase was by the dye decolorization test of Motulsky and Campbell. In P. berghei infected mouse erythrocytes with parasitemias ranging from 28–78% there was no deficiency in enzyme except at the 78% level. Similarly, P. lophurae-infected duck erythrocytes with parasitemias of 29–114% showed no enzyme deficiency except above the 80% level. No linear relationship existed between parasitemia and enzyme level. The reduced glutathione stability test of Beutler in duck erythrocytes infected with P. lophurae in the range 27–67% showed no glutathione instability.

Notes: SYNOPSIS. Axenic cultures of Tetrahymena pyriformis W were used to obtain fractions rich in kinetosomes by alcoholdigitonin extraction techniques followed by centrifugation. The morphology of the kinetosomes was examined in the electron microscope at various stages during the isolation procedure, and compared to the morphology of the in situ kinetosome. In the latter preparation the well known cartwheel structure was present, and in addition 9 electron dense dots were displayed at the end of each spoke of the cartwheel.The prepared kinetosomes could easily be identified during the entire process, and there was no apparent change until after the digitonin step. However, with the further fractionation, alteration was found to have taken place in the interior and in the kinetosome wall. The inside appeared “empty,” and we were not able to find 9 triplets in the wall but only doublets.In view of the morphological alterations in the kinetosomerich fractions, chemical analysis still appears to us to be premature.

Notes: SYNOPSIS. Excystment of Didinium nasutum is solely dependent upon dense bacterial populations and is independent of the type of medium in which the bacteria have been grown. Beers' hypothesis of the need for a factor from proteose-peptone is thereby not confirmed, but the need for living, intact bacteria as postulated by him is fully shown. The process of excystment is initiated by bacteria, but their presence is not required throughout the excystment. Axenically grown paramecia, shown to be adequate as food organisms for didinia, will not induce excystment. Five types of bacteria including Gram-positive, Gram-negative, aerobic and anaerobic all suffice to induce excystment, suggesting that the initiation of this process is caused by some general metabolic process or product of bacteria.

Notes: SYNOPSIS. About 50% of the amoebae found in early prophase through metaphase stages of mitosis have at least some mitochondria (ca. 25%) that contain complex internal structural patterns. These patterns are less frequently seen in mitochondria after metaphase, and they are extremely rare or absent during interphase. In the most typical pattern, larger than normal tubules are arranged in a parallel zig-zag configuration with a small amount of matrix between them. Complex patterns typically comprise about 30% of the mitochondrion; they are usually confined to one area, the remaining portion consisting of a clear matrix with few, if any, peripheral tubules.

Notes: SYNOPSIS. Examination of feces obtained from wild-trapped woodchucks, Marmota monax, near Chambersburg, Pennsylvania, revealed three previously described species: Eimeria monacis, E. perforoides, and E. os. In addition I found a new coccidium, E. tuscarorensis n. sp., described in this paper. Structurally the new species resembles E. wisconsinensis and E. bilamellata. An unidentified polysporocystic coccidium, possibly the genus Klossia, was found in small numbers in one sample.

Notes: SYNOPSIS. Laboratory cultures of the boll weevil, Anthonomus grandis Boheman, became infected with Mattesia grandis n. sp. (Neogregarinida, Ophryocystidae). The ensuing epizootic resulted in destruction of the weevil colony. Infection occurred per os in larval and adult weevils. Sporozoites penetrate the intestinal wall and infect adipose tissue cells. Micronuclear schizogony with production of merozoites is the primary method of multiplication and spread to new foci. Micronuclear schizonts may grow as large as 30 μ in size and produce up to 200 or so merozoites, which may be 20 μ long and 1–2.5 μ wide and are motile. Macronuclear schizonts are formed from these 1st schizogony merozoites, and can become 20–30 μ in size, producing up to 80 or so macronuclear merozoites. These can be 15 μ long but 2–3 μ wide with limited motility. Second schizogony merozoites form gamonts, which pair, forming gametocysts. Nuclear division occurs, resulting in 4 equal sized nuclei and 2 pairs of residual nuclei. Four gametes are formed by cytoplasmic constriction around the nuclei. The gametes rapidly pair to form 2 zygotes in the gametocyst, resulting in 2 spores. Nuclear pairing in 1 of the 2 zygotes often lags slightly behind. Abnormal development of zygotes was rare, but could result in 1 spore with 3 poles and a normal spore, or with only 1 spore developing. Near maturity gametocysts are about 12.5 μ long and 14.0 μ wide, with the gametocyst wall tightly stretched over the poles of the spores. Spores often are slightly flattened on the adjacent side in the gametocyst but frequently attained evenly curved walls on all sides after release. The spores are octozoic, with sporozoite development occurring after release from the gametocyst. Spores measured 7.1 μ X 11.8 μ. Characters are given to separate M. grandis from other species of Mattesia.

Notes: SYNOPSIS. A microsporidian, Nosema muris n. sp., is described from laboratory white mice in Czechoslovakia. I t differs from Nosema cuniculi (Levaditi, Nicolau and Schoen, 1923) and other Microsporidia in mice in that it develops in the omentum and heart muscle, iorming large masses of schizonts and spores. The parasite is distributed to other tissues (liver, spleen, fat, peritoneal muscles, connective tissue and brain) by infected mononudear cells, and then forms localized cysts in them. Kidney, lungs, adrenal glands, pancreas and salivary glands are not infected. The parasite can be transmitted via the placenta, by feeding on infected tissues, or by experimental injection of ascitic fluid.

Notes: SYNOPSIS. Babesia bigemina was identified in the erythrocytes of calves as early as 9 days 21 hours after infected larval ticks (Boophilus microplus) had been placed on them. This confirms the circumstantial data [Hoyte, (1961): J. Protozool. 8, 462–61, which indicated that there is no pre-erythrocytic schizogony in the life cycle of B. bigemina.The earliest time at which parasites were themselves found to be capable of infecting ticks was between 11 and 12 days, (i.e., about two days after parasites were first seen in the blood). It is suggested that this delay occurs because, until this time, parasites are present in the blood in such small numbers that none survive digestion within the tick.

Notes: SYNOPSIS. Diophrys scutum, collected from four locations on the New Hampshire coast, ranged from 89–195 7mu; in length, 50–105 μ in width, and 68–88 μ in buccal cavity length. The end of the adoral zone of membranelles (AZM) extends 37–59 μ (average = 45.6 μ) posteriorly in a groove on the right side of the body. Dorsally are five rows of stiff cilia. The silverline system (Chatton-Llvoff technique) appears as a fine meshwork, entirely different from that found in Euplotes or Uronychia. There are two elongate macronuclei (Feulgen reaction) and several micronuclei. Diophrys peloetes n. sp., collected from one location in Alligator Harbor. Florida, ranged from 95–134 μ in length, 62–84 μ in width. and 60–80 μ in buccal cavity length. The terminal portion of the AZM extends posteriorly in a groove 30–44 7mu; (average = 36.8 μ) on the right side of the body. Dorsally are eight rows of stiff cilia. The details of the silverline system are similar to those of D. scutum.There is insufficient difference in ranges of body length, width. and buccal cavity length to use these characters in separating the two species. However, a statistical analysis shows that the length of the portion of the AZM on the right side of the body in D. scutum is significantly different (longer) from that of D. peloetes. Furthermore, these two species differ not only in number of dorsal ciliary rows, but also in the number of cilia per row. The degree of difference in these two species is similar to that between closely related species in other hypotrich genera, and also to that between some varieties of Paramecium aurelia.

Notes: SYNOPSIS. The mechanism of carbohydrate metabolism was studied in homogenates of the ameba, Mayorella palestinensis. The utilization of intermediates with the formation of lactic acid as the end product of the anaerobic breakdown of the carbohydrates was established. Evidence was obtained for the presence of the main enzymes associated with the Embden-Meyerhof glycolytic scheme. The activity of hexokinase and phosphorylase was ascertained in a M. pakstinensis homogenate. These enzymes have not yet been found among other soil amebas grown in axenic cultures.

Notes: SYNOPSIS. Chloramphenicol inhibits growth of Euglena gracilis. It also interferes in the “greening” process by inhibiting protein synthesis (measured by leucine uptake), but RNA synthesis is essentially unafiected. The antibiotic acts on all cell fractions, but prefermtially inhibits the synthesis of plastid protein. Inhibition of chlorophyll synthesis is transitory and does not affect the self-reproduction system for chloroplast formation.

Notes: SYNOPSIS. Thirty to 80% of Tetramitus rostratus amoebae were induced to transform into the flagellated stage. The procedure involved growth in a dilute hydrolyzed casein medium with living Escherichia coli dispensed in microdrops approximately 0.5 mm3 in volume and sealed in a slide-depressionchamber. Single amoebae placed in such microdrops did not transform until growth and division had produced a population density of 100 amoebae/mm3. Flagellation then began and proceeded rapidly.Analysis of growth and transformation in microdrops of different sizes but with equal numbers of amoebae, or of microdrops of the same size but different numbers of amoebae, suggested that the amoebae themselves were elaborating substances into the medium which brought about their own transformation. The effects of bacteriostasis induced by a variety of antibiotics did not clearly rule out a bacterial contribution to the factors causing transformation. Osmotic effects within physiological limits did not play any demonstrable role in inducing the response.It was concluded that transformation of amoebae to flagellates involved rapid growth and subsequent undetermined changes in the medium.

Notes: SYNOPSIS. Thymidine-methyl-H2 is incorporated into the cytoplasm of Euglena. The label is non-nuclear and not in DNA; evidence for its presence in RNA and protein is presented. Only Euglena which maintain the potentiality to develop chloroplasts show this incorporation; it was not observed in streptomycin. uv, benadryl, O-methyl threonine or heat “bleached”Euglena, nor in Astasia longa.Preliminary incorporation experiments show that exogenous pyrimidines are not utilized as nucleic acid precursors in Euglena in general. However, the tritiated purines are incorporated into DNA and RNA. The use of thymidine to localize DNA autoradiographically in Euglena is completely excluded.

Notes: SYNOPSIS. A survey of the genus Lagenophrys Stein, 1852 (Ciliata, Peritricha) on freshwater crayfish (Parastacidae) revealed a wide range of new species in Australia and New Zealand. Fourteen new species are described. L. seticola sp. nov. is close to L. vaginicola Stein. L. spinosa, L. bispinosa, L. latispinosa, L. communis, L. occlusa, L. lawrii, L. lingulata spp. nov. form one species group. L. willisi, L. rugosa, L. darwini, L. deserti, L. ditngogi and L. engaei spp. nov. form a second group distinguished by characters of the lorica, lorica mouth and macronucleus.Nenninger's classification of degree of specificity of commensal-host relationship is applied to the whole genus and expanded in the light of the Australian material. The zoogeographic problems resulting from the specificity of Lagenophrys and the limited range of some of its hosts are indicated.

Notes: SYNOPSIS. Blood films made from the “shoveller duck”, Anas clypeata Linnaeus 1758, in Lin-pien Ping-tung Hsien, Taiwan, showed a new species of avian malaria parasite, for which the name Plasmodium anasurn is proposed. This species is characterized by elongate gametocytes often closely resembling Huemopvoteus, about 15 merozoites per segmenter (although such stages were too few for really accurate counts), and trophozoites and schizonts which very often surround the extremities of the host cell nucleus in U-shaped fashion. Pigment is abundant, appears early, and is very dark. The host cell shows little or no alteration. No infected reticulocytes or blood cells other than erythrocytes were observed.

Notes: The purpose of this paper is to describe and evaluate the quarterly national income and product accounts of the United States (to be referred to henceforth as N.I.P.). The historical development of these accounts is reviewed first. Next, a summary of the statistical methodology underlying them is provided. An analysis of the errors to which they have been subject follows. An attempt is then made to define the area of their usefulness. Finally, suggestions for their improvement are formulated.The most general conclusions are as follows:〈list xml:id="l1" style="custom"〉1The quarterly N.I.P. estimates were developed in close response to an urgent need for them in economic analysis and policy formulation. Their development was a gradual process covering about two decades in which experience gained at one stage suggested improvements and extensions for the next.2The quarterly figures are based on abundant data sources. To be sure, the information is not as comprehensive as that available for the preparation of the annual estimates, but we are dealing only with differences in degree - there is no sharp contrast.3The series are subject to a considerable margin of error. There is bias in some of them - the initial estimates tend to be too low; and quite apart from bias they differ from the revised figures.4The margin of error attaching to the statistics disqualifies them from serving as precision instruments, but they are indispensable as a systematic framework for the order-of-magnitude analysis of the major forces determining the short-run movements of the economy. At present, the outstanding handicap in such analysis is not statistical error, but the inadequacy of economic theories and of our ability to test them.5The opportunities for mechanizing estimating techniques are assessed; the work on seasonals is discussed in this context; and a thorough investigation is proposed of the problems involved in the synchronization of the various components of the accounts. In addition, proposals for improving the data available for the estimation of specific income and product flows are formulated. Quarterly estimates of the physical volume of national output by industry, and quarterly accounts showing the financial transactions that mediate between saving and tangible investment are considered the two high-priority major extensions of the present accounts. Other, less basic, extensions of these accounts are also proposed.

Notes: An iterative process is proposed that computes a distribution of masses giving rise to a certain gravitational field. The possibility of applying a similar procedure to magnetic and electric fields is also discussed.

Notes: The method presented takes the influence of refraction rigidly into account. All travel-times available are used in an application of the method of least squares. The solution is illustrated by a computer flow diagram.

Notes: Charts are presented for the computation of the vertical component of the attraction of horizontal laminas and of horizontal cylinders bounded by irregular w-sided polygons. Contrary to older methods no restricting conditions are made for the directions of the sides of the polygons.

Notes: A theory is developed to predict the amplitude and velocity of the first arrival produced by a thin solid refractor embedded in a solid environment. Laboratory experiments on a three dimensional model substantially confirm the theory. The essential conclusion may be found in Figure 8 where it is shown that for a constant wavelength, and for thicknesses up to about one half a wavelength, the attenuation per unit distance decreases monotonically with increase of refractor thickness.The assumption is made that the amplitude, A, attenuates as (x)-n exp(-βx), where x is horizontal distance and n and β are constants. It is emphasised that it is difficult to obtain reliable values for n and β from the initial amplitude measurements.

Notes: Book reviewed in this article: State of Stress in the Earth's Crust, Proceedings of the International ConferenceF. A. Vening Meinesz, The Earth's Crust and Mantle (Development in Solid Earth Geophysics)

Notes: Book reviewed in this article:M. R. J. Wyllie, The Fundamentals of Well Log Interpretation.

Notes: Proton precession magnetometers usually operate discontinuously since thy rely one intermittent impulses. The aerial versions of these magnetometers suffer from relatively high background noise. The type of magnetometer discussed in this paper has solved the two problems of discontinuity of measurements and reduced sensitivity due to background noise.Comparative texts with an established flux-gate apparatus have given significant and convincing results.

Notes: Book reviewed in this article:S. I. Kuznetsov, M. V. Ivanov and N. N. Lyalikova, Introduction to Geological Microbiology Organic Geochemistry, Editor I. A. Breger

Notes: The formula for the Bouguer anomaly contains the density of the masses above the datum plane. If we use a wrong value for the density we obtain on the Bouguer map additional anomalies which coincide with the topographic features.If we do not know the Bouguer density we can compute several Bouguer maps based on different arbitrary densities. Then we select that map which shows the least correlation with the topography and obtain in this way a reasonable value for the density. This method has been found by Nettleton.Several authors have formulated this process mathematically and have elaborated numerical methods. This paper will present such a method. It differs from the former methods by the following:〈list xml:id="l1" style="custom"〉1A general formula for the Bouguer density is presented, using a non-specified linear operator. By choosing special definition for this operator, we can obtain the formulae of several of the known methods.2It is shown that the determination of the density by “Nettleton Profiles” gives less reliable results than the statistical investigation of the whole area covered by the gravity survey.3The known methods do not consider the variations of the vertical gradient. It is shown that in areas with a regional gravity anomaly or an extended topographic feature the known methods yield poor results.4It is shown that the vertical gradient of gravity used as operator gives a most exact and simple formula.5It is shown how the electronic computer—after reading the Bouguer values based on an arbitrary initial density—can compute the residuals, derivatives etc., which are based on the corrected Bouguer density.

Notes: An electronic analogue was used to obtain geophone distortion of typical seismic pulses. Some of the results were checked by computation and in all cases agreement was extremely close. For late arrival events estimates of attenuation and phase shift may be made from the steady-state response curves. It is explained why these curves are not applicable to the first peak, for which one must use the results in Table III.Ground-geophone coupling introduces the same distortion as a very lightly damped galvanometer with a natural frequency usually in the range 100c/s—200c/s. In swampy terrain this frequency may reduce to 30c/s—40c/s and coupling effects may be severe.An electronic unit whose characteristics are the inverse of those of a geophone has been used to improve the first peak amplitude of a seismic refraction record. Since 1c/s geophones are often desirable in refraction survey it may well be more economic to use higher frequency geophones followed by their inverse filter.

Notes: The paper describes a new method for the calculation of standard-graphs i.e. resistivity-curves for assumed resistivity profiles. It starts from the integral of Stefanesco and arrives at a system of image poles, similar to, but simpler than earlier developed systems. The advantages of the new method are described, the accuracy is discussed and it is indicated how the accuracy can be improved by a simple artifice.

Notes: In the present study an attempt is made to relate the general pattern of reflection seismograms obtained over a coal basin to the acoustical properties peculiar to the Coal Measures. The Carboniferous is characterized by a very rapid succession of distinct lithological units, resulting in a surprising variability in their physical properties. Coal seams in particular are conspicuous by their low density and velocity and they produce acoustical contrasts of 35–50 % with respect to country rock. The resulting heavy shielding action prevents the seismic energy from penetrating deeply into this type of formation.With the aid of synthetic seismograms, arranged into synthetic profiles, it is shown that only a minor part of the Coal Measures reflections is of primary origin. The majority has a secondary character brought about by reverberations inside the weathering zone. Thus the conclusion is reached that reflection shooting allows of mapping only the structure of the top section of the Carboniferous, which is sufficient for the purposes of the coalmining industry.

Notes: A permanent pasture was ploughed, 5 rates of potassium were incorporated in the seed-bed and a timothy/white-clover seed mixture was sown direct without a companion crop. Plant counts were taken during the fourth week of establishment. The highest rate of potash increased the size and number of timothy/white-clover plants considerably, without altering the timothy/white-clover ratio. Half the plots were cut once during the seeding year and the other half twice. Increasing rates of K increased dry-matter yields, particularly on the plots cut 7 weeks after sowing. Botanical analysis in the following year showed that, under both cutting systems, increasing rates of K tended to increase the proportion of white clover and decrease that of unsown species.

Notes: Book reviewed in this artilce:THRAN, P.; BROEKHUIZEN, S. Agro-ecological atlas of cereal growing in EuropeTHE READER'S DIGEST ASSOC. [Ed.] Complete atlas of the British IslesM. A.F. F. At the Farmer's service.

Notes: Two experiments were conducted to study the effect on nutrient loss and feeding value of making hay by different means, using a barn-drier, a forage-harvester, a crimper and conventional tedding. Both forage-harvesting and crimping of the herbage significantly increased the rate of drying, compared with tedding alone. In Exp. 2 this effect enabled the crimped and forage-harvested hays to be baled for storage 3 days earlier than the tedded hay. The use of the forage-harvester significantly reduced the yield of herbage compared with conventional mowing. Nutrient losses from cutting until storage were highest for the forage-harvested hays, the loss of dry matter between cutting and storage in the forage-harvested hays being 39·9 and 19·3%, respectively, in Expt 1 and 2 with corresponding losses in the conventionally made hays of 7·1% and 9·3%. Crimping the hay resulted in higher nutrient losses than tedding. In Expt 2 there was a loss of dry matter of 17·5% in the conventionally made hay during an 18-week storage period, compared with 3·6% in barn-dried hay, 10·8% in forage-harvested hay and 8·8% in crimped hay.In Expt 2, in which digestibility determinations were made, conservation decreased the total digestible nutrients and starch equivalent in all treatments. The use of the barn-drier gave the most efficient conservation of total digestible nutrients, followed by the crimped, forage-harvested and conventional treatments in that order. The starch equivalent values of hays made from the same sward were 43·0 when barn-dried, 39·8 when crimped, 38·6 after forage-harvesting and 31·6 after tedding.

Notes: Two different sizes of seed of a tetraploid and a diploid Italian ryegrass were sown in pure stands. Harvests were made at frequent intervals from 14 to 54 days after sowing, the root-and shoot-yields and numbers of leaves and tillers being recorded at each harvest. The results suggest that seed size per se has little influence on leaf- and tiller-numbers and that large seed increases yield potential only during the first few weeks of growth.

Notes: In a survey in the West of Scotland, utilized-starch-equivalent (U. S.E.) outputs from the grassland of 67 farms, mainly dairy farms, and 9 hill-grazing units associated with them, were assessed by the farm-recording method. The limitations and possibilities of the method are discussed. The results obtained were above average, but the farms were a selected group. The wide range of U. S.E. outputs from farms of similar type indicates the scope for improvement on farms with low levels of output. The need for more surveys to clarify existing production levels on commercial farms is emphasized.

Notes: Three experiments examine the effects of giving small supplements of flaked maize to steers on the digestibility and retention of nutrients from rations of grass silage, lucerne hay and fresh lucerne. The digestibility of the dry matter, crude fibre and crude protein of the silage ration was depressed by the successive additions of 1, 2 or 3 Ib flaked maize per day. There was a tendency for the steers to retain more nitrogen as the level of starch supplementation increased, in spite of a lowered crude-protein digestibility. The digestibilities of the constituents of lucerne hay and fresh lucerne were slightly increased by the addition of 2 and 4 Ib flaked maize per day. The reasons are discussed for the different effect of the supplemental starch on the digestibility of the crude fibre from grass silage and from fresh or cured lucerne. Attention is drawn to the increase in the retention of N following the supplementation of silage with starch.

Notes: Seven species or varieties of grass, and a mixture of 3 of them, were sown in pure swards and treated with 4 levels of nitrogenous fertilizer (0,17·5, 35 and 70lb N per acre per cut). Each species, and the mixture, was also sown with white clover. The experiment was cut 4 or 5 times per year. The effect of fertilizer on the yield of each grass was compared with the effect of clover on the yield of the grass/clover swards. Mean annual yields showed an approximately linear response to N; there was a small but significant fall in response to the highest level of N. Response among the species ranged from 20 to 30 Ib of dry matter per Ib N applied for the intermediate level of fertilizer and from 14 to 23 Ib for the final increment of fertilizer.S37 cocksfoot, S48 timothy, S24 ryegrass, and a mixture of these grasses, were high yielding and responded well to fertilizer N; Irish ryegrass and Agrostis tenuis were less productive and gave poorer responses to N. S215 meadow fescue and S23 ryegrass were intermediate in yield and response.There were no significant differences between the annual yields of the 8 grass/clover mixtures; the yields of the grass and clover components of each mixture were inversely related. The effect of clover on the yield of the grass/clover mixtures was estimated to be equivalent to the effect of an annual application of 205 lb N per acre to Agrostis tenuis and 120 lb N to S48 timothy. The fluctuations in annual yields were greater with grass/ clover mixtures than with grass swards receiving N.The yields of grasses when sown with clover were in similar order to their yields when sown pure; but whereas the latter tended to fall from year to year, the yields of the grass components of mixtures (except Irish ryegrass) did not.

Notes: Seed shedding was studied in 50 clones each of S5I and S48 timothy during 1961–3. Some clones retained on average during 2 or 3 seasons from 80–90% of their maximum seed weight until 42 days after peak anthesis; this was up to 28% above the varietal mean. The results suggest that clones which retain their seed also produce high yields of seed and of dry matter; they can also be easily threshed.

Notes: It has been found that the rate of herbage production from perennial grass swards, cut at a stage suitable for grazing, is lower in midsummer than in late spring. This occurs even with an abundant supply of water and fertilizer. The growth rate of green material was measured in swards differing in leaf area and light interception, Results did not suggest that higher growth rates could be obtained by attention to this relationship. Examination of the tiller population of grass swards showed that, in summer, herbage yields from cocksfoot and timothy were correlated with the average tiller size. This was not so in either of 2 varieties of perennial ryegrass. During May, June and July there were changes in the erectness of the swards as measured by the proportion of the crop which could be harvested with a mowing machine. This proportion was maximal when the highest rates of production of herbage were recorded. The importance is discussed of the change from a phase when mature tillers are forming inflorescences to one when herbage is derived from young, vegetative tillers formed in the same summer.

Notes: Trials are described in which the intake of silage of varying length was determined. The results indicate that a higher voluntary dry-matter intake occurred as the length of the silage became progressively shorter, but this effect appeared to diminish when the silages were supplemented with concentrates. Data from one trial indicate that reducing the length of hay had no effect on voluntary intake when concentrates were fed.

Notes: The effects of 4 levels of applied nitrogen, ranging from nil to a maximum of 417 lb N/ acre/annum, in all combinations with 3 frequencies of defoliation, ranging from 2 to a maximum of 10 cuts per annum, on herbage production from a perennial ryegrass/ timothy/meadow fescue/white clover sward were measured. These treatments were operative for 2J years, and in a subsequent year the residual effect of cutting frequency was tested. Dry-matter yields of total herbage and of the clover fraction are quoted, together with N yields of total herbage. Yield response to N was higher than in some other experiments in the U. K. Cutting frequency had a very large effect and, in general, the longer the interval between cuts, the higher was the dry-matter (though not the N) yield. There was a marked interaction between cutting frequency and level of N: at the high cutting frequency, dry-matter yield increased linearly with increasing level of N; at the medium frequency, response tended to fall off at the highest level of N; at the low frequency, yield declined with increasing level of N beyond 139 lb N per acre per anum.

Notes: The effects of wilting and of various chemical additives on the digestibility and palatability of wet legume silages are reported. These silages showed most of the characteristics associated with the ensiling of wet herbage with a low content of soluble carbohydrate. Digestibility of all silages by wether lambs was low and exhibited little difference that might be attributed to the treatments. The untreated silage or the one sprayed with valeric/isovaleric acid, just before feeding, were more palatable to dairy heifers. Silage consumption was sharply reduced when urea was added during ensiling.

Notes: This new method of calculation, of the second vertical derivative of gravity or magnetic fields is appreciably different from the classical methods because it is based upon the variations of the distance between the isogams rather than a regular grid with “constant spacing”. In a certain way, it is a method of “constant interval”. A number of practical advantages are inherent to the method, among these, the possibility to use the cartesian charts with bi-logarithmic scales which make the calculation much easier, and the creating of iso-error maps which are indispensable for the interpretation of the derivative maps. Three examples of practical application are given, two of them pertain to gravimetry, the third to aeromagnetism. These results are compared with second derivative maps obtained with other methods.

Notes: A description and classification is given for those later events in seismograms of refraction–and wide angle reflection shooting which travel nearly parallel and at constant time intervals behind the first arrivals and which are frequently observed in field surveys. Multiple events with the velocity V1 of the uppermost layer may be caused by multiple P-reflections and certain velocity conditions or by PS-conversions. In addition to these types multiple events with the velocity V2 or Vn may be caused by reflected refractions or by reflected diving waves. The different types will be distinguished mainly by means of travel time–and amplitude-considerations.

Notes: Electronic circuits are described which simulate the effects of galvanometers and geophones. By placing these circuits in the feedback loop of an operational amplifier it is possible to obtain transfer functions which are the inverse of those of the transducers. That is, they will remove the distortion on the signal which was produced by the geophone or the galvanometer.Both a geophone simulator and its inverse filter have been built and used (O'Brien, 1965). The simulator is accurate over at least seven octaves and the inverse filter restores the ground signal to what it would have been if the recording geophone had had a natural frequency √n+1 times that of the actual geophone, where A is the gain of the operational amplifier used in the circuit.

Notes: Uphole recordings in sediments very often reveal shear waves. With their velocity and that of the P-waves Poisson's ratio may be determined, this usually has unexpectedly high values.A number of up-hole shots were recorded with a linear spread of geophones and with constant gain amplifiers. Calculations were made to show the effect of the free surface and ray divergence (the spread factor). The theoretical, relative amplitudes of the ground motion were plotted together with the observed values. In general, there is good agreement between theory and observation which is better for the P-waves than for the S-waves. The reasons for this difference are discussed.Finally, an absorption coefficient is calculated from the amplitudes measured at the surface.

Notes: Attenuation caused by transmission is known to be the greater the closer the samples are taken together. As a result, the amplitudes of seismograms with multiple reflections can be expected to be negligible within a more or less brief time interval, as is the case for seismograms without multiple reflections with attenuation. This paper examines the process by which multiple reflections regenerate these greatly attenuated reflections. It is also ascertained that a sampling interval of one ms for continuous velocity logs is valid for any survey. For economic reasons, we recommend the selection of a larger interval without, however, overdoing things and thus losing too much information.

Notes: After a brief reference to the various possibilities of measuring induced polarization, the experimental setup of a transistorized earth resistance meter is shown which allows one to measure the (real) resistance at the frequencies 9 cps and 1.5 cps. As a measure of the induced polarization, it supplies directly the resistivity percentage difference. The possibilities of its use are explained in detail and further development is considered.

Notes: The headwave system for an incident P-wave in a two-layer case has been traced in the ‘inside’ of a two-dimensional model and it is found that the measured fronts do not coincide with the wavefronts constructed according to the Huygen's principle. A refraction profile indicates different velocities near the critical distance but shows the true value for the higher velocity medium at greater distances. An error in the intercept time, which is about 6 % too high in the example, should, however, always be present even if extrapolation is done from the region where the profile shows the true velocity of the medium.

Notes: In this paper direct interpretation methods of resistivity observations are discussed, which use the kernel function in the integral expression for the potential as an intermediary step. This kernel function can be expressed in the form of an integral expression, involving in the integrand a Bessel function and the apparent resistivity. This expression is the basis for the determination of the kernel function from the apparent resistivity curve. The integral can be determined directly; this method of computation, however, although practically feasible, is rather time consuming. Another method of computation is to approximate to the resistivity curve by a sum of a small number of two-layer curves which are asymptotic to the observed resistivity curve. This method, which was described in a previous paper by the present author, is briefly restated. A more general method is to approximate to the observed resistivity curve by a sum of functions of other types; the choice of such functions is only restricted by the requirement that the contribution to the kernel function corresponding to them should be easily computable. Two different types of functions, that satisfy this condition, are discussed. The standard curves required for the application of the method are presented. An example of application of the method is given.The problem of determining the resistivity stratification from the kernel function has been solved by Pekeris in 1940. The method of Pekeris is briefly restated.

Notes: Whereas the first success of petroleum exploration in France (the gas deposit in the St. Marcet anticline in the St. Gaudens region) was essentially based on geological surveys, the second (the Lacq field in the Pau region) was the fruit of reflection shooting. In fact, the Lacq anticline cannot be detected by surface geology because of the Quaternary and Tertiary cover. Besides, electric and telluric prospecting methods could not be used over this zone as an electrified railway line passes through it.As stated then, it was the reflection shooting method that revealed the Lacq structure in 1948, during a reconnaissance survey conducted by Compagnie Générate de Géophysique using a very simple technique (only one geophone per trace).By the seismic technique of 1948, quite good reflections were obtained from a level adjacent to the top Cretaceous, but only sporadic reflections were picked up from a deep level and then only on the flanks of the structure, except for the southern one where results were nil.Towards the end of 1949, the first well, La 1, using a heavy rig designed to reach deep layers, led to the unexpected discovery of the upper oil deposit at a depth of 600 m in the Upper Cretaceous (lower Senonian), while the third well, La 3, led to the discovery by blow-out of the lower gas accumulation at a depth of 3,500 m in beds later identified as lowermost Cretaceous and, more particularly, Upper Jurassic (Purbeckian).As no great geophysical effort was called for, the upper oil deposit was rapidly developed, its depth and dimensions being modest (6 km2).As far as the deeper gas deposit is concerned, the main objective up to 1954 was to gain a picture of the central part of the anticline. Despite the use of a more detailed seismic technique, it was difficult to plot the top of the structure at the level of the uppermost Jurassic. From 1952 to 1957 the wells La 101, La 102, La 103, La 104, La 105, La 106 and La 113 were drilled, which made it possible to evaluate the gas reserves.Then began the wide-scale and systematic exploration of the structure, by drilling on the one hand and by reflection shooting on the other. Profiles were shot perpendicular to the axis, but long enough (20 to 30 km) to cover the entire anticline (seismic surveys of 1956–57–58).The eastern pericline and the northern flank were quite easily plotted by seismic survey at the level of the top Jurassic, whereas the southern flank, which has a distinctly steeper slope than the northern one, could not be traced very far–so that the problem of the relationship between the uncomplicated structure of Lacq and the country to the south, with its complex, deep tectonics, still remains an open question.The western pericline, however, remained a subject of concern. Its relationship to the anticline of Ste. Suzanne (outcropping Jurassic) was a mystery.In 1956–57 the well SV 101 confirmed the hypothesis of an overthrust which, without affecting the anticline of Lacq, borders it to the south and west. The thrust is not very large in the south (Lagor wells) but assumes considerable proportions in the west: the Ste. Suzanne anticline actually forms part of a thrust from the south, about 5, 000 to 6, 000 m thick, as the exploration of the region by reflection shooting and drilling (SSE 101, OR 102) has shown. This exploration had been undertaken in search of a new structure under the thrust that might form an extension of the Lacq structure.In 1959 a detailed gravimetric survey (2 to 3 st./km2) was carried out in the Lacq region because the old survey map (1948–1 station/8 km2) had proved progressively inadequate for interpreting the seismic data. It was found that the structure of Lacq had only a small anomaly in comparison with its dimensions. This surprising phenomenon is still difficult to explain. Are the surfaces of equal specific gravity independent of the stratigraphic planes, or has the effect of the anticlinal roof of the Cretaceous and the Jurassic been balanced by that of a saliferous and intumescent Triassic right in the core of the structure?The small anomaly which it was possible to detect may be explained by a thick sequence of reef limestones in the centre of the anticline on the Lower Cretaceous, as indicated by drilling results. These severely fissured limestones are undoubtedly partly to blame for the bad seismic results obtained on the central part of the structure as far as the deep horizon, adjacent to the top Jurassic, is concerned. They are also responsible for the considerable anomalies in the velocity of seismic wave propagation.

Notes: Book reviewed in this article:E. I. Hamilton Applied GeochronologySolar System Radio Astronomy, edited by Jules AaronsMary Sears, Progress in OceanographyClays and Clay Minerals, edited by W. F. Bradley, Proceedings of the Twelfth National Conference, Monograph No. 19, Earth Science Series.

Notes: Until such time as digital seismic recording techniques are in widespread use in the field and partly because it cannot afford digital equipment, C.E.P. has decided to build a processing system which can digitize and process seismic information in analog form on magnetic tapes.C.E.P. was prompted to adopt the digital technique to enable it to proceed with its stratigraphical investigations, starting with the elaboration of synthetic records and followed by the study of signals and deconvolution.Though the analog form of recording is not too suitable for digital processing owing to its low dynamic range, it seemed to us that it was nevertheless perfectly feasible to enhance the analog information by processing it digitally through an automatic computer.This approach to the problem of data enhancement is more satisfactory than the (conventional) analog method, which is more complicated and less accurate.〈list xml:id="l1" style="plain"〉The digital processing system comprises:a magnetic playback systema two-channel reproduction devicean analog-digital convertera 1620 IBM computeran automatic plotting device for graphical presentation of results.Examples of different processing forms are presented:〈list xml:id="l2" style="plain"〉cancellation of A.G.C. actioncomputation of seismic signaldeconvolutioncorrelation techniquesanti-singingstudy of the response of the various items of equipment.We have come to the conclusion that very interesting results have been obtained in spite of the low dynamic range of the analog tapes.With this equipment it is possible to study and process the data in digital form and compare results with those obtained by analog processing. Also, the experience gained will be very useful when digital field crews start operating.Unfortunately, it is not possible for the time being to operate the equipment on a commercial production basis, but only to develop working methods, to conduct short studies or to guide and control analog processing techniques.At present our efforts are therefore aimed at shortening the time required for processing and plotting.