ALBERT

Notes: Summary Cephalotes atratus, the “giant turtle ant” of the Neotropical tribe Cephalotini, exhibits an intermediate stage in the evolution of polymorphism. The allometric growth line is straight, but the distribution of worker sizes is bimodal. An ethogram of workers in laboratory nests showed pronounced differences in behavior according to age. Under natural conditions, individual foraging specializations based on worker size were also found. Compared to other advanced cephalotines, this species appears to be less strongly adapted for arboreal life. A model is presented for the evolution of polymorphism in ants.

Notes: Summary In females ofPolistes gallicus the activity of corpora allata (CA) was determined volumetrically as well as radiochemically using the in vitro assay for juvenile hormone (JH). The results we have compared with the ovarian activity. During the period of egg maturation after overwintering the volume of CA is well correlated with the synthetic activity. But in overwintering females and in ovariectomized females we have observed very large glands which produced only little amounts of JH like the small glands of parasitized wasps. In all dominant females the CA we have found to be larger and more active than in subordinated females indicating that changes in the endocrine activity may be a primary result of social hierarchy.

Notes: Summary The colony-moving ofMyrmica rubra L. was induced in he laboratory by worsening the microclimate of the nest. A detailed analysis of the whole process is given; it is based both on observation and on traffic measurements between the old and the new nests. Three periods can be recognized: exploration, emigration, and final exploration. Two recruitment methods occur, initiated by distinct motor displays: group recruitment takes place first, whilst carrying behaviour becomes the main technique later. The organization of the group is described. The recruiter extrudes its sting while returning to the old nest and while leading the group. Tracks left on soot-coated glasses are analyzed. Sticks crushed with either the poison gland or the Dufour's gland are effective in leading the ants. Most adult carrying postures are typical for myrmicines: the occurrence of atypical postures is discussed. All the carrying acts (of brood and adults) are effected by 25% of the workers (on average); carrying activity is age-dependent. The stability of the group of carriers is tested during successive emigrations. Social regulation potentiality is strong: even queens or callows can move with their larvae when isolated from the rest of the colony.

Notes: Summary The reproductive rate of unmanaged European honeybee races was studied in Kansas, U.S.A. Colonies produced a mean of 3.6 daughter colonies per original queen during one year. This high reproductive rate was largely due to the frequent occurrence of afterswarms, a factor not adequately considered in previous studies. The rate of afterswarming was influenced by at least two factors: the amount of sealed brood (pupae) in the colony and the season when swarming occurred. Factors which may influence the survival and subsequent reproduction of prime swarms and afterswarms are discussed.

Notes: Summary The effect of temperature upon the development of large hibernated larvaæ of fourMyrmica species has been tested experimentally. Over the viable temperature range of 15–25°C, it was found that: 1. There are no differences between the species in the effect of temperature upon development times. All fit the model log Dev. time=a-b T°C with a common value for b. This gives an effective Q10 of about 3.1 which agrees with respirometrical estimates for worker ants. 2. The value for the intercept (a) differs significantly between most species confirming the intrinsic difference that has been demonstrated at a constant 22.5°C in previous work. The development times of larvæ can be ordered from fastest to slowest being:Myrmica ruginodis Nyl.,Myrmica rubra L.,Myrmica scabrinodis Nyl. andMyrmica sabuleti Meinert. At any temperature it takesM. sabuleti about 1.5 times as long asM. ruginodis to grow from a large hibernated larva to a white pupa. 3. No large differences in larval survival or gyne production could be detected between the temperature treatments. There was an indication that most species, survived best at about 22°C. 4. The results are discussed briefly in terms of the ecological distribution of the four species in the South of England. 5. The possible effects of a fluctuating temperature regime are discussed, it is suggested that the amplitude of fluctuations may not have any great effect whereas the periodicity could be more important.

Notes: Summary The chromosome numbers of 40 ant species are reported. For 22 species the karyotypes as well as the chromosome numbers are presented. The chromosome numbers range between n=8 and n=26. Remarkable karyotypes are those of the genusLasius in exhibiting mainly acrocentric chromosomes. In all other karyotypes the majority of chromosomes show medio- or submediocentric centromere position. Differences in chromosome numbers in the genusCamponotus reflect the grouping in subgenera with the exception ofTanœmyrmex. This pattern is not true for the generaAphœnogaster andLeptothorax, where a variety of chromosome numbers were found in the different subgenera.

Notes: Resume Les effets de la densité ont été testés sur des lots de larves de l'espèceEublaberus distanti, lots de 20, 100 et 500 individus par 615 cm2. Lorsque la densité augmente, la mortalité larvaire s'accroit, surtout chez les larves jeunes. L'augmentation de densité accentue les différences entre individus à développement rapide et développement plus lent, de même qu'elle implique une réduction de taille chez les adultes. Les effets de la densité s'expliquent par la dynamique de la régulation des populations de Blattes, comparable aux modifications phasaires des Acridiens migrateurs.

Notes: Summary A colony ofHarpagoxenus sublœvis was artificially established in a near-natural habitat. The sexual calling behavior of young ergatomorphic queens was observed for the first time under field conditions on July 7 and 8 1981, between 2015 and 2130 Central European Time. Simultaneously, on July 7, theHarpagoxenus colony conducted a slave raid on a neighboring nest ofLeptothorax acervorum (Fabricius). Previously the sexual behavior was known only from laboratory studies, these observations now show that it is performed in an identical manner under natural conditions.

Notes: Resume L'auteur propose une nouvelle méthode de marquage, au moyen de ceintures de métal, permettant d'identifier chaque membre de la société.

Notes: Resume Chez la fourmiCataglyphis cursor, on peut définir 4 catégories d'ouvrières: minimes, petites, moyennes, grandes et très grandes. Dans chaque catégorie, les ouvrières sont capables de pondre et de produire par parthénogenèse, des reines, des mâles et de nouvelles ouvrières de toutes tailles. Les ouvrières moyennes présentent la plus forte productivité. La grosseur moyenne des œufs et la fécondité varient avec la taille des ouvrières; tous les œufs semblent capables de se développer. Les différences entre ouvrières apparaissent donc davantage comme quantitatives que qualitatives; le polymorphisme monophasique de l'espèce correspond bien à cette similitude biologique.

Notes: Summary Queens of the Oriental hornet are aggressive towards one another in the beginning of the active season, during the months of May, June and July: they defend their “Lebenraum” within the nest and do not enable any other queen to enter their territory. At that period any encounter between two queens, whether within the nest of the one or anawhere else, releases mutual aggressive behavior. The ensuing combat may last for hours and in its course, if the one queen beats the other, it stings it to death in the neck. In many instances, however, the combat remains unresolved and the exhausted combatants withdraw to recuperate before resuming their battle. At other times, one of the queens may succeed in maiming its rival by amputating the tips of its limbs at which point the disabled queen concedes the fight by assuming an “inferior” posture towards the victor and making a food offering. The various phases in the combat between queen pairs are described in detail.

Notes: Summary The distributions of three “forms”, actually sibling species, of meat ant were studied near Morgan, South Australia, an area with mean annual rainfall of 230 mm. Colony dispersion is described for a “blue form” and for formpurpureus sens. strict. which occurs in this locality far beyond its normal low rainfall limit. An unusually large colony ofpurpureus had a territory covering 10 ha with more than 85 nests and over 1,500 individual nest entrances. Worker interactions between forms, and within and between colonies within forms are described. The ant fauna of the locality as a whole and the faunas accompanying differentIridomyrmex species were investigated by means of hand collections and pitfall trapping. Diversity (species — richness) and the occurrence of widely adapted ant species are related to vegetation type and associatedIridomymex. Catches of pitfall traps suggested that the numbers of individuals and species of other taxa active on the soil surface, predominantly Collembola, were affected by numbers of ants, particularlyIridomyrmex species and other, widely adapted ants.Iridomyrmex also influence associated fauna at an evolutionary level. The presence of zodariid spiders which are sibling species-specific colour mimics and predators of meat ants is noted. Possible cases of mimicry of meat ants by ants of the genusCamponotus are recorded and discussed.

Notes: Abstract The integral equation for the electromagnetic response of a sphere in a layered medium may be solved as follows. First, the unknown time harmonic electric field in the sphere is expanded in spherical vector waves. Secondly, the coefficients for these wave functions are found by a set of equations. The equations are found by multiplying the integral equation throughout by each wave function and integrating over the spherical conductor. Once the unknown coefficients have been determined, then the transient response may be found by taking the inverse Fourier transform. In carrying out the Fourier transform one learns that for most of the time range used in prospecting, only the lowest order vector wave function is significant. A study of the singularities of the spectrum of the transient shows that, for the time range considered, only a single branch cut is significant. There are no pole type responses. That is, the field does not decay exponentially. Previous studies of a sphere in free space reported only pole type responses. That is, at the later stages, the field decays exponentially. This study shows that, in order to model satisfactorily the effect of the host rock on transient electromagnetic fields, the sphere must be placed in layered ground.

Notes: Abstract Tidal records at Hanasaki, southeastern Hokkaido, are analysed to clarify the post-seismic crustal vertical movement in the 1973 Nemuro-oki, Japan, earthquake. The result shows that the post-seismic uplift, as speculated byKasahara (1975), terminated in late 1975 and reverted to the previous rate of rapid subsidence of about 1 cm/yr. Ceasing of the post-seismic uplift, which occurred much earlier than previously speculated, could be explained by supplementary mechanisms, such as frictional resistance against creeping at the fault surface. This unexpected mode of movement, however, raises a new question about the accumulation of tectonic movements in this district. Since the subsidence rate extrapolated from geomorphological data for the past several thousand years is almost one order of magnitude lower than the recent rate as mentioned above, we have to provide some alternative explanation for the discrepancy between the two rates. In other words, simple repetition of co-, post- and inter-seismic movements in seismic cycles due to plate subduction, must be modified in this district. Several possible modifications to the subduction process are suggested, and a brief discussion of vertical movements expected in each case is given.

Notes: Abstract Recent advances in the use of dynamical and statistical models to forecast the weather are described. High resolution physical-mathematical models can now predict the development of synoptic weather systems in great detail for a few days ahead, while large-scale phenomena like blocking can be predicted for about a week or more. The local forecasting problem is presently being attacked by statistical- and meso-scale models using the large-scale predictions as input parameters. Very encouraging results have been obtained to predict the local weather, in particular when the local weather is influenced by topography and the underlying surface.

Notes: Abstract In recent years there has been much progress in describing and understanding the detailed dynamical and microphysical structure of frontal precipitation systems. In this article we consider phenomena on a hierarchy of scales: the broad synoptic-scale flows in mid-latitude depressions, the mesoscale patterns of precipitation, the nature and origin of convection at the surface and aloft, and the microphysical properties of the resulting precipitation. The influence of orography is also briefly discussed.

Notes: Abstract Spectral analyses were made of derived area-index series of areas subject to extreme temperatures and precipitation as well as cross-spectral analyses of the area-index series with double sunspot cycle (Zurich) numbers. Superposed epoch analyses also were made of area-index series versus various double-sunspot cycle phases. Area series for wet and dry Junes, warm Junes, defined June drought, and warm Januaries all show statistically significant double sunspot cycle (∼21 year) periodicities. The 21-year cycle of above-normal June precipitation is most striking and has not received previous recognition.

Notes: Abstract An examination is made of the hypothesis that internal cloud properties are determined by the mixing of dry air from above the cloud top and cloud base air in such a way that the mixture is neutrally buoyant with respect to the clear air environment at each level. It is concluded that the resulting mixture is much drier than is actually observed. Comments are made about observed cloud properties which need to be taken into account in any model of the mixing process.

Notes: Abstract Riming growth of ice particles is simulated by numerically solving the stochastic collection equations, simultaneously considering coagulation of water droplets. By introducing a special criterion which defines the habit of a riming particle, the influence of this habit on the growth of several kinds of ice particles assumed to be formed during riming was investigated. It was found that (i) hexagonal rimed ice plates are growing more efficiently than lump graupel or rimed columns, (ii) the use of different collection kernels for the lump graupel evolution leads to widely differing results and that (iii) the time dependent decrease of liquid water substance and the size of the resulting ice particles were more strongly influenced by the initial ice crystal concentration than by the initial ice crystal size and the habit of the ice particles. By decreasing the number density of ice crystals gradually a critical ice crystal concentration was found at which the present liquid water was not completely consumed by the riming process even after 1800 s model time, causing large drops of radii 〉100 μm to be formed in appreciable concentrations.

Notes: Abstract Helicopter measurements of solar irradiance and meteorological data within the atmospheric boundary-layer were made in Lagos during February 1979. Filter samples of aerosols were collected both during flight in February 1979 and at ground level in December 1978. Profile data on spectral aerosol optical depth were obtained and, from these, the aerosol extinction coefficient at two wavelengths (0.5 and 0.88 μm) were calculated. Precipitable water was low and was contained mainly within the 750 m layer above ground, suggesting the establishment of a deep unstable boundary layer. Calculated channel energy depletions by aerosols show that, within the first 750 m of the surface, the 0·88 μm might be more efficient at attenuating solar energy than 0·5 μm. The lagoon (maritime) aerosol sample indicated a more monodisperse size-distribution than the dusty harmattan aerosol sample.

Notes: Abstract After briefly reviewing the observational data on the stratospheric sulfate aerosol layer, the chemical and physical processes that are likely to fix the properties of the layer are discussed. We present appropriate continuity equations for aerosol particles, and show how to solve the equations on a digital computer. Simulations of the unperturbed aerosol layer by various published models are discussed and the sensitivity of layer characteristics to variations in several aerosol model parameters is studied. We discuss model applications to anthropogenic pollution problems and demonstrate that moderate levels of aerospace activity (supersonic transport and space shuttle operations) will probably have only a negligible effect on global climate. Finally, we evaluate the possible climatic effect of a ten-fold increase in the atmospheric abundance of carbonyl sulfide.

Notes: Abstract Solar radiation of λ〉175 nm and of Lyman-alpha at 121.6 nm is absorbed in the mesosphere and stratosphere by molecular oxygen (λ〈242 nm) and also by ozone molecules at λ〉200 nm. This paper describes the photodissociation processes resulting from absorption in the Schumann-Runge bands and Herzberg continuum of molecular oxygen and also in the Hartley, Huggins and Chappuis bands of ozone. Special consideration is given to differences between the stratospheric and mesospheric problems.

Notes: Abstract The catalytic destruction of stratospheric ozone by the oxides of nitrogen is believed to be an important part of the global ozone balance. The lack of sufficient measurements of NO x concentrations has impeded efforts to quantify this process. Recent measurements of stratospheric nitrogen dioxide from ground-based stations as well as aircraft and balloons have provided a first approximation to a global distribution of NO2 vertical columns at sunset. These observed vertical columns have been translated into time-dependent vertical NO2 profiles by means of a one-dimensional atmospheric photochemical model. Using recent observations of air temperature and ozone along with this information, the independent instantaneous (one second) rates of ozone production from oxygen photolysis P(O3), of ozone destruction from pure oxygen species (Chapman reactions) L(O x ), and of ozone destruction by nitrogen oxides L(NO x ) were estimated over the three-dimensional atmosphere. These quantities are displayed as zonal average contour maps, summed over various latitude zones, summed over various altitude bands, and integrated globally between 15 and 45 km. Although the global summation between 15 and 45 km by no means tells the complete story, these numbers are of some interest, and the relative values are: P(O3), 100; L(O x ), 15; L(NO x ), 45±15. It is to be emphasized that this relative NO x contribution to the integrated ozone balance is not a measure of the sensitivity of ozone to possible perturbations of stratospheric NO x ; recent model results must be examined for current estimates of this sensitivity.

Notes: Abstract An assessment is made of the relative contribution of certain classes of energetic particle precipitation to the chemical composition of the middle atmosphere with emphasis placed on the production of odd nitrogen and odd hydrogen species and their subsequent role in the catalytic removal of ozone. Galactic cosmic radiation is an important source of odd nitrogen in the lower stratosphere but since the peak energy deposition occurs below the region where catalytic removal of O3 is most effective, it is questionable whether this mechanism is important in the overall terrestrial ozone budget. The precipitation of energetic solar protons can periodically produce dramatic enhancement in upper stratospheric NO. The long residence time of NO in this region of the atmosphere, where catalytic interaction with O3 is also most effective, mandates that this mechanism be included in future modelling of the global distribution of O3. Throughout the mesosphere the precipitation of energetic electrons from the outer radiation belt (60°≲Λ≲70°) can sporadically act as a major local source of odd hydrogen and odd nitrogen leading to observable O3 depletion. Future satellite studies should be directed at simultaneously measuring the precipitation flux and the concomitant atmosphere modification, and these results should be employed to develop more sophisticated models of this important coupling.

Notes: Abstract Using standard ‘two-scaling’ techniques we calculate the Eulerian- and Lagrangianmean flows induced at second order in amplitude by small-amplitude, transient, non-dissipative, vertically-propagating inertio-gravity waves on anf-plane. The example is an idealized one, but illustrates a number of important features that are typical of wave, mean-flow interaction in a rotating, stratified fluid. Physical discussion of the solution is given in Section 4 of the review byMcIntyre (1980), which appears elsewhere in this issue.

Notes: Summary This article analyzes the nature of the aerosol information that current or planned spacecraft measurements could contribute toward the required input data for studies of natural anthropogenic influences on the middle atmosphere, and their consequent effects on our weather and climate. The analysis is conducted with particular reference to the solar occultation sounding technique as applied by the SAGE I experiment on the Atmospheric Explorer Mission B spacecraft. Its conclusions should prove to be of use in both the interpretation of the SAGE I data, and in the design of the follow-on mission on the Earth Radiation Budget satellite. Our analysis shows, in particular, that further studies are required in: the choice and number of sounding channels; the data taking sequence in relation to the atmospheric regions probed; the accuracy and vertical resolution of the atmospheric profiling, and their dependence on both the instrument/spacecraft parameters and the data inversion techniques; and the data reduction procedures. Neither of the selected channels is in a one-to-one relationship with an atmospheric constituent; hence, unless further assumptions are introduced, inversion techniques based on such a property are not applicable. The aerosol wavelengths are not satisfactory as they are only sensitive to the large size tail of the aerosol size distribution rather than to the predominant sizes; for these, UV wavelengths would be required. Owing to the change of the Sun's shape due to atmospheric refraction as the Sun either sets or rises, the higher altitudes will be scanned fewer times than the lower altitudes. Also, because transmission approaches rapidly unity above ∼40 km, the same high altitudes are more sensitive to measurement errors-errors that will propagate to lower altitude determinations when inverted profiles are reconstructed from the top of the atmosphere. These two factors, combined with the small air mass values at the high altitudes, are the cause of the mathematical ill-conditioning of the inversion problem. They point toward the need for a data-taking sequence strategy that would trade off between data storage and transmission constraints, larger accuracy at the high altitudes, and proper division of the atmosphere in order to overcome the ill-conditioning. Likewise, and as a result of the above considerations, there is a need for a detailed trade off study between data accuracy and vertical resolution of the reconstructed profiles. This should take into account the seasonal and geographical variations in the distribution of atmospheric constituents, as well as a representative statistical set at any given location and time, appropriate error measures and their vertical profiles, and several inversions utilizing as initial guesses profiles that depart from the true ones. It is also shown that the aerosol and ozone number densities cannot be recovered simultaneously without introducing some formula for the aerosol extincition or assumptions on the form of the aerosol size distribution. This problem is not resolved by the addition of sounding channels because each such channel introduces an additional unknown aerosol extinction. Thus, one is led to a separate rather than a simultaneous determination of the various constituents by resorting to complementary measurements. For a future experiment, it is suggested to determine the ozone separately from measurements at a close pair of appropriate wavelengths between which the aerosol extinction varies slowly whereas that of ozone exhibits a rapid variation. A similar technique could also be used for the separate determination of NO2. The relaxation-type of inversion suggest byChu andMcCormick (1979) does not seem to be appropriate because each channel is not sensitive selectively to an individual constituent, the aerosol channels are not sensitive to the important sizes in the distribution, and the sensitivity of the channels to the constituents of interest varies greatly with altitude. In the retrieval of the vertical profiles, the cause of the ill-conditioning of the inversion is identified. Two approaches are suggested for overconing this problem: (i) build the profile starting from the top of the atmosphere (forward procedure) but with an initial layer of sufficient air mass, or preferably (ii) reconstruct the profile from the lowest altitude reached (backward procedure) with a renormalization at the top of the atmosphere. In this process, the minimization search method (Fymat, 1976) would appear to be a better technique than the onion-peeling technique, as demonstrated byMill andDrayson (1978). In order to maximize the scientific return of SAGE I, a data inversion procedure is proposed. It assumes that (i) there are no aerosols above ∼25 km, and no NO2 below this altitude (as suggested byChu andMcCormick, 1979), (ii) below ∼25 km, ozone (and NO2, if present) could be determined separately, and (iii) the aerosol has a known refractive index at all wavelengths of interest, is assumed to be spherical (or describable in terms of ‘equivalent spheres’), and the minimum and maximum radii of its size distribution are known a priori. Under these assumptions, it is possible to retrieve the neutral density, NO2 and O3 profiles above ∼25 km, by either the forward or the backward procedure described above. Taking into consideration the power law variation of the air density with altitude, it is further possible to reconstruct the corresponding profiles at all the lower altitudes from the determinations in the altitude range ∼30–40 km. Below ∼25 km, the four SAGE I channels would then all become available for the aerosol inversion. While the profile reconstruction could proceed as for the higher altitudes, the aerosol inversion at each individual altitude presents problems of its own. Results of numerical experiments for aerosol inversion using all four SAGE wavelengths and seven different inversion routines are presented. If good a priori information is available on the sought size distribution solution, reasonably satisfactory inversions can be performed (see line 1 of Table 2, and Fig. 3c and 3d). However, in the absence of such information, there are as many solutions as inversion methods tried, in complete conformity with the well-known ill-conditioning of the problem. Among methods providing physically meaningful solutions, no method could be singled out as preferable to the others. In these inversions, the data were assumed to be exact, and 99% of the distribution were used. Under different conditions, the nonuniqueness of the inversion would be further compounded. Lastly, based on the present study, a strategy is suggested for the design and data interpretation of a follow-on SAGE-type experiment. Considering the important advantages to this problem presented by forward scattering, as demonstrated byFymat andMease (1978), a composite (extinction-forward scattering) experiment is recommended for the future experiments.

Notes: Abstract Solar radiance measurements covering over seventeen months are analysed for a location beside the Lagos Lagoon. The aerosol extinction coefficient was generally higher in the dusty months than in the wet months. ‘Clean air’ estimates of the coefficient are made. Data on its wavelength dependence are also presented.

Notes: Abstract Phase velocities of Rayleigh waves for the Adriatic Sea area are obtained in the period range 25–190 sec along the path (l'Aquila-Trieste) AQU-TRI and 20–167 sec along the path (Trieste-Bari) TRI-BAI. The phase velocities are systematically higher than the known values for the surrounding regions. The data inversion indicates the presence of a lithosphere typical of stable continental areas with clear high-velocity lid (V s ∼4.6 km/sec) overlying a well developed low velocity zone (V s ∼4.2 km/sec).

Notes: Abstract Model uncertainty is introduced into direct-current resistivity data by adding random changes to layer thicknesses in a ten-layer model. The resulting information is then aliased by generating a sounding curve which contains less information than the ten resistivities and nine thicknesses. These sounding curves are then inverted via the Backus-Gilbert algorithm using singular value decomposition to obtain solutions in terms of simpler two-or three-layer models. Quantitative results confirm what has been known qualitatively for many years as the principle of equivalence. An interesting result is that the geometric average of a given suite of noisy models is virtually identical to the best-fit model for the average of the noisy curves. The results show that the inversion of resistivity data by nonlinear least-squares parameter fitting is stable in the sense that noise in the data inverts to the same magnitude of noise in the model.

Notes: Abstract Results are presented from a two-dimensional, time-dependent model of the atmosphere which has been used to investigate perturbations to the ozone layer due to chlorofluorocarbons. The unperturbed stratosphere is modelled well with the observed features of the ozone distribution reproduced. The main features of the perturbation calculations are the large latitudinal and seasonal variations found in the modelled ozone reductions with greates reductions where the total ozone amounts are largest. The importance of at least a two-dimensional study in problems of this kind is stressed and the important role of dynamical and radiative processes, as well as chemical, is indicated.

Notes: Abstract For a thermal starting from rest, the scales of motion consistent with the initial conditions are given. An alternative time scale based on the motion of the thermal is derived. The anticipated similarity solutions for thermals are summarised and possible qualitative differences between solutions are given. Within this consistent framework previously published laboratory and numerical models of thermals are discussed. Reasons why numerical models have not rigorously demonstrated the existence of a self-similarity solution are considered. Comparisons of all available results show that a single similarity solution valid for all thermals does not exist.

Notes: Abstract The measurement of the atmospheric electric field was carried out with a field mill at a small island in a bay on the Pacific coast of Japan. The data obtained during 80 months from 1971 to 1977 were analysed. It was found that characteristically the diurnal variation regularly alters with the seasons. Whereas the electric field in winter has the same diurnal pattern as that observed at globally representative stations, it exhibits in summer a pattern depending on the variation of the local electric conductivity. The alteration is inferred to be associated with regional atmospheric conditions surrounding the observation site.

Notes: Abstract This paper examines the evidence for the model of a small cumulus cloud represented as a quasi static but turbulent entity, growing on the upshear side and decaying on the downshear side. While the air just outside the cloudy outline is, on average, stationary relative to the embedding airmass, there is a slight flow, upwards and forward as though the updraft has induced upward motion in the clear air outside the cloud, on the growing side. On the decaying side the motion is downwards and away from the cloud. This is a flow pattern which is not consistent with the air flowing around the cloud as it moves forward but it agrees well with the picture given. Decayed remnants of cloud are found throughout the air previously occupied by the cloud. The cloud outline moves through the embedding air at a velocity which is almost as large as the relative motion of the subcloud feeding airflow (which is almost free from internal wind shear in strong convection). The mixing of dry air from above the inversion yields the observed diluted liquid water content in small cumuli, if such mixing is allowed to proceed until the cloud density equals that of the surrounding air. Quantitative conditions relating the liquid water to inversion temperature and moisture changes, and to the stability of the environment are presented. The strong vertical mixing from the top of the cloud downwards is important to microphysical processes.

Notes: Zusammenfassung Die Anfangsadjustierung der atmosphärischen Zustandsvariablen und die sehr kleinen Rechenzeitschritte sind Kernprobleme der numerischen Simulation von grossräumigen Wetterentwicklungen auf der Basis strenger hydrodynamischer Vorhersagemodelle. In dem vorliegenden Aufsatz wird ausführlich diskutiert wie beide Prognosehindernisse mit geeigneten Verträglichkeitsbedingungen (diagnostische Differentialgleichungen) zwischen den atmosphärischen Feldgrössengemeinsam beseitigt werden. Diese Bedingungsgleichungen sind gleichzeitig verwendbar, um (1) die Anfangsfelder der meteorologischen Variablen so aneinander anzupassen, dass kurzperiodische Lärmeffekte weitgehend unterdrückt werden (ungefilterte Systeme) (2) originäre Modellgleichungen zu ersetzen, so dass die meteorologisch irrelevanten Lärmwellen (mit lästig kleinen Zeitschritten) in den mathematischen Lösungen eliminiert werden (gefilterte Systeme). Die konsequente Nutzung der Lärmfiltertechnik führt (bei einem vertretbaren mathematischen Aufwand) in der Praxis dazu, dass während des numerischen Lösungsprozesses Lärmwellenanteile bis zur Unwirksamkeit reduziert und meteorologisch relevante Rossby-Wellen hinreichend gut konserviert werden. Die Praktizierbarkeit der Lärmfiltertheorie wird an einem (barotropen) 1-Schichtenprognosemodell rechnerisch realisiert und veranschaulicht. Die Kernprobleme der Initialisierung und der Lärmfilterung (Zeitschritt) werden dabei separat diskutiert.

Notes: Abstract Atmospheric mercury concentrations were measured during a nautical expedition on the Atlantic Ocean between Hamburg (54°N, 10°E) and Santo Domingo (20°N, 67°W). In addition, samples were taken during flights on a commerical aircraft in the upper and middle troposphere between 60°N and 55°S, mostly over the Pacific Ocean. The data obtained in the lower troposphere over the Northern Atlantic show considerable variation in the Hg concentrations, with values ranging between 1 and 11 ng/m3; the average concentration was found to be 2.8 ng/m3. The upper tropospheric data show an interhemispheric difference with average values of 1.45 ng/m3 and 1.08 ng/m3 in the Northern and Southern Hemisphere, respectively. This suggests that mercury production occurs predominantly over the continents both by natural and anthropogenic processes. The mercury content in aerosols was found to be ≤0.3 ng/m3, or one-tenth of the atmospheric concentration. The data indicate a mean residence time of mercury in the atmosphere of a few months to one year.

Notes: Abstract Compressional and shear-wave velocities (V p andV s ) were measured during the generalized triaxial deformation (i.e.σ 1≠σ 2=2σ 3) of pyrophyllite. Observed velocity changes could be ascribed to crack development during dilatancy. Velocity changes were very localized with respect to the ultimate failure plane. The orientation and development of the failure plane was continuously observed with laser holography. Velocity reverals, i.e. changes from a decreasing trend to an increasing trend, were documented in a wet sample in bothV p andV s . These changes in bothV p andV p are inconsistent with dialatancy-diffusion models. The reversals were interpreted as a reflection of local stress reorientation caused by a slowly propagating fault.

Notes: Abstract Meteorological rocket soundings, launched between 1968–74 at six locations representative of low, middle, and high latitudes in the northern hemisphere, are employed to determine the vertical, meridional and off-diagonal components of the eddy diffusivity in the northern hemispheric statosphere and lower mesosphere. It is shown that the distribution of the vertical and meridional components of the eddy diffusivity are similar in the northern hemisphere, although the magnitude of the former is 107 smaller than that of the latter; the magnitude of the off-diagonal eddy diffusivity is about 103 smaller than that of the meridional eddy diffusivity. In the troposphere, a maximum eddy diffusivity occurs in the mid-latitude at about 7 km above the mean sea level for both the summer and winter seasons. In the stratosphere, a maximum eddy diffusivity occurs in the mid-latitude at about 33 km in the winter, but no maximum in the summer.

Notes: Abstract The results of numerical models or of new observational programs are checked by comparing them with past observations. Also, it is desirable that the eddy diffusion coefficients used in two-dimensional models be derived from the same data set as the circulation statistics which the model outputs are checked against, so that all results refer to the same atmospheric conditions. For the first time, the three components of the eddy diffusion matrix, from 30–60 km, 80°N–10°S are computed, together with the means, variances and covariances of the wind and temperature through the same region using the same data set for 1960–76 and the same handling and analysis methods for all variables. Horizontal diffusivities,K yy , are obtained from the variance and integral time scale of the meridional wind speed. The present values are generally smaller than past estimates, presumably because temporal variations longer than a month have been removed in this work. Estimates ofK yz are based on the tentative assumption that the diffusivity is proportional to the slope of isentropic surfaces, and estimates ofK zz are based on the assumption that small-scale gravity waves are primarily responsible for vertical mixing.

Notes: Abstract Computations of concentrations of minor stratospheric gases using a two-dimensional model of the stratosphere are reported. The model includes Rayleigh scattering. This results in an increase in the photodissociation rate computation time by a factor of 1.5. The effect of ground albedo is assessed by comparing our results with a calculation of photolysis rates for a constant albedo with latitude. Comparison of results with a reference model including only molecular absorption are also made. The largest differences (≲50%) occur in NO and OH. An approximate expression for including the effects of Rayleigh scattering and surface reflectance in multi-dimensional models is suggested.

Notes: Abstract It is shown how to retrieve the atmospheric ozone profile by means of ground based microwave measurements of the radiative intensity. Chahine's iteration method is used. The method is tested by a numerical experiment. The retrieval rms about the mean error is approximately 0.4 ppm. The required measurement accuracy for the brightness temperatures is ±0.01 K.

Notes: Abstract Values for mean precipitable water are computed for four seasons of the year and for different regions of the Southern Hemisphere. Relationships between surface dew-point temperature and precipitable water were studied for these regions. A harmonic analysis of our data on precipitable water is attempted. Out results are presented and discussed.

Notes: Abstract The paper defines the intertropical convergence zone. (ITCZ) in the Indian monsoon region during the northern summer, identifies it with the northern boundary of the advancing monsoon and suggests that its seasonal movement can serve as an indicator of onset, advance and withdrawal of the monsoon. Evidence suggesting the movement of the ITCZ which is associated with the equatorial trough of low pressure is indirectly furnished by an analysis of the isallobaric or height-tendency field which reveals a distinct gradient towards the north/south during period of advance/withdrawal of the monsoon. A comparative study of the dates of onset of monsoon during two successive years appears to suggest that some of the problems encountered in using rainfall as the sole criterion for determining the onset and advance of the monsoon may be over-come by using the ITCZ concept as proposed in the present paper. Attention is drawn to the effects of synoptic-scale disturbances on the normal dates of onset, advance and withdrawal of the monsoon.

Notes: Abstract A theoretical model is presented which allows computing the efficiency with which aerosol particles of 0.001 ≤r≤1 μm are collected by columnar ice crystals in air of various relative humidities, temperatures, and pressures. Particle capture due to Brownian diffusion, thermo- and diffusiophoresis is considered. It is shown that phoretic effects importantly determine the particle capture process of 0.01≤r≤1 μm. The various pressure-temperature levels studied are found to affect the collection efficiency only ifr〉0.1 μm. Comparison shows that water drops generally are better aerosol particle scavengers than columnar ice crystals.

Notes: Abstract A theoretical model is presented which allows computing the efficiency with which aerosol particles of radius 0.1≤r≤10 μm are collected by simple ice crystal plates of radius 50≤a c ≤640 μm in air of various relative humidities, temperatures and pressures. Particle capture due to thermophoresis, diffusiophoresis and inertial impaction are considered. It is shown that the capture efficiency of an ice crystal in considerably affected by phoretic effects in the range 0.1≤r≤1 μm. For aerosol particles ofr〉1 μm the efficiency is strongly controlled by the flow field around the crystal and the density of the aerosol material. Trajectory analysis also predicts that aerosol particles are preferentially captured by the ice crystal rim. Our theoretica results are found to agree satisfactorily with the laboratory studies presently available. Comparison shows that for the same pressure, temperature and relative humidity of the ambient air ice crystal plates are better aerosol particle scavengers than water drops.

Notes: Abstract The paper deals with the atmospheric gaseous nitrogen-compounds under special consideration of the ocean being a source for NH3. The distribution of NH3 and NH4 + in the ocean is discussed. Additionally a survey of measured marine pH-values is given. While in temperate latitudes the source-strength of the ocean seems to be low, no such statement can be made at present for tropical latitudes owing to lack of measurements.

Notes: Abstract A Fourier transformation of the magnetic field from a magnetized sphere allows a particularly simple interpretation of the parameters of the sphere. The depth to the centre and total magnetic moments of the sphere are related to the intercept and slope of the power spectrum. The horizontal centre and direction of magnetization are related to slope and intercept of the phase spectra in two perpendicular, horizontal directions. Examples with artificial data contaminated by various noise components are presented.

Notes: Abstract Ion exchange and flameless atomic absorption spectrophotometry methods were used to measure the concentrations of sodium, manganese, iron and silver in snow accumulating at several sites on the Antarctic continent. The results show that the ratio of Mn/Fe is consistently close to the crustal value at all sites. The silver concentrations observed suggest a different origin, probably oceanic. When referenced to sodium, the degrees of enrichment of silver, manganese and iron increase by factors of 8, 2 and 2 respectively over a distance of 500 km from the ocean, after changes in sodium are accounted for. Investigation of the heavy metal content of fresh falling precipitation occorring on the Ross Ice Shelf, has shown that more enhanced enrichments of silver, manganese and iron occur in this fresh precipitation by factors up to 100, than in samples of snow and firn collected from shallow (up to 2 meters depth) pits at the same locations. Because the occurrences of these precipitation types vary temporally and geographically, it seems apparent that the shear stress conditions in the near surface boundary layer need to be considered in studies of snow and ice chemistry, particularly in polar regions where the chemical composition of permanent snow and ice fields are often investigated for evidence of climatic change, of glaciological behavior and of origins of chemical constituents.

Notes: Abstract Rayleigh's principle and the concept of the local wave number have been utilised for the approximate determination of the dispersion of Love waves propagating in a laterally heterogeneous layer lying over a homogeneous half-space. The shear wave velocity and the rigidity in the surface layer have been assumed to decrease with the increase of the lateral distance from the origin. The range of validity of the dispersion equation obtained by this method has been examined critically. It was found that: (a) for existence of Love waves the minimum value of shear wave velocity in the layer must be less than that in the matter below, and (b) the phase velocity of Love waves decreases with the increase of the lateral distance from the origin.

Notes: Abstract TheP-arrival times of local and regional earthquakes that are outside of a small network of seismometers can be used to interpret crustal parameters beneath the network by employing the time-term technique. Even when the estimate of the refractor velocity is poorly determined, useful estimates of the station time-terms can be made. The method is applied to a 20 km diameter network of eight seismic stations which was operated near Castaic, California, during the winter of 1972–73. The stations were located in sedimentary basins. Beneath the network, the sedimentary rocks of the basins are known to range from 1 to more than 4 km in thickness. Relative time-terms are estimated fromP-waves assumed to be propagated by a refractor in the mid-crust, and again fromP-waves propagated by a refractor in the upper basement. For the range of velocities reported by others, the two sets of time-terms are very similar. They suggest that both refractors dip to the southwest, and the geology also indicates that the basement dips in this direction. In addition, theP-wave velocity estimated for the refractor of mid-crustal depths, roughly 6.7 km/sec, agrees with values reported by others. Thus, even in this region of complicated geologic structure, the method appears to give realistic results.

Notes: Abstract It is shown, through numerical experiments, that the effect of ignoring ellipticity and rotation of the earth when inverting free oscillation data in moment tensor studies, is to introduce spurious spectral components in the solution. For numerical simulation of the data conditions of the 1970 deep Colombian event the spurious part has isotropic and deviatoric components, besides a distortion in the phase spectra which may lead to artificial precursive source in the solution. The magnitude of the artificial isotropic component is of the order of 10% of the real source moment tensor, depending on the data set used in the inversion. Measuring the excitation of each mode at each station using the technique of integrating over the spectral peaks does not cancel completely the effect of multiplet splitting, in particular that splitting due to rotation of the earth. The effect of lateral heterogeneities was simulated by introducing arbitrary splitting parameters which produced scattering in the eigenperiods compatible with those observed. For that splitting the inversion rendered additional isotropic components. We conclude that the observed implosive precursor the the 1970 Colombian event could have been artificially introduced by ignoring rotation, ellipticity and lateral heterogeneities of the earth. A procedure to invert free oscillation data for an elliptical rotating earth is proposed. It could be applied to a laterally inhomogeneous earth if the excitation for that model could be computed. Its application to real data for the deep Colombian event indicates that we will need to improve our knowledge on the effect of rotation, ellipticity, lateral heterogeneities and anelasticity on free oscillation and their excitation in order to solve accurately for the six components of the moment tensor independently.

Notes: Abstract The precision of measurement of surface-wave phase velocities at very long periods has reached a point where the exact, rather than asymptotic, form of the spherical harmonics must be considered in order to compute theoretical phase velocities or phase delays. The zeroth-order (i.e. constant) polar phase shift afterBrune et al. (1961) applies only between stations antipodal to each other. Everywhere else a correction for incomplete polar phase shift must be applied even if the waves do not cross a pole between the stations. The correction can exceed one percent of the total phase delay and thus be of the same order as the expected regional anomalies. It depends on the epicentral distance on the signal period and on the focal mechanism; the latter dependence can make the practical application cumbersome. We derive first-order asymptotic formulae for the correction of local phase velocities and total phase travel times of Rayleigh waves.

Notes: Abstract Long-period recordings of dispersive Rayleigh waves along numerous station lines, or ‘profiles’, in Europe have for the first time permitted a uniform inversion of these observations based on a new method of phase velocity regionalization. Regional dispersion relations obtained by this method have then been subjected to a complete inversion procedure commonly known as the ‘hedgehog’ method. The results are presented in a map outlining the thickness of the lower lithosphere (‘lid’) and the shear (S) velocities in both the ‘lid’ and the asthenosphere ‘channel’. A comparison of these results with the minimum compressional (P) wave velocities in the asthenosphere and their corresponding depths provides an estimate of theV p /V s ratio for the asthenosphere in the European area.

Notes: Summary To derive the structure of the Lower Mantle, observations of P and S waves at epicentral distances beyond 90 degrees have been used. The arrival times and amplitude decay with distance proved to be a source of information to derive the structure near the core-mantle interface. These observations were compared with results of theoretical calculations based on full wave theory [1, 2, 5, 6]. Another important theoretical method is the reflectivity method [4]. Differences between the two methods have a direct bearing on the interpretation of the observations and therefore need to be investigated. In the two methods the wave propagation involved in diffraction is simulated in different ways. In this paper the importance of approximations involved in each of the methods will be discussed. For this purpose the calculation of the frequency-dependent decay with distance of diffracted SH waves has been chosen. The approximations are considered to be important both in P and SH diffraction. The advantage of studying SH waves is the simpler and more straightforward formulation.

Notes: Summary The SH body-wave spectrum of a deep earthquake, which occurred at the foot of the Kamchatka peninsula and was recorded in the Solomon Islands, presents a regular modulation. The distribution of minima in the amplitude spectrum, corresponding to jumps in the phase spectrum, conforms with that expected from the interference between direct and surface reflected waves. The strong dependence of the modulation on the focal depth, emerging from theoretical SH body wave spectra obtained with the contribution of the first 21 higher Love-wave modes, was used to investigate the focal depth of the event here considered. The value estimated, 140 km, agrees with an earlier focal depth determination by travel time data.

Notes: Abstract Shallow strike slip earthquakes on vertical faults are modelled as two-dimensional antiplane strain ruptures in a uniformly prestressed homogeneous halfspace. Behind the rupture front, which is specified, the stress drops to a lower value. The elastodynamic boundary value problem is solved with a finite difference method. Several cases are studied, which include symmetric and one-directional rupture propagation, surface faulting, multiple events, variable rupture velocity, sticking and rebreaking of the fault plane. The time function of displacement, velocity and acceleration are interpreted as signals generated by events in the focus, namely starting, stopping and breaking through the surface of the rupture. The model explains peak velocity and peak acceleration in the near field of M≈5.5–6 earthquakes; which are typically about 0.2 m/s and 5 m/s2 at 10 km epicentral distance, if the rupture velocity is close to the shear wave velocity. Sticking of the fault does not alter the accelerograms significantly, but it increases the seismic moment in simple events and decreases it in multiple events.

Notes: Abstract The paper discusses basic ideas and principles underlying methods, which have proved useful in the interpretation of diffraction and scattering phenomena by a smooth or slightly rough solid-liquid interface. Generally, the wave interaction may be formulated as an excitation problem; it involves (1) finding an equivalent dislocation or source distribution on the interface, and (2) evaluating the excited wave field. These steps are taken through perturbation theory and/or adopting the appropriate generalization of ray theory. In this context an explicit form of Green's function is also given. The methods have been applied to the core-mantle boundary, with a view toward the interpretation of recent data: (a) diffracted P and S waves around the core (in particular, their attenuation); (b) scattered short-period core phases (in particular, precursors to PKP and PKKP). Other types of wave interaction, and implications for models of the core-mantle boundary structure, are briefly mentioned.

Notes: Abstract The derivation of P and S velocities at the core-mantle boundary (CMB) from long-period diffracted waves by the use of the simple ray-theoretical formulav CMB=r c /p (v CMB=velocity at the CMB;r c =core radius;p=ray parameter) yields apparent velocity values which differ from the true velocities. Using a dominant period of about 20 sec for calculating theoretical seismograms, we found a linear relation between the apparent velocity and the average velocity in a transition zone at the base of the mantle with fixed velocity on top. The ray parameters determined from long-period earthquake data are found to be 4.540±0.035 and 8.427±0.072 sec/deg for Pdiff and Sdiff, respectively. These values yield apparent velocities of 13.378±0.103 for P and 7.207±0.062 km/sec for S waves. By means of the theoretical relation between apparent and average velocity and under the assumption of linear variation of velocity with depth, one can invert the apparent velocities into true CMB velocities of 13.736±0.170 and 7.320±0.124 km/sec. These results imply positive velocity gradients at the base of the mantle and hence no significant departures from adiabaticity and homogeneity.

Notes: Abstract Data from a reversed seismic crustal profile crossing the Caledonides of southern Norway suggest a continuously increasing P-wave velocity followed by a low-velocity zone extending from a depth of about 14 km downwards. Interpretation of observed travel time and amplitude characteristics leads to a thickness of 4 km and velocity of 6.0 km/s for this layer, the velocity above and below it being about 6.6 km/s. The role of such a velocity inversion is discussed in the tectonic framework of the Caledonian orogeny and other relevant geophysical information, and it is suggested that the low-velocity zone materializes deep-seated sediments under Precambrian crystalline rocks. The structure of the lower crust is more tentatively established, but still in reasonable agreement with other seismic investigations in the general profiling area.

Notes: Abstract A scheme of a system of physical and chemical processes controlling the production, transport and destruction of ozone and its gaseous catalysts, as well as other related gases in the low and high stratosphere is presented. An account is made of temperature variations of the stratospheric layer resulting from changes in ozone content; also included is the effect of temperature variations on photochemical reaction rates and ozone and other gases transport between atmospheric layers. Parameters describing major relations of the system are inferred from the analysis of ozone and trace gas data and from the results of model calculations of interdependence between variations in temperature and ozone content of the layer. An analysis of minor fluctuations of the linearized system shows that photochemical processes are responsible for its aperiodic stability and that gas transport between atmospheric layers destabilizes the system.

Notes: Abstract The effect of the time change of static stability and wind shear on a two-level quasigeostrophic baroclinic wave is considered. First, by keeping the wind shear as a constant the effect of the increase of static stability is that the amplitude of the temperature wave reaches a maximum first while that of the stream field is still amplifying and, as that of temperature wave reaches a minimum, that of the stream field becomes a maximum, and both are in phase. Next, by keeping the static stability as a constant, a life cycle of disturbance associated with the time change of wind shear is obtained. In this case the maximum amplitude of the wave appears at about 6 days and the life cycle is about 11 days for reasonable values of the model parameters. Finally, both effects are considered. The results show that as the wind shear decreases, the static stability increases, and the percentage change of wind shear is larger than that of static stability. This paper is not an entirely convincing analysis of the finite amplitude dynamics of an unstable wave in the two-level model, but rather a pedagogically useful approximate theory in which the retention of some terms rather than others is justified in view of the plausibility of the results.

Notes: Abstract This paper examines the effects of the mixing of dry air into a cloud top from the point of view of the droplet spectra. It is shown theoretically that the resulting cycling of the air up and down in the cloud, as seems to be the essential mechanism by which cumuli have been diluted to their observed liquid water mixing ratio, can double the largest drop radius and generate cloud parcels containing drops of all sizes up to this maximum. These changes in the droplet distribution with size occur by a process which is not greatly influenced by the cloud condensation nuclei or the details of droplet growth since ‘maritime’ like spectra can develop in ‘continental’ type cumuli. It shows that large numbers of cloud condensation nuclei should not have much effect in inhibiting the rainforming process by reducing coalescence growth. On the contrary, the controlling parameters which determine precipitation efficiency and times seem to be those which control the mixing.

Notes: Summary The hemocytes oftu-Sz ts melanotic tumor larvae ofDrosophila melanogaster encapsulate heterospecific and surface-modified homospecific tissue implants, but do not encapsulate unmodified homospecific implants (R. Rizki and Rizki 1980). In the present study we usedtu-Sz ts hosts to assay changes in larval fat body surfaces during development. Donor fat bodies from various ages of larvae were accepted (remained unencapsulated) intu-Sz ts hosts whereas fat bodies from donors with everted spiracles and all subsequent stages of development that were tested were rejected (encapsulated). Since the demarcation between acceptance and rejection by thetu-Sz ts blood cells did not coincide with the gross morphological changes that appear in the fat body during metamorphosis (dissolution of the basement membrane and dispersal of the freed fat body cells at pupation), we compared acceptable and nonacceptable fat body surfaces by three other methods. Fat body surface ultrastructure was examined, fat bodies were treated with fluorescein isothiocyanate-conjugated lectins, and fat body surfaces were reacted with a monoclonal antibody specific for basement membrane. These approaches did not uncover fat body surface changes associated with eversion of the anterior spiracles, suggesting that recognition of tissue surface heterogeneities by the insect hemocytes exceeds the resolving power of the other three methods. However, the monoclonal antibody fails to bind to the basement membrane ofD. virilis larvae, whose fat body is always rejected intu-Sz ts hosts. This supports our suggestion that the molecular architecture of the basement membrane may be important in eliciting the encapsulation response.

Notes: Summary Fertilization in the freshwater hydrozoanHydra carnea has been examined by light, scanning and transmission electron microscopy. Sperm penetrate the jelly coat which covers the entire egg surface only at the site of the emission of the polar bodies. The egg surface exhibits a small depression, the so called fertilization pit at this site. Sperm-egg fusion takes place only at the bottom of the fertilization pit.Hydra sperm lack a structurally distinct acrosome and in most of the observed cases, fusion was initiated by contact between the membrane of the lateral part of the sperm head and the egg surfacce. Neither microvilli nor a fertilization cone are formed at the site of gamete fusion. The process of membrane fusion takes only a few seconds and within 1 to 2 min sperm head and midpiece are incorporated in the egg. Electron dense material is released by the egg upon insemination but cortical granule exocytosis does not occur and a fertilization envelope is not formed. The possible polyspermy-preventing mechanisms in hydrozoans are discussed. Hydra eggs can be cut into halves whereupon the egg membranes reseal at the cut edges and the fragments assume a spherical shape. Fragments containing the female pronucleus can be inseminated and exhibit normal cleavage and development. The observation that in such isolated parts the jelly coat will not fuse along the cut edges was used to determine its role in site-specific gamete fusion. These experiments indicate that site-specificity of gamete fusion can be attributed to special membrane properties at the fertilization pit.

Notes: Summary In the polysteelid ascidian,Polyandrocarpa misakiensis, buds can arise at any antero-posterior positional level around the basal margin of a functional zooid. In this study, each bud was cut into anterior and posterior halves along its proximo-distal axis. When an anterior half was combined with a posterior half from a higher (more posterior) level, the future zooid developed the same anteroposterior polarity as a normal bud. When the same operation was performed with a posterior half from a lower (more anterior) level, the antero-posterior polarity was inverted, resulting in a reversed body asymmetry (situs inversus viscerum). Bud polarity depended not on the size or the growth stage of the fragmented buds, but on the difference in parental positional levels from which respective buds to be fused had originated. Surgically constructed doublehalf buds developed a single polarity instead of a pattern reduplication. Insertion experiments with bud pieces showed that the gap between the positional levels was recognized at the proximal region of operated buds. The results of this study are inconsistent with the predictions of the polar coordinate model for pattern formation. It is concluded that a parent zooid possesses antero-posterior position-specific potential for determining bud polarity.

Notes: Summary Bufo arenarum eggs at late blastula and gastrula were treated with tunicamycin, an inhibitor of glycoprotein glycosylation, to investigate its effects on morphogenesis and neural induction. Because of the low permeability of the amphibian egg to a number of drugs, the blastocoel was opened surgically prior to treatment. Almost all of the eggs treated with the antimetabolite, at a concentration of 10 μg/ml, from late blastula stage for 24h exhibited exogastrulation. The effect is dose- and stage-dependent as shown by the lower proportion of exogastrulae obtained when eggs are treated at a lower concentration (5 μg/ml) or after the onset of gastrulation. Treatment with the antimetabolite did not interfere with neural induction, as partial exogastrulae developed a small neural tube. The most striking biochemical effect was an enhanced uptake of glucose, mannose and leucine. The incorporation of mannose into acid-insoluble material was severely inhibited by tunicamycin, with a concomitant decrease of leucine incorporation into the acid-soluble pool.

Notes: Summary Females ofDrosophila melanogaster, crossed with males ofDrosophila mauritiana, produce only female offspring. The male hybrid larvae grow very slowly, fail to pupate and die after prolonged larval life. Imaginal discs from these male hybrids transplanted into Drosophila melanogaster larvae can give rise to adult structures with normal patterns. Differentiation of hybrid imaginal disc tissue is improved by short term culture in non-hybrid larvae prior to metamorphosis, suggesting that the hybrid larval haemolymph is inadequate to sustain normal imaginal disc growth. This may represent the physiological basis of the reproductive isolating mechanism separating the twoDrosophila species

Notes: Summary During previtellogenesis, the oocytes of the telotrophic meroistic ovary ofDysdercus are provided with ribosomes and ribonucleoprotein (RNP) particles by the nurse cells. At the end of vitellogenesis, the oocyte itself becomes active as shown by autoradiography. The proteins synthesized by the oocyte are stored in cytoplasmic postribosomal particles which are preformed by the tropharium. The proteins of these particles were separated by SDS polyacrylamide gels and their endogenous oocyte proteins revealed by fluorography. The synthesis, transport, and storage of the postribosomal particles are demonstrated by indirect immunofluorescence. The young oocytes of previtellogenic follicles show a diffuse distribution of these particles. In late vitellogenesis, fluorescence becomes more and more concentrated in spots throughout a distinct region in the middle part of the oocyte. Thus, in freshly laid eggs, the periplasm is free of fluorescence. During migration of the cleavage nuclei the postribosomal particles were shifted into the cortex. Fluorescence is then most intense in the periplasmic region. During blastoderm formation, however, fluorescence decreases.

Notes: Summary The central nervous system (CNS) ofDrosophila develops from precursor cells called neuroblasts. Neuroblasts segregate in early embryogenesis from an apparantly undifferentiated ectoderm and move into the embryo, whereas most of the remaining ectodermal cells continue development as epidermal cell precursors. Segregation of neuroblasts occurs within a region called the neurogenic field. We are interested in understanding how the genome ofDrosophila controls the parcelling of the ectoderm into epidermal and neural territories. We describe here mutations belonging to seven complementation groups which effect an abnormal neurogenesis. The phenotypes produced by these mutations are similar. Essential features of these phenotypes are a conspicuous hypertrophy of the CNS accompanied by epidermal defects; the remaining organs and tissues of the mutants are apparently unaffected. The study of mutant phenotype development strongly suggests this phenotype to be due to misrouting into the neural pathway of development of ectodermal cells which in the wildtype would have given rise to epidermal cells, i.e. to an initial enlargement of the neurogenic region at the expense of the epidermogenic region. These observations indicate that the seven genetic loci revealed by the mutations described in this study contribute to control the neurogenic field. The present results suggest that in wildtype development neurogenic genes are supressed within all derivatives of the mesoderm and endoderm and some derivatives of the ectoderm, and conditionally expressed in the remaining ectoderm. The organisation of the neurogenic field in the wildtype is discussed.

Notes: Summary In equally cleaving gastropods, the interactions between micromeres and macromeres involved in the determination of the mesentoblast mother cell (3D) were studied by changing the spatial arrangement of the micromeres by deleting one first quartet micromere or its progeny. A fixed relation was found between the deletion site and the place of origin of 3D; therefore, a fixed relation also exists in the configuration of the three remaining first quartet micromeres and the 3D. These results argue against the possibility that the animal-vegetal interactions do not choose between macromeres, but only permit the expression of a choice already made in another way and at another moment. The results are consistent with a stochastic model in which accidental differences between the macromeres in the number or extent of contacts with first quartet micromeres play a discriminating role during micromere — macromere interactions, that lead to 3D determination. Embryos which lack a given first quartet micromere show a total absence of regulation in the larval head pattern; only the cephalic plates show regulative abilities while forming the adult head structures. Therefore, in later stages new activating and restraining factors seem to play a part in the head development.

Notes: Summary The appearance and spatial distrubution of ultrastructural markers ofDictyostelium discoideum differentiation were quantitatively analysed. Our results combined with data from the literature on the functions of cells at various stages of development lead to the following conclusions. When food is no longer available all amoebae initially develop an autophagic apparatus in order to sustain metabolism. After slugs have been formed, autophagy is suppressed in the prespore cells. During aggregation a number of cells gradually form prespore characteristics. These cells arise at random but later they become located in the basal part of the tip-forming aggregate. From the early slug stage onwards, cells of the posterior two third region gradually enter into the prespore pathway. During prolonged slug migration the optimal acquirement of prespore characteristics is blocked. Cells of the anterior region show no active differentiation but they maintain the morphology and most of the functions of aggregating cells. At the rear-guard of the slug and later on in the basal region of the maturing fruiting body, a second anteriorlike region appears. Actual stalk cell differentiation takes place only at the apex and at the base of the developing fruiting body.

Notes: Summary When exposed to a “winter” light-temperature cycle, reproduction in the polychaeteTyposyllis prolifera is inhibited by a hormone from the proventriculus. When exposed to a “summer” cycle, worms show periodic reproduction following an endogenous lunar rhythmictiy. The endocrine system mediating the stimulation of reproduction by summer conditions, was studied by extirpation and transplantation of prostomium and/or proventriculus. A previously unknown prostomial hormone was found to play a major role in this process. Summer conditions induce a temporary endocrine activity in the prostomium. This homone probably does not act directly on peripheral targets, but stimulates reproduction by inactivating the proventricular endocrine system. The experimental evidence of a hierarchic neuroendocrine system governing reproductive activity in syllid polychaetes is discussed.

Notes: Summary Correlative histological, histochemical and biochemical investigations on laminar compartments from four different areas of fetal human neopallium at 28 weeks of gestation revealed discrete distribution of gangliosides in the cerebral wall. Highest level of total ganglioside concentration was found in the layers of cortical anlage (cortical plate and “subplate layer”) which are concomittantly characterized by highest activity of acetylcholinesterase (AChE) and which are known to be involved in intensive synaptogenesis at this stage of cortical development. In three of four areas the proportion of GD1a — ganglioside from total ganglioside amount tended to increase and that of GT1b to decrease from inside (ventricle) to outside (cortical anlage) throughout the cerebral wall.

Notes: Summary Antisera against larval and adultXenopus hemoglobins as well as adult human hemoglobin showed no cross-reaction when tested by immunodiffusion against each heterologous antigen. In this test hemoglobin of a single animal produced two precipitation lines for larvae, but only one for adult stages. Immunoelectrophoresis also revealed more complex precipitation patterns for larval than for adult hemoglobins. Hemoglobin of the isogenic hybrid cloneXenopus laevis/X. gilli also reacted with antisera against normalXenopus hemoglobin. Quantitation of hemoglobins, analyzed by radial immunodiffusion showed fewer than 1% of adult hemoglobin in red cells of larvae, but 30% at completion of metamorphosis. Two weeks later adult hemoglobin attained over 90%, and in red cells of adultXenopus an average of 1% larval hemoglobin were detected. The relatively short transition period suggests that the loss of larval hemoglobin may be due to the elimination of larval red cells, and that the increase in adult hemoglobin may be indicative of a new cell line.

Notes: Summary The embryo ofSabellaria cementarium (Polychaeta) forms a polar lobe at each of the first two cleavage divisions which becomes absorbed into one of the blastomeres at the end of the division. Lobe removal experiments show that the polar lobe preceding first cleavage is necessary for the development of the apical tuft and the posttrochal region of the trochophore larva. The polar lobe preceding second cleavage is smaller than the first polar lobe and is necessary only for post-trochal region development. In blastomere isolation experiments, isolates containing the C but not the D blastomere form apical tufts. Isolates containing the D but not the C blastomere do not form apical tufts. When the polar lobe preceding second cleavage is removed and the C and D blastomeres are separated and raised in isolation, each can form an apical tuft. When the second cleavage is equalized with sodium dodecyl sulfate (SDS) such that both the C and the D blastomeres receive second polar lobe material, no apical tuft is formed. These results suggest that apical tuft determinants are distributed to both the C and D blastomeres at second cleavage but that the second polar lobe contains an inhibitor for apical tuft formation which is shunted to the D blastomere after the completion of second cleavage.

Notes: Summary Early amphibian gastrula ectoderm (Xenopus laevis) has been treated with vegetalizing factor using the sandwich technique, varying the period of incubation and the inducer concentration. The pattern of induced tissues depends on three factors: the inducer concentration, the size of inducer pellet and the time of exposure of ectodermal target cells to inducer. Short treatment with inducer will result in the formation of blood cells and heart structures. An increase in incubation time or inducer concentration, or both, will cause the formation of increasing amounts of such dorsal mesodermal structures as pronephros, somites and notochord. Neural structures can only be observed in explants with considerable amounts of somites and notochord. Ectoderm treated with high concentrations of vegetalizing factor for the whole period of competence will differentiate into endoderm. Furthermore, the results show thatX. laevis ectoderm does not show any autoneuralizing tendency under our experimental conditions. It therefore seems to be a suitable tool for the study of primary embryonic induction.

Notes: Summary The cleavage of fertilized mouse eggs was prevented during cytochalasin B incubation and consequently these eggs became tetraploid the following day during in vitro culture. When the eggs were cultured further in normal medium, they cleaved and gave rise to tetraploid blastocysts. Protein synthesis was analysed in these embryos at different developmental stages using two-dimensional polyacrylamide gel electrophoresis. The protein synthesis pattern of one-cell tetraploid eggs was intermediate between those of normal one- and two-cell embryos. Tetraploid two-cell embryos expressed protein sets equivalent to those of untreated four-cell embryos, and tetraploid four-cell embryos synthesized proteins similar to those of four- to eight-cell controls. At subsequent pre-implantation stages the asynchrony was no longer detectable. When fertilized eggs were cultured continuously in the presence of cytochalasin B, they became tetraploid, octoploid and more and more polyploid without cleavage occurring. The protein synthesis patterns expressed by these one-cell polyploid eggs did not resemble that of normal fertilized eggs, but were similar to those of cleaving control embryos and blastocysts of equivalent age and nuclear division. These results strongly suggest that in early mouse embryos stage-specific translation is temporally correlated with chromosome replication (karyokinesis) and independent of cell division (cytokinesis) or cell interaction.

Notes: Summary In vivo labelling of RNA polymerases I and II with S35-methionine shows that ecdysterone causes a de novo synthesis of both enzymes in nuclei of fat body cells inCalliphora 3rd instar larvae. Binding experiments with H3-α-amanitin demonstrate that the concentration of RNA polymerase II molecules increases two- to threefold within 3 h after ecdysterone treatment. The enhanced polymerase concentration coincides with an enhanced enzymatic activity and an increase in RNA synthesis in response to ecdysteroids.

Notes: Summary Undifferentiated metanephric mesenchymes, when grown in transfilter contact with an inductor tissue, differentiate into epithelial kidney tubules. The segregation of these tubules into the different segments of the nephron was studied. In explants grown in continuous transfilter contact with the inductor, immunohistological and histochemical markers specific for the glomerular epithelial, proximal tubule, and distal tubule cells appeared by 4 1/2 to 5 days, 4 days, and 5 days of culture, respectively. Electron microscopy confirmed segmentation of the tubules: Avascular glomeruli with glomerular basement membrane material, proximal tubules with brush border formation, and distal tubules were revealed in the explants after 5 days of culture. A short (18 h) transfilter induction pulse, followed by a prolonged subculture in the absence of the inductor, resulted sulted in the formation of only a small number of tubules in about half of the explants while the rest remained undifferentiated. These scarce tubules showed the markers specific for the proximal tubules only. The segregation of all three aspects of the nephron seems to be programmed during the transfilter culture, but apparently the time needed for the induction of the different segments varies.

Notes: Summary The total amount of ATP and UTP was measured in embryos ofDrosophila melanogaster andBruchidius obtectus at different development stages. The pool-sizes were measured by their ability to enhance poly(AU) synthesis in an in vitro test, using RNA polymerase ofE. coli, poly-d(AT), ATP, and3H-UTP. In embryos ofD. melanogaster, the amount of UTP decreased from 4.5 pmoles/ embryo during cleavage and early blastoderm to 2 pmoles at later stages. The ATP pool decreased from 14 pmoles/ embryo to 6 pmoles at the same developmental stages. In embryos ofB. obtectus, the UTP pool expanded from about 1 pmole/embryo during cleavage and early blastoderm to about 3 pmoles during gastrulation and organogenesis. Much more ATP was found inB. obtectus embryos: during fertilization 23 pmoles/embryo were found. At late syncytial blastoderm stages the amount of ATP rose to about 50 pmoles/embryo. At cellular blastoderm stages and during gastrulation only 26 pmoles/embryo of ATP were found. During organogenesis the ATP pool decreased to about 14 pmoles/embryo.

Notes: Summary Drosophila melanogaster chorion proteins are characterized on one-dimensional isoelectric focusing (IF) gels. The six major chorion components previously identified on SDS gels are shown to resolve into at least 11 components in our IF system. IF screening of 102 geographic strains ofDrosophila melanogaster revealed seven cases of variation in major chorion components. Two strains, Crimea and Falsterbo, which were monomorphic for a variant B1 protein and two strains, Skafto and Lausanne, which were monomorphic for a variant C1 protein, were chosen for further study. After IF developmental analysis of F1 hybrids had indicated that the sources of the variation resided in the structural genes for these proteins, each variant was crossed to a multiply marked and inverted strain (BLT) to determine the linkage group of the variant gene. To localize genes to more specific sites multiply marked 3rd (SKERO) or X-chromosomal (CB1) (X-PLE) mapping strains were used. In both Crimea and Falsterbo the gene for the B1 protein is located near map location 26 on the 3rd chromosome. In both Lausanne and Skafto the C1 gene is located on the X chromosome. Hence, for the first time, we have demonstrated genetically the non-linkage of two chorion genes, B1 and C1.

Notes: Summary Mirror-image doublets of the hypotrich ciliateParaurostyla weissei were induced by modifying culture conditions. Successive steps of doublet formation involve inhibiting the separation of daughter cells during cell division and the shifting of these to attain a parallel configuration. The posterior part of the adoral band of membranelles in the right component then turns to the left and fuses with the distal terminal of the membranellar band in the left component. In effect, part of the adoral band and some of the paroral membranelles become apposed upside down, and the paroral membranelles of the right component are located on the left side of the adoral membranelles. A new site of oral primordium formation is initiated at the junction of the two oral apparatuses, the ciliature of which is arranged in a mirror-image pattern. During further cortical reorganization, the whole body ciliature of the right component becomes organized as a mirror-image of the normal left component. Both components of the doublet show the same ultrastructure of body ciliature and lack the right marginal cirri; the symmetry-reversal half, however, possesses multiple rows of left marginal cirri. The individual adoral membranelles and paroral membranelles in the symmetry-reversal component are rotated anteroposteriorly. Some aspects of the patterning of cortical structures are discussed.

Notes: Summary The effects of nitrogen mustard (methylbis-chlorethylamine) on limb organogenesis were studied inPleurodeles waltlii at different stages of fore and hind limb development. The effects of four different doses of nitrogen mustard (1.25; 2.5; 5 and 10 μg/ml) on the limb bud mesoderm and epidermis were studied histologically. This analysis was carried out on cylindrical unchondrified hind limb buds treated at stage 45. The effects of these doses on all stages of fore and hind limb development were investigated. This included the effect on the establishment of the proximo-distal sequence (segment chondrification) and the antero-posterior sequence (pre-postaxial zeugopod, basipod chondrification and progressive pre-postaxial organization of fingers and toes. Correlations were established between the mesodermal necrosis observed in hind limb buds treated at stage 45 and the skeletal abnormalities occurring in fore and hind limbs after treatment at all stages of their development. Thus, it appears that the effects of nitrogen mustard on organogenesis demonstrates the existence of a state in the differentiation of the mesoderm that is not revealed by morphological studies.