Origin and production of phosphatases in the acid Lake Gårdsjön

The activity of acid phosphatases was followed for one year in Lake Gårdsjön as well as in the inlet and the outlet of the lake. A budget of the phosphatases was calculated, including an estimation of the production of phosphatases. The phosphatase activity was also measured in two basins upstream of L. Gårdsjön: the north basin and the south basin of L. Stora Hästevatten.The acid phosphatase activity was very high compared with reported alkaline phosphatase activities in other lakes. About 95% of the phosphatases in L. Gårdsjön was produced in the lake, and the production was highest in early summer.Small Chrysophyceae (< 10 µm) probably produced the majority of the acid phosphatases in the investigated lakes, and accordingly could be favoured in environments with low phosphorus supply due to their ability to produce large amounts of phosphatases.     

Differences in the breeding success of the Common CraneGrus grus between South and Central Sweden

Summary The population density and breeding success of the Common Crane were studied in Gästrikland, Central Sweden, and Småland, South Sweden. The densities were 1.5 and 1.7 pairs per 100 km² total area in the two regions, but the amount of fen area is larger in the latter region. A higher proportion of the pairs fledged young in Småland compared to Gästrikland. Also, brood sizes were higher in Småland. On average a breeding pair in Gästrikland fledged 0.47 young (n=38), but in Småland 1.00 young (n=37). I suggest that the difference is due to the population being nearer the carrying capacity of the habitat in Gästrikland compared to Småland.

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Zusammenfassung In zwei Gebieten Schwedens (Gästrikland in Mittelschweden, Småland in Südschweden) wurden Siedlungsdichte und Bruterfolg des Kranichs untersucht. Als Dichten ergaben sich 1,5 bzw. 1,7 Paare/100 km² in den beiden Regionen für die jeweils von der Art besiedelten Flächen. In Småland ist jedoch die Ausdehnung des potentiellen Bruthabitats wesentlich größer. In Småland brütet auch ein größerer Anteil der Paare erfolgreich als in Gästrikland; die Anzahl flügger Junge pro Paar betrugen in Gästrikland 0,47 (n=38), in Småland 1,00 (n=37). Diese Unterschiede in den Ergebnissen sind möglicherweise damit zu erklären, daß die Population in Gästrikland näher der durch den Lebensraum vorgegebenen Kapazitätsgrenzen liegt als in Småland, wo noch potentielle Brutgebiete nicht besiedelt sind.

     

Nutrient responses to the liming of lake Gårdsjön

The acidified lakes Lake Gårdsjön and Lake Stora Hästevatten the reference lake have been monitored since 1979 and 1980 respectively. The lakes are situated in SW Sweden; in an area severly affected by acid deposition. Lake Gårdsjön was limed in spring 1982. This paper analyses changes in nutrient concentrations upon liming of Lake Gårdsjön. The liming of Lake Gårdsjön was followed by a slight increase in ammonium, nitrate, and dissolved organic nitrogen concentrations. A drastic decrease occurred in particulate nitrogen and particulate carbon, whereas dissolved organic carbon increased. Total phosphorus and particulate phosphorus concentrations were similar to pre-limed conditions. The long-term decrease in phosphorus concentration, exhibited by the reference lake, was not identified in Lake Gårdsjön after liming, but total phosphorus concentration was still less than half compared to Lake Gårdsjön in the early 1970's. Additional measures such as phosphorus fertilization, should in certain cases be considered in addition to liming if the goal is to restore lakes to their pre-acidic conditions.     

Sedimentation of phosphorus in limnetic and estuarine environments in the River Öre system,northern Sweden

Sedimentation of phosphorus was studied during the spring flood in April and May 1991 in Lake Örträsket and the Öre Estuary, northern Sweden. Lake Örträsket has an area of 7.3 km² and a mean depth of 22 m and is located 100 km from the coast halfways along the course of the River Öre. The river ends in a semi-closed low salinity estuary with an area of ca. 50 km² and a mean depth of 16 m. Sedimentation of phosphorus, iron and organic carbon were measured with sediment traps in Lake Örträsket and in the Öre Estuary. Characterization of particulate phosphorus in river water, sediment trap material and sediments were performed by the sequential extraction procedure proposed by Hieltjes & Lijklema (1980). Apart from being an efficient trap for suspended particles including particulate phosphorus, Lake Örträsket was shown to serve as a source for particulate material during spring 1991. The Öre Estuary, on the other hand, constitutes an efficient trap for the total supply of river-borne phosphorus during the spring flood period. Phosphorus was shown to be closely related to iron in particulate material in both the lake and the estuary. Adsorption of phosphorus on settling inorganic particles seems to be an important process, which is particularly pronounced in the estuary.     

Deposition and soil leaching in stands of Norway spruce and European Beech: Results from the Höglwald research in comparison with other European case studies

Stands of Norway spruce (Picea abies K.) and European beech (Fagus sylvatica L.) were investigated at the Höglwald research area, Southern Germany from 1985–1988 and from 1994–1997 in order to determine the effects of tree species on deposition and soil solution fluxes. The results were compared to 15 European case studies representing different deposition levels and site conditions. At the Höglwald site, which is characterised by a high nitrogen and a moderate sulphur load, throughfall deposition of nitrogen and sulphur compounds was about two-fold higher in spruce stands compared to beech stands. The differences in elemental input were clearly reflected in soil solution chemistry with a higher leaching of nitrate and sulphate in the spruce stands. The turnover of sulphur and nitrogen compounds induced a strong soil internal production of protons especially in the spruce stands. These results are in accordance with the other European case studies. Throughfall deposition and soil leaching of nitrogen and sulphur compounds was generally higher for spruce stands compared to beech stands. The species-related differences were mainly caused by dry deposition and were relatively small in remote areas. The consequences for the forest ecosystem itself and for the hydrosphere are discussed.     

Wing polymorphism in Japanese and foreign strains of the brown planthopper, Nilaparvata lugens

Great variations in nymphal density and wing-form relationships occur in field populations of the brown planthopper, Nilaparvata lugens (Stål) (Homoptera: Delphacidae). When tested under uniform laboratory conditions, half of the female populations collected from 20 locations in Japan exhibited higher ratios of macropters with increasing nymphal density, but one quarter were macropterous over broad ranges of density, both types being classified as group III. Three predominantly brachypterous populations (group I) were found, even under crowded conditions and one intermediate (group II).The populations from South Asian countries, i.e. Philippines (one), Indonesia (two) and Malaysia (one) belonged to group I, but the three populations from the coastal areas of China belonged to group II. Those from Taiwan differed in responses to density; one was of group II type, and two of group III type.From these comparisons, immigration routes of N. lugens to Japan were estimated, and survival strategy of this migratory species is discussed.

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Zusammenfassung In Feldpopulationen von Nilaparvata lugens (Stål) (Homoptera: Delphacidae) gibt es grosse Variationen in der Larvendichte und in den Flügelform-Beziehungen. Unter einheitlichen Laboratoriumsbedingungen wurden diese Verhältnisse geprüft. Von 20 japanischen Herkünften zeigte die Hälfte der Weibchenpopulationen mit zunehmender Larvendichte einen höheren Macropterenanteil; ein Viertel was über einen grossen Dichtebereich macropter; beide Typen werden als Gruppe III bezeichnet. Drei Populationen wurden gefunden, die auch bei hoher Dichte vorwiegend brachypter waren (Gruppe I). Einer Zwischengruppe (II) gehörte eine einzige Population an.Die Populationen aus südasiatischen Ländern (1 aus den Philippinen, 2 aus Indonesien un 1 aus Malaysia) gehörten zu Gruppe I, die 3 Populationen aus den Küstenregionen von China jedoch zu Gruppe II. Die Populationen aus Taiwan unterschieden sich in der Reaktion auf die Dichte: 1 gehörte zu Gruppe II and 2 zu Gruppe III.Von diesen Daten werden Einwanderungswege von N. lugens nach Japan abgeleitet und die Überlebensstrategie dieser Wanderart diskutiert.

     

Spring migration of some anadromous freshwater fish species in the northern Bothnian Sea

Quantitative estimations of spring migrating fish have been made in the mouth part of the small coastal river Ängerån which flows into the northern Bothnian Sea (63°35N, 19°50E). In 1981 nearly 3 000 fish were counted ascending to the spawning grounds in the lower reaches of the Ängerån. These species, such as pike, perch, roach and ide, adapted to the oligohaline environment in the Bothnian Sea for most of the year, migrate to spawn in the coastal stream. The reason for these migrations can be interpreted to indicate that the Ängerån offers more favourable water temperature conditions at spawning time compared with the Bothnian Sea, which is ice-covered up to the beginning of May. The most important result of the investigation in the Ängerån is that these fish species, in the same way as the salmonids, return to theirhome-stream every year as adults.Andreasson & Petersson (1982) listed 69 species of fish in the oligohaline Gulf of Bothnia (Table 1) where salinity varies from 2 near the mouth of the River Torneäly to 6 in the vicinity of the Åland Islands (Fig. 1). The fish fauna comprises freshwater and marine species, fish migrating between brackish and freshwater rivers and streams, and recently introduced non-endogenous species.Andreasson & Petersson (1982) designated only five species as anadromous migrators, whereas our studies show that 11 species migrate from the sea to spawn in the Ängerån, a small river discharging into the northern Bothnian Sea (Fig. 2). Earlier reports on these migrations have been given by Berglund (1978) and Johnson (1978, 1982) and for another small stream in the area by Berg (1982).The present paper describes the annual spring migrations of pike, perch, roach and ide between the northern Bothnian Sea and the Ängerån, for the year 1981.     

Atmospheric deposition of sulphur, nitrogen and base cations in Scots pine stands of south-eastern Finland and the Karelian Isthmus, NW Russia in 1992

This paper presents initial results of a joint Finnish-Russian investigation (1991–1996) of air pollutant deposition in Scots pine (Pinus sylvestris Linné) stands of Karelian Isthmus (north-western Leningrad Region, Russia) and south-eastern Finland. Bulk precipitation and canopy throughfall analyses revealed relatively high sulphur and nitrogen loads in the Karelian Isthmus and in the southern part of south-eastern Finland. The deposition load decreased gradually northwards, the highest levels of S and N deposition in the vicinity of St. Petersburg being two to three times higher than the values considered to be background level in Finland. Besides the acidifying elements, a high calcium deposition was detected in the Karelian Isthmus and in the southern part of south-eastern Finland. The high load of calcium, which probably emanates from oil shale burning in NE Estonia, alleviates the acidifying effect of sulphur and nitrogen deposition.     

Drainage history and land use pattern of a Swedish river system — their importance for understanding nitrogen and phosphorus load

During the 19th and the first half of the 20th century, approximately 300 km² of lakes and wetlands, representing 29% of the River Kavlingean catchment in Southern Sweden, were drained to make land available for agriculture. Published accounts of nutrient loads from the catchment indicated that until the mid 20th century, factories and urban point sources were the major contributors of both nitrogen and phosphorus. By the middle of the 20th century, the construction of sewage treatment plants had effectively reduced phosphorus pollution. Concurrently, the land drained in the previous century underwent a more intense cultivation, with productivity being maintained by commercial fertilizers. Subsequently, net nutrient loads from agriculture continued to increase, reaching an annual load of 2652 tons total-nitrogen and 70 tons total-phosphorus for the River Kävlingeån. Whilst high nutrient leakage from agricultural watersheds may be a problem which is only recently recognized, it had its origins in nearly a hundred years of commonly accepted agricultural policy.To assess the importance of agriculture as the major source of nutrients to the River Kävlingeån system, three tributary catchment areas, differing in terms of their land use patterns (high, medium and low intensity of agricultural use), were studied and compared with literature figures. Results indicated that agricultural nutrient loss areal coefficients were substantially higher than the literature figures, demonstrating the role of agriculture as source of nutrients to the River Kävlingeån system. The agricultural land use policies of the last fifty years were revealed to be most important with regard to this role. Of such land use policies, the cultivation of the last 10–15% of land employed for agricultural use (primarily riparian ecotones) may be of most significance. The literature indicates that intense agricultural use of this final 10–15% may account for a ca. 50% increase in nitrogen loss. This suggests that one solution to the problem of agricultural diffuse pollution may lie in the restoration and sustainable management of riparian ecotones of agricultural streams.     

Origin of spores of anaerobic microorganisms in milk

Summary Samples from silage, hay, milk, air, and faeces were taken at 25 farms in mid-Sweden, farms with different hygienic standards of milk-production being chosen.The correlation between fodder and milk-quality was investigated. The investigation was limited to the transfer of spores of anaerobes to the milk during feeding with silage of various qualities.The role of grassland fodders other than silage in spore-infection of milk is discussed.These studies are still in progress. We are indebted to the Swedish Foundation: Fonden för främjande av forsknings- och försöksverksamheten på jordbrukets område for generous financial support. We also gratefully acknowledge the encouraging interest and support of Professor R. Nilsson.     

Incidence of cardiac malformations in Greenlandic Eskimos

Summary 757 eskimo children born in Godthåb, Greenland, in the years 1957–1964 have been reexamined 1966. 10 certain and 4 probable cases of congenital heart disease were diagnosed, mostly cases of ventricular septal defect. The incidence of 1.3–1.9% is the highest registered in any ethnic group.The average mother's age of the patients was 32.1 years, the average mother's age of the total material was 26.8 years (0.01> P>0.001). The patients' average number in the sibship was 6.3, differing significantly (0.01> P>0.001). The patients' average number in the sibship was 6.3, differing significantly (0.01> P>0.001) from that of 3.2 in the total material. The social standard of the families of the patients was low.There is some indication that the incidence of cardiac malformations in the Greenlandic population is decreasing. This may be due either to improved social conditions or to a changing reproductive pattern with relatively fewer children born to old mothers.

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Zusammenfassung 757 Eskimokinder, die in Godthåb, Grönland, während der Jahre 1957–1964 geboren wurden, sind 1966 wieder untersucht worden. 10 sichere und 4 zweifelhafte Fälle von angeborenen Herzfehlern, insbesondere Fälle von Ventrikelseptumdefekt, wurden diagnostiziert. Die Incidenz von 1,3–1,9% ist die höchste, die in irgendeiner Bevölkerung registriert ist.Bei den Patienten war das durchschnittliche Alter der Mutter 32,1 Jahre gegen einen Durchschnitt im Gesamtmaterial von 26,8 Jahre (0,01> P>0,001). Die durchschnittliche Nummer der Patienten in der Geschwisterreihe ist 6,3, während die des Gesamtmaterials 3,2 ist (0,01> P>0,001). Die soziale Schicht der Patienten war insgemein sehr niedrig.Die Incidenz der angeborenen Herzfehler in der grönländischen Bevölkerung scheint abzunehmen. Dies mag eine Folge von besseren sozialen Verhältnissen sein, kann aber auch darin begründet sein, daß das reproduktive Muster der Grönländer sich geändert hat mit weniger Geburten bei älteren Müttern.

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Based on a paper read at the Second International Symposium on Circumpolar Health, June 1971, Oulu (Finland).     

Die Entwicklungsdauer der Honigbiene in Abhängigkeit von Ihrem Entwicklungsort im Brutnest

Zusammenfassung Je 1 Carnica- und Ligustica-Königin sowie 3 Königinnen aus einer Gynandromorphen erzeugenden Linie wurden während der Eiablage beobachtet. Registriert wurden Eiablagedauer, Lage der Eier auf der Wabe und Verhalten von Königinnen und Arbeiterinnen.Die durchschnittliche Eiablagedauer beträgt 6–12 sec. Bei intensiver Ablage werden Gruppen von 10–15 Eiern schnell hintereinander abgelegt, worauf eine längere Pause zur Fütterung und Körperpflege der Königin eintritt.Das Schlüpfen der Imagines — Arbeiterinnen und Gynandromorphen — wurde kontroliert. Eine Voraussge, ob aus einem Ei ein normales Tier oder ein Gynandromorph entsteht, ist aufgrund der Verhältnisse während der Ablage jedes einzelnen Eies nicht möglich.Eine Verlängerung der Entwicklungsdauer der Arbeiterinnen vom Zentrum des Brutnestes ausgehend zur Peripherie hin konnte festgestellt werden. Mehr als 50% der Tiere waren nach Ablauf des 19. Tages bereits geschlüpft. Der von der Brutnestmitte zum Rand vorhandene Temperaturgradient auf Brutwaben wird als Ursache für diese Erscheinung angesehen.

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Summary One Carniolan queen, one Italian queen and three queens of a gynandromorph producing strain were observed during egglaying. Egg deposition time, position of the deposited egg in the comb and behaviour of queens and workers were recorded.The average time for egg deposition is 6–12 sec. During intensive egg laying batches of 10–15 eggs are deposited quickly, after this a longer break occurs for feeding and grooming of the queen.The emerging of the adult bees — worker-bees and gynandromorphs — was controlled. It is impossible to make predictions after the special circumstances of the egg deposition process whether a normal worker or gynandromorph will develop.A prolongation of the developmental period of worker bees from the center of the brood area to the margin was observed. More than 50% of the whole workerbrood had emerged already after the 19. day after egg deposition.The temperature gradient from the center to the border of the brood combs is considered as a cause for this phenomenon.

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Die Untersuchungen wurden mit Mitteln der Deutschen Forschungsgmeinschaft durchgeführt.     

Uptake of SO2 in shoots of Scots pine: field measurements of net flux of sulphur in relation to stomatal conductance

Abstract. Net fluxes of gaseous sulphur compounds, water vapour and carbon dioxide to current- and one-year-old shoots of Scots pine were simultaneously measured in the field. The shoots were fumigated in temperature-controlled assimilation chambers with sulphur dioxide at concentrations ranging from 40 to 250 μg m⁻³ (15–95 ppb). The hypothesis that stomatal opening regulates the uptake of sulphur dioxide was tested. The following conclusions were reached concerning the dry deposition of sulphur dioxide to a dry coniferous shoot.
There was a marked diurnal variation in the uptake rate of sulphur dioxide. The net deposition velocity of sulphur was about three times higher during the day than during the night during July-October. Stomatal opening was not the primary factor controlling the dry deposition rate of sulphur dioxide. The net dry deposition rate was significantly smaller than the calculated rate based on stomatal conductances for water vapour.
Part of this deviation could be explained by re-emission of reduced sulphur compound(s) from the needles. The re-emission of sulphur was a light-dependent process and might be of great significance for the sulphur balance calculations.
A variable deposition velocity should be used in atmospheric transport models to account for the diurnal and seasonal variation in the surface resistance of a dry canopy.     

Meiosis in males of the brown planthopper, Nilaparvata lugens

Meiosis in spermatocytes was studied among the three biotypes of the brown planthopper, Nilaparvata lugens (Stål). The chromosome number, morphology, and behavior of the biotypes were similar. The autosomes divided normally, reductional for the first division and equational for the second. The X chromosome had an unstable segregation behavior; it may segregate equationally or reductionally during the first division depending on its chromatid's orientation. Metaphase I plates contained 14 autosomal bivalents and an X chromosome (14_II + X). The co-oriented sister chromatids of the X chromosome moved together to either one of the poles during anaphase I, while auto-oriented sister chromatids segregated to opposite poles. Because of the anomalous segregation behaviour of the X chromosome, metaphase II plates may both contain 14_I + X chromatid, or one with only 14_I and the other with 14_I + X chromosome. Male N. lugens has a diploid chromosome number of 29.

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Zusammenfassung Die Meiose in Spermatozyten wurde in drei Biotypen von Nilaparvata lugens (Stål) studiert. Die Anzahl der Chromosomen, die Morphologie und das Verhalten der Biotypen waren ähnlich. Die Autosomen teilten in einer normalen Weise, reduzierend für die erste und äquatorial für die zweite Teilung. Das X-Chromosom hatte ein unstabiles Teilungsverhalten; es kann sich äquatorial oder aber auch reduktional trennen, je nachdem wie sich sein Chromatid orientiert hat. Die Ebenen der Metaphase I enthalten 14 autosome Bivalente und ein X-Chromosom (14_II + X). Die co-orientierten Schwester-chromatiden des X-Chromosoms bewegen sich während der Anaphase I zusammen zu einem der beiden Pole, während auto-orientierte Schwester-chromatiden sich nach entgegengesetzten Polen trennen. Wegen des ungewöhnlichen Teilungsverhaltens des X-Chromosoms, können beide Metaphase II Ebenen 14_I und X Chromatid enthalten, oder aber eine Ebene enthält 14_I und die andere 14_I + X.

     

Observations on malachite green in relation to its application to fish diseases

Summary Experiments were carried out to evaluate several properties determining the mutual influence of the system: fish-bath-malachite green-pathogen.The toxicity of malachite green solutions in concentrations varying between 1 : 80,000 and 1 : 2,560,000 was tested on immature sand whiting. As regards the toxicity of 1 : 80,000 solutions, for practical purposes no distinction between fish of different size, between equal concentrations of chloride and oxalate salts of the dye, or between fresh and decolourized solutions appears necessary.The survival time increased appreciably with decreasing temperature for the range 13.5–28.0°C.The dye solutions always showed significant decolourization when the pH was higher than 5.Several body tissues of the fish, notably the central nervous system and the lateral red muscles, were stained by fresh as well as decolourized malachite green solutions.The dye proved bacteriostatic but not bactericidal, to pseudomonad and coccus cultures when 1 : 80,000 solutions were used. Once decolourized, the dye became a less effective bacteriostatic.The addition of the dye, or formaldehyde, to the bath induced hyperventilation in the fish.A triple dye mixture, consisting of malachite green, brilliant green and crystal violet, was found to be a valuable therapeutic agent.

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Zusammenfassung Einige Versuche werden durchgeführt zur Erklärung verschiedener Eigenschaften, die die gegenseitige Einwirkung in dem System: Fisch - Bad - Malachitgrün - Pathogen bestimmen.Die Toxizität von Malachitgrün-Lösungen in Konzentrationen welche variierten zwischen 1 : 80,000 and 1 : 2,560,000 wurde geprüft an jungen Sand Whiting. Was die Toxizität der 1 : 80,000 Lösungen betrifft, scheint, für praktischen Zwecke, kein Unterschied zu sein zwischen Fischen verschiedener Länge, zwischen gleichen Konzentrationen von Chlorid und Oxalat-Salzen des Farbstoffes, oder zwischen frischen und entfärbten Lösungen. Die Überlebungszeit nahm merklich zu, wenn die Temperatur erniedrigt war, im Gebiet von 13.5°–28.0°C. Die Farbstoff-Lösungen zeigten erhebliche Entfärbung, wenn der pH - Wert grösser war als 5. Verschiedene Körpergewebe des Fisches, insbesondere das Zentralnervensystem und die lateralen roten Muskeln, werden von frischen sowie entfärbten Lösungen grün gefärbt. Der Farbstoff zeigte in 1 : 80,000 Lösungen bakteriostatische, aber keine bakterizide Wirkung, wenn geprüft an Pseudomonas und Kokkus Kulturen. Zusatz des Farbstoffes, oder Formaldehyde, zum Bade veranlasste in dem Fisch Hyperventilation. Ein Tripelfarbstoff-Gemisch, das bestand aus Malachitgrün, Brilliantgrün und Kristallviolett, zeigte sich ein wertvolles Therapeutikum.

     

The initial density of avian eggs derived from the tables of Sch?nwetter

Summary Two independent sources are presented which show that in spite of differences in relative yolk content, the density of egg content is virtually the same, namely, 1.031 g/cm³, SD=0.003, n=41. This constant allows one to calculate egg volume provided egg mass, shell thickness, shell mass, and surface area of the egg are known and to predict the initial egg density (egg mass/egg volume) using the surface area equation ofPaganelli et al. 1974. Measured initial egg densities reported in the literature for 53 species are compared with calculated values, using for each species the egg dimensions reported in Schönwetter's tables. The mean difference=–0.04 %, SD=0.8 %. Initial egg density values were calculated for all species listed inSchönwetter's Handbuch, and for extant, non-passerine birds ranged from 1.049 to 1.19 g/cm³ (n=3217). Density changes during incubation are discussed.

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Zusammenfassung Zwei voneinander unabhängige Quellen zeigen, daß trotz Unterschiede im Dottergehalt die Dichte des Eiinhalts konstant ist, nämlich 1,031 g/cm³ ±0,003; n=41. Damit kann man das Eivolumen berechnen, wenn Eimasse, Schalendicke, Schalenmasse und Oberfläche des Eies bekannt sind; die anfängliche Eidichte (Eimasse/Eivolumen) läßt sich mit Hilfe der Oberflächengleichung vonPaganelli et al. (1974) berechnen. Meßwerte in der Literatur für die anfängliche Eidichte bei 53 Arten werden mit berechneten Werten vonSchönwetter verglichen. Die mittlere Differenz beträgt –0,04 %. Die Werte für Eidichten frisch gelegter Eier werden für alle Arten, die inSchönwetters Handbuch aufgeführt sind, berechnet; für Nicht-Singvögel variieren sie zwischen 1,049 und 1,19 g/cm³ (n=3217). Dichteänderungen während der Bebrütung werden diskutiert.

     

Die Siebröhren-Plastiden der Monocotyledonen

Zusammenfassung In vergleichenden feinstrukturellen Beobachtungen an 24 Monocotyledonen aus 21 Familien wird ein für Monocotylen-Siebröhren charakteristischer Plastidentyp näher beschrieben. Neben gelegentlichen Ablagerungen von Siebröhrenstärke enthalten ausdifferenzierte Siebröhren-Plastiden zahlreiche keilförmige, kontrastreiche und proteinhaltige Kristalloide. Sie entstehen in der Matrix der noch amöboiden Formveränderungen unterworfenen Proplastiden; in reifem Zustand werden sie aus gekreuzten Reihen paralleler, gerader und kontrastreicher Filamente (50–60 Å) aufgebaut.Die Siebröhren-Plastiden von Nymphaea alba und Nuphar luteum bilden keine Kristalloide aus, dagegen läßt sich Siebröhrenstärke wie in den übrigen bisher untersuchten Dicotylen nachweisen.

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Sieve-tube plastids of monocotyledonsComparative investigations of the fine structure and distribution of specific plastids

Summary Fine-structural investigations of 24 monocotyledons from 21 families and all but one order succeeded in revealing a plastid with cuneate proteinaceous inclusion bodies as being typical of monocot sieve-tubes. Inclusion bodies originate in large numbers during plastid differentiation; they concentrate in the matrix and aggregate around an invisible centre, that mostly lies at one end of the elongated ameboid proplastid. The inclusion-free part of the young plastid contains countless vesicles and short membranes, presumably invaginations of the inner plastid envelope. Proteinaceous inclusion bodies show a crystal-like structure composed of 50–60 Å subunits in straight and parallel order. Besides these crystal-like inclusion bodies sieve-tube plastids of many monocotyledons also contain starch. — Sieve-tube plastids of Nuphar luteum and Nymphaea alba look like plastids in dicotyledon sieve-tubes, starch being their only inclusion.

     

Silage studies. III. some characteristics of the silage microflora

Summary The microfloras in grass-legume silage of high and low quality have been investigated using small laboratory silos of special design.The development of the silage microfloras was followed by analyses at intervals by determination of the occurrence of the main groups bacteria and fungi as well as of lactic acid and proteolytic bacteria.Nearly all organisms occuring were isolated and the occurrence of the single types estimated.Physiological characteristics of the isolates such as acid production, proteolytic activity and antibioses against certain test organisms were investigated.The buffer capacity of chopped and macerated plant material before and after fermentation was determined.These studies are still in progress. I am indebted to the Swedish Foundation Fonden för främjande av forsknings-och försöksverksamheten på jordbrukets område for generous financial support. I also gratefully acknowledge the encouraging interest and support of ProfessorRagnar nilsson.     

Histochemical demonstration of carbohydrates by a convenient sulphation technique

Summary A simple and convenient procedure has been devised for the staining of carbohydrate derivatives in tissue sections. Dewaxed sections are sulphated either by immersion in a 1:1 acetic-sulphuric acid mixture for 10–15 minutes or by exposure to sulphuryl chloride vapour for 15–20 minutes. The slides are then stained in a 0.05% solution of methylene blue buffered to aph of 2.4. Highly selective staining of tissue carbohydrates is obtained. The acetic-sulphuric mixture rapidly hydrolyses glycogen which is therefore lost, but the sulphuryl chloride technique produces intense staining of glycogen. The various steps in the technique are discussed, with particular emphasis on the reasons for the final choice of conditions. These sulphation techniques have several advantages over the PAS procedure: the overall picture obtained is clearer; definition at high magnifications is often better; and the versatility of the technique can be widened by varying the precise conditions of sulphation and staining to suit the particular problem being studied.

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Zusammenfassung Es wird eine einfache und handliche Methode zur Darstellung von Kohlenhydratderivaten in Gewebsschnitten beschrieben. Entparaffinierte Schnitte werden 10–15 min in einem 1:1 Essigsäure-Schwefelsäure-Gemisch bzw. durch Behandlung mit Sulfurylchloriddampf während 15–20 min sulfatiert und anschließend mit einer 0,5%igen Methylenblaulösung (gepuffert aufph 2,4) gefärbt. Man erhält eine stark selektive Färbung der Gewebskohlenhydrate. Das Essigsäure-Schwefelsäure-Gemisch hydrolysiert und entfernt das Glykogen sehr rasch. Demgegenüber ist nach Sulfurylchloridbehandlung eine starke Anfärbung von Glykogen möglich. Die einzelnen Schritte der Technik werden diskutiert, besonders die Gründe, die uns bei der endgültigen Wahl der Methodik geleitet haben. Die Methode bietet verschiedene Vorteile gegenüber der PAS-Reaktion: Das Übersichtsbild ist klarer, die Schärfe ist bei starken Vergrößerungen oft besser; die Plastizität der Methode ermöglicht es, Sulfatierung und Färbung den Bedürfnissen verschiedener Probleme anzupassen.

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With 5 Figures in the Text     

Zur individuellen Variabilit?t der Habitatwahlen von H?nflingen(Acanthis cannabina)

Zusammenfassung An 17 Hänflingen wurde der Einfluß früher Erfahrung mit einem speziellen Habitat (Laub, Nadel, Plastik) auf die Wahl und die Variabilität bei der Habitatwahl in automatisch registrierenden Habitatwahlkäfigen 3 Tage lang untersucht. Von den auf Laub gehaltenen Vögeln (n=7) bevorzugten 3 an allen, sowie einer an 2 und zwei an einem Versuchstag das Laubhabitat (Abb. 1). Von den auf Nadeln gehaltenen Vögeln (n=4) wählten zwei an allen, sowie einer an zwei und einer an einem Versuchstag eindeutig die antrainierten Bedingungen (Abb. 2). Von den auf Plastikstangen gekäfigten Vögeln (n=6) wählte einer an allen drei Tagen, einer an zwei Tagen und drei an einem Tag die Plastikstangen als Vorzugshabitat (Abb. 3). Insgesamt bevorzugten die Vögel der Laub- und Nadelgruppe im Test wieder ihre entsprechenden Habitate (Abb. 4). Die Tiere der Plastikgruppe verhielten sich indifferent (Abb. 4). Der Wahlindex (H) hatte bei den verschiedenen Gruppen keine unterschiedlichen Werte.

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Variability of choices in habitat by Linnets(Acanthis cannabina)

Summary 17 Linnets were tested to determine the influence of early experience with a special habitat (foliage-, spruce- and plastic-perces) on the later choice of habitat and the variability of individual habitat choices. The experiment was carried out over a period of 3 days in a specially designed cage equipped with automatic registration devices which featured all three habitats. Three of the birds kept on foliage-perches (n=7) preferred the foliage habitat on all 3 days, one preferred it on 2 days, and two on one day. Two of the birds kept in a spruce environment chose the learned condition on all three days, one chose it on two days, and one on one day. One of the birds that had been kept on plastic-perches preferred those on all three days, one on two days and three on one day. Alltogether the birds of the foliage-groups preferred their relative habitats during the test. The plastic-group behaved indifferently. The index of choice (discriminant index) H did not have different values for the three different groups.