Swedish Bog Research Articles

Becoming-with the bog born: emotional collectives in ecological fieldwork

AbstractFieldwork in ecology education does things. By employing Donna Haraway’s concept becoming-with companion species and Cathrine Hasse’s emotional collectives to explore fieldwork practice on a bog in Sweden, a piece of the doings will be told. The aim of this study is to explore how ecology fieldwork affords emotional engagement and facilitates growth of ecological literacy in the emotional collectives of students, teachers and nonhumans to become-with each other. The study is based on an overnight field trip with upper-secondary students experiencing black grouse lekking and the ecology of a bog. The empirical material consists of video and audio recordings. In the study, becoming-with is operationalised through the notion of emotional collectives. The result shows three orientations of becoming-with: mimetic, anthropomorphic and fact oriented. Overall, this is a story of fieldwork as a practice of producing companion species; how becoming-with companion species works in practice, how companion species come to matter as emergent ecological literacy.

Reoxidation of Reduced Peat Organic Matter by Dissolved Oxygen: Combined Laboratory Column‐Breakthrough Experiments and In‐Field Push‐Pull Tests

AbstractElectron transfer to peat particulate organic matter (POM) as terminal electron acceptor (TEA) in anaerobic respiration has been hypothesized to lower methane emissions from peatlands by competitively suppressing methanogenesis and/or allowing for anaerobic oxidation of methane. We herein provide evidence for two critical aspects of this hypothesis: (a) peat POM is present in a reduced state in situ in the anoxic peat subsurface, and (b) reduced POM at the oxic‐anoxic interface in peat soils can be oxidized by dissolved oxygen (DO), restoring its TEA capacity. We reacted reduced POM from three ombrotrophic bogs in Sweden with DO in soil‐packed column‐breakthrough experiments (CBEs), mimicking oxidation reactions at the oxic‐anoxic interface. Breakthrough of DO was substantially retarded relative to the inert tracer bromide, consistent with DO reduction by POM. Control experiments confirmed abiotic DO reduction and excluded DO consumption through aerobic respiration. Modeling DO breakthrough revealed fast and slowly reacting POM moieties with reaction times spanning minutes to days. Complementary push‐pull tests (PPTs) in the anoxic subsurface of one bog confirmed results from laboratory CBEs: lower recoveries of injected DO compared with bromide supported DO reduction by reduced POM. Rates of reduction of injected DO decreased with increasing number of injections, consistent with continuous oxidation of reduced POM. Electron‐donating capacities of POM to DO in CBEs and PPTs were comparable at 40–130 μmol e−/g dry POM. Our results substantiate that POM is a regenerable TEA at oxic‐anoxic interfaces in peat soils and, thereby, may substantially lower CH4 emissions from peatlands.

Splitting bodies – A close-up study of a South Swedish bog deposition from the Pre-Roman Iron Age

A detailed taphonomic study of human and faunal remains recovered in a wetland in Southern Sweden is presented with specific focus on taphonomy, chronology and the possible practices associated with the handling of the remains of humans and animals, especially dogs. The finds from the wetland include remains of seven humans together with 21 dogs and skeletal remains of additionally 21 individuals of red fox, cattle, sheep, horse, red deer, and pig deposited in three pits located in different parts of the bog. Remains of five adults, three of which are female and of different age were identified in two of the pits as well as two children. The adults are represented by selected body parts only while the two children exhibit a more complete anatomical representation. Radiocarbon dating place the depositional activities mainly in the latest Bronze Age and Pre-Roman Iron Age (c.750–250 BCE), however, probably mainly in the latter part of the interval. Separate depositional events occurred in the 7th–8th century and 9th-10th centuries CE.There are taphonomic indications of pre–depositional handling of the bodies. Parts of human bodies were deposited when in some cases the bones were dry and in other cases when soft tissue still was present. The handling of the human body parts may be connected to a “pars pro toto” concept, including a ritual practice of individual bone circulation before deposition. Selective recovery needs to be considered but that or secondary movement of elements after deposition due to water movement cannot explain the patterns observed in the anatomical representation. A minimum of 17 dogs were deposited in the largest pit, probably as almost complete bodies. Two thirds of the recovered dog crania show evidence of healed traumatic injuries showing they were handled in a harsh manner in encounters with the humans. Other animals in the deposition were represented by selected parts of the bodies deposited both in a fresh state, probably as meat cuts, and by isolated elements. As a case study, the composition and character of the finds at Östra Vemmerlöv have to be considered unique in providing intriguing insights into the Latest Bronze Age/Earliest Iron Age wetland depositions, though parallels are found both locally and in a larger area, e.g. present day Denmark and Germany.

New major element analyses of proximal tephras from the Azores and suggested correlations with cryptotephras in North‐West Europe

ABSTRACTThe Azores Archipelago is one of the most active volcanic areas in the North Atlantic region. Approximately 30 eruptions have been reported over the last 600 years with some major VEI 5 (Volcanic Explosivity Index) eruptions further back in time. The geochemical composition of associated tephra‐derived glass, however, is not well characterized. An Azorean origin of cryptotephras found in distal areas such as North Africa, the British Isles and Greenland has been suggested, but proximal data from the Azores are scarce and the correlations have only been tentative. These tephras have a traychtic composition, which excludes an Icelandic origin. In a previous study, we presented major element analyses of proximal tephra‐derived glass from five Holocene eruptions on the Azores Islands. There is a striking geochemical similarity between tephras from volcanoes on São Miguel and Irish cryptotephras, and especially with eruptives from the Furnas volcano. Here we present new analyses of proximal tephras that confirm and strengthen a link between Furnas and cryptotephras found in south‐west Ireland. We also suggest a correlation between a previously unsourced tephra found in a Swedish bog with an eruption of the Sete Cidades volcano c. 3880 a cal BP.

Electron-Donating Phenolic and Electron-Accepting Quinone Moieties in Peat Dissolved Organic Matter: Quantities and Redox Transformations in the Context of Peat Biogeochemistry.

Electron-donating phenolic and electron-accepting quinone moieties in peat dissolved organic matter (DOM) are considered to play key roles in processes defining carbon cycling in northern peatlands. This work advances a flow-injection analysis system coupled to chronoamperometric detection to allow for the simultaneous and highly sensitive determination of these moieties in dilute DOM samples. Analysis of anoxic pore water and oxic pool water samples collected across an ombrotrophic bog in Sweden demonstrated the presence of both phenolic and quinone moieties in peat DOM. The pore water DOM had higher quantities of phenolic but not quinone moieties compared with commonly used model aquatic and terrestrial DOM isolates. Significantly lower phenol content in DOM from oxic pools than DOM from anoxic pore waters indicated oxidative DOM processing in the pools. Consistently, treatment of peat DOM with laccase, a phenol-oxidase, under oxic conditions resulted in an irreversible removal of phenols and reversible oxidation of hydroquinones to quinones. Electron transfer to peat DOM was fully reversible over an electrochemical reduction and subsequent O2-reoxidation cycle, supporting that quinones in peat DOM serve as regenerable microbial electron acceptors in peatlands. The results advance our understanding of redox processes involving phenolic and quinone DOM moieties and their roles in northern peatland carbon cycling.

Fine‐scale dynamics and community stability in boreal peatlands: revisiting a fen and a bog in Sweden after 50 years

Multi‐decadal studies of community and ecosystem dynamics are rare; however, this time frame is most relevant for assessing the impact of anthropogenic influences and climate change on ecosystems. For this reason, we investigated changes in vegetation and microtopography over 52 years in two contrasting mire ecosystems, one ombrotrophic (bog) and one minerotrophic (fen), representing different successional stages and contrasting hydrological settings. In both peatlands, floristic composition was recorded in the same permanent plots (n = 55‐56, 0.25 m2) in both 1960 and 2012 and microtopography was mapped over a large area (ca. 2500 m2) that encompassed these same plots. We quantified and compared the community‐level changes and internal spatial dynamics, tested associations between pH/microtopography and community/species change, and examined how the area and location of hummock microforms had changed over time. The bog exhibited little site level change in vegetation, where few species changed significantly in cover and plot frequency. However, detailed analyses revealed some large within‐plot changes over time in the bog, illustrating that bogs can be highly dynamic systems at a fine scale. In contrast, the rich fen experienced a clear directional change; specifically, bryophyte abundance decreased by 70% and brown mosses were almost extinct. Although pH had decreased over time at the rich fen, this decrease at the plot‐level was not associated with the decline of brown moss abundance. The microtopographic structure did not change substantially at the bog where ∼70% was covered by lawn/hummocks; however, in the rich fen hummocks expanded (from 10% to 16% cover) and moved or expanded down slope. Our study suggests, that at the site‐level, the bog ecosystem was more resistant to environmental changes over time compared to the rich fen, as evidenced by shifts in vegetation and microtopography. The contrasting scales of vegetation dynamics observed within a bog (i.e., within‐plot changes vs. site‐level) indicate that plant‐environment feedbacks contribute to the peatland level stability. While in rich fens, internal feedbacks may be weaker and the ecosystem's vegetation and microtopographic structure are vulnerable to shifting hydrological fluxes.

Evaluating paleoproxies for peat decomposition and their relationship to peat geochemistry

The past decade has seen a rapid increase in interest in the biogeochemical record preserved in peat, particularly as it relates to carbon dynamics and environmental change. Importantly, recent studies show that carbon dynamics, that is, organic matter decomposition, can influence the record of atmospherically derived elements such as halogens and mercury. Most commonly, bulk density, light transmission, or carbon/nitrogen (C/N) ratios are used as a proxy to qualitatively infer the degree of decomposition in peat, but do these three proxies reflect the same patterns? Furthermore, how do each of these proxies relate to other geochemical data? To address these questions, we analyzed bulk density, light transmission, and C/N ratios, as well as multielement geochemistry (wavelength-dispersive x-ray fluorescence (WD-XRF)), in three hummock cores (70 cm in length, c. 500 years) from an ombrotrophic Swedish bog. To compare the proxies, we applied principal component analysis (PCA) to identify how the proxies relate to and interact with the geochemical matrix. This was coupled with changepoint modeling to identify and compare statistically significant changes for each proxy. Our results show differences between the proxies within and between cores, indicating each responds to a different part of the decomposition process. This is supported by the PCA, where the three proxies fall on different principal components. Changepoint analysis also showed that the inferred number of changepoints and their depths vary for each proxy and core. This suggests that decomposition is not fully captured by any one of these commonly used proxies, and thus, more than one proxy should be included.

Exploring climate forcing of growth depression in subfossil South Swedish bog pines using stable isotopes

Comparison between growth variability, based on ring-width (RW) analysis, and moisture-sensitive signals in tree-ring carbon and oxygen stable-isotope composition provides increased understanding of how climate and hydrology influenced bog pines (Pinus sylvestris L.) at two sites in southern Sweden during the mid- and late Holocene. Tree-ring sequences from two subfossil trees collected at raised bogs having different hydrology and catchment size were analyzed to probe the stable-isotope signals associated with two bog-wide episodes of growth depression, one during the Holocene Thermal Maximum and the other during the Neoglacial Transition. The occurrence of lower whole-wood δ13C and cellulose δ13C and δ18O values immediately prior to the onset of growth depression in both trees, suggesting increased atmospheric relative humidity, is consistent with the notion that excessive effective moisture impeded tree growth. Correlation analysis indicates that the growth response lagged about three years behind the decline in δ13C and δ18O values in each tree, possibly reflecting relatively slow rise in the local water table in response to wetter climate.

Tundra in the rain: differential vegetation responses to three years of experimentally doubled summer precipitation in Siberian shrub and Swedish bog tundra.

Precipitation amounts and patterns at high latitude sites have been predicted to change as a result of global climatic changes. We addressed vegetation responses to three years of experimentally increased summer precipitation in two previously unaddressed tundra types: Betula nana-dominated shrub tundra (northeast Siberia) and a dry Sphagnum fuscum-dominated bog (northern Sweden). Positive responses to approximately doubled ambient precipitation (an increase of 200 mm year(-1)) were observed at the Siberian site, for B. nana (30 % larger length increments), Salix pulchra (leaf size and length increments) and Arctagrostis latifolia (leaf size and specific leaf area), but none were observed at the Swedish site. Total biomass production did not increase at either of the study sites. This study corroborates studies in other tundra vegetation types and shows that despite regional differences at the plant level, total tundra plant productivity is, at least at the short or medium term, largely irresponsive to experimentally increased summer precipitation.

South Swedish bog pines as indicators of Mid-Holocene climate variability

Dendroclimatic investigations of subfossil Scots pine (Pinus sylvestris) from two raised bogs in southern Sweden yielded a continuous floating 1492-year long tree-ring record. By cross-dating with bog-pine chronologies from Lower Saxony, Germany, the South Swedish record was assigned an absolute age of 5219–3728 BC. The cross-match between ring-width chronologies from these two regions, separated by 500–700km, is remarkably strong and the correlation positive, which indicates that large-scale climate dynamics had a significant impact on the growth of bog pines during the Holocene Thermal Maximum (HTM) when bog-pine distribution reached a maximum in both regions. However, local population dynamics were also influenced by peatland ontogeny and competition, as shown by differences in replication and mean tree age between the Swedish and German records. Comparisons with chronologies developed from modern bog pines in southern Sweden indicate that more coherent climate was controlling pine growth on natural peatlands during warm periods in the past. This study demonstrates the usefulness of Swedish subfossil bog-pine material as a climate proxy, with particular potential for decadal- to centennial-scale reconstructions of humidity fluctuations.

Multiple gradients in mire vegetation: a comparison of a Swedish and an Italian bog

The major environmental gradients underlying plant species distribution were outlined in two climatically and bio-geographically contrasting mires: a Swedish bog in the boreo-nemoral zone, and an Italian bog in the south-eastern Alps. Data on mire morphology, surface hydrology, floristic composition, peat chemistry and pore-water chemistry were collected along transects from the mire margin (i.e., the outer portion of the mire in contact with the surrounding mineral soil) towards the mire expanse (i.e., the inner portion of the mire). The delimitation and the extent of the minerotrophic mire margin were related to the steepness of the lateral mire slope which, in turns, controls the direction of surface water flow. The mineral soil water limit was mirrored in geochemical variables such as pH, alkalinity, Ca2+, Mg2+, Al3+, Mn2+, and SiO2 concentrations in pore-water, as well as Ca, Al, Fe, N and P contents in surface peat. Depending on regional requirements of plant species, different species were useful as fen limit indicators at the two sites. The main environmental factors affecting distribution of habitat types and plant species in the two mires were the acidity-alkalinity gradient, and the gradient in depth to the water table. The mire margin – mire expanse gradient corresponds to a complex gradient mainly reflected in a differentiation of vegetation structure in relation to the aeration of the peat substrate.

Input rates, decay losses and accumulation rates of carbon in bogs during the last millennium: internal processes and environmental changes

In peatlands the balance between litter input and decay loss in the oxic acrotelm determines the rate of carbon input to the anoxic catotelm with carbon lost at very slow rate. In the acrotelm the C/N-quotient decreases with depth and indicates the loss of carbon from the acrotelm. On one boreo-nemoral and three subalpine ombrotrophic bogs in Sweden the carbon losses in the acrotelm plus the apparent carbon-accumu lation rates in the catotelm for the last millennium revealed a constant carbon-sequestering rate up to the end of the nineteenth century equalling that in recent Sphagnum-dominated communities. On the boreo-nemoral bog the carbon-accumulation rate in the catotelm decreased by 50% over the same period while it remained constant on the subalpine bogs. A catotelm with permafrost may have provided more constant conditions for the carbon accumulation than a rising water level creating anoxic conditions. Due to vegetation changes, the recent carbon sequestering in the peat-forming communities is lower than previously and only just enough to compensate for the integrated losses. It is argued that because of internal processes the bogs up to the end of the nineteenth century had obtained or were approaching a steady-state with regard to the carbon input to the catotelm and the supply of mineral nutrients. In contrast, an increased climatic humidity around 1000 cal. BP resulted in high carbon-accumulation rates in the boreo-nemoral bog. Climate could have triggered the recent vegetation changes, but an increased nitrogen deposition is also a probable reason.

A 200‐year tree‐ring chronology of pine from a raised bog in sweden: implication for climate change?

A dendrochronological study was made on fossil tree trunks of Scots pine, Pinus sylvestris, preserved in a peat bog at Hanvedsmossen, 50 km SW of Stockholm, Sweden. Of 56 sampled pines, 48 were assembled in a 204‐year long floating chro‐nology. The chronology spans 1686‐1483 BC ± 23 years. The trunks are found at the very bottom of the peat accumulation. Because the roots stand in underlying clay, the tree stand germinated before or simultaneously with bog growth and provides maximum age for bog vegetation development which started c. 1480 BC. The pine growth steadily decreased during the last 30 years of the chronology and most trees died during the same period. It is proposed that the drainage outlets from Hanvedsmossen overgrew with brushwood simultaneously with the succession of pines, resulting in a higher sensitivity of tree growth to small changes in water levels. The preservation of the logs is suggested to be a result of a raised water table providing anaerobic conditions and later the logs were enveloped by peat growth. It is suggested that this period was the initial phase of the ensuing climate deterioration. The climate shifted to wetter conditions, i.e. higher amounts of precipitation, lower temperature or both. This resulted in lower evaporation giving additional peat bog growth and a locally raised water table.

A 200-Year Tree-Ring Chronology of Pine from a Raised Bog in Sweden: Implication for Climate Change?

A 200-Year Tree-Ring Chronology of Pine from a Raised Bog in Sweden: Implication for Climate Change?

Mass balance and nitrogen accumulation in hummocks on a South Swedish bog during the late Holocene

Two peat cores from the Store Mosse mire in the central part of South Sweden have been analyzed for dry bulk density, carbon, and nitrogen They cover the development of the peat mound from the time of the conversion of the initial fen to an ombrotrophic bog at 5450 BP through three different bog stages, the Fuscum. the Rubellum‐Fuscum and the Magellanicum bog stages, each one characterized by a specific macrofossil assemblageAll N supplied to the bog surface is assumed to be contained in the organic matter At the beginning of the Magellanicum bog stage, 1000 BP, the nitrogen accumulation rate increased from an earlier value of ca 0.4 g m–2 yr–1 to 0.8 g m–2 yr–1 These accumulation rates for N have been used to establish time scales for the periods between the 14C‐datingsThe estimated litter deposition rate in the hummocks is 120 g m–2 yr–1 in the two older bog stages and 270 g m–2 yr–1 in the Magellanicum bog stage The decay losses in the acrotelm increased, as a proportion of the addition, with time through each one of the bog stages The range of variation in the cores for the acrotelm decay losses was 25‐80%. and the annual input of organic matter to the catotelm, 30‐130 g m–2 These ranges are greater than those found among recent bog hummocks in NW Europe and North America The decay losses during 5000 yr in the catotelm may not have exceeded 20% of the original input The over‐all net rate of accumulation of C was highest, ca 40 g m–2 yr–1, at the beginning of the Fuscum bog stageThe changes in the macrofossil assemblages are all associated with rapid increases in the peat accumulation rate, but decreases in accumulation rate are not At the conversion from fen to bog the increased input of organic matter to the catotelm depended on expansion of Sphagnum fuscum which formed a decay resistant litter Later increases depended on rapid rises of the mean water table, resulting in shorter residence times and smaller decay losses from the acrotelm The periods of decreases in input of organic matter to the catotelm depended on longer residence times in the acrotelm when the water table fell relative to the bog surface However, comparisons with recent conditions suggest that the variation in mean water level relative to the surface may not have exceeded 10‐15 cm

Competition between Sphagnum fuscum and Drosera rotundifolia: A Case of Ecosystem Engineering

In a three-year field experiment in a subarctic Swedish bog, the moss Sphagnum fuscum and the perennial vascular plant Drosera rotundifolia were selectively fed with a growth-limiting factor, nitrogen. When fertilised, S. fuscum responded by an increase in the height of its green parts. D. rotundifolia also responded to S. fuscum fertilisation with an increase in height of the vertical stem that connects the leaf rosettes of two successive years. Thus, D. rotundifolia avoided being overgrown. Fertilisation of D. rotundifolia led to increases in number of leaves and specific leaf mass. No leaf area effect was seen ; i.e., the leaves were smaller and thicker, implying that the increased nitrogen was allocated to resources that increased survival probabilities but did not shade the moss. It is concluded that competition for growth-limiting mineral nutrients in Sphagnum peatlands strongly influences community structure and species diversity and that the mechanism whereby this is brought about lies in the spatially differentiated uptake zones of the moss and the vascular plant. The moss acts as a small-scale autogenic ecological engineer by capturing mineral nutrients early in their circulation through the ecosystem and the moss retains and relocates them within itself, thereby counteracting the potential spread of vascular plants.

Naturally produced adsorbable organic halogens (AOX) in humic substances from soil and water

The present study has shown that surface water, groundwater and soil, even in areas far from industrial activities, contain measurable amounts of adsorbable organic halogens (AOX). Although the concentrations are relatively low, the pools of AOX in the environment are considerable. In surface water, the ratio between AOX and total organic carbon (TOC) varied between 730 and 8600 μg/g. In soil, the AOX content ranged from 210 to 1400 μg AOX per g organic matter. The fact that organohalogens (230–370 μg/g) could be detected in fulvic acids isolated from old groundwaters (1300, 4600 and 5200 yrs) indicates a large natural production of organohalogens. This hypothesis was further strengthened by mass balance calculations for a raised bog in Sweden. The pool of AOX in this bog is at least 300 times larger than the present annual deposition. The total pool of AOX in peat in Sweden was estimated to be at least 300,000 metric tons. Potential artefacts in the analytical procedures used are discussed.

Recognition of peat-forming plant communities from their peat deposits in two south Swedish bog complexes

Peat samples, 3 015 from 103 boring points, on two mires (Akhult mire, Store Mosse mire) south Sweden, have been subjected to macrofossil analysis. Based on plant remains, 9 peat groups were distinguished in the field. A further classification using phytosociological methods revealed 29 peat types. The affinities between the peat types were determined from TABORD classification and a Reciprocal Averaging ordination. The primary floristic differentiation is correlated with a gradient from treeless-to wooded stands, which coincides largely with the mire expanse-mire margin gradient. The poor-rich gradient seems to parallel the treeless-wooded gradient as well and may reflect the natural conditions in this mire before it was affected by man. The hummock-mud-bottom gradient is easy to distinguish in peat, formed by bog communities, but is not distinct in peat formed by fen communities and impossible to detect in peat dominated by wood remains. The amount of identifiable remains depends on the decomposition, which is determined by (1) the period of time the plant litter stays in the acrotelm, and (2) the nutrient status. The decomposition is greatest in fen-peat with abundant wood remains. This probably depends on a good supply of oxygen caused by greater horizontal water movements and better nutrient status.

Bogs and Fens in the Hudson Bay Lowlands

Describes structural and vegetative features of bogs and fens in the peatlands area south and west of Hudson Bay, examined in summer 1957 mainly near the confluence of the Attawapiskat and Muketei Rivers (approx. 53 N, 86 W). Distinctive features of the ridge-shaped raised bogs are their undulating surfaces, large shallow pools, and lateral seepages (small, shallow pools termed flarks, in a stepped arrangement down the bog edges). Bog vegetation, typical of ombrotrophic peatlands, is acidophilous and low in pH value except in limited areas, e.g. fissures caused by frost heaving where fen plants are found, also the lateral seepages where patches of true fen vegetation appear along the rows of flarks. The plant communities are almost identical with those of similar raised bogs in Sweden and Finland. Fen surfaces are covered by large pools, and alternating low ridges low ridges and flarks. The fen water is highly minerotrophic, resulting in vegetation richer in mineral nutrients than that of the bogs, and similar to the "rich fen" or "brown fen" vegetation of Scandinavia. Roundish "black-spruce islands" are conspicuous fen features; they have permafrost cores as do knolls (palsas) north eastward near Sutton and Hawley Lakes.

Michigan Academy of Science, Arts and Letters

VOLUME 22 of the Michigan Academy of Science, Arts and Letters contains communications upon a wide range of subjects including, inter alia, forestry, geography, anthropology, history and philosophy (Papers of the Michigan Academy of Science, Arts and Letters. Vol. 28 (1942). Pp. xiii + 701 + 52 plates. Ann Arbor, Mich.: University of Michigan Press; London: Oxford University Press, 1943. 28s. net). Most of the botanical papers deal with the determination of species in the lower plants. There is an ambitious and critical monograph on the Leucopaxillus (toadstools) by R. Singer and A. H. Smith, with chemical and microscopical data. Several papers deal with tropical marine Algæ, and a number of new Red Algæ are described. G. W. Prescott and A. M. Scott give about a hundred good line drawings of American forms of Micrasterias (a desmid), including many known in Britain and several new ones. Finally may be mentioned a charming little paper on the pollen of a Swedish bog by E. Janson and E. Halpert, who wondered whether the European facts could be as clear-cut as have been reported, but found they were so. The zoological papers deal with various topics from Arthropods to reptiles. It is known that the common garter snake of North America can mate either in the autumn or in the spring. F. C. Blanchard has investigated the matter more fully and found evidence to show that effective mating occurs commonly in the autumn in the wild state. The offspring from such matings, if the females are kept isolated, exhibit normal Mendelian ratios in their colour pattern. In the wild, such females may copulate again in the spring and the resulting offspring show colour patterns that bear no relationship to any Mendelian ratio, and so it would appear that the actual insemination resulting from the autumn mating does not occur until after the spring mating. W. C. Beckman shows that in a number of game fishes in Michigan, temperature plays the leading part in the annulus formation in the scales. The mean temperature of the first days on which the majority of the scales showed an annulus is 58° F. An interesting paper by C. L. Hubbs and R. R. Miller deals with the influence of changed environment upon interspecific hybridization of two generations of Cyprinodont fishes.