Armin von Tschermak-Seysenegg (1870–1952): Physiologist and Co-‘Rediscoverer’ of Mendel’s laws

The ‘rediscovery’ of Mendel’s laws in 1900 was a turning point in modern research of heredity/genetics. According to the traditional view, adopted and fostered by many textbooks of genetics, Mendel’s principles were presented in the first half of 1900 simultaneously and independently by three biologists (H. de Vries, C. Correns, E. v. Tschermak-Seysenegg). Having thus laid the foundations of further development, the ‘rediscovery’ continues to attract considerable interest. Since the 1950s, however, serious questions arose concerning both the chronology and specific conceptual achievement of the scientists involved. Not only the independence but also parallelism was analysed in the context of individual research programmes of these three scholars. The youngest of them, Erich v. Tschermak-Seysenegg, was even excluded from the list of ‘rediscoverers’. The aim of this paper is to use new archival evidence and approximate the contribution of the physiologist and ophthalmologist Armin von Tschermak-Seysenegg (1870–1952) to the events of 1900 and 1901.     

‘Further Development’ of Mendel’s legacy? Erich von Tschermak-Seysenegg in the context of Mendelian–biometry controversy, 1901–1906

The contribution of Erich von Tschermak-Seysenegg (1871?C1962) to the beginning of classical genetics is a matter of dispute. The aim of this study is to analyse, based on newly accessible archive materials, the relevance of his positions and theoretical views in a debate between advocates of early Mendelian explanation of heredity and proponents of biometry, which took place in England around 1901?C1906. We challenge not only his role of an ??external consultant??, which at the time de facto confirmed his status of ??rediscoverer?? of Mendel??s work but also analyse his ambivalent positions which are to be seen as a part of ??further development?? (Weiterführung), a development of Mendel??s legacy as he understood it. Second, there is an interesting aspect of establishing connections within an ??experimental culture?? along the Mendel??s lines of thought that was parallel to the first step of institutionalizing the new discipline of Genetics after 1905/06. Part of the study is also the analysis of contribution of his older brother Armin von Tschermak-Seysenegg (1870?C1952) who??much like in the case of ??rediscovery?? of 1900?C1901??was for his younger brother an important source of theoretical knowledge. In this particular case, it regarded Bateson??s ??Defence?? of Mendel from 1902.     

Hugo De Vries: from the theory of intracellular pangenesis to the rediscovery of Mendel

On the basis of the article by the Dutch botanist Hugo De Vries 'On the law of separation of hybrids' published in the Reports of the Académie des Sciences in 1900, and the beginning of the controversy about priority with Carl Correns and Erich von Tschermak, I consider the question of the posthumous influence of the Mendel paper. I examine the construction of the new theoretical framework which enabled its reading in 1900 as a clear and acceptable presentation of the rules of the transmission of hereditary characters. In particular, I analyse the introduction of the idea of determinants of organic characters, understood as separable material elements which can be distributed randomly in descendants. Starting from the question of heredity, such as it was defined by Darwin in 1868, and after its critical developments by August Weismann, Hugo De Vries was able to suggest such an idea in his Intracellular Pangenesis. He then laid out a programme of research which helps us to understand the 'rediscovery' published in 1900.     

A Norway spruce tree-ring width chronology for the Common Era from the Central Scandinavian Mountains

Fennoscandia is one of the most prominent regions in the world for dendroclimatological research. Yet, millennium-long tree-ring chronologies in this region have mainly been developed from Scots pine (Pinus sylvestris L.). To explore the possibility of building long-term chronologies using other dominating tree species in the region, this paper presents the first two millennia-long Norway spruce (Picea abies (L.) Karst.) ring-width chronology from Northern Europe. The chronology is composed of living trees and subfossil wood and covers the period from BCE 115 to 2012 CE. A sufficiently replicated and robust chronology is built for the past 360 years back to 1649 CE. Further back in time, the common growth signal is reduced, and hence the reliability of the earlier section of the chronology is lower. The climate calibration results show that the spruce ring-width correlation with June-July mean temperatures over the period 1901–2012 is positive and significant (r = 0.6, p < 0.01) and representing the temperature variability of a spatial domain covering west-central Scandinavia. These results show the ability of Norway spruce to serve as a proxy for paleoclimatic research and the possibility of extending the chronology far back in time in the region, and therefore present an opportunity for carrying out new inter-and intraregional proxy analyses.     

The reception of Mendelism in the United States, 1900-1930

Scholars have differed on the question of why Mendel's work was neglected between 1865 and 1900, and the (by contrast) relatively rapid acceptance of Mendelism in many countries after 1900. This paper focuses on two factors that have not been well explored in the debate. The first is that Mendelism fit perfectly into the atomistic philosophy associated with mechanistic materialism in western science, and thus was strongly promoted by a younger group of biologists around 1900 to raise the prestige of biology to the rigorous level of the physical sciences. The second factor was that Mendelian theory, with its experimental and predictive qualities, fit well into the new demands for industrialization of agriculture both to feed a growing urban population and to provide an arena for capital expansion. This paper proposes that the early promotion of Mendelian research, by both private and public funds, owed as much to economic and social as to biological causes.     

Carl Correns' experiments with Pisum, 1896-1899

The circumstances under which classical genetics became established at the turn of the nineteenth century have become an integral part of the standard narrative on the history of genetics. Yet, despite considerable scholarly efforts, it has remained a matter of debate how exactly the so-called 'rediscovery' of Mendel's laws came about around 1900. In this situation, unpublished research records can be invaluable tools to arrive at a more substantial and more satisfying picture of the order of historical events. This paper makes extended use of the research protocols covering Carl Correns' hybridisation experiments with Pisum sativum between 1896 and 1899. The resulting reconstruction sketches the portrait of a scientist following a particular research question--xenia--struggling with his experimental material, and slowly building up an epistemic regime in which questions and observations could acquire a relevance which did not strike Correns when he first took note of them. The microhistorical gaze through the magnifying glass of research notes reveals the kind of delays that appear to be constitutive for empirically-driven thinking in general. The research notes of Correns help not only to make this point, they also display some of the intricacies and material peculiarities which characterise the experimental process of hybridisation and the particular type of inferences it allows one to make.     

Pineapple Nematode Research in Hawaii: Past,Present, and Future

The first written record of pineapple in Hawaii is from 1813. In 1901 commercial pineapple production started, and in 1924 the Experiment Station for pineapple research was established. Nematode-related problems were recognized in the early 1900s by N. A. Cobb. From 1920 to approximately 1945 nematode management in Hawaiian pineapple was based on fallowing and crop rotation. During the 1920s and 1930s G. H. Godfrey conducted research on pineapple nematode management. In the 1930s and 1940s M. B. Linford researched biological control and described several new species of nematodes including Rotylenchulus reniformis. In 1941 nematology and nematode management were advanced by Walter Carter''s discovery of the first economical soil fumigant for nematodes, D-D mixture. Subsequently, DBCP was discovered and developed at the Pineapple Research Institute (PRI). Since 1945 soil fumigation has been the main nematode management strategy in Hawaiian pineapple production. Recent research has focused on the development of the nonvolatile nematicides, their potential as systemic nematicides, and their application via drip irrigation. Current and future research addresses biological and cultural alternatives to nematicide-based nematode management.     

Responses of tree-ring growth and crop yield to drought indices in the Shanxi province,North China

In this paper, we analyze the relationships among the tree-ring chronology, meteorological drought (precipitation), agricultural drought (Palmer Drought Severity Index PDSI), hydrological drought (runoff), and agricultural data in the Shanxi province of North China. Correlation analyses indicate that the tree-ring chronology is significantly correlated with all of the drought indices during the main growing season from March to July. Sign test analyses further indicate that the tree-ring chronology shows variation similar to that of the drought indices in both high and low frequencies. Comparisons of the years with narrow tree rings to the severe droughts reflected in all three indices from 1957 to 2008 reveal that the radial growth of the trees in the study region can accurately record the severe drought for which all three indices were in agreement (1972, 1999, 2000, and 2001). Comparisons with the dryness/wetness index indicate that tree-ring growth can properly record the severe droughts in the history. Correlation analyses among agricultural data, tree-ring chronology, and drought indices indicate that the per-unit yield of summer crops is relatively well correlated with the agricultural drought, as indicated by the PDSI. The PDSI is the climatic factor that significantly influences both tree growth and per-unit yield of summer crops in the study region. These results indicate that the PDSI and tree-ring chronology have the potential to be used to monitor and predict the yield of summer crops. Tree-ring chronology is an important tool for drought research and for wider applications in agricultural and hydrological research.     

History of the discovery of the mode of transmission of yellow fever virus

This essay documents and examines the historical circumstances and events surrounding the discovery of the mode of transmission of yellow fever virus in Cuba. Close scrutiny of the articles published by Walter Reed and his colleagues in 1900, 1901 and 1902 reveals their limitations as historic documents. Fortunately, other sources of information from that period survive in letters and documents written by individuals involved in the quest for the mode of transmission. Examination and comparison of those sources of information unveiled a fascinating story which reveals that misunderstandings engendered by published articles accorded merit where it was not fully due.     

Growth/climate response shift in a long subalpine spruce chronology

A new Norway spruce (Picea abies (L.) Karst.) tree-ring width chronology based on living and historic wood spanning the AD 1108–2003 period is developed. This composite record combines 208 high elevation samples from 3 Swiss subalpine valleys, i.e., Lötschental, Goms, and Engadine. To retain potential high- to low-frequency information in this dataset, individual spline detrending and the regional curve standardization are applied. For comparison, 22 high elevation and 6 low-elevation instrumental station records covering the greater Alpine area are used. Previous year August–September precipitation and current year May–July temperatures control spruce ring width back to ～1930. Decreasing (increasing) moving correlations with monthly mean temperatures (precipitation) indicate instable growth/climate response during the 1760–2002 period. Crucial June–August temperatures before ～1900 shift towards May-July temperature plus August precipitation sensitivity after ～1900. Numerous of comparable subalpine spruce chronologies confirm increased late-summer drought stress, coincidently with the recent warming trend. Comparison with regional-, and large-scale millennial-long temperature reconstructions reveal significant similarities prior to ～1900 (1300–1900 mean r=0.51); however, this study does not fully capture the commonly reported 20th century warming (1900–1980 mean r=?0.17). Due to instable growth/climate response of the new spruce chronology, further dendroclimatic reconstruction is not performed.     

Plant thioredoxins: role of the French School

A seminal discovery made by Pierre Gadal and his collaborators in Nancy, almost 30 years ago, has served as a nucleus for further development of research on plant thioredoxins. By attracting other investigators, research in the area has flourished and enabled France to assume a leadership position in the field. The chronology of development of this research is traced in the present review, from its origin in Nancy to its current distribution throughout France. A summary of the achievements of participating French scientists documents their influence on the field and the international thioredoxin community. The article closes with a personal perspective of Gadal’s scientific and professional contributions that was developed by the senior author during visits to Orsay over the past three decades.     

Notes from the New York Botanical Garden Herbarium II. The Herbaria of Charles Warfield Trow and Albert T. Beals

Two private herbaria have been donated to the Garden. The Trow herbarium consists of 87 mounted plants collected in Massachusetts between 1895 and 1900. The Beals herbarium contains 325 mounted plants from New Jersey and Pennsylvania, collected between 1898 and 1901.     

Were medieval warm-season temperatures in Jämtland,central Scandinavian Mountains,lower than previously estimated?

Today few high-quality tree-ring based temperature reconstructions extending over the past millennium exist, and those have, in general, low replication in their early parts. Here we present a new and updated maximum latewood density (MXD) chronology extending over the last 1200 years, built from local Scots pine wood sources (living trees, drywood preserved the ground, and subfossil wood extracted from lakes) all collected within 20 km in the Scandinavian Mountains in Jämtland. The MXD data was used to reconstruct April-September mean temperatures, where 60% of the variance in observed temperatures could be explained. The reconstruction exhibited distinct multidecadal variability, with the coldest periods centred on ca. 900, 1450, 1600 and 1900 CE, and the warmest periods on ca. 1160, 1250, 1500, 1660 CE. The last part of the 20th – early part of 21st century was the warmest period throughout the whole record, and the reconstruction suggests that, on average, the Medieval Climate Anomaly (MCA, 950–1250 CE) was only slightly warmer than the Little Ice Age (LIA, 1450–1900 CE). In fact, compared to earlier reconstructions from the region, the new reconstruction suggested lower MCA warm-season temperatures. However, despite sufficient replication during that period, high inhomogeneity among the MXD series makes this period slightly uncertain. The unique drywood on which the chronology was built, displayed a distinct regeneration pattern, where changes in Scots pine establishment was interpreted as responses to changes in forest fire activity and climate throughout the past millennium.     

Bronze age dating of timber from the salt-mine at Hallstatt, Austria

The prehistoric salt mine of Hallstatt together with its burial ground is one of the most prominent archaeological sites in Austria, which has also given name for the “Hallstatt period” of human civilisation (800–400 BC). Due to the perfect conservation in rock salt a great number of organic materials have been found, among mostly wooden artefacts. Currently, the major archaeological focus is on the Bronze Age salt mining activities with excavations taking place at the historic Christian von Tusch-Werk, Alter Grubenoffen mine.

Chronology building started at the Dachstein plateau, in the vicinity of Hallstatt, where tree-trunks were discovered in an alpine lake (Schwarzer See) and after recovery a spruce-larch chronology was compiled that dates back to 1475 BC. In addition, at the bog Karmoos, very close to the mining place of Hallstatt, preserved trees were intensively sampled resulting in a spruce chronology reaching even 1523 BC.

Over 500 samples were taken at the Christian von Tusch-Werk, Alter Grubenoffen. They also included samples from the recently discovered world's oldest wooden staircase. The spectrum of wooden species encompassed Norway spruce, Silver fir, beech, European larch and maple. We were able to synchronize 128 samples, ending in a 282-year long floating chronology. While the staircase dated back to 1344 BC, the end year of the floating chronology dated even to 1245 BC. Tree felling dates showed clusters within the chronology, providing evidence for archaeologists to find construction phases and usage periods.

The Dachstein–Hallstatt spruce chronology currently holds 840 synchronized series, and includes samples from the lake at the Dachstein, from the Karmoos bog at Hallstatt, from the prehistoric Hallstatt salt mine, and from historical buildings, as well as living trees. The chronology covers the period between 1523 BC through 2004 AD.     

Lake Level Changes Recorded by Tree Rings of Lakeshore Shrubs:A Case Study at the Lake West-Juyan, Inner Mongolia, China

Variation in water resources is a main factor influencing ecohydrological processes and sustainable development in arid regions. Lake level changes are a useful indicator of the variability in water resources. However, observational records of changes in lake levels are usually too short to give an understanding of the long-term variability. In the present study, we investigated the tree rings of shrubs growing on the lakeshore of Lake West-Juyan, the terminus of the Heihe River in western China, and found that Lake West-Juyan had undergone degradation three times over the past 200 years. The lake level decreased from 904.3 to 896.8 m above sea level (a.s.l.) during the period 1800-1900, to 892.0 m a.s.l. from around 1900 to the late 1950s, and the lake dried out in 1963. The trend for changes in lake levels, which was represented by the composite chronology of three beach bars, showed that the phases of increasing lake levels over the past 150 years were during the periods 1852-1871, 1932-1952, 1973-1982, and 1995-1999. Comparison with the history of regional economic development showed that human activity has played an important role in regulating the water resources of the lower reaches of the Heihe watershed over the past 200 years.     

Mendelian inheritance in Germany between 1900 and 1910. The case of Carl Correns (1864-1933)

Carl Correns (1864-1933) came to recognize Mendel's rules between 1894 and 1900 while trying to find out the mechanism of xenia, that is, the direct influence of the fertilizing pollen on the mother plant in maize and peas among other species. In this paper, I am concerned with the ten years of Correns' work after the annus mirabilis of 1900 until 1910, when the main outlines of the new science of genetics had been established. It is generally assumed that after 1900 Correns quickly began probing the limits of Mendelian inheritance, both as far as the explanatory force of formal transmission genetics and the generality of Mendel's laws are concerned. A careful examination of his papers however shows that he was much more interested in the scope of Mendelian inheritance than in its limits. Even his work with variegated Mirabilis plants, which historiographical folklore still presents as a result of Correns' growing interest in cytoplasmic inheritance, can be shown to have been conducted to corroborate just the opposite, namely, the validity of the nuclear paradigm. The paper will show that Correns' research results in those years (among them the Mendelian inheritance of sex in higher plants) were the outcome of a complex experimental program which involved breeding experiments with dozens of different species.     

Lake Level Changes Recorded by Tree Rings of Lakeshore Shrubs： A Case Study at the Lake West-Juyan, Inner Mongolia, China

Variation in water resources is a main factor influencing ecohydrological processes and sustainable development in arid regions. Lake level changes are a useful indicator of the variability in water resources. However, observational records of changes in lake levels are usually too short to give an understanding of the long-term variability. In the present study, we investigated the tree rings of shrubs growing on the lakeshore of Lake West-Juyan, the terminus of the Heihe River in western China, and found that Lake West-Juyan had undergone degradation three times over the past 200 years. The lake level decreased from 904.3 to 896.8 m above sea level （a.s.1.） during the period 1800-1900, to 892.0 m a.s.1, from around 1900 to the late 1950s, and the lake dried out in 1963. The trend for changes in lake levels, which was represented by the composite chronology of three beach bars, showed that the phases of increasing lake levels over the past 150 years were during the periods 1852-1871, 1932-1952, 1973-1982, and 1995-1999. Comparison with the history of regional economic development showed that human activity has played an important role in regulating the water resources of the lower reaches of the Heihe watershed over the past 200 years.     

The background to Otto Warburg's conception of the Atmungsferment

Conclusion In the 1930s Warburg's spare prose and disciplined respect for the facts set the style for a new generation of biochemists who had not known the conceptual revolutions of earlier years. Led by Warburg, they rejected the excesses of the colloid school and the false starts of the teens and twenties. Talk of active structure virtually disappeared as chemists began to identify enzymes, coenzymes, vitamins, and hormones. In the gradual transformation of the Atmungsferment from an ironcolloid complex to a specific haem-protein, the roots of Warburg's inspiration were readily forgotten-the richer and more varied intellectual currents of the early decades of biochemistry. Experimental cytology and pharmacology were important strands. Most of what Warburg was doing on narcosis from 1908 to 1912 was typical of this school. He was deeply influenced by Loeb and his theory of the fertilization membrane. In the period from 1900 to 1914 the ups and down of belief in Hofmeister's enzyme theory was an important trend which helped determine the style of biochemistry in later decades. Warburg's conception of the Atmungsferment was shaped by the general reaction c. 1910 against Buchner's optimistic view. Warburg's Heidelberg lecture was framed as an answer to Hofmeister's lecture of 1901 and turned out almost as an imitation or second edition of it. It was a style that was soon out of fashion. The affinity between the early concept of enzymes and the old concept idea of living protein should not be neglected in discussions of Warburg's distaste for enzymology. The colloid school is too easily dismissed as a mere impediment to the chemical triumphs of the 1930s. Warburg's Atmungsferment was obviously colored by the colloidal cast of biochemical thought in 1912. The Atmungsferment represented, in short, a hybrid transition from the romantic biochemistry of the period 1900–1925 to the mature, classical of the 1930s. It is fascinating precisely because it reflects, and refracts through a unique and powerful mind, the varied local traditions of the early history of modern biochemistry.