Stand und Aufgaben der Pflanzensoziologischen Systematik in Europa

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Ausgangsform und Entwicklung der rhombischen Schuppen der Osteichthyes (Pisces)

Ganoid and cosmoid scales, the two types of rhombic scales within the osteichthyans, can be traced back to a primitive scale similar to the scales ofLophosteus. The primitive rhombic scale did not have a peg-and-socket articulation, it is composed of lamellar bone superposed by many layers of spongy bone + dentine. That kind of superposition of layers of spongy bone + dentine (+ enamel) has been retained in the cosmoid scale; in contrast in the ganoid scale the growth of the dentine has become restricted to the lateral surface, the growth of ganoin to the outer surface and the growth of bone to the inner surface of the scale. The scales ofAndreolepis have a position between the primitive rhombic scale and the ganoid scale. — Scales from the Gedinnian (Lower Devonian) of New Sibirian Islands, USSR, are described asDialipina markae n. sp. The morphological features are very typical for the genus, but the histology is different from the type speciesD. salgueiroensis. Within the two Devonian palaeoniscoid generaDialipina andOrvikuina acellular bone with irregular non-vascular canals of Williamson has developed twice from cellular bone.     

Entwicklung,Cytologie und Histochemie der Knorpel und der chondroiden Gewebe des Auges der Sepia (Sepia officinalis)

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Zur Phylogenese und Systematik der Edelfalken

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Zur Systematik und Physiologie der Spondylomoraceen

Zusammenfassung Die GattungSpondylomorum ist zweifelhaft, da Kolonien mit 4 Geißeln an jeder Zelle seit der Erstbeschreibung nicht mehr sicher festgestellt worden sind.BeiChlamydobotrys ist eine Artunterscheidung auf Grund morphologischer Merkmale nicht gelungen, Stämme von weit auseinanderliegenden Orten zeigten nur geringe und schwankende Unterschiede bei starker Variabilität innerhalb der Klone.Die Reinkultur von 10 Stämmen vonChlamydobotrys gelang mit Hilfe der Waschmethode, sobald ihr Bedarf an organischen Nährstoffen berücksichtigt wurde. Lösungen, die Azetat, eine Aminosäure und die Vitamine B₁ und B₁₂, sowie die üblichen anorganischen Nährsalze und Spurenelemente enthalten, ermöglichen am Licht gutes Wachstum. Die beste Konzentration der Nährstoffe für die Vermehrung ist der Ausbildung regelmäßiger Kolonien nicht günstig. Dafür muß die Lösung auf die Hälfte bis ein Zehntel verdünnt werden. Im Dunkeln findet keine Vermehrung statt. In physiologischer Hinsicht bestehen konstante Unterschiede zwischen den Stämmen. Chlamydobotrys weist Eigenschaften auf, die für das Gedeihen und den Wettbewerb am Standort günstig sein müssen.     

Variabilität, Verbreitung und Systematik der Arten und Unterarten in der Gattung Pungitius Coste, 1848 (Pisces, Gasterosteidae)

On the systematics and the evolution of variation and distributional patterns in the species and subspecies of the genus Pungitius Coste, 1848 (Pisces, Gasterosteidae) 1. In the genus Pungitius (similarly as in Gasterosteus) there seems to be of some interest the bony armature, especially from the zoogeographical point of view. These lateral bony shields are developed in the skin (instead of scales which are completely lacking in the family of Gasterosteidae) and are more or less present just as to the provenance of the individuals. 2. Preponderantly with respect to this bony armature several species and subspecies have been distinguished in the genus Pungitius, the variability, distribution and systematics of which are critically reviewed and compared in the present paper on the basis of museum material and data from the literature. 3. For the sake of adequate interpretation of modern distributional patterns there may be assumed an originally fully armoured type at the end of the Tertiary from which (after having escaped the ice by southward migration) during the Pleistocene period in several refugial areas new species or subspecies have derived, partially by reduction of the bony armature under freshwater conditions. During postglacial times these subspecies penetrated different areas but in some localities also produced mixed populations ofter having contacted within the same region. At least in some cases this may have led to subsequent hybridization. 4. The species P. platygaster in its modern distribution in the ponto-caspi-aralic region is now geographically isolated from the holarctic-circumpolarly distributed P. pungitius in its recent subspecies pungitius with reduced bony armature. Of this latter (originally fully armoured) species populations are assumed to have penetrated, at latest during the penultimate (= Riß) glaciation the Caspian Sea and subsequently the Black Sea and Lake Aral. These populations are the assumed ancestors of the nowaday still fully armoured P. platygaster. A decision as to the real degree of differentiation between the recent P. pungitius and P. platygaster has to be left to future crossbreeding experiments the results of which will possibly lead to a subspecies concept only. 5. In contrast to the foregoing the fully plated original type of P. pungitius underwent a serious reduction in its bony armature especially in the Southwest European refugium which led to a total loss of bony shields in the subspecies P. p. laevis. 6. As may be concluded from the now occurring types, this reduction seems to have been generally less pronounced in the East Asiatic refugium. We are confronted here, probably as a result of postglacial spread with the occurrence of three subspecies within the same area, i. e. the fullyarmoured P. p. sinensis on the one hand, and P. p. tymensis with reduced lateral plates (and also reduced lateral processes of the pubic bones in the pelvis girdle) and the holarctic-circumpolarly distributed P. p. pungitius with likewise reduced bony armature on the other hand. Of these subspecies the fully plated sinensis seems in its appearance to approach best what we perhaps may imagine as the original type of P. pungitius at the end of the Tertiary.     

Ziele und Grenzen der Quantifizierung genetischer Risiken

This present article deals with the question of how meaningful statistical risk assessments in genetic counseling may be for the decision-making process of individuals who ask for genetic advice. Even in some Mendelian diseases and generally in the case of multifactorial diseases it is not satisfactory to provide an a priori risk for all affected families. The question of whether a given person or his or her future children may develop the disease in question with severe, possibly untreatable symptoms may largely depend on individual circumstances. Accordingly, the inclusion of such circumstances in the assessment of an individual’s a posteriori risk may largely deviate upwards or downwards from this a priori risk. Currently, the lack of such data often prevents the quantification of an individual a posteriori risk; it is, however, obvious that individual risk assessment will play an increasing role in future genetic counseling. Besides a better understanding of individual environmental influences our growing insight into the impact of epigenetic changes will enforce a re-evaluation of individual risks. Epigenetic changes acquired during fetal development or early childhood may lead to lasting physiological changes and, accordingly, may significantly affect the risk of an individual to develop a certain disease during his or her later life. Due to the complexity of genetic and epigenetic networks it is as inappropriate to categorize mutated genes or alleles which increase the risk for a certain disease as “bad” or “sick” genes as it is to consider genes with apparently health-promoting properties as “good” or “healthy” genes. Such rhetoric may foster feelings of either guilt or superiority in individuals and may have an even more politically dangerous impact by encouraging neo-eugenic thinking. In contrast, the goal of non-directive genetic counseling is to provide individuals seeking advice with reliable information which helps them arrive at a personal decision. Given their personal circumstances this decision should be ethically acceptable and realistically allow them to cope with their problem in their future lives. As seen in cases of Mendelian diseases, such as sickle cell anemia or thalassemias, heterozygous carriers may have selective advantages, in this particular case a natural resistance against Malaria tropica. This example demonstrates that a genetic burden may not have only disadvantages but also advantages for the health of a whole population. This consideration may hold for many alleles which have been present in the gene pool of a population for many generations, although they contribute to a genetic predisposition for a multifactorial disease. In debates about the heritability of a given trait, the heritability coefficient has often been used as an argument for and against the predominant impact of genes on the trait in question. The authors wish to remind their readers that this coefficient reflects the genetic variation measured in a given population divided by the variation of all possible parameters which affect the phenotypic trait. It neither gives an answer about the absolute influence of genes and other factors on this trait nor does it provide information about how unforeseen changes in the environment may affect the heritability of the trait in the future. Contrary to a common misunderstanding in public discussion this coefficient does not allow any conclusion on the interaction of genetic, epigenetic and environmental factors involved in the development of the trait in question in an individual. Finally, in the closing section the authors highlight the opportunities of risk-adapted disease prevention.     

Ergänzungen zur Morphologie und Systematik der GattungBilinia ObrhelovA 1971 (Pisces,Percoidei)

The typical series of the genusBilinia ObrhelovA 1971 (Pisces, Percoidei) from the diato-mite beds of Ku?lín near Bílina (North of Bohemia, ?SR) kept in the National Museum of Prag was re-examinated. Morphological comparisons with other Eocene percoid fishes were supplemented with several very important features. As far as necessary, other observations were corrected. Deviations of certain morphological details, which sometimes are noticed among different specimens ofBilinia, are discussed with respect to the probable range of intrageneric variability. A new, revised diagnosis is proposed for the genusBilinia Obrhelová. Concerning the systematics, an assignment of this genus to the Percichthyidae in their widest meaning (c. t. Gosline 1966, Johnson 1984) seems to make more sense than the former classification with the Serranidae. Within this group, especially the genusAmphiperca Weitzel 1933 must be regarded as the presumably closest relative ofBilinia Obrhelová.     

Zur Genetik und Systematik der Amoena-Gruppe der Gattung Godetia

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Bedeutung der Genetik in der Systematik und Geographie der Pflanzen

Ohne ZusammenfassungVortrag, gehalten in der 3. ordentlichen Tagung des Verbandes Baltischer Pflanzengeographen in Riga-Lettland am 4. Juni 1931.     

Untersuchungen zur Verbreitung und Systematik der Mortierellen

Ohne ZusammenfassungHerrn Professor Dr. Peter Claussen zum 80. Geburtstag!     

Zur Entwicklung und Taxionomie der Tricornidae (Ostracoda) in Mitteleuropa

This paper is an attempt to summarize the existing knowledge on the Tricornidae Contrary toBlumenstengel (1965) the range of the family is vastly extended and its position as well as the taxonomic significance of its characteristic features are discussed. Several trends as to lateral view, strengthening of sculpture and marginal structures can be discerned within the entire generic group consisting ofOvornina—Tricornina—Bohemina—Saalfeldella. Probably these genera listed constitute a genuine phylogenetic line. The author gives a review on the range and delimitations of the most important genera. As a new genusOvornina (type speciesTricornina ovata Blumenstengel 1962; Ordovician—Devonian) is described; new subgenera of the same genus areOvornina andTricornella.     

Zur Kenntnis von Morphologie und Systematik einiger Arten der Gattung Arctodiaptomus Kiefer (Crustacea, Copepoda)

In the present study the author continues the revision of several species of the genus Arctodiaptomus Kiefer. Based on a detailed morphological comparison of animals from 34 different localities the species Arctodiaptomus similis (Baird), A. dudichi Kiefer, A. stephanidesi (Pesta) and A. byzantinus Mann are redescribed. Arctodiaptomus osmanus is characterized as a new species. For A. similis a list of synonyms is given. The centre of distribution of this interesting diaptomid seems to be in Israel, Lebanon and Jordan. Some populations are known also from Iran, Anatolia and Bulgaria. A. byzantinus is found not only in SE-Europe but recently also in the peninsula of Krim. Finally, there are only two habitats known of A. osmanus , both situated in 2 000 m above sea-level in NW Turkey and in Armenia.

Zusammenfassung

Verfasser setzt in der vorliegenden Studie seine Revisionsarbeit an mehreren Arten der Gattung Arctodiaptomus Kiefer fort. Arctodiuptomus similis (Baird), A. dudichi Kiefer, A. stephanidesi (Pesta) und A. byzantinus Mann werden auf Grund neuer vergleichend-morphologischer Untersuchungen eingehend gekennzeichnet und A. osmanus als neue Spezies in die Wissenschaft eingefuhrt. Fur A. similis wird eine Liste von Synonymen rusammengestellt. Der Schwerpunkt der Verbreitung dieses interessanten Diaptomiden scheint in den Landern des ostlichen Mittelmeers zu liegen, namlich in Israel, Libanon und Jordanien. Einzelne Funde stammen auBerdem aus Iran, Zentral- und West-Anatolien sowie aus Bulgarien. A. byrantinus ist nicht nur in Siidosteuropa verbreitet, sondern konnte nunmehr auch fur die Halbinsel Krim nachgewiesen werden. A. osmanusschlieDlich ist vorerst nur aus zwei 2000 m hoch gelegenen Seen in Nordwest-Anatolien und in Armenien bekannt.