Weitere biologische Literatur (eingeschränkter Zugriff)
457 search hits
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The seed surface morphology of the Gesneriaceae utilizing the scanning electron microscope and a new system for diagnosing seed morphology
(1983)
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Helen T. Beaufort-Murphy
- The seed collection of the species of the Gesneriaceae on which this
study is based was obtained, for the most part, during a number of visits to
the herbaria of the Smithsonian Institution, Washington, D.C., and the Royal
Botanical Garden of Kew, London, and Edinburgh, Scotland. The seed collection
comprises well over 800 samples of about 700 species of the Gesneriaceae,
representing 113 genera of the 127 in the family, and provides a good
taxonomic representation of the Gesneriaceae. Following an examination of
all the samples in the seed collection, over 300 species of the 113 genera
were selected to represent the wide range of seed morphology characters observed
among the examined species of the Gesneriaceae.
A system with which to analyze and diagnose seed surface morphology,
designed by the author, is based on a format of six major categories and 60
tertiary terms of seed morphology characters and a companion diagnostic
table. The categories are arranged in a sequence of increasingly smaller seed
characters, ranging from seed shape to the ultrastructural characters of the
individual cells. To ensure that the system would also apply to seed plants in
general, the seeds, achenes and nutlets of a wide variety of species from families
other than the Gesneriaceae were examined. Twenty species from 13
families other than the Gesneriaceae were then selected and are included in
this study and, together with the Gesneriaceae, represent eight of the ten
subclasses of the flowering plants (Cronquist 1968).
The seeds, achenes and nutlets of all the species included in this study are
illustrated with SEM photomicrographs on the 54 plates of the Seed Atlas,
and the seed morphology data of each species are recorded on the diagnostic
tables that face each of the Atlas Plates. To facilitate the comparison of the
taxa of the Gesneriaceae, and to assist in the identification of the seeds of
the examined species of the Gesneriaceae, the seed morphology data are also
recorded on a summary table at the genus, tribe, subfamily and family levels.
The seed morphology of the Gesneriaceae is compared and contrasted with
the current classifications of the family at the species, genus, tribe, subfamily
and family levels.
The seed analysis system designed for this study has proven to be a rapid,
efficient, uniform, objective method to deal with the analytical, diagnostic,
and taxonomic aspects of an investigation of seed morphology. In addition,
the system readily lends itself to the substitution or addition of terms and
categories if needed, or to programming for a computerized analysis of seed
morphology. It is hoped that the system will prove useful to other investigators,
as well as prove helpful to standardize future investigations of seed
morphology.
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Floral evolution in the Ranunculaceae
(1964)
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Elmar Emil Leppik
- Six clearly separable evolutionary levels in the floral evolution of the Ranunculaceae were found to
coincide with the six corresponding stages of sensory development of their pollinators as follows: amorphic -> haplomorphic -> actinomorphic -> pleomorphic -> stereomorphic-zygomorphic. This is a basic trend of floral evolution, fully recapitulated in a single family. Except for the first (amorphic), all upper levels are represented in the present-day floras as clearly separable type-classes. They are therefore accessible to direct observations and experimental study. Extensive
statistical data on flower visitors of the Ranunculaceae confirm the proposed theory of the mutual
interrelationship between the evolutionary levels of flower types and sensory stages of pollinating insects. The new picture, obtained by this study, gives us a better understanding of the evolutionary relationship between insects and plants and explains the extreme diversity in the floral structure of the Ranunculaceae.
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Ältestquartäre Säugetiere aus der südlichen Serengeti, Deutsch-Ostafrika
(1942)
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Wilhelm O. Dietrich
- Die Knochenansammlung im grauen vulkanischen Tuff der Südserengeti gibt als ökologisch unmögliches
Gemisch ein gutes Abbild des Gesamtbestandes und des Lebensraumes der altquartärcn ost- und innerafrikanischen Fauna. Diese lebte formenreich in Urwald, Savanne und offener Steppe. Das Fehlen wasserlebender Tiere ist hier auf örtliche Umstände zurückzuführen: die vulkanischen Aschen gingen auf Steppenboden nieder, Die benachbarten, ungefähr gleichalten Knochenlager enthalten solche Tiere. Neu ist an der Serengetifauna der bereits beträchtliche Anteil von Kleinsäugern (Nager; Insektivoren fehlen noch). Diese wird weitere Forschung vermehren. Die klimatische Entsprechung der Fauna wird in tropischen, feuchtwarmen Bedingungen erblickt. Obwohl viele tertiäre Formen enthaltend, wird die Fauna nicht als jungtertiär angesehen, sondern wegen des Auftretens moderner· Formen als eine Tiergesellschaft, welche das Quartär eröffnet. Als Leitfossil für dessen Beginn wird der Gattung Archidiskodon, aus welcher die echten Elefanten, darunter auch der afrikanische (Loxodonta africana ) entstanden sind, vor den Equiden der Vorzug gegeben.
Ostafrika, das ja als Tierparadies schlechthin gilt, lebte bis vor kurzem noch im Quartär. Das Schrifttum über seine Tierwelt scheint zwar fast unermeßlich groß, aufs Ganze gesehen ist das Wissen weder tief noch auch nur oberflächlich vollständig. Die Hauptleistung des "weißen Mannes" bestand in der Störung und Vernichtung der Fauna. Aber die Natur ist groß; sie hält noch einen Schatz im Inneren ihrer Gebirge bereit, damit der Mensch seine Stellung zu ihr und den Sinn seines Lebens ergründe, einen von vielen: dle quartäre Lebewelt selbst. Möge die hohe Aufgabe, ihn zu heben, uns Deutschen vergönnt sein! Eine Probe hat Dr. KOHL-LARSEN gesichert.
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On submicroscopic structure of the nautilus shell
(1962)
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Charles Grégoire
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Studies on the Xeniidae of the Red Sea : their ecology, physiology, taxonomy and phylogeny / by H. A. F. Gohar (Ḥāmid ʿAbd-al-Fattāḥ Ǧauhar). [Mit arab. Zsfassung]
(1940)
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Ḥāmid ʿAbd-al-Fattāḥ Ǧauhar
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Neue Tipulidenfunde aus den Braunkohlenschiefern von Rott am Siebengebirge
(1934)
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Georg Statz
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Studies on the cirripedian fauna of Japan : II. Cirripeds found in the vicinity of the Seto Marine Biological Laboratory
(1937)
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Fujio Hiro
- The purpose of the present paper is to describe the thoracic cirripeds found in the waters around the Seto Marine Biological Laboratory. The material dealt with in this paper was collected almost entirely by myself during the period extending from the summer of 1930 up to the present time, except a few species obtained from the Soyo-maru Expedition undertaken by the Imperial Fisheries Experimental Station during the years 1926-1930. Descriptions of the latter have already been given (HIRO, 1933a). The present material consists, with few exceptions, of specimens from the littoral zone and shallow water; none of the specimens are from deep water. However, I have paid special attention to the commensal forms from the ecological and faunistic standpoint, and have thus been able to enumerate a comparatively large number of species in such a restricted area as this district.
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ΣΤΑΘΜΟΛΟΓΙΚΑΙ ΕΡΕ1'ΝΑΙ ΕΙΣ ΔΑΣΗ ΟΞ1ΆΣ
(1969)
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Spiros Dafis
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The action of cobra poison on the blood : a contribution to the study of passive immunity
(1898)
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John William Watson Stephans
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Milben aus dem Naturschutzgebiet auf dem Spieglitzer (Glatzer) Schneeberg
(1956)
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Carl Willmann
