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V. Miller 《Planta》1928,6(1):1-21
Ohne ZusammenfassungMit 20 Textabbildungen.  相似文献   

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Zusammenfassung Von der AcanthaceengattungMellera, die einen Rippenpollen besitzt, wird eine neue GattungOnus abgetrennt, die eine bisher unbekannte Pollenform besitzt, nämlich einen Rahmenpollen, dessen Poren auf den Rippen sind. Dieser Gattung gehörtOnus submuticus (C. B.Clarke)Gilli comb. nov. (Syn.Mellera submutica C. B.Clarke) und die neubeschriebene ArtOnus cochlearibracteatusGilli sp. n. an.  相似文献   

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Quantitative and qualitative analyses of chromosomal polymorphism in 38 Palearctic populations of Chironomus plumosus were made. It was shown that most of the populations studied were highly polymorphic: in average 63.2 +/- 4.0% of larvae were heterozygous for inversions with 0.95 + 0.08 heterozygous inversion per larvae. Polymorphism on the size of centromeric heterochromatin and the presence of B-chromosomes were observed in many populations studied. The karyofund of Ch. plumosus in Palearctic was estimated. In total 35 banding sequences were found in Palearctic Ch. plumosus. Fifteen banding seguences have been described for the first time. On mapping the used banding sequences, we employed the conventions of Keyl (Keyl, 1962; Devai et al., 1989) and Maximova (Maximova, 1976; Shobanov, 1994a) for arms A, C, D, E and F, and the conventions of Maximova for arms B and G.  相似文献   

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Ohne Zusammenfassung(Hierzu Taf. I, nach dem Originalbilde von W. F. Bädeker.)  相似文献   

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Lateral shoot tips from young Asparagus setaceus (Kunth) Jessop (syn. A. plumosus Baker) shoots were grown on a modified Murashige and Skoog medium. Tips from 5 to 20 mm lateral shoots had significantly better growth and development than tips from lateral shoots (2 mm) still covered by leaf-scale. The optimum temperature for growth and development of the explants was 17 to 24°C. The initial growth was fast at 24°C but stopped after about 4 weeks. At 17°C the growth was slow but in return the cultures continued to grow. Kinetin was necessary for growth. Without any kinetin all cultures died. Optimum growth was found with 2 mg/l kinetin. There was no growth at all with IAA alone. A low IAA concentration had no effect, but at high concentrations IAA inhibited the kinetin induced growth.  相似文献   

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Ohne ZusammenfassungDie ausführliche Arbeit befindet sich unter der Presse und wird mit dem Titel: Die Protrophie, eine neue Lebensgemeinschaft in ihren auffälligsten Erscheinungen im Verlage von R. Friedländer & Sohn zu Berlin vor-aussichtlich Ende März 1896 erscheinen.  相似文献   

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Zusammenfassung Die GattungSiphonostylis — begründet aufIris unguicularisPoir.,I. cretensisJanka undI. lazicaAlb. — wird beschrieben.Es werden 4 Pollentypen charakterisiert, die für die Gliederung der Arten von Bedeutung sind.S. cretensis bildet drei geographisch vikariante Rassen, die als Subspecies ausgegliedert werden.Systematisch unklar bleiben die in Griechenland und den Ionischen Inseln verbreiteten Pflanzen, die als Hybridpopulationen, entstanden aus Kreuzungen zwischenS. unguicularis undS. cretensis, aufgefaßt werden.Meinem hochverehrten Lehrer, Herrn Prof. Dr. O.Schwarz, zum 65. Geburtstag gewidmet.  相似文献   

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Ohne ZusammenfassungMeinem verehrten Lehrer, Herrn Prof. Dr. O.Schwarz, danke ich sehr für seine wertvollen Hinweise.  相似文献   

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The locomotory kinematics of Chironomus plumosus larvae and pupae were investigated in order to determine how different locomotory techniques may be related to (a) possible underlying patterns of muscle activation and (b) the particular lifestyles and behaviours of these juvenile stages. Larvae display three independent modes of motile activity: swimming, crawling and whole-body respiratory undulation. Swimming and respiratory undulation involve the use of metachronal waves of body bending which travel in a head-to-tail direction. Whereas swimming is produced by side-to-side flexures of the whole body, respiratory undulation employs a sinusoidal wave. Crawling appears to result from an independent programme of muscle activation. Instead of a longitudinally transmitting metachronal wave of body flexure, a simultaneous arching of the body, combined with the alternating use of the abdominal and prothoracic pseudopods as anchorage points, produces a form of locomotion analogous to caterpillar-looping. Larval swimming has a set speed and rhythm and is an 'all-or-nothing' locomotory manoeuvre, but the neural programme controlling larval crawling is adaptable; switching from a less to a more slippery substrate resulted in a shorter, faster stepping pattern. The pupa displays two swimming modes, somersaulting and eel-like whole-body undulation, the former being principally a brief, escape manoeuvre, the latter being a faster form of locomotion employed to deliver the pupa to the surface prior to adult emergence. Comparison with the pupa of the culicid Culex pipiens shows that this insect also uses the somersault mechanism but at a higher cycle frequency which produces a faster swimming speed. This appears to be related to differences in lifestyle; the surface-living culicid pupa is exposed to greater predator threat than the bottom-dwelling chironomid pupa, and consequently needs a faster escape.  相似文献   

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Zusammenfassung 1. Die neubeschriebene marinePorphyridium-Art unterscheidet sich von dem terrestrisch lebenden, aber auch im Meerwasser gefundenenPorphyridium purpureum durch ihre größeren, violett gefärbten Zellen.2. Teilung und Wachstum der Zellen vonPorphyridium violaceum passen sich dem Belichtungsrhythmus an. Die während der 10stündigen Dunkelheit geteilten Zellen sind 9 bis 11µ dick, sie vergrößern sich während der Lichtperiode auf 11 bis 14µ.
Porphyridium violaceum, a marine new species
The new species is marine, whereasPorphyridium purpureum (= P. cruentum), first known only from terrestrial habitats, is halophilic and has been found several times in seawater.Porphyridium violaceum differs from the above mentioned species by a larger diameter and the colour of its cells.
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