Allgemeine Chemie der Enzyme. II. Die chemische Dynamik der Enzymreaktionen

Ohne Zusammenfassung     

Über die Umkehrung der Polarität in den Sporenkeimlingen einiger Laubmoose

Ohne ZusammenfassungMit 3 Textabbildungen.     

The genetics of chemotaxis in Drosophila melanogaster: Selection for repellent insensitivity

Summary In a Y-unit maze wild-type flies of Drosophila melanogaster were tested for their chemotactic behavior reactions to insect repellents. Selection over 12 generations in two parallel experiments yielded two insensitive lines. Crosses indicated that the genes that were responsible for insensitivity were at least in part dominant. Lines selected for insensitivity to one repellent were also insensitive to a second repellent.     

Ein neuer Orchideenbastard:Spiranthes aestivalis ×autumnalis

Ohne Zusammenfassung     

Eine Excursion auf den Hochschwab

Ohne Zusammenfassung     

A series of mutable alleles of the white locus in Drosophila melanogaster

Summary The origin and phenotypes of a number of zeste mutant stocks with mutable white loci are described. Each newly arising form was lighter in eye color than the mutant it originated from. In each case the lighter pigmentation is believed to be due to an increase in genetic material in the proximal region of the white locus, the increase supposedly being the result of unequal crossing over. Some of the mutations which arose in the mutable stocks are reversions. They occurred in males as well as in homo- and heterozygous females. The reversions are believed to be due to a decrease in genetic material in the proximal region of the white locus. The decrease is assumed to be the result of intrachromosomal recombination. At least some of these events took place premeiotically. New mutants which originate frequently from mutable stocks are stable. In addition to the structure of the mutable white locus there is probably at least one still unknown factor which affects its mutability since the frequency of mutations arising in the mutable stocks decreases over the years.     

Cytotopochemische Beiträge zum Lipidvorkommen in Vakuolen

Summary The content of vacuoles of the two yeastsEndomyces lactis andCandida utilis and of the nucleolus in the cell nucleus ofAsterias sp. have been analysed upon the occurrence of lipids. For this reason, it were contrived observations and measurements in polarization optics, and used a few cytochemical reactions for lipids, employing partly the fluorescence microscope, partly the phase contrast technique. From the behaviour of the vacuolar leptones in this reactions it is concluded that at least the vacuoles of the two yeasts contain phospholipids, and the vacuoles of the starfish nucleoli, perhaps, beside this also lipoproteins in different amounts. From preliminary measurements with the yeasts in absorption photometry, it. moreover, follows that the tested reactions do not indicate the same substances, but, verisimiliter, a different inferior group of phospholipids.

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Prof. Dr. Karl Höfler in celebration of his seventieth birthday.