Ultrastruktur der Symbionten in Ovozyten vonOrnithodorus moubata,Murray (Ixodoidea:Argasidae) nach simultaner Glutaraldehyd-Osmiumfixierung und Nachbehandlung mit Uranylacetat (Triple-Fixation)

Summary The nucleoplasm of rickettsia-like microorganisms living in the oocytes of the soft tickOrnithodorus moubata is preserved by TF (triple-fixation) in a fine fibrillary form, resembling the results obtained by the standard-method for DNA-containing plasms.

---

---

Die Arbeit wurde vom Schweiz. Nationalfonds unterstützt.

---

Frau S.Latscha-Stoller möchte ich für ihre unentbehrliche technische Mitarbeit meinen besten Dank aussprechen.     

Anoxygene Reaktivierung der Zellvermehrung nach anoxybiotisch hervorgerufener Zytostase (Anabiose)

Summary In cell juice of aerobic fermenting and of only respiring yeast cells, a thermostable respiratory energy reserve is found which under rigorous anoxybiotic conditions effects a generative reactivation in contact with anabiotic fermenting yeast cells, butnot with only respiring ones. Also in cell juice of Jensen sarcoma and other carcinoma tissues, an adequate energy substance is recognized as being able to replace oxygen biologically.     

Entwicklung der Symbiontenorgane einer Kleinzikade (Euscelis plebejus Fall.) nach Ausschaltung der Symbionten

Summary Embryos of the leafhopperEuscelis plebejus Fall. deprived of their intracellular symbionts are known to develop larval mycetomes of apparently normal topography late in embryogenesis. New experiments indicate that even the provisional mycetome preceding the larval structure is formed during early development of asymbiotic eggs.     

Veränderungen der aggressiven Handlungsbereitschaft männlicher Schwertträger,Xiphophorus helleri,nach sozialer Isolation (Fische,Poeciliidae)

Summary IfXiphophorus helleri males are kept in social isolation for 14–56 days, the fights for rank order position showed an increasing duration and intensity. These results support the idea of a spontaneous accumulation of attack readiness and are in contrast to the results in cichlid fishes. It is supposed that the different influence of social isolation to aggressive behaviour corresponds to different types of social organisation anp ecological adaptations.

---

---

Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Untersuchungen der Pollenkörner vonAlnus rugosa (Du Roi) Spreng. im Interferenzmikroskop nach Nomarski

Summary With the aid of the differential interference contrast microscope (systemNomarski), the pollen grains ofAlnus rugosa were examined. The characteristic surface structure, the arci and certain structures in the vestibules of the pores are thus very clearly visible. A further use of this microscopic method may be possible for the investigation of pollen grains.     

Kolbenzellen in der Epidermis der Galaxiidae,Galaxias attenuatus (Salmoniformes)

Summary The epidermis ofGalaxias attenuatus (Galaxiidae, Salmoniformes) was found to contain club cells that are like the alarm substance cells of the Gonorhynchiformes and Cypriniformes. Whether they are alarm substance cells, can be decided only by experiments on the fright reaction. The existence of club cells in the Galaxiidae confirms the opinion that both the Gonorhynchiformes and the Ostariophysi derived from salmonoid-like fish.     

Raster-elektronenmikroskopische Untersuchungen an der Hausstaub- und Asthma-MilbeDermatophagoides pteronyssinus (Trouessart, 1897) (Acarina: Astigmata)

Summary Various methods of fixation ofDermatophagoides pteronyssinus for the REM were tested. OsO₄ vapor yielded the best results. The morphology of male and female mites is described, based on REM exposures.

---

---

Naturhistorisches Museum Basel.     

The effect of locality,breed and previous tick experience on seasonal changes in the resistance of cattle toBoophilus microplus (Ixodoidea: Ixodidae)

Summary A seasonal cycle in the expression of resistance to the tickBoophilus microplus occurs in cattle in central and southeastern Queensland, Australia. This is due to a seasonal fluctuation in the capacity of cattle to mount an effective immune response against the parasitic tick and is manifest as a waning of the expression of resistance in autumn and early winter which occurs irrespective of breed or the nutritional state of the cattle.     

Die Struktur der Cadmiumhydroxyhalogenide CdCl0,67(OH)1,33, CdBr0,6(OH)1,4, CdJ0,5(OH)1,5

Summary The crystal structure of CdCl_0,67(OH)_1,33, CdBr_0,6(OH)_1,4 and CdJ_0,5(OH)_1,5 is determined, the first crystalizes in the C-19-, the latter in the C-6-type. The dimensions of the lattice of the named compounds and of CdCl_0,67(OH)_1,33 are tabulated together with those of Cd(OH)₂ and of the halogenides. It follows that when in Cd(OH)₂ OH-ions are substituted by halogen-ions, the distancea of the Cd-ions in the layers are changed very little, while the distance of the layersc is increased according to the size of the halogen-ion.     

Zum Proliferations-Stoffwechsel der Rattenleber nach Teilhepatektomie. Autoradiographische Untersuchungen mit3H-Cytidin,-Phenylalanin und -Thymidin

Summary During the first wave of parenchymal liver regeneration in adult rats after partial hepatectomy, the cellular synthesis and migration of RNA and the metabolism of protein were studied by autoradiography following an injection of³H-cytidine or³H-l-phenylalanine and double injections of 1 of these precursors +³H-thymidine. The following results were obtained: the synthesis and migration of RNA and the metabolism of protein are enhanced under these conditions of proliferation. In spite of this, the relation of metabolic activity in nucleolus, karyoplasm and cytoplasm remains constant. By double injection techniques it is proved that no differences exist in migration of RNA into the cytoplasm and cytoplasmic protein synthesis between cells with or without DNA synthesizing nuclei.

---

---

Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Artbastarde in der GattungTilapia (Cichlidae,Teleostei) und ihr Verhalten

Summary The young ofTilapia mossambica (mouth-brooder) show a characteristic contact-behaviour, which is related to the behaviour of the mother fish, who takes them back into the mouth cavity in cases of disturbance. This contacting is lacking in the young ofTilapia tholloni (substrate spawner). Contacting, as studied in our experiments with models, is genetically determined and is dominant over thetholloni pattern in the crossT. mossambica ×T. tholloni .     

Nachweis circanualer Periodik bei der Quappe (Lota lota L.) (Pisces,Gadidae)

Summary Investigations on daily rhythm in the burbot (Lota lota L.) in the Arctic Circle showed that a phase-shift in the locomotor activity occurred under nLD; the fish, which is night-active in the summer, phase-shifted 180 degrees in relation to the phase-timing factor. This phase-shift was also found in a fish kept in artificial light (LD 1212) which occurred at almost the same time of year. Accordingly an endogenous circaannual rhythm is suggested.

---

---

Die Untersuchungen erfolgten mit Unterstützung der Max-Planck-Gesellschaft zur Förderung der Wissenschaften und des Staatlichen Schwedischen Naturwissenschaftlichen Forschungsrates.     

Das Auftreten von Koproporphyrin in Kulturen vonPoteriochromonas stipitata nach Inkubation mit 3-Amino-l,2,4-triazol (Amitrol)

Summary In the presence of more than 2×10^–3 M amitrole, a red pigment was synthesized in the unicellular algaPoteriochromonas stipitata. By means of TLC it was confirmed that it consists mainly of coproporphyrine.     

Beeinflussung der DNS-Synthese durch Sulfit im Wurzelmeristem der Puffbohne (Vicia faba)

Summary Sulfite inhibits the DNA-synthesis in the root meristem fromVicia faba L.     

Physiologische Untersuchungen an der innervierten glatten Muskulatur der Vogelfedern (Mm. pennarum)

Summary The tension development of the smooth feather muscles of the pigeon was measured (a) on the wing in situ (b) on an isolated innervated skin preparation and (c) on an isolated muscle preparation. The contraction produced by nerve stimulation is biphasic. The second phase can be blocked by -receptor blocking agents. The mechanism of the first phase is unknown. The preparation seems very suitable for the investigation of neuromuscular transmission in smooth muscle.     

Die Veränderungen der Succinodehydrase-Aktivität in Detroit-6 (VA) Zellen,infolge der Infektion mit demHepatitis-infectiosa-Virus

Summary The inhibitory action ofHepatitis infectiosa virus on the SDH activity of Detroit-6 (VA) cell lines was investigated. The full inhibition of the SDH activity took place at the end of the third day after the infection. As this phenomenon precedes the cytopathogenetic effect of viral infection, it may be of some help in the early detection of the infection.