Differenzierendes Kaulquappen-Fressen durch Molche

Summary Differential predation on tadpoles by newts (Triturus). 4 EuropeanTriturus species (T. alpestris, T. cristatus, T. helveticus, T. vulgaris) feed upon the tadpoles of the following Anura species which occur in sympatry with the newts:Rana esculenta, R. temporaria andBombina variegata. OnlyTriturus cristatus prey also upon the tadpoles ofBufo bufo andB. calamita. Triturus alpestris, T. helveticus andT. vulgaris do not eat anyBufo tadpoles. Even larvae ofTriturus alpestris prey upon tadpoles ofRana esculenta, R. ridibunda andBombina variegata but avoid tadpoles ofBufo calamita.

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Mit Unterstützung des Schweizerischen Nationalfonds zur Förderung der wissenschaftlichen Forschung.     

A modification of the technique of the gaddum and stephenson microbath

Résumé Une modification à la technique du microbain pour le dosage de matériel biologique est décrite. La contraction musculaire, amplifiée mécaniquement, est mesurée par le trajet d'un rayon de lumière sur un écran.     

Förderung der gastrointestinalen Resorption von Heparin durch Calciumbindungsmittel

Summary The gastroenteral absorption of heparin in rats as measured by clearing-factor activation is considerably enhanced by simultaneous administration of a number of calcium-binding substances as ethylendiamine-tetraacetate, sodium citrate, ion-exchangers, soaps and phosphates.Single oral administrations of heparin at the very high dose of 2 g/kg also lead to a maximum activity of the clearing factor.A binding of calcium ions seems to enable the intestinal absorption of heparin in all these cases.