Abstract
The X-ray microanalyzer makes possible a sensitive and localized detection of minerals in cryostat sections of freshfrozen plant tissues. The principles of the instrument and the different methods used to obtain information concerning the specimens are described. During our investigation of calcium and strontium transport to fruits and seeds, microcrystalline deposits of calcium-strontium phosphate were demonstrated in the sclerenchyma of the fruit stalk of Pisum sativum with the X-ray microanalyzer. The content of these ions in the xylem sap diminishes in the direction of the fruit. This finding is a possible explanation for the low calcium and strontium content in seeds.