Effect of Mitogenetic Rays on Eggs of Drosophila melanogaster

THE different methods for the demonstration of Gurwitsch rays have in common that the technique is always subtle and requires much practice; Magrou alone has described a simple method while using the eggs of the sea-urchin, but these eggs are only obtainable in certain months of the year and in marine laboratories; so we have sought for a more convenient object and have found it in the eggs of Drosophila melanogaster.