A new stain-fixative method for chromosomes, namely acetic-orcein, is described, which gives results that are equally good in fresh and permanent preparations. A 45% acetic and 1% orcein content is recommended as a standard solution. For salivary glands of Drosopkila a 2% stain gives the best results, and with the two species D. melanogaster and D. miranda the acetic strength has been raised to 70% with advantage. The addition of chloroform proves necessary for hardening in species of Sciara. Acetic-orcein is equally good for rapid chromosome counts. For root tips the addition of 1 cc. of N HC1 solution to 10 cc. of the standard solution together with gentle heating of the tissues in a drop of the mixture assists in the softening and separation of cells necessary for chromosome study. Orcein can also be used successfully in other combinations such as acetic-propionic or acetic-lactic. The latter is useful for making preparations that do not require ringing. Preparations so made keep from 7 to 14 days.