A comparative study has been made of the methods proposed by various investigators for the single-solvent extraction of growth hormone from plant tissue. Dormant maize endosperms and endosperms removed from germinating grains at intervals up to 7 days were used as material throughout. There are wide differences in yield, depending on the solvent used and the extent of hydration of the tissue. The water and alcohol extraction methods gave the most reliable results. Water gave the highest yields and was the only method not involving drying down of the residue, i.e., the extract was at all times in water solution. Only preliminary investigations have been made on the extent to which growth inhibiting substances are involved in the yields reported here. In general, the amount of growth hormone extractable decreased as germination proceeded. Multi-solvent extraction is proposed for assaying the total hormone content of a tissue. It consists of making successive extractions of the same tissue with several different solvents, and shows that not all the growth promoting substance or substances are extracted with any one solvent. Some of the difficulties and uncertainties encountered in hormone extraction work are discussed.