A method is described whereby hard tissues may be softened by the use of somewhat high temp, using an ordinary dental vulcanizer. In the mass method of imbedding, several similar small objects like anthers or carpels are oriented in a row so that all may be cut together.[long dash]A device is described for imbedding in nitrocellulose by which the latter becomes concentrated very gradually.[long dash]To exhaust the air from vegetable tissues in the field preparatory to preservation, an ordinary automobile pump may be used, with the parts so arranged that a suction force or negative pressure is created.