Two =dissecting needles= (Fig. 48) should form a part of the histologist’s mounting set. The handles may be of any material, but the needle should be of tempered steel and about two inches long. SCISSORS [Illustration: FIG. 49.--Scissors] Almost any sort of =scissors= (Fig. 49) will do for histology work, but a small scissors with fine pointed blades, are preferred. Scissors are useful in trimming labels and in cutting strips of leaves and sections of fibrous roots that are to be embedded and cut. SCALPELS [Illustration: FIG. 50.--Scalpels] =Scalpels= (Fig. 50) have steel blades and ebony handles. These vary in regard to size and quality of material. The cheaper grades are quite as satisfactory, however, as the more expensive ones, and for general use a medium-sized blade and handle will be found most useful. TURNTABLE [Illustration: FIG. 51.--Turntable] Much time and energy may be saved by ringing slides on a =turntable= (Fig. 51). There is a flat surface upon which to rest the hand holding the brush with cement, and a revolving table upon which the slide to be ringed is held by means of two clips. In ringing slides, it is only necessary to revolve the table, and at the same time to transfer the cement to the edge of the cover glass from the brush held in the hand. LABELING There are many ways of =labeling slides=, but the best method is to place on the label the name of the specimen, the powder number, and the box, the tray or cabinet number. For example: Powdered Arnica Flowers No. 80--Box A--600. PRESERVATION OF MOUNTED SPECIMENS [Illustration: FIG. 52.--Slide Box] [Illustration: FIG. 53.--Slide Tray] Accurately mounted, labeled, and ringed slides should be filed away for future study and reference. Such =filing= may be done in slide boxes, in slide trays, or in cabinets. Slide boxes are to be had of a holding capacity varying from one to one hundred slides. For general use, slide boxes (Fig. 52) holding one hundred slides will be found most useful. Some workers prefer trays (Fig. 53), because of the saving of time in selecting specimens. Trays hold twenty slides arranged in two rows. The cover of the tray is divided into two sections so that, if desired, only one row of slides is uncovered at a time. Slide cabinets (Fig. 54) are particularly desirable for storing large individual collections, particularly when the slides are used frequently for reference. Large selections of slides should be numbered and card indexed in order to facilitate finding. [Illustration: FIG. 54.--Slide Cabinet] Part II TISSUES CELLS, AND CELL CONTENTS CHAPTER I THE CELL