In preliminary identification it is very often imminent to hare a look through the dried leaf in order to observe details of nervature, glands, lines, dots, crystals, etc. These are often difficult to observe against the light of a window or the light from the sun. An exceedingly easy, cheap, and satisfactory way is to have an extra cover over the top of the lamp used for bringing light to the subject under the binocular lens, with a circular hole (1½ cm diam) made in the centre of this. The leaf is put over this hole and one looks through it with a normal hand lens. The extra cover we use at Leyden is the metal cap of old jelly containers. The second improvement is the etching of a net of sq. millimetres in the glass bottom of petri dishes, at least in most of the central portion of these. This facilitates taking exact measurements under water; no loose special metal or glass millimeter strips are needed any longer. The etching proved to be rather expensive in Holland; each dish costed about US $.4.-, but we are very glad to have them.