Arithmetics and Economy. The cover plate was drawn by the editor himself and shows some parts of a dissected flower, the whole page measuring 20 by 15 cm. The flower thus analyzed was first boiled up and examined under water against a grid. This can be found on so-called millimetre paper, or be engraved in plastic petri-dishes (like the glass one figured on page 431 but smaller and the lines 2 mm apart), which are quite cheap and available from Dr. J. van Brummelen, Rijksherbarium. They are mostly used for counting colonies of bacteria. The parts are drawn under a standard magnification of 5, 10, 15, or 20, on a paper which has a 1 cm grid; such paper is now also on sale. Such drawing can indeed, as Corner says, be learnt like arithmetic. In (too sporadic) use since at least one century, and only in degree perfected since C.B. Clarke, F. Gagnepain and others drew their dissections on a small strip of paper which they later stuck to the sheet, this method serves to make a 3-dimensional flower visible in one plane. It takes about 1-1½ hour to make a thorough, annotated analysis of a flower, and ideally, for each species, several have to be prepared. All this is well-known. Yet more than one fellow-taxonomist who had prepared a number of such sketches, put them away among his notes. Even if he took care to preserve the dissected flower fragments, it is evident that his labours thus are lost to others. The place where such an analysis belongs is with the specimen from which it was drawn, and which only then can be easier and more fruitfully examined. If we realize that each drawing easily costs taxonomist-time equivalent to $ 6-12, it seems even economical to have the sketches xeroxed (which can be done very well if sharp pencils are used) and copies glued to all duplicates, as a kind of service to other institutes, who often went to great expense to send materials on loan. It is much better for the specimens, too, if they only need to be plundered once.