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not to be satisfactory explained, or technically overcome, without a de-tailed knowledge of the grałn size freąuency, the morphoscopic habitus of gravel and finer grains, and the clay minerał composition.

Especially where the soil survey makes only limited use of clay minerał investigations, there is even morę reason for geomorphological survey and investigation in order to make wider use of this aid. As far as I can see, it is indispensable for geomorphology.

IV.    How many of the 5 principia can be shown on a morphological map is also dependant for a large part simply, and only, on a few prac-tical premises:

a)    How much time (in connection with the naturę of the commission) is available for the survey?

b)    Together with the scalę of the map, the number of colors that are available is also of great importance. A map like the one from Jungerius (1958), using 35 colors, has many morę possibilities than one in 8 colors, to say nothing of the Russian morphological maps, with their morę than 100 colors.

c)    Actually good results can be obtained using a limited number of colors, if several maps of the same region are madę, if necessary partly in black and white, and with different scales, if reąuired. This has above all as far as I can see the advantage that the 5 essential principles (categories) of morphological survey then have increased applications. Above all, it is so easier to prove the directives for the key to the maps mostly settled in the early stadium of the survey.

V.    In morphological mapping it is also important to know by whom they will be used. In Poland one was forced to make parts of the geomorphological map morę simple, for the use of planners. The motto must naturally be: make the map readable for the person who must use it. But it is eąually natural that the geographer-geomorphologist is the only person who will understand the map in its finest detail. There-fore it seems obvious to me, that in a team of advisers there should be at least one physical geographer rather than that the map should be madę so simple that advisers interested in sociology and town planning should be able to understand it completely. This calls to mind an advise, given by a professor of theology in Leiden (in about 1900) to futurę clergy: “Gentlemen, it is not important whether you preach an orthodox or free sermon. But you must always have two pages in it, that your trusty parishoner do not understand. Only then will they think you a good clergyman.” In translating this remark for physical geography, geomorphology and geomophological survey, I should only want to say: let our science give what it has to offer. It must not hide its light under a bushel. One should do one’s best to improve ones field- and laboratory eąuipment as much as possible. If as a result of this maps are published that are difficult for the planners and other users to interpret, let them then cali in a professional, i. e. a physical geographer.

VI.    Finally one must not forget that the naturę of the map is largely controlled by its subject. Wiggers’ (W i g g e r s and Sm its 1959) un-derwater survey of one of the new IJsselmeerpolders (Flevoland) in the Netherlands is an example of geomorphological mapping of a young sedimentation region. The young sediments do not show any develop-ment of a soil due to weathering. Allied examples are to be found in the investigations of the Amsterdam physical geographic school in various provinces of the Netherlands (see Bakker 1960), where survey of the

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