There is no need to stress that at the present day it is becoming increasingly accepted that the further expansion of prehistory depends not only on the development and ever greater precision of the actual methods of archaeology, but also to an equal degree on the application of natural scientific research methods. This has been well exemplified in the series of systematic studies on petrological research on stone artifacts published in these Proceedings.
A similar tendency can be noted of late in many other European countries, France (Cogné and Giot, 1957; Giot, 1964), Austria (Zirkl, 1956–9), Germany (Frechen, 1965; Wiegers, 1950; Scholz, 1968), Hungary (Végh and Viczian, 1964), Poland (Kowalski and Kozlowski, 1959), the Soviet Union (Gajduk, 1963; Kovnurko, 1963; Petruň, 1967) and Switzerland (Hugi, 1948).
In Czechoslovakia, too, from 1960 onwards, regular petrological-archaeological co-operation has been carried on between the Department of Prehistory at the Philosophical Faculty of the Purkyně University of Brno and the Department of Mineralogy and Petrology of the same University. To begin with, the stone building material of Great Moravian architecture in the region of the lower Dyje valley and the lower Morava valley (Štelcl and Tejkal, 1961–7) was petrologically examined and latterly the investigation has been extended to cover the chipping and polishing industry of the Stone Age (Štelcl, 1967; Malina, forthcoming; Štelcl and Malina, 1966, and forthcoming).