ALBERT

Description: In this paper we described the molar teeth of E. primigenius found in our country and stored in the Rijksmuseum van Geologie en Mineralogie at Leyden. Special attention is paid to the individual age of the animals at the moment when the grinders were rendered inoparative. As a rule this must have taken place at the moment of the animals dying. In fig. 3 is shown that proportionately the greater number of animals died at the age of 30\xe2\x80\x9460. There are sound reasons to suppose that most of the animals died in the period of life between the 30th and the 45th year. This seem to point to unfavourable life conditions during the time that the woolly mammoth dwelled in the Netherlands. (That time lies between the Mindel-Riss interglacial period and the \xe2\x80\x9cLate glacial time\xe2\x80\x9d of the W\xc3\xbcrm glacial period. Remnants, however, of mammoths found in deposits of pre-W\xc3\xbcrm age are rare).\nTo obtain more arresting proofs that these animals lived so short because of unfavourable climatic conditions and not because of their ordinary struggle for life, it is necessary that data about the individual ages of mammoths of (1\xc2\xb0) various parts of the world and (2\xc2\xb0) several geological times are collected.\nIn this paper we have tried to give such data. The reader finds here the individual ages of an amount of Dutch mammoths. Unfortunately however, the data necessary for an exact fixing of the geological age were in much cases not available. Many specimens were dredged and recovered in rivers, or found by non-geologists. It is not improbably that investigations, established with better dated material will show a correlation between the individual duration of life and the several climatic changes of Pleistocene time.