Horváth Géza (szerk.): A Magyar Természettudományi Múzeum évkönyve 18. (Budapest 1921)

Éhik, Gy.: The glacial-theories in the light of biological investigation

THE GLACIALrTHEORIES. 103 such strata are unknown, at least in Europe. A further explanation of the occurrence of a „mixed fauna" has been given by other specialists assuming that some single specimens of the Lemmings remained hereand-there on the path of their companions. I am fully convinced of the absolute wrong of this supposition as well. Even if some specimens belonging to arctic species might have settled the respective territory in the course of their migration, they have never been permanent inhabitants of the plains, but took their refuge into the high mountains, offering them convenient climatic conditions.

1 I have already pointed out the fact that the time in which the formation of the steppe fauna took place synchronises with that of the regression of the Lemmings ; the arctic and steppe fauna were only Fig. 7. The easternside of the gypsum-pit at Thiede near Braunschweig. (After NEHRING.) separated after the ice having withdrawn as far as to leave behind it a territory the extension and the biological conditions of which sufficiently secured the existence of the Lemmings. This may be expressed also by the following terms : The psychrophil species emigrated into the coldest 1 Dr. ST. J. BOLKAY, Additions to the Herpetology of the Western Balkan Peninsula. (Glasnik Zemaljskog Muzeja u Bosni i Hercegovini. Sarajevo 1919. p. 37.) .These species were distributed probably all over the Balkan Peninsula during the glacial period and after the definite withdrawel of the glaciers, took their refuge in the varions high mountains. The coasts, valleys and plains having been populated again with thermophil species originating from southern and south-eastern countries."