@misc{_Reguła_1979, volume={25}, editor={Polska Akademia Nauk. Instytut Ekologii}, number={2}, copyright={Creative Commons Attribution BY 3.0 PL license}, journal={Wiadomości Ekologiczne}, address={Warszawa}, howpublished={online}, year={1979}, publisher={Państwowe Wydawnictwo Naukowe}, language={pol}, abstract={Intense studies over many years on several homothermic species have allowed S. S. Svarc to reach the following thesis: species specialized for extreme conditions (Arctic, montane) are adapted better (energetically, economically) than the co-occurring interspecific forms (subspecies, population) of species having a broad range of occurrence. This thesis is illustrated by four tables where the vast documentation of Svarc and his school is compiled. This concerns the heart index expressed in per milles of weight of this organ. Table I and IV show that the heart index of arctic species and those from high mountains does not differ basically from the heart index of species in the temperate zone. However, the heart index of polar populations or those from high mountains, species of temperate zones but with a broad range of occurrence, is much higher than for populations of temperate zones (Tables II and III). It seems that this thesis is significant, enough to be called Svarc’s principle.}, title={Reguła Švarca}, type={Text}, URL={http://rcin.org.pl./Content/172304/PDF/WA058_135800_P3259-25_Eko-Pol-B.pdf}, keywords={Shvarts, S. S., Shvarts, Stanislav Semenovich (1919-1976), animal ecology}, }