but these are not inhabited by a fauna different from that of the surrounding districts; for it is rare to find a group of organisms confined to a small area, of which the conditions are peculiar in only a slight degree.
baina haietan ez da bizi inguruetako eskualdeetan bizi denetik bestelakoa den faunarik; izan ere, nekez aurkitzen baita organismo talderik, baldintza bereziak neurri txikian besterik ez dituen arlo txiki batera mugaturik.