| Summary: | ABSTRACT: In meltwater pools of the Clark Peninsula area of Antarctica fresh water biota spend most of the year frozen into the ice or in underlying sediments. In the absence of dynamic pressure (as is the case in pools) , ice exerts no pressure on organisms. Survival of organisms appears to be a function of their ability to dehydrate: or encyst. Brachionus and cosmopolitan forms have been introduced into Antarctica. Thr most likely agency of transport is skua gulls. WATER SAMPLES taken from 12 meltwater pools on the Knox Coast, Wilkes Land, Ant-arctica show that the majority of them support myriads of animalcules. This is remarkable be-cause these organisms spend most of the year frozen into solid ice or bottom sediments and in the absence of light. We will discuss here reasons for survival, freedom from ice-crushing, and means by which biota may have been intro-duced into Antarctica. The collection of specimens and data for this study was made on Clark Peninsula and on an unnamed islet one mile northeast thereof, ( 66 ° 18'S). This area on the Knox Coast of Wilkes Land has been described in some detail by Hollin and Cameron (1961). Collecting was done during the construction of a perma-nent scientific base on Clark Peninsula, Janu-ary 27 to February 11, 1957. Clark Peninsula, which is generally ice-free, is a headland about 5 km long and with a maximum width of 4 km. A snow field covers approximately 30 % of the land area. The south end of the peninsula is overridden by inland ice which terminates in a moraine. At the time of pool sampling, ablation of the snow field had begun. Twelve pools were sampled at the height of the antarctic summer. These had probably been
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