The significance was investigated of any relationship between germination and lipid content or lipid degradation of seeds of Norway spruce [Picea abies] stored for a long period. The germination ability and energy of seeds subjected to vacuum dehydration was also investigated. In seeds stored for 20 yr the content of fat fraction lipids (32.92%) was smaller than in seeds stored for 15 yr (34.12%) or 4 yr (37.03%). All seeds stored for 2-3 yr at temperatures close to 0 degrees C were characterized by a low acidic number of the lipid fraction extracted with hexane, in spite of differences in susceptibility of the seeds to accelerated aging. This finding indicates that triglycerides, which make >99% of this fraction, did not hydrolyse. The spruce origins investigated were also characterized by a low acidic number, and differences in acidic number were not significant between rapid and slow aging seeds. The acidic number was significantly higher in seeds stored for 20 yr (5.02%) than for 15 yr (4.10%) or 4 yr (1.91%). This finding, together with the observation that seeds stored for the longest period have reduced germination capacity, indicates that lipid acidic numbers of 4 to 5% may represent a threshold for germination decline. Acidic number may also serve as an indicator of seed germination capacity during the whole storage period. Seeds subjected to vacuum dehydration were vigorous in germination energy and ability. The length of the seed storage period could be prolonged in air-tight containers and at low temperatures of vacuum dehydration. During the first 12 h of dehydration seeds lost about 60-70% of all volatile substances; 3-4 days of vacuum dehydration gave a seed mass approximately 1% higher than the dry mass obtained after drying at 105 degrees C.