Since the temperature of the experimental environment is known to be an important factor relevant to cff threshold determinations (Landis, 1951), one logically could expect some similar effects to be operating while phosphene threshold determinations were being made. To date, only one report (Suzuki, 1950) exists in which some relationships between temperarure and the phosphene threshold measure are discussed. Suzuki found that induced sweating in S greatly increased the absolute value of the phosphene threshold, as obtained by a method of limits. However, he found that the overlap or difference between the ascending and descending determination was little affected. Suzuki utilized a dc stimulation device which gave pulses at a rate of 20 cps. Using a similar apparatus, Gocka (1957) found (for 14 Ss, with 20 measures averaged for each S) an I. of .55 between room temperature and the absolute chreshold and an r of .58 between room temperature and the phosphene overlap measures. These r values are significant at the .05 probabiliry level. In a further analysis of the relationship between room temperature and the ascending phosphene determinations (made on 12 Ss) an r of .50 was obtained. This r value does not quite reach significance at che .05 probabiliry level. Clearly then, neither the phosphene threshold measure nor the phosphene overlap measure can be considered independent of temperature. TG findings show that a positive relationship exists between the environmental temperature and rhe obtained phosphene threshold measures; a relationship which must be accounted for in any reports using values of phosphene threshold determinations.