Properties of a Myxomycete P lasmodium. 183 
Plasmodium placed in this compartment, with the heated 
end ranging from if to 28° C., and the cold end from 
1 6° to i8°C., could be observed to constantly stream toward 
the higher temperature h Shutting off the cold water, and 
placing the plasmodium close to the heated end of the box, 
a temperature of 38° C. could be attained. When the tem- 
perature reached 3o°-3i°C,the creeping movement became 
less rapid, but there was no turning from the heat till the 
temperature rose to between 33 0 and 34 0 C 1 2 . The turning 
1 In 1884, Stahl described plasmodium as positively thermotropic, within 
certain limits, loc. cit., p. 161. 
2 Wortmann found the limit of positive thermotropism to be 36°-38°C.; Der 
Thermotropismus von Fuligo varians ( Aetkalium septicuni ) , Ber. d. deutsch. bot. 
Ges., p. 1 17, 1885. 
