TOLERANCE OF HIGH TEMPERATURES BY PISHES, ETC. 



177 



two of them were run simultaneously. The numbers of trials and individuals in the 

 various series were very unequal, being small when all the individuals died quickly 

 or survived easily and much larger at some crucial points in the experiments in which 

 the results were seriously in doubt. 



RECORDS 



The record of each trial included (1) remarks on any peculiarities of the speci- 

 mens at the beginning of the test (for example, size and condition), (2) temperature 



"Normal" Individuals. 



34° 



3 individuals -3 trials 



Aoollm. 30°, 1 day 

 36° 



3 individuals -3 trials 



Acclimatization 30°, 4 days 

 36° 38° 



8 individuals-5 trials 6 individuals-4 trials 2 individuals-1 trial 



Acclimatization 10°, 1 day 



30° 



2 individuals, 1 trial 

 Acclimatization 10°, 4 days 



2 individuals, 1 trial 5 individuals-4 trials 3 Individuals -3 trials 



Acclimatization 10°, 15 days 

 30° 



6 individual8-3 trials 



Fig. 4.— Effects of high temperatures on young sunflshes (pumpkinseed). 



symbols see Figure 1 



For explanation of 



and exact duration of acclimatization, (3) notes on the behavior of the specimens 

 immediately following transfer to the trial temperature, and (4) notations made at 

 the time of each observation. The latter included a statement of the exact time at 

 which the observation was made and a brief description of the condition of each of 

 the specimens as. indicated by its appearance and behavior, together with notations 

 on any of the experimental conditions that seemed important. 



