. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 236 PETER DOUDOROFF against the logarithm of the duration of acclimatization. After 20 days at 26° complete acclimatization (, a constant 24-hour lower median tolerance limit) was apparently achieved. The converse ac- climatization curve of fishes transferred from 26° to 14° does not show the above logarithmic relationship. Acclimatization was somewhat slower during the first day, but, the curve being somewhat flatter, complete acclimatization again appears to be achieved in 20 days. o i 31. 42 49 0 I 12 20 DAYS OF ACCLI
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 236 PETER DOUDOROFF against the logarithm of the duration of acclimatization. After 20 days at 26° complete acclimatization (, a constant 24-hour lower median tolerance limit) was apparently achieved. The converse ac- climatization curve of fishes transferred from 26° to 14° does not show the above logarithmic relationship. Acclimatization was somewhat slower during the first day, but, the curve being somewhat flatter, complete acclimatization again appears to be achieved in 20 days. o i 31. 42 49 0 I 12 20 DAYS OF ACCLIMATIZATION 31 42 49 FIG. 4. Rate of change of cold-tolerance with acclimatization (acclimatization curves): The 24-hour lower median tolerance limits of Girella, initially acclima- tized to 14° (solid circles), 20° (dotted circles) and 26° (empty circles) in relation to the duration of acclimatization to new temperatures. The initial (first) and the new (second) acclimatization temperatures are indicated on each curve. Points obtained with fishes transferred from 14° to 26° and to 20° are indicated by large and by small solid circles, respectively. Days of acclimatization (abscissas) refer to time at the second (new) temperatures only. The initial tolerance limit (0 days of acclimatiza- tion) is in each case a mean of two determinations. Data from Table III. The single determinations with fishes transferred for two days from 20° to 26° and vice versa are not plotted. To what extent are the above acclimatization curves applicable to and descriptive of changes of cold-tolerance which result from smaller changes of temperature, such as may occur in nature? Although the available data for smaller changes (, 14° to 20° and vice versa, etc.) are not complete, since complete acclimatization has not in any case been achieved, a satisfactory comparison can be made with correspond- ing portions of the curves obtained with larger temperature changes. The relationships can
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
