Fig. 24.—Rapid Fatigue under Continuous Stimulation in (a) Muscle; (b) in Leaf-stalk of Celery
The effect of rest in producing molecular recovery, and hence in the removal of fatigue, is well illustrated in the following set of photographic records ([fig. 25]). The first shows the curve obtained with a fresh plant. The effect is seen to be very large. Two minutes were allowed for recovery, and then stimulation was repeated during another two minutes. The response in this case is seen to be decidedly smaller. A third case is somewhat similar to the second. A period of rest of five minutes was now allowed, and the curve obtained subsequently, owing to partial removal of residual strain, is found to exhibit greater response.
Fig. 25.—Effect of Continuous Vibration (through 50°) in Carrot
In the first three records, two minutes’ stimulation is followed by two minutes’ recovery. The last record was taken after the specimen had a rest of five minutes. The response, owing to removal of fatigue by rest, is stronger.
The results thus arrived at, under the simple conditions of vegetable life, free as they are from all possible complications and uncertainties, may perhaps throw some light on the obscure phenomena of fatigue in animal tissues.
FOOTNOTES:
[10] Biedermann, Electro-physiology, p. 86.
[11] Biedermann, loc. cit.