VARIOUS TYPES OF RESPONSE
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irresponsive, and only after a period of rest can it exhibit excitation. The same phenomena are observed in the case of the contractile organ of Mimosa. Here also, after
Fig. 40.—Alternating response; differences between alternate responses become accentuated.
erection (expansion) under continuous stimulation, the leaf is irresponsive and only renews its excitability after a definite period of rest.
As regards this particular reaction in Mimosa, we are
Fig. 41.—Fatigue-decline in frog's muscle under continuous stimulation. (Brodie.)
in a position to trace out the various phases through which contraction under single stimulus is reversed to expansion under fatigue induced by continuous stimulation. It has
