On the Electromotive Properties of the Leaf of Dionaea in the Excited and Unexcited StatesSecond Paper . on of resistance was such thatwith the same length of wire the deflection representing the difference, which beforemodification was 370 scale, increased after modification to 115 X 10, that is, 115 scale,with one-tenth of the current through the galvanometer. It will be noticed that inthis leaf the resistance both before and after the passage of the external current wasmuch less than in Experiment I. When the first rheotome observation was made, PROPERTIES OF THE LEAF OF DION^SA. 437 the ex
On the Electromotive Properties of the Leaf of Dionaea in the Excited and Unexcited StatesSecond Paper . on of resistance was such thatwith the same length of wire the deflection representing the difference, which beforemodification was 370 scale, increased after modification to 115 X 10, that is, 115 scale,with one-tenth of the current through the galvanometer. It will be noticed that inthis leaf the resistance both before and after the passage of the external current wasmuch less than in Experiment I. When the first rheotome observation was made, PROPERTIES OF THE LEAF OF DION^SA. 437 the excitatory variation was (with the galvanometer) f 120, {220. It showed already,therefore, the characters of the modified state, although the difference was still {.But from the rheotome readings it appeared that the first phase was of relativelyshort duration, for during the second half of the first second the relative negativityof the under surface was very rapidly diminishing, and during the second second itwas reversed. The comparison of the two records shows that the change of sign did Diagram not occur until a second later, the operation in the less modified state of what may bedesignated the } element in the excitatory effect of the external current being toannul this action, or so far to diminish it as to give complete predominance to itsopposite. Here again it must be noted that the great amplitude of the deflections inthe second rheotome observation was due to diminution of resistance. Experiment III. (diagram 4).—In this preparation the difference remainedconstant, namely, between 14 and 15, during the whole observation. The excitatoryeffect was observed with the electrometer, and had the character shown in photograph 13(Plate 70). The rheotome observation showed that the oscillation was, as in Experi-ment I., completed during the first second. After modification, which was promptlyeffected in the usual way, the difference changed sign from }7 to 0, or {0*5, andt
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Keywords: ., bookcentury1800, bookdecade1880, bookidphiltrans019, bookyear1888
