Page:Life Movements in Plants.djvu/261

Rh results described vnalile us to vnunciah' general Laws of EIIeUIa of Direct and Imlirvct stimulus nn tissnvs in nm'mal and in sub-tunic. ('mulilion.

I. THE EFFECT OI“ DIREC" STIMI'LUS IS NEGATIVE VARIATION OI“ 'I‘URGOR, NEGATIVE MECHANICAL ANI) ELEC- TRICAL RESPONSE, NEGATIVE VARIATION, OR RE'I‘ARIIA'I‘ION OF RATE OF GROWTH. (t. SUB-MINIMAL STIMULUS GIVES POSITIVE RESPONSE. ’1. POSITIVE RESPONSE IS ALSO GIVEN BY A TISSUE IN A Sl’R-TONH‘ CONDITION: CONTINUOUS STIMULA- TION CONVER'I‘S THE ABNORMAL POSITIVE 'l‘O NORMAL NEGATIVE RESPONSE.

('. AUTONOMOUS ACTIVITY IN A STATE OI“ STANDSTILL, MAY RE REVIVEI) RY STIMULUS.

(I. THE EREEC'I‘S OI" STIMI'LI'S ANH WARMTH ARE ANTAGONISTIC.

2. THE EFFECT OI“ INDIRECT STIMULUS IS POSITIVE VARIATION OF TURGOR, POSITIVE MECHANICAL ANI) ELEC- TRICAL RESPONSE ANI) POSITIVE VARIATION OR ACCELERA- TION OF RATE OI" GROWTH.

I haw referred In tlu- fact pruvimmly (ll'IlIOHSlI‘lltPll, that while Din-ct Slllnllllh‘ IIHIIICPS contraction and r-lamlation of growth, Ilimlcratv rim- ul' tompvralurc IIIIIIICPS the OppOSltH i-ll'cct of uxpansiun and accvlvratinn nl‘ grnwtli. Further (It‘lllOllSII‘ilIIUn (if the antagnnistic ulI'vcts uf stimulus

and warmth will ln- gin-n in NW nle Paper.

The autonnmuus activity of pulsating lc-ullel. ni' Desmu diam gyl'rms Conn-s tn a stop under doplution of internal energy. A cut leaf isolated from the plant maintains the