37 



3°. 

 4°. 

 5°. 

 6°. 



The following points are worthy of notice : 

 1°. Percentage of curved (100*^/o) too liigh (normally 

 60—80 '^Vo). 

 2°. Reaction-time too short (30 min. instead of 36 min.). 

 The reaction subsides with extraordinary rapidity. 

 After 70 — 75 min. reaction vigorously positive. 

 Positive reaction subsides rapidly. 

 Reaction oscillating, after 40 min. maximum of 

 négative reaction, , after 70 min. maximum of positive 

 reaction, after 95 ? min. négative again, after 120 — 150 

 min. positive again. 



This tailles exactly with the supposition that the geotropic 

 stimulation has taken place exactly at the moment, that 

 the nutating coleoptiles were vertical and were on the 

 point of starting a curvature in the same direction as 

 would be induced by the negatively geotropic stimulation. 

 Suppose the nutation-period to be 70 minutes — and 

 Rothert's figures do not conflict vi^ith this supposition, 

 as he himself gives various values for this period — , 

 then we find, calculating where the maxima of positive 

 and négative curvation are to be seen : 



Maximum. Maximum, 



calculated from nutations observed 



négative 85 min. 40 min. 



positive 70 „ 65 — 75 „ 



