The Cause of the Excrelion of "Water on the surface of Nectaries. 1 9 



Inactire Nectaries Placed under Pressure in Order to See 

 if This Would again luduce the Excretion. 



Frilillaria imperialis. 



Inflorescence wilh four flowers. The excrelion of nectar in three 

 flowers enlirely stopped by washing. The flowers still young, none of the 

 anthers having shed their pollen. This entire stem subjected to a pressure 

 first of 20 ctm. quieksilver for five hours; and second to 40 ctm. quick- 

 silver for another five hours. No change in the nectaries in either case 

 observed. None of them became inoist. The water was driven into the 

 leaves, oozing out at wounded places and standing in pools on some of Ihe 

 under surfaces. The secretion in the one flower with active nectaries un- 

 changed in quanlily and apparently normal. The pressure seemed to have 

 no perceptible influence either on the active or inactive nectaries. 



Acer pseudoplatanus. 



A braneh of A. pseudoplatanus in the flowers of which the excretion 

 of nectar had been stopped by washing was subjected to a pressure exerted 

 by a column of quieksilver 45 ctm. high for more than 24 hours. No efiect 

 was observed on the dry nectaries. The water was driven to the surface 

 of the delicale stems and young leaves, standing here and there in small 

 drops. A similar trial with P. laurocerasus gave like results. 



Excretion of Nectar under low Temperatures. 



Prunus laurocerasus. 



Several branches of P. laurocerasus whose nectaries were excreting 

 finely in a room 4 7° to 20^ G. were placed in a cold room. The nectar was 

 removed with a pipette. 



Feb. 2*1. Monday 12 o'clock Ther. + 1 ° C. 



- 3^. Tuesday 12 - - 5,5° C. 

 All the nectaries secreting slowly. 



- 4*^^. Wed. 12 o'clock Ther. 5° C. 

 Nectaries active. 



- h^^. Thursday 3 o'clock Ther. 3,5° G. 

 Nectaries secreting well. 



- 6t\ Friday 10 o'clock Ther. 1,6° G. 

 Nectaries provided with large drops of nectar. 



2* 



