﻿1903] 



CHEMICAL STIMULATION 



179 



I 



Sing the protoplast predominates over the chemical stimulation, 

 and the respiration sinks below normal. 



2N 



June 4. Test of — KNO3 and 



bottle has 150*=^ - KNO3. 



N ^ 



has 150"^^ - KCI. 



I 



TABLE XXIV. 



KCi, Exp. is Elodea in 225*^*^ dist, 

 Control Elodea in 225*^^ dist. HjO. Small bottle 



H3O. Small 



Time 



Control 



10:15 



6 :09 

 6 :09 

 8:27 

 10:39 

 7:21 

 2 :o9 



- 6 :09 



Bottles 

 -8:27 



-10:39 



- 7 :2i (8.7) hrs, 



- 2 : 09 

 ■10 :09 



0.073 

 poured toget 



0.063 



0.064 



0.044 



0.052 



0.140 



her. 



0.070 



0.059 



0.057 

 0.045 



0.077 



0.144 



The low figures for the third period after applying the salt are partly due to a fall 

 of 1.3" C. in temp. 



n the evolution of COo occurred 



The very rapid Increase in lh.. v:v.^it^Li^... ^.^ w^2 ^ 



about as long after the application of the salt as was to have been 



expected with a solution but half 

 as strong, from which it appears 

 probable that the physical action 

 ~~ of the salt has tended to protect 

 the plant. The case is roughly 



TABLE XXXV. 

 May 27. Test of - NaNO 



5 



Time 



6: 58-11 : 52 

 11:52 



11:52-6:22 



Bottles po 



Experiment 



10 : 00 P.M,-io :00 A.M. 



10:00-6:00 (8 hours.) 

 6:00 P.M., May 28 



turgor and 

 ^^15-9:45 



0-033 

 ured together. 



0.052 



0.038 



0.087 



Tested as to 



found dead. 



0.107 



analogous to those of the seeds 

 of Lepidium49 and the sporocarp 

 of Marsilea 5^ which retain their 



vitality indefinitely in very strong 

 alcohol, but succumb quickly if 



the alcohol contains water enough 



The exceptional acceleration of 58 to soften the coats and make them 



per cent, by NaN03 (table XXXIII) permeable. 



comes from computing it from the first 

 6.5 hours of the salt's action. If i8 

 hours had been included it would hav 

 been only 30 per cent. 



It remains to present a few of 

 the experiments with K and Na 

 fully enough to illustrate, as the 



last table does, the final rise of the curve of respiration, usuall} 

 about a day after the application of the salt. 



•^'F. NoBBE, Handbuch der Samenkunde ii6. Berlin. 1876. 



5° C. R. Barnes, Vitality of Marsilea quadrifolia. Box. Gaz. 20 : 229. 1895. 



Ju 9_ 



