1920] 



SNO W—DIA PHRA GMS 



299 



of sheath; the second was cl 

 third culm was marked again 



and 4. mm. from 



The 



disappeared and the second mark was 4 mm. from the 



From these experiments it seems reasonable to conclude that the 



Scirpus validus takes place within 



distance 





Experiment 4 



While the foregoing experiments were in progress, others were 

 started, to test the effect of the medium upon the growing region. 

 Pieces of rhizome were potted, practically at the surface of the soil, 

 and placed under water. When the culms were well grown, the 

 water was allowed to evaporate until the surface of the soil was 

 exposed to the air. When the water level had fallen to about an 



TABLE 11 



Variation in growth of Scirpus validus when changed from one medium to 



A 

 B 



C 



D 

 F 

 G 



AA 



BB 



CC 



DD 



EE 



Pot 



ANOTHER 



Water to air 



Accelerated 



No. of 



culms 



Averages . 

 Total nos . 





3 



Mm. per 

 day 



16.0 



2.0 



42.O 



Retarded 



No. of 



culms 





20.0 





I 

 I 



8 



Mm. per 

 day 



22.0 



5.0 



II. O 

 I2.0 



ISO 



2.5 



24.0 



17-5 



136 



Air to water 



Accelerated 



No. of 



culms 



I 

 I 



I 

 I 

 I 



16 



Mm. per 

 day 



o.5 

 4-5 

 45 

 1.5 



1.0 



1-5 

 5.° 



.3-° 



1.0 

 2.0 



3-o 



2-5 



2.0 



1.0 



6-5 



2.6 



Retarded 



No. of 



culms 



Mm. per 

 day 



Unchanged 



No. of 



culms 



4 



2.5 



3 



