486 



T. YOKOI. 

 TABLE n. 



Percent cf water 



Calculated ratio of plumule to radicle. 



in sand. 



ri 



2nd day. 



u 



>^ 

 -a 





6th day. 



>^ 



rt 



8th day. 



T3 



On 



No. 



Water without ) 



p. r. 



D. r 



P- 









n 





P- 





P- 





P- 





P- 





I 



sand covering r 











I 



: 0.32 



I 



■ 0.33 



I 



: 0.46 



I 



: 0.62 



I 



: 0.80 



I 



: I.IO 





seed. ) 





































Su]^erfluous 1 



































II 



water in sand I 















I 



0.24 



I 



• 0.34 



I 



• 0.49 



I 



: O.So 



I 



: 0.71 





coverinp; seed. ) 



































III 



30 %' 



— 



1 : 0.74 



I 



1.40 



I 



: 1-57 



I 



2.51 



I 



2.24 



I 



2-45 



I 



: 2.22 



I 



: 2.09 



lY 



27 





I : 0.71 



I 



'•39 



I 



: 1.58 



I 



2.22 



I 



1-93 



I 



: 1.69 



I 



: 1.59 



I 



: 1-57 



V 



24 





I : 2.50 



1 



2.88 



I 



: 3-39 



I 



2.45 



I 



: 2.18 



I 



2.04 



I 



: 2.28 



I 



: 1.92 



VI 



20 „ 





I : 1.25 



I 



1.44 



I 



: 1.66 



I 



2.20 



I 



: 2.34 



I 



2.63 



I 



= 2.54 



I 



: 2.26 



VII 



18 „ 







I 



1.60 



I 



: 1.88 



I 



2.69 



I 



2.66 



I 



2.61 



I 



: 273 



I 



: 2.61 



VIII 



15 







I 



I. So 



I 



: 2.87 



I 



3.0S 



I 



3-44 



I 



3-53 



I 



: 3-92 



I 



: 3.66 



IX 



12 „ 







I 



4-75 



I 



: 4.51 





5.26 



I 



5-09 



I 



503 



I 



■■ 4-54 



I 



: 4.64 



X 



7 5" 











I 



14.14 



I 



7.00 



I 



5-36 



I 



4-75 



I 



■■ 5-50 



I 



: 5.60 



From these figures and the subjoined sketches, it ma)' clearly 

 be seen that the quantity of water in the sand has a great influence 

 upon the relative development of the plumule and radicle ; when 

 allowed to germinate under water with or without sand, the 

 plumule alone develops 2 or 3 days before the radicle could be 

 clearly recognised. On the contrary, when the quantity of water 

 contained in the sand is scanty (between 15% — 7.5 %) the radicle 

 develops before the plumule. When the percentage of water falls 

 below 27 or in one case 24 germination is greatly retarded and with 

 it the whole development of seedling, and some irregularities are 

 observed in the ratio of the plumule to the radicle ; but carefully 

 comparing the figures, it may clearly be seen that with the decrease 

 of the percentage of water, the difference becomes greater, that is 

 to say tlie redicle develops comparatively faster than the plumule. 

 It has also been observed that when the radicle is surrounded with 

 abundant quantity of water very few or no root hairs could be found 

 on it. 



Such a phenomenon seems to be very natural as the main 

 function of the radicle is the absorption of water, and to absorb a 



