Groivth o/Lemna minor in Mineral Culture Solutions. 489 



7,000 

 6,500 

 6,000 

 5,500 

 ^5,000 

 ^4,500 

 ^4,000 

 03,500 

 ^3,000 

 ^2,500 

 2,000 



1,500 



1,000 



500 



o 



I Z 3 4 5 6 

 Time in weeks 



_ 



N P K 



Fig. 1 



1. Detmers solution. 



2. „ „ + water extract. 



3. „ „ + water extract (free from huinic acid). 



4. ,, „ + alcoholic extract. 



5. „ „ + phosphotungstic fraction. 



(The black portions at the top of each column represent the maximum percentage 

 addition (Series II) of N (4'8 per cent.), P (1-8 per cent.), and K (0"04 per cent.), to the 

 quantities already present in Detmers solution.) 



Table IV. 



Series. 



At 

 beginning 

 of experi- 

 ment. 



1st 

 week. 



2nd 

 week. 



3rd week. 



4th week. 



5th week. 



6th week. 



7th 

 week. 



8th 

 week. 



No. 



No. 



No. 



Wt. 



No. 



Wt. 



No. 



Wt. 



No. 



Wt. 



No. 



No. 



I 

 II 

 III 

 IV 

 V 



100 

 100 

 100 

 100 

 100 



100 

 123 

 117 

 109 

 107 



100 

 195 

 145 

 114 

 107 



100 

 426 

 262 

 159 

 121 



100 

 536 

 288 

 166 

 122 



100 

 814 

 415 

 207 

 126 



100 100 

 1,519 j 1,451 

 690 660 

 255 ; 256 

 164 | 137 



100 

 4,100 

 1,711 

 492 

 223 



100 

 2,059 

 957 

 337 

 148 



100 

 6,267 

 2,934 

 736 

 260 



100 

 3,590 

 1,774 

 580 

 177 



100 

 6,587 

 3,684 

 1,232 



215 



