1905.] Function of Silica in the Nutrition of Cereals. 475 



acid by the plant, to which phosphoric acid the observed effects are due. 

 There is no evidence that the silica within the plant causes a more 

 thorough utilisation of the phosphoric acid that has already been assimilated, 

 or itself promotes the migration of food materials from the straw to 

 the grain. 



(4) The seat of the action is within the plant and not in the soil. 



Appendix. 

 Table VII— Hoos Field Barley, 1904. 



Actual Dry Weights of Grain and Total Plant. 







No silica. 







With silica. 

























Mean 



of 



all plots. 



Date 

 of sample. 



Plot 1. 

 Nitrogen 

 only. 



Plot 2. 



No 

 potash. 



Plot 3. 

 No 

 phosphate. 



Plot 4. 

 Complete. 



Plot 1 S. 

 Nitrogen 

 only. 



Plot 2 S. 



No 

 potash. 



Plot 3 S. 



No 

 phosphate. 



Plot 4 S. 

 Complete. 











mole Plant. 











June 13... 



„ 20... 



„ 27... 

 July 4... 



» 11- 

 „ 18... 

 „ 25... 

 Aug. 1... 

 „ 8... 



grammes. 

 84 -5 

 112 -0 

 107 9 

 116 -5 

 138 -9 

 124-2 

 161 -4 

 158 -9 

 173 -3 



grammes. 

 134 5 

 187 -5 

 218 -5 

 236 -5 

 225 

 215 -1 

 279-2 

 260 -9 

 270-2 



grammes. 

 53 1 

 70 -1 

 96 -5 

 103 

 104-0 

 134 -7 

 139 -3 

 111-1 

 154 -4 



grammes. 

 135 -3 

 180 "6 

 186 -3 

 201 -1 

 244 -5 

 266 -9 

 263-1 

 226 "5 

 217 -1 



grammes. 

 140-4 

 163 -0 

 184 -7 

 194-0 

 226 -6 

 241 -4 

 245 -1 

 223 -0 

 211 -4 



grammes. 

 101 -5 

 186 -3 

 216 -4 

 203 -8 

 280 -7 

 304-0 

 219 -5 

 244 -8 

 249-9 



grammes. 

 109 -4 

 146 -9 

 195 -1 



193 -7 



194 -9 

 212-2 

 260 -2 

 139 -4 

 248 -7 



grammes. 

 146-7 

 164 -9 

 202 -0 

 184 -7 

 258-0 

 255 -6 

 260 -0 

 214 -3 

 301-1 



grammes. 

 113 -2 

 151 -4 

 175-9 

 179-2 

 209 -1 

 219 -3 

 228 -5 

 197 -4 

 228 -3 











Grain. 











July 4... 



„ 11... 



„ 18... 



„ 25... 

 Aug. 1... 



„ 8... 



3-2 

 13 -5 

 26 -2 

 50-4 

 53 8 

 63 -8 



18 -8 

 34-9 

 61 -0 



102- 

 99 -0 



103- 6 



3-3 

 6-8 

 24 -5 

 38 -6 

 35 -8 

 52 -7 



15 -8 

 41 -7 

 71 -0 

 87 -7 

 83 -3 

 74 -2 



12-5 

 29 -5 

 67 -9 

 84-0 

 88 -3 

 80 -4 



16 -4 

 49-6 

 85 -0 

 70 -6 



94 -9 



95 -6 



7-6 

 18 -9 

 40-3 

 80 -5 

 48 -7 

 92 -7 



14-6 

 41-4 

 69 -1 



85 -4 i 

 75 -5 

 108 -0 



11 -5 

 29 -5 

 55 -6 

 74 -9 

 72 -4 

 83 -9 



