432 Phytin on the Growth of Seedlings [Mar. 



The particular methods in the studies of the effects of 

 phytin. In distilled water, growth of the seedlings was very slow 

 and ceased after three days. In very dilute Solutions of magnesium 

 sulphate, potassium phosphate, or potassium nitrate, results were 

 almost equally negative; but when calcium sulphate or calcium ni- 

 trate was used, growth was pronounced. One or the other of these 

 last two substances was therefore used as a sort of "basal ration," 

 and the phytate whose influence was to be studied was added to a 

 Solution containing it. Sometimes magnesium sulphate, potassium 

 phosphate and potassium nitrate, substances so commonly used in 

 making artificial soils for experimental purposes, were added, to 

 determine the effect of their association with the phytate. 



Many seedlings were planted, some in duplicate Solutions, others 

 in media containing various combinations of the Compounds men- 

 tioned above, many of them without any phytates. From volumi- 

 nous data a selection has been made of the results which seem to 

 be of the most importance in this connection. The figures which 

 are tabulated below show, in each case, the average growth per 

 plant per day in millimeters, for the period designated, usually 

 from one to three days. 



To facilitate comparison between plants grown in different 

 media, there is given in the last column the average growth per 

 plant per day during the first six days, as this Covers in all cases 

 the period of most rapid growth. A slight discrepancy between the 

 data in this column and in the others occasionally results from the 

 fact that these averages were made from the recorded data on those 

 plants which flourished to the end of the experiment. Thus, in 

 beaker No. 37, the average per plant per day for the first six days 

 is 12.7 millimeters, whereas the average of the separate day reports 

 would be 12.4 millimeters. These differences are negligible, being 

 very much less than the variations in rate of growth of individual 

 plants in the same beaker. The measurements from period to 

 period are given to show the changes in the rate of growth, because 

 of the depletion of the nutrient medium, or increase of acidity, due 

 to the selective action of the root, or both. (Table 4. ) 



Discussion of the results. When the seedlings were placed 

 in a very dilute Solution of calcium inosite hexaphosphate 



