244 Physiological Pre-determhiation 



(c) "Seed I m/pr agnation'' (i.e. Soaking Seeds in Solutions 

 of Nutrient Salts). 



Wollny (ii)and Tautphoeus (35) in the first instance, and later Schleh (as), 

 Koch (24) and others, investigated the effect of soaking seeds in solutions 

 of various nutrient salts upon their germination and subsequent growth 

 and yield. 



Table XI gives the results of experiments recorded by Wollny, 

 From the table (p. 245) it appears that the results obtained by the 

 use of solutions of nutrient salts are not appreciably better than those 

 obtained with pure water, and this general conclusion is supported by 

 the results obtained by the other authors mentioned above. Schleh used 

 (1) a 20 per cent, solution of potassium nitrate, and (2) a nutrient solution 

 consisting of 5 per cent, phosphoric acid, 10 per cent, nitrogen, and 

 10 per cent, potassium, and soaked his seed for 48 hours. 



{d) Enzymes. 



The enzymes of the seed are primarily concerned in the physiological 

 processes whereby the food-reserves are prepared for consumption and 

 utilised in growth. Factors influencing in any way the utilisation of the 

 food-reserves of the seed may have an important pre-determining 

 influence upon the whole course of subsequent development of the 

 plant. 



In this connection two different lines of experiment have occurred 

 to a number of investigators, namely: — 



(i) To supply the seed artificially with those products which are 

 likely to result from the breaking down of its own food-reserves under 

 the action of enzymes (Sharpe(34)). 



(ii) To supply the seed with the enzymes themselves (Babcock(2), 

 Waugh(37) and (38), Lehmann(27)). Under this category may be included 

 those treatments which are believed to stimulate enzyme action in the 

 seed (Effront(]3)). 



It is unfortunate that the results recorded stop short either at 

 germination or at the early seedling stage. 



Babcock {I.e.) reports the results of an experiment conducted at the 

 Wisconsin Agricultural Experiment Station with corn (Zm Ma'is), less 

 than 50 per cent, of which germinated after soaking in ])ure water. But 

 seeds from the same lot and treated in the same manner as the controls, 

 except that the water in which they were soaked contained commercial 



