4 I*li!),slolvylcal Pre-detenuuuitiou 



Phaseoliis. In the case of Phaseolus, soaking the seeds previous to 

 germination has an even more marked effect upon the subsequent course 

 and vigour of development. Soaking for only 8 hours reduces the total 

 growth after 12 days to 7-2 cm. as compared with 13-8 cm. for those sown 

 dry on damp sand in spite of the fact that those which were soaked had 

 a considerable start in germination and sprouted earlier. 



The second point of importance brought out by these experiments is 

 that the striking effects of soaking the seed upon its subsequent develop- 

 ment are not visible in first observations upon germination. For instance, 

 the seeds soaked for 24 hours showed a full percentage of germination 

 and at first the radicles of these seeds appeared to be the largest and 

 strongest of the whole series. At this stage the seedlings were such as 

 would obviously be selected for physiological experiments, for example, 

 on the rate of growth as influenced by temperature, etc. Nevertheless, 

 on the twelfth day of the experiment half these plants had died and the 

 remainder showed only about one-sixth of the growth of those plants 

 which had arisen from seeds not soaked previous to sowing. 



Hordeuin. There is a progressive decrease in dry weight with time of 

 soaking of seeds previous to sowing. The seeds, which had not been soaked 

 at all, gave rise to the heaviest plants after 12 days in spite of the fact 

 that during the first 4 or 5 days they were obviously behind the others 

 owing to their slower germination. 



Experiment 2. Seeds sown in soil. 



In this experiment the following seeds were used: 



Wheat (Sutton's, Sept. 1917), 



Oats (Sutton's, Sept. 1917), 



White Mustard [Brassica alba] (Carter's, Sept. 1917), 



Dwarf Bean [Phaseolus vulgaris] (Sutton's, Sept, 1917), 



Inroad Bean [Vicia Faba] (Carter's, Nov. 1916), 



White Lupin (Carter's, March, 1916). 



Samples of the above-mentioned seeds were soaked for the following 

 periods, 6, 24, 48 and 72 hours respectively under conditions similar to 

 those of the previous experiment. They were then sown in potting soil in 

 a greenhouse with an average temperature of 65° F., and were transferred 

 to a greenhouse with an average temperature of 55"^ F. as follows: White 

 Mustaifl after 4 days. Wheat and Oats after 5 days, Lupins after 7 days. 

 Dwarf Beans and Broad J:}eans after 9 days. 



