10 PJiysioloyical Pre-determination 



results being obtained by similar treatment upon closely allied plants. 

 Beans, which give the most striking results, illustrate these three points 

 effectively. 



Firstly, the result of soaking Dwarf Beans {Phaseolus vulgaris) even for 

 a period of 6 hours becomes evident after a month's growth by a decrease 

 in the dry weight yield of the tops of the plants of 26 per cent, as com- 

 pared with the control crop produced from seeds planted dry (Exp. 2). 

 Secondly, seeds of the same species, which were soaked for a period of 

 24 hours before sowing, showed by far the most rapid and vigorous 

 germination (Exp. ] ), while later, 12 days after sowing, the total length 

 of these plants as compared with the controls set dry was as 2-4: : 13*8. 

 Lastly, when the results obtained with the Broad Bean {Vicia Faba\ are 

 compared with the above (Exp. 2), an absolute reversal in the effects 

 following soaking is observed. In the case of the Broad Bean the effect 

 of soaking the seeds for periods up to 3 days was found to be increasingly 

 beneficial, not only on the percentage of germination, but also upon the 

 size of the plant produced. Thus, after an interval of 3 weeks the average 

 height of the plants produced from seeds planted dry was only 4 cm. as 

 compared with 10-4 cm. in the case of those soaked for 3 days before 

 sowing. 



The thanks of the authors are due to Mr W. Hales, A.L.S., Curator of 

 the Chelsea Physic Gardens, for assistance in the culture of the seedlings. 



EXPLANATION OF PLATE FIGURES. 



PLATE I 



Fig. 1. ^Vheat plants from seeds sown dry (0), soaked in water previous to sowing for 

 periods of liour.s (^), 24 hours (1), 48 hours (2), and 72 hours (3) respectively. Photo- 

 graphed 4 w(;('ks after sowing. 



Fig. 2. Dwarf bean plants from seeds sown dry (0), soaked in water previous to sowing for 

 periods of hours (J), 24 hours (I), and 48 hours (2) respectively. Pliotographed 

 4i weeks after sowing. 



Fig. 3. A parallel series to that shown in Fig. 2. Photographed 4J weeks after sowing. 



PLATE II 



Fig. 4. A. Dwarf bean plants from seeds sown dry. 



B. Dwarf bean plants from seeds soaked for 12 hours previous to sowing. Photo- 

 graphed 8 weeks after sowing. 

 Fig. 5. A. Dwarf bean plants from seeds sown dry. The testas were removed. 



B. Dwarf bean plants from seeds soaked for 12 hours previous to sowing. The 

 testas were removed previous to the soaking treatment. Photographed 8 weeks after 

 sowing 



