PAPERS ON BIOLOGY A.VD AGRICULTURE 121 



respectively; while the maximum weight for each group 

 is in a seedling from a seed of Density 3 ; the minimum 

 weights are in those of Density' 5 or 6, usually 6. 



In the dry weights we find a definite relation between 

 density and weight. This correlation with plant weight is 

 graphically represented in Plate III. Without exception 

 the highest average and maximum weights for each size 

 group are in the seedlings from seeds of Densities 1, 2 or 

 3. This statement holds true for dry weights of root, 

 shoot and plant. Moreover, the second highest average 

 and maximum weights are in most cases also in seedlings 

 from seeds of these higher densities. The lowest average 

 and minimum weights are for seedlings from seeds of the 

 lower densities. 



Comparison of Weights. — The facts pointed out for seed- 

 lings grown in water with respect to correlation between 

 dry and fresh weights and specific gravity of seed hold 

 true for those gro\\Ti in soil. The seedlings from seeds 

 of Density 6 appear to lead in making the best use of their 

 reserve food as was the case in the water culture. 



Rate of Growth. — A study of the daily growth incre- 

 ments also points to a superiority of the seedlings from 

 the denser seeds. In the case of average daily increments 

 (Tables 37-39) we find the greatest average increment for 

 the small seeds is 7.56 cm on the third day for seedlings 

 from seed of Density 1; for medium seeds, 8.9 cm on the 

 second day by those from seeds of Density 3 ; for large 

 seeds, 7.67 cm on the second day by those from seeds 

 of Density 1. From * Tables 21-36 we obtain as maximum 

 daily increments, for small seeds, 8.5 cm on the third day 

 by a seedling from a seed of Density 1 ; for medium seeds, 

 10 cm on the second day by two seedlings from the seeds 

 of Density 5 and one from those of Density 3 ; for the large 

 seeds, 10.1 cm on the second day by a seedling from seed 

 of Density 1. 



Summing up the results from the data for seedlings 

 grown in water and in soil at 25 "C we find the following 

 relations exist between specific gravity and growth : 



