17 



drawn for temperature 25 may be applied to seedlings 

 from similar seeds grown at 20 and 30 C respectively. 

 Because of the limited number of large seeds no data is 

 available save at 25 C. The discussion will be confined to 

 a consideration of average values. The data for seedlings 

 grown at 20C are found in *Tables 40 to 43, that for those 

 grown at 30C in Tables 44 to 47. 

 a. Growth as Related to Specific Gravity. 



A study of the above tables shows that with but few ex- 

 ceptions the conclusions drawn for the relation of growth 

 to the specific gravity of the seed, for temperature 25 C are 

 also true for temperatures 20 and 30C. At 25C there 

 was no correlation evident between length of hypocotyl 

 and specific gravity of seed; at 20, however, the greatest 

 average length of hypocotyl in seedlings grown in soil ap- 

 pear in those of Densities 1, 2 and 3. 



At 25 C, the percentage of the dry plant weight to the 

 seed weight is higher for seedlings from seeds of Density 

 6 than for those from seeds of Densities 1 and 2. At 20 C, 

 this is true only for seedlings grown in water, and at 30 C, 

 it applies solely to seedlings from medium seeds grown in 

 water. 



b. Growth as Related to Size of Seed. 



The seedlings grown at 30 C show the same correlation 

 between growth and size of seed as is shown by those grown 

 at 25 C. For the seedlings grown at 20 C, however, the 

 following points of difference seem evident: 



(1) The average heights and average weights of seed- 

 lings from small seeds are more nearly equal to the similar 

 average values of seedlings from medium seeds of like 

 densities, at 20 C than at 25 C. In a few cases the average 

 values for seedlings from small seeds exceed those for 

 seedlings from medium seeds. 



(2) From the total dry weight it may be inferred that 

 at 20 C the seedlings from small seeds use their reserve 

 material to better advantage than those from the medium 

 seeds. 



(3) At 20 C, the greater rate of growth is shown by 

 seedlings from the small seeds. 



