PAPERS ON BIOLOGY AND AGRICULTURE 119 



Rate of Growth. — Not only is the amount of growth 

 related to the specific gravity of the seed but there also 

 exists a relation between the rate of growth and the spe- 

 cific gravity of seed. Considering the rate of growth as 

 shown by the daily growth increments we find that, in gen- 

 eral, seedlings from seeds of the higher densities have a 

 greater grov/th rate than those from seeds of the lower 

 densities. The greatest average daily increment for the 

 small seeds, 5.8 cm, was made on the second day after be- 

 ing placed in the constant temperature case by the seed- 

 lings from seeds of Density 6. For the medium seeds, the 

 greatest average daily increment, 7.63 cm, was made on 

 the second day by seedlings from seed of Density 3 ; and 

 for the large seeds, an average daily gi'owth of 6.85 cm 

 was made on the third day by seedlings from seeds of Den- 

 sity 1. The maximum daily growth increment of the seed- 

 lings from small seeds is 7 cm, made on the second day by 

 a seedling from a seed of Density 3 ; the maximum for the 

 medium seeds is 9.3 cm, made on the second day by a seed- 

 ling also from a seed of Density 3. For the large seeds, the 

 maximum increment 7.7 cm was made on the third day by 

 a seedling from a seed of Density 2. The average rate 

 of growth often decreases more rapidly in the seedlings 

 irom seeds of the lower densities and although the total 

 height of the seedlings from these densities is less than 

 that for those from the denser seeds, growth usually con- 

 tinues for as many days as in seedlings from the seeds of 

 higher densities. 



b. Soil Culture. 



The data for seedlings gro\\Ti in soil at temperature 25 - C 

 is given in Tables 21 to 40. Tables *21 to 36 contain the 

 records of the individual seedlings while the average values 

 are shown in Tables 38 to 40. Because of the limited num- 

 ber of large seeds of Densities 1 and 6 none were grown 

 in soil. 



Size. — Proceeding as in the discussion of the seedlings 

 grown in water, we find the greatest average shoot heights 

 for the small, the medium and the large seeds respectively, 

 are for seedlings from seeds of Densities 1, 3 and 3. The 

 highest shoot from the small seeds is that of a seedling 



