124 ILLINOIS STATE ACADEMY OF SCIENCE 



again in Density 2, all dry root, shoot and plant weights 

 vary as the size of the seeds provided we compare seed- 

 lings from seeds of the same density. Plate IV represents 

 the average dry plant weights for soil grown seedlings. 



Comparison of Weights. — In general, the percentage 

 which the dry weight of shoot and plant is of the fresh 

 weight of like member is greater for seedlings from the 

 large seeds than from the medium or the small seeds. The 

 percentage which the dry plant weight is of the seed weight 

 is also higher for seedlings from the large seeds than from 

 the medium or small seeds. 



Rate of Groivth. — That the rate of growth is also influ- 

 enced by the size of the seed is shown by the daily growth 

 increments. For water culture seedlings the average daily 

 increments (Tables 18 to 20) on the second and third day 

 are greater for the seedlings from m.edium seeds than for 

 those of either small or large seeds of like density. The 

 greatest average daily increments, except in seedlings from 

 large seeds of Densities 1 and 2, are found in the seedlings 

 from the medium seeds. The maximum daily increment 

 occurs on the second day in seedlings from the small and 

 the medium seeds but not until the third day for those from 

 the large seeds. The same superiority in the rate of growth 

 for seedlings from the medium seeds grown in soil is seen 

 from Tables 37 to 39. 



In so far as amount and rate of growth are influenced 

 by the size of the seed, we find: 



(1) The amount of growth varies with the size of the 

 seed; 



(2) There is more variation in amount of growth be- 

 tween small and medium seeds than between medium and 

 large seeds; 



(3) The rate of growth of seedlings from medium seeds 

 is greater than that for those of small or large seeds of 

 equal density. 



3. Temperature in Relation to Specific Gravity 

 and Size of Seed. 

 It is not the intention to discuss in detail growth at 

 20° and 30 °C, but rather to determine whether conclusions 



