308 HOW CROPS GROW. 
Baron Liebig asserts (Watural Laws of Husbandry, 
Am, Fd., 1863, p. 24) that “the strength and number of 
the roots and leaves formed in the process of germination, 
are, (as regards the non-nitrogenous constituents,) in di- 
rect proportion to the amount of starch in the seed.” 
Further, “poor and sickly seeds will produce stunted 
plants, which will again yield seeds bearing in a great 
measure the same character.” On the contrary, he states 
(on page 61 of the same book, foot note,) that “ Boussing- 
ault has observed that even seeds weighing two or three 
milligrames, (1-30th or 1-20th of a grain,) sown in an ab- 
solutely sterile soil, will produce plants in which all the 
organs are developed, but their weight, after months, does 
not amount to much more than that of the original seed. 
The plants are reduced in all dimensions; they may, how- 
ever, grow, flower, and even bear seed, which only requires 
a fertile soil to produce again a plant of the natural size.” 
These seeds must be diminutive, yet placed in a fertile soil 
they give a plant of normal dimensions. We must thence 
conclude that the amount of starch, gluten, etc.—in other 
words the weight of a seed—is not altogether an index of 
the vigor of the plant that may spring from it. 
Schubert, whose observations on the roots of agricul- 
tural plants are detailed in a former chapter (p. 242,) says, 
as the result of much investigation—“ the vigorous devel- 
opment of plants depends far less upon the size and 
weight of the seed than upon the depth to which it is cov- 
ered with earth, and upon the stores of nourishment. which 
it finds in its first period of life.” 
Value of seed as related to its Density.—From a series 
of experiments made at the Royal Ag. College at Ciren- 
cester, in 1863-4, Prof. Church concludes that the value 
of seed-wheat stands in a certain connection with its spe- 
cific gravity, (Practice with Science, p. 107, London, 1865.) 
He found :— 
