308 HOW CEOPS GEOW. 



Baron Liebig asserts {N'atural Laws of Susbaneh'y, 

 Am. Ed., 1863, p. 24) that "the strength and number of 

 the roots and leaves formed in the process of gernunation, 

 are, (as regards the non-nitrogenous constituents,) ia di- 

 rect proportion to the amount of starch in the seed." 

 Further, "poor and sickly seeds will produce stunted 

 plants, which wUl 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, (l-30th or l-20th of a grain,) sown in an ab- 

 Svolutely sterile soil, will produce plants in which all the 

 organs are developed, but their weight, after mouths, 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 ex2)eriments 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 : — 



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