REPRODUCTIVE GROANS OF PLANTS. 333 



of unfavorable conditions, will, under the continuance 

 of those conditions, produce stunted plants (varieties), 

 whose seeds will be small and light. (Compare Tuscan 

 and pedigree wheat, p. 158.) 



Schubart, whose observations on the roots of agricul- 

 tural plants are detailed in a former chapter (p. 263), 

 says, as the result of much investigation, "the vigorous 

 development of plants depends far less upon the size and 

 weight of the seed than upon the depth to which it is 

 covered with earth, and upon the stores of nourishment 

 which it finds in its first period of life." Eeference is 

 here had to the immediate produce under ordinary agri- 

 cultural conditions. 



Value of Seed as Related to its Density. From 

 a series of experiments made at the Royal Agricultural 

 College at Cirencester, in 1863-6, Church concludes that 

 the value of seed-wheat stands in a certain connection 

 with its specific gravity (Practice with Science, pp. 107, 

 342, 345, London, 1867). He found: 



1. That seed-wheat of the greatest density produces 

 the densest seed. 



2. The seed-wheat of the greatest density yields the 

 greatest amount of dressed corn. 



3. The seed-wheat of medium density generally gives 

 the largest number of ears, but the ears are poorer than 

 those of the densest seed. 



4. The seed-wheat of medium density generally pro- 

 duces the largest number of fruiting plants. 



5. The seed- wheats which sink in water, but float in a 

 liquid having the specific gravity 1.247, are of very low 

 value, yielding, on an average, but 34.4 Ibs. of dressed 

 grain for every 100 yielded by the densest seed. 



6. The densest wheat-seeds are the most translucent 

 or horny, and contain about one-fourth more proteids 

 (or 3 per cent more) than the opake or starchy grains 

 from the same kind of wheat, or even from the same 

 individual plant, or even from the same ear. 



