DEVELOPMENT AND STRUCTURE. 83 



The progress made by the roots during the first few 

 days is quite remarkable. They not unfrequently 

 attain to a length of fifteen or eighteen inches before 

 the stem has made three inches above the surface of 

 the ground. 



From the relative positions of the stem and the 

 early roots, the former springing from the crown, and 

 the latter from the base of the embryo, it is evident 

 that the most natural and favorable position of the 

 grain for incipient growth is with the base downward 

 and the crown above. When this condition is re- 

 versed, as continually occurs in planting, the stem 

 and root are each compelled to describe a curve, 

 sometimes equal to a half circle, in order to acquire 

 their normal position. When this position is reached, 

 if the seed should be turned over, the stem and root 

 would again promptly bend themselves through an- 

 other curve, to recover once more the situation natu- 

 ral and indispensable to their proper growth. 



That the position of the kernel when planted is 

 calculated to affect the progress of germination is an 

 obvious and natural conclusion. The author has 

 found, in some experiments having reference to this 

 point, that grains planted in an inverted position are 

 retarded from ten to fifteen hours in the time of their 

 appearance above ground, as compared with others 

 planted in an upright position. 



As soon as the germination of the seed begins, the 

 stem, obeying a natural instinct, springs upward tow- 

 ard the sunlight, while the roots, equally obedient 

 to an instinct of their nature, travel downward into 



