20 



Development and Activities of Roots of Crop Plants. 



turned downward and penetrated deeply into the subsoil (fig. 6). Some of 

 the roots, just described, descended almost vertically, others ran obliquely 

 outward 0.3 to 1.3 feet and then took a perpendicularly downward course. 

 The soil was fairly well filled with roots to a depth of 3.7 to 4.2 feet, while 



FiQ. 6. — Manchuria barley at maturity. 



many penetrated to a depth of 5 to 5.8 feet. The maximum penetration 

 was 6.3 feet. The roots were 1 to 1.5 mm. in diameter. They were all 

 abundantly supplied with branches from 0.2 to 2 or 3 inches in length. The 

 branches now extended quite to the root-tips, showing that growth was 

 complete. 



