4o8 
RICHARD M. HOLMAN 
In the course of the experiments upon the curvature of primary 
roots in different media, I had noted that the secondary roots arising 
from the upper side of a primary root, which had been planted hori- 
zontally in loose moist sawdust or just below the surface of very loose 
soil, showed little tendency to bend downward. They frequently 
bent so slowly that they emerged from the medium and grew obliquely 
Fig. I. Secondary roots of Vicia faba, which arose from a primary root 
planted horizontally near the surface of fine moist soil. After emerging from the 
soil the roots grew upward into the air as shown in the figure. 
Upward into the moist air above the cultures for several centimeters. 
In such cases they never re-entered the medium from which they 
2 Compare Sachs, Ueber das Wachsthum der Haupt- und Nebenwurzeln. Arb. 
Bot. Inst. Wiirzburg. i : 633. 1874. Here Sachs reports the emergence of secondary 
roots from the soil when the mother root was growing perpendicularly. The second- 
ary roots arose from the hypocotyl but those of which I speak had their origin i to 
4 cm. below the root base. 
