GROWTH OF THE ROOT AND STEM 29 
apart, as shown in Fig. 48. Now place the seedling 
back in the germinator in position, the root pointing 
downward. In twenty-four hours see the result. The 
spaces between the marks are no longer equal, showing 
that stretching of the root takes place over a limited area. 
Figs. 48 and 49 show the result with maize and marrow 
seedlings. The root has not grown per- 
ceptibly at the tip, for the space marked 
- off by the first line does not appear to be 
any greater than it was twenty-four hours 
ago. Growth in length occurs in a region 
a short distance back of the tip. The 
spaces between the marks back of the 
tip, especially those between the third, 
fourth, fifth, and sixth marks, are much Sea einer 
show where growth 
wider. This is the place, then, where takes place in the 

roots. 
the root stretches or grows in length. 
The stretching is greatest in the middle of this region. 
Direction of the roots of seedlings. The first root 
from the seedling grows downward, as we have seen. 
In the germinating seed, what advantage is there to 
the plant in this downward direction of the first root? 
The roots which grow out from this first or primary 
root are called lateral roots. What direction do they 
take? What advantage is there to the plant in the 
direction which the lateral roots take? Look at the 
root system, as a whole, of the seedling when well 
