»- 30 FOUNDATIONS OF BOTANY 
/ 39: Root, Stem, and Leaf. — By the time the seedling is 
well out of the ground it, in most cases, possesses the three 
kinds of vegetative organs, or parts essential to growth, of 
ordinary flowering plants, 7.e., the root, stem, and leaf, or, 
as they are sometimes classified, root and shoot. All of 
these organs may multiply and increase in size as the 
plant grows older, and their mature structure will be 
studied in later chapters, but some facts concerning them 
can best be learned by watching their growth from the 
outset. 
‘ 40. Young Roots grown for Examination. — Roots grow- 
ing in sand or ordinary soil cling to its particles so tena- 
ciously that they cannot easily be studied, and those grown 
in water have not quite the same form as soil-roots. Roots 
grown in damp air are best adapted for careful study. 
' 41. Elongation of the Root. — We know that the roots 
of seedlings grow pretty rapidly from the fact that each 
day finds them reaching visibly farther down into the 
water or other medium in which they are planted. A 
sprouted Windsor bean in a vertical thistle-tube will send 
its root downward fast enough so that ten minutes’ watch- 
ing through the microscope will suffice to show growth. 
To find out just where the growth goes on’ requires a 
special experiment. 
* EXPERIMENT XIV 
In what Portions of the Root does its Increase in Length take Place ? 
— Sprout some peas on moist blotting paper in a loosely covered tum- 
bler. When the roots are one and a half inches or more long, mark 
them along the whole length with little dots made with a bristle 
dipped in water-proof India ink, or a fine inked thread stretched on 
a little bow of whalebone or brass wire. 
