ROOTS 



CHAPTER III 



ROOTS 



I. Examine the root of a well-grown plant of the Bean 

 and notice that : 



1. It is a single main root. We know from our previous 



study (cf. Chapter II, V, 4) that it is a primary 

 roof. A single, persistent, primary root, such as this 

 of the Bean, is called a tap roof. 



2. From the sides of the primary root are given off 



branches growing obliquely outwards. These are 

 secondary roots. They in turn give rise to tertiary 

 roots, etc. 



3. There are no nodes and internodes on these roots. 



4. All the roots grow more or less downwards and away 



from the light. 



5. Make a sketch showing these points. 



II. Examine the roots of a well-grown seedling of the 

 Squash and notice that : 



1. The several roots all spring from near the same point at 



the base of the elongated caulicle. Such roots as 

 these are called multiple primary roots, as distin- 

 guished from the single primary root of the Bean. 



2, 3, 4, and 5 as in I. 



