MAIZE STEM 161 



VEGETATIVE ORGANS. (B) MONOCOTY- 

 LEDONS 



i, STEM HERB A CEO US TYPE 



I. Cut transverse sections from about the middle of 

 an internode of a well-grown stem of Zea Mais : mount 

 in water, or glycerine. 



N.B. Fresh material may be used, but stems preserved in 

 alcohol are preferable, for when fresh the tissues are crowded with 

 air-bubbles. The sections should be cut from the upper part of 

 one of the lower internodes, otherwise the vascular bundles may 

 be found to be imperfectly developed. 



Examine with a low power, and, beginning the 

 study of the tissues at the periphery of the section, 

 observe 



a. A single layer of rather irregular epidermis : 

 immediately below this are 



I. Irregular groups of sclerenchyma with thick 

 lignified walls : internally lies 



c. A mass of parenchyma, which forms the ground- 

 work of the whole section : embedded in this are 



d. Numerous vascular bundles : note that they 

 are smaller, but more numerous near the periphery 



M 



