ESSENTIALS OF BOTANY. 



CHAPTEE I. 



PROTOPLASM AND PLANT-CELLS. 



1. Protoplasm. — The living part of every plant is a soft- 

 ish, viscid, granular substance called protoplasm. It may 

 be seen in ordinary plants by making thin slices of the 

 rapidly growing parts, and then magnifying them under a 

 good microscope. Such a specimen is made up almost 

 wholly of protoplasm. 



2. When protoplasm is studied carefully under a high 

 magnifying power it is found not to be a homogeneous sub- 

 stance; accordingly its several constituent parts have re- 

 ceived different names, as follows : 



(1) The larger mass which makes up the bulk of the 

 protoplasmic substance is now distinguished as the cyto- 

 plasm (Fig. 1, cy), which is itself separable into (a) a more 

 active portion, the formative cytoplasm (or Mnoplasm), 

 and (b) the nutritive cytoplasm, which is more abundant 

 but less active. 



(2) A rounded, usually centrally placed mass, known as 

 the nucleus (Fig. 1, n), and composed of (a) a mass of 



