58 HISTOLOGY OF MEDICINAL PLANTS 



Yet all cells performing a given function will structurally re- 

 semble each other. In the present work the nucleus and other 

 parts of the living protoplast will not be considered, for the 

 reason that these parts are not in a condition suitable for study, 

 because most drugs come to market in a dried condition, a con- 

 dition which eliminates the possibility of studying the proto- 

 plast. The general structure of the cells forming the different 

 tissues will first be considered, then their variation, as seen in 

 different plants, and finally their functions. 



