

PART SECOND. 

 PHYSIOLOGICAL BOTANY. 



CHAPTER I. 



VEGETABLE HISTOLOGY AND PHYSIOLOGY. 



368. The vegetable cell is the foundation of all 

 plant structure, and when complete is a sac or bag-like 

 body containing a semi-fluid substance 

 called Protoplasm. The cell -wall in- 

 creases by expansion. Spaces (vacuoles) a 



appear among 

 the particles 

 of protoplasm, 

 which are occu- 

 pied by a watery 

 substance called 



-1-1 T c, c, protoplasm mass sep- 



Ceil-Sap. In SOme arated from the cell-wall 



*m part of the cell b< 



a spot appears where the 

 granules of Protoplasm are 

 crowded together, forming a 



465 

 465, Mature cell of 



466, Section of pith-cell of Taxodium ; a, v.i-.plpi-.q TTU p ppll 



nucleus ; &, nucleolus ; c, , protoplasm sac Z >US< 



contracted toward the wall, from which it has p OrnT VJpfp o nr q fhyiq 



been separated by reagents ; p, cell-sap In a C tG ai] 



XTS^tT^iSniSS:! i* ^ organism capable of ex- 



ellularspace ' ercising vital functions, and 



possesses the ability to multiply itself or produce new 



