8 GENERAL NATURE OF PLANTS. 



nute bladders called cells, which are filled with 

 juices and lie close to each other, leaving how- 

 ever intermediate passages where they do not 

 touch — this is Cellular tissue ; or in slender 

 tubes called woody fibre which are closed at 

 each end, conical, and placed side by side. 



Or in a fibre either rolled up spirally like a 

 wire spring, or forming long cylindrical vessels 

 placed end to end, which finally become con- 

 tinuous and lie close to each other ; this is called 

 vascular tissue — from vas a vessel. 



Cellular tissue when just formed is very lax 

 or coheres loosely and possesses great powers 

 of absorption. 



Late microscopic discoveries have enabled 

 botanists to distinguish several varieties of Cel- 

 lular tissue. Even their names, however, 

 would be misplaced here. 



It constitutes the soft and brittle parts of 

 plants, as pith, pulp, the soft part between the 

 veins of leaves, the tender parts of the flower, 

 fruit, &c. 



Succulent plants, as the Cactus, have an ex- 

 cessive development of this tissue. 



It may be considered the most essential kind 

 of tissue, because, while no plants exist without 

 it, many are composed of nothing else. 



