134 



BOTANY OF THE LIVING PLANT 



of growing organs, which arc slow in action, and take their origin in 

 variations of the osmotic turgor of the hving cell, and of the resistance 



Fig. 94- 

 Whole fruit of Hura crepitans, before rupture of its woody carpels {after Le Maout.) 

 a. b, single carpels after the explosion, showing each coccus with gaping halves. 

 The rupture happens suddenly, each coccus taking a wider shape ; "the cocci and 

 seeds are thus thrown asunder. c = a sinRle large seed. 



1 IG. 'J5. 



Fern sporangia: A, with the cells of the aiinulus daikiy siiadcd, and cur\-cd 

 strongly back\v;irds by drying of its cells, B, tUv aiiimlus alter its sudden recovery, 

 while the previous; position is shown in dotted hnes. C shows in detail cells of the 

 annulus in A , and D shows similar cells in the state seen in Z>\ See Chapter XXI. 



of the cell-wall that holds it in. All of these phenomena of movement 

 in growing parts play within the limits of turgor of the constituent 



