FRUIT AND SEED 



PI. IV, fig. 13 shows a cluster of mature fruits, and, as may be 

 seen, the form varies somewhat, but is always bluntly pointed at 

 the apex, with a one-sided base, the whole being sHghtly oblique 

 with respect to the axis of the stipe. At the maturity of the fruit, 

 the stigma generally drops off, leaving the blunt apex shown in the 

 figure. 



Figure 30. — Section tlirougli ovary ^wall 

 of ripe fruit, showing the three inner- 

 most hardened layers, -which form the 

 covering of the seed, and the outer 

 soft parts. X 210. 



Figure 31. — Two ripe achenes, 

 after disintegration of the outer 

 soft parts of the fruit covering ; 

 showing the pronounced beaks. 

 X 35. 



During the development of the seed, changes occur in the wall 

 of the ovary, the most important of which is the thickening of the cell- 

 walls of portions contiguous to the seed, with the result that this 

 inner layer of the ovary -wall becomes quite hard. This hardened 

 portion is limited to about three layers of cells. Outside of this 

 hard layer are about five or six layers of thin-walled cells, copiously 

 supplied with starch, and these, in turn, are bounded by the epi- 

 dermis, also rich in starch (Text-fig. 30). 



