Origination of Varieties 219 



mature before the seed parent is ready for it. In such 

 a case the anthers can be kept in a small phial until 

 wanted, as the pollen will retain its vitality for three 

 or four days; but the sooner the pollen is used after 

 its maturity the better. 



Each style-branch is provided with a pollen-duct. 

 This duct is made by the two overlapping flaps along 

 the upper or ventral side of the style-branch, appearing 

 to the eye simply as a raised midrib. Well down to- 

 ward the ovary the edges of these flaps coalesce, but 

 the duct still remains distinct and open all the way 

 to that cell of the ovary (Fig. XX, 3, page 130) 

 with which the style-branch is connected (the one 

 immediately below it). This arrangement is well 

 shown in Fig. LVI. 



When a pollen-grain touches the mature stigmatic 

 surface (Fig. LVI, st) it develops a tube which extends 

 down through the stigma and style through the 

 pollen-duct (Fig. LVI, e and pd) and through this 

 tube the contents of the pollen-grain reach the ovule 

 (Fig. XX, 3, page 130) and fertilization ensues and 

 the ovule becomes a seed. 



He * * in its case, 



Russet and rude, folds up the tender germ 

 Uninjured, with inimitable art, 

 And, ere one flow'ry season fades and dies, 

 Designs the blooming wonders of the next. 



Cow per: The Task. 



