SCIENCE PRIMERS. 



[XVIII. 



style to the cavity of the ovary, finally conveying 

 protoplasmic fluid from the pollen to the ovule. 



FIG. 51. Pollen grains of, a, evening primrose ; and b, cherry ; both emitting 

 pollen tubes very greatly enlarged. 



XVIII. THE PISTIL. 



OVARY, STYLE, STIGMA. 



109. The pistil is by far the most complicated organ 

 of the flower, and consists of one or more carpellary 

 leaves (Par. 82 d). If it is composed of many such 

 leaves, these may be so combined as to form a one- 

 or many- celled ovary. Its use is to produce within 

 its cavity ovules, destined to become seeds, and to 

 provide means for conducting the contents of the 

 pollen to the ovules. 



no. The ovules are generally produced on the 

 edges of the carpellary leaf; which presents a spongy 

 thickening called the placenta, to which the ovules 

 are attached by a short or long cord or stalk called 

 the funicle. 



The position of the placenta depends on the 

 composition of the pistil; if the latter is formed 



