VIOLA CE^E. 



261 



nated, because being closed, and because of the position of the anthers around 

 the stigma the pollen from the opening anthers comes directly in contact with 

 the stigma. In the flowers of the pansy cross-pollination often takes place 



Fig. 222. 



Viola cucullata ; blue flowers above, cleistogamous flowers smaller and' curved below. 

 Section of pistil at right. 



through the agency of insects. While the blue flowers of the blue violet 

 rarely set fruit, nevertheless pollination and fertilization do take place in some 

 of the flowers, though fruit sets more abundantly in the cleistogamous flowers. 

 Material. — Entire plants with the flowers ; collect some early in the season 

 when the blue flowers are abundant, and some later when the small flowers 

 underneath the soil or leaves are formed. Mature fruit is also desirable. 



