28 



NATUEE STUDY. 



spongy, sticky surface on which the pollen must fall in 

 order to develop. When the insects visit the flower in 

 search of the nectar at the base of the corolla, and feome 

 in contact with the pollen, they carry some of it away. 

 Even if the pollen grains come in contact with the 

 outer and under surface of the recurved stigma, the 

 grains are not apt to adhere, and will not develop. 

 When the insect visits a new dan- 

 delion flower, and brushes against 

 the upper inner surface of the 

 forked end of the style (as it is 

 almost compelled to do when push- 

 ing its proboscis, or mouth parts, 

 into a flower), some of the pollen 

 may adhere, develop, send its pro- 

 toplasm down through the style, 

 fertilize the ovule, and insure the 

 development of the seed. 



If, for any reason, cross-fertili- 

 zation is not secured, then the two 

 divisions of the style bend down- 

 ward and outward (see Fig. 13), 

 each curving into a circle, and 

 bring their inner spongy surface' in contact with the 

 pollen above the' anther tube, thus insuring self-fertili- 

 zation and the development of their ovules. 



When fertilization has been secured, the work of 

 corolla, stamens, style, and stigma is about completed, 

 and they soon shrivel, and are pushed off by the growth 

 of the beak. 



Fig. 13. Floret of Dandelion, 

 Self-Fertilization. 



