50 



SPICES 



CHAP. 



The stigma, being very sticky, retains the pollen and 

 withdraws it from the stick ; the rostellum then released 

 flies back to its original position and helps to press the 

 pollen into the stigma. 



Another method sometimes used is to employ a thin 

 flat stick and to press the rostellum upwards beneath 

 the anther cup, pressing this with the thumb so as 



VANILLA FERTILISATION. 



A. Column from in front. 



B. Side view. 



C. Side view showing position of fertilising 



stick. 



D. Rostellum pushed up and pollen touching 



stigma. 



E. Side view of column showing attachment 



to lip. 

 a. Anther. 

 p. Pollen. 

 r. Rostellum. 

 s. Stigma. 



to slide it over the rostellum, and force the pollen into 

 the stigma. This method, however, is not so satisfactory 

 as the first one. It is rougher and perhaps easier to 

 effect, but there is a certain amount of uncertainty as 

 to whether the pollen has quite reached the stigma and 

 is well inside. 



By both these methods the pollen of a flower is used 

 to fertilise its own stigma. It is probable that better 

 results would be obtained by transferring the pollen of 



