2(>2 PHYSIOLOGICAL BOTANY. PART II. 



there was a female date-palm growing at Brimles, 

 which flowered regularly but never bore fruit. At 

 length a male plant of the same species growing 

 thirty miles off at Otranto, having attained a sufficient 

 height to overtop the trees in its neighbourhood, its 

 pollen was then wafted by the wind across the inter- 

 vening space, and the tree at Brimles produced its 

 fruit. The poet Pontanus who flourished at the time, 

 has also recorded the fact. The late colonel W r ilkes 

 when governor of St. Helena, procured some pollen 

 from dates growing on the continent of Africa, with 

 which he fertilized some trees on the island that had 

 never before perfected their fruit. It is certainly not 

 necessary that the ripe pollen should immediately be 

 brought into contact with the stigma ; and instances 

 are recorded of its having been sent in a letter from one 

 part of the country to another and still retaining its 

 activity. Dr. Graham mentions that a female specimen 

 of the Chinese pitcher-plant (Nepenthe* divtillatoria) 

 was fertilized in the Edinburgh Botanic Garden, by 

 pollen thus procured from a male plant which happened 

 fortunately to be in flower in another part of Scotland. 



(258.) Dispersion of Pollen. Before the pollen is 

 scattered from the anther, some plants seem to make 

 preparation for increasing the certainty of its taking 

 effect, by bringing the stamens nearer to the pistil. 

 This is remarkably evident in the Grass-of- Parnassus 

 (Parnassia palustri*), whose stamens on the first ex- 

 pansion of the flower are inclined away from the pistil, 

 but are afterwards brought in succession towards it 

 when their anthers are about to burst. In Geranium, 

 Kalmia, &c. the filaments bend until the anther is placed 

 immediately over the stigma. In the berberry (as we 

 have described in art. 149. 3.), the filament may be 

 caused to incline suddenly towards the stigma by gently 

 touching it near the base on the inside. The genus 

 Stylidium affords one of the most singular examples of 

 this kind of floral irritability ; though in this case the 

 object is not so clearly to be perceived, since the anthers 



