CHAPTER XVII. 



INSECT-POLLINATION FERTILISATION. 



The significance of Entomophily Wanderings of small insects 

 Flowers with no very special mechanism Protection of pollen 

 from rain, &c. More elaborate mechanisms Fig Broom 

 Explosive mechanism Barberry Horse-chestnut Guelder 

 Rose Honeysuckle Artificial pollination Pollen-tube Pene- 

 tration of style Conifers Results of pollination Chala- 

 zogamy. 



IN the consideration of insect-pollination (Entomophily) 

 we must never lose sight of the two aspects of the phe- 

 nomenon, namely, the advantage gained by the flower and 

 that gained by the insect. The flower must be looked 

 upon as a trading house which advertises its wares by 

 means of coloured posters bright-hued petals, sepals, or 

 bracts, &c. and by means of more or less powerful scents. 

 But if the visits of insects are to be repeated in other 

 words, if the customer is to be induced to repeat his 

 call something substantial must appear at back of the 

 attraction, or the bees, &c., who have much work to do 

 to feed their young, are just as unlikely to keep up fruit- 

 less visits as would be a thrifty housekeeper to a shop 

 where she was ill- served. 



The solid wares exposed so that the insects may take 

 them, under certain conditions, as honest reward for work 

 done, are the honey and the pollen, or in some cases even 

 other things. 



