134 



BOTANY. 



[chap. IV. 



common garden nasturtium {Tropceolum majus) the long 

 spur is a development of the calyx. Another advantage 



Fig.'rsS. Lime (Tilia 

 Europcea). Showing a re- 

 gular and perfect flower, 

 with the parts (except 

 those of the pistil) free 

 from each other ; there is 

 no colour in the flower, but 

 bees are informed of the 

 proximity of a lime tree 

 by the strong scent ; the 

 flowers also secrete large 

 quantities of nectar. The 

 flower-stalk is attached for 

 half its length to a leaf- 

 like bract that serves as a 

 dispersive organ of the 

 fruit when mature, becom- 

 ing dry and light, and be- 

 ing blown by the wind for 

 some distance, carrying the 

 fruit along with it. (Na- 

 tural size. ) 



of the spur over the open nectary is that the nectar is 

 prevented from being washed away by rain. 



So long as the flower is constructed on the buttercup 

 type, that is, regular in form, and all the parts free from 



