80 



PLANT KELATIONS. 



Fig. 73. A flower of the tobacco plant : a, a complete flower, showing the calyx with 

 its sepals blended below, trie fnnnelform corolla made up of united petals, and the 

 stamens just showing at the mouth of thecorolla tube ; &, acorolla tube split open 

 and showing the five stamens attached to it near the base ; c, a pistil made up of 

 two blended carpels, the bulbous base (containing the ovules) being the ovary, the 

 long stalk-like portion the style, and the kuob at the top the stigma. — After 

 Stkasburger. 



last set of floral leaves (carpels) appear, the growth of the 

 stem in length is checked and the cluster of floral leaves 



Fig. 74. A group of flower forms : a, a flower of harebell, showing a bell-shaped 

 corolla composed of five petals ; 6, a flower of phlox, showing a tubular corolla 

 with its five petals distinct above and sharply spreading ; c, a flower of dead-nettle, 

 showing an irregular corolla with its five petals forming two lips above the funnel- 

 form base ; d, a flower of load-flax, showing a two-lipped corolla, and also a spur 

 formed by the base of the corolla ; e, a flower of the snapdragon, showing the two 

 lips of the corolla closed.— After Gray. 



