REPRODUCTION 



191 



but two entire circles may even be united. The corolla is some- 

 times attached to the calyx and is thus episcpalous (Fig. 102, D). 

 Similarly, the stamens may be epipetalous (attached to the corolla 

 Fig. 103, D) and the calyx epigynous (attached to the ovary, Fig. 

 103, B) and so on. In shape, floral parts vary enoi'mously. In 



Fig. 104. — An irregular flower, the toadflax [J^uin m i uli/cn i.s). Tlic corolla 

 has two lips, which are spread apart by the bee as he enters in search of the nectar, 

 which is secreted by a gland or nectary at the end of the long spur. 



the higher plant groups, too, some of the sepals, petals or stamens 

 are different from the rest, with the result that an unsymmetrical 

 or irregular flower (Figs. 104 and 240) is produced, as opposed to 

 the more primitive regular type (Figs. 97, 98, and 109). In color, 

 flowers range through practically the entire spectrum, except 

 that green is comparatively rare in the corolla. In size there is 

 also great diversity, although flowers more than a decimeter in 

 diameter are rare. In texture, flowers are generally soft except 

 for the calyx, the firmness of their parts being produced by 



