566 



DICOTYLEDONES. 



instances are raised as 5 large, flat, membranous bodies, e.g. in 

 species of Xeranthemum, Catananche, Sphenogyne, etc. ; in other 

 instances each of these bears a shorter or longer bristle on its 

 apex, followed by others in rather uncertain numbers and with 

 but slight indications of order, on the edge and on the outer side 

 of the calyx between the 5 points ; in other instances, again, the 

 c:ilyx is covered with bristles and hairs without any indication of 

 order or definite number (Fig. 606 a, b) ; finally instances occur 

 in which the edge is raised as a membranous collar, irregularly 

 toothed and notched, or divided into small scales. There are 

 naturally differences in the means of distribution corresponding 1 to 



FIG. 600. a Fruit of Taraxacum; I of Senecio; c of Bidens. 



the differences in structure of the calyx. The fruits o and b re- 

 presented in Fig. 606 are distributed by the wind, those like c, on 

 the other hand, by attaching themselves to animals and human 

 beings. The rays of the pappus are termed rough when special 

 cells project a little beyond the surface, but if these grow out, and 

 are hair-like, the pappus is said to be feathery. In some genera 

 the pappus is raised on a long stalk, which is developed from the 

 upper part of the fruit, and termed a beak (Fig. 606 a). The 

 pappus does not attain its full development till the ripening of 

 the fruit, i.e. until it is about to be of use. 



The COROLLA has various forms : (a) tulmlar (Fig. 605 I)}, with a 



