396 



The Living Plant 



itself in the fur of lions. But innumerable small plants use this 

 method, as one's clothing bears visible testimony after rambles 

 through fields in the autumn. The hooks are most diverse in 

 form as well as morphological origin, some coming from seed 

 coat, some from ovary, some from calyx, some from bracts, no 

 doubt in each case along the lines of development that were 

 easiest at the moment. However tightly these hooks may cling, 



FIG. 167. The Unicorn plant, ex- 

 plained in the text. 



FIG. 168. The Grappling plant, ex- 

 plained in the text. (Copied from 

 Miss Stoneman's Plants of South 

 Africa.) 



the seeds sooner or later fall to the ground, either brushed away 

 by contact with some hard object, or else dropped when the hair 

 of the animal is shed. Nor is the employment of hooks confined 

 only to seeds, for they exist also on some separable joints of small 

 Cactus, or the slender stems of the Bedstraw or "Tear-thumb," 

 both of which secure some transport through the contact of 

 wandering animals. 



Hooks are efficient with fur but less so with feathers, to which 

 some adhesive material is better adapted. Thus, seeds which are 

 carried by birds commonly possess a covering of mucilage, as hi 

 very many water plants; and so effective is this method, in con- 

 junction with that where the adhesive is simply the mud of a 

 pond, that water plants are among the most widely-distributed 



