337 



? I 



occurs between plants and animals. Various species of plants 

 attach themselves to ani- 

 mals by which they are 

 carried about. The plant 

 is thus aided in obtaining 

 the materials for food, 

 and not infrequently the 

 plant conceals the animal 

 from another which seeks 

 it as prey. In this way 

 certain fish are hidden by 

 algae attached to them. 

 One of the most striking 

 cases of protective mimicry 

 is that in which an Aus- 

 tralian fish has acquired 

 surface outgrowths which 

 imitate almost precisely the 

 appearance of brown sea- 

 weeds, SO that, when quiet, FIG. 376. A young clover plant, showing tuber- 

 cles, /, on the roots. Natural size. After 



it looks like a stone to Goff. 



which seaweeds had attached themselves. In this it imitates 



other species which have real seaweeds at- 

 tached to them. 



B. Helotism. 



462. i. Fungi and algae. Helotism 

 exists between fungi and algee, constituting 

 3* the bodies known as lichens, in which the 

 {nveifpin ( g ee an g aig 5 a; fungus is the master and the alga the slave. 

 ~ l *L (See 1| 54<z, and fig. 377.) The same 

 fungus may be found enslaving more than 

 one species of algae even within the same mycelium. The 

 protonema of mosses or even the leaves of some small 





