2l6 



STRUCTURE AND LIFE HISTORIES 



many small pieces with a pair of scissors, each piece can 

 regenerate a new plant. In many species the tips of the 

 lobes of the thallus become separated from the plant 

 naturally, by the dying off of portions back from the tip. 

 In such cases each tip develops an entire new individual. 

 A thorough study of these phenomena has led botanists 



FIG. 161. A liverwort (Lunularia) . Below, portions of the thallus, 

 showing the lunar-shaped cupules, with brood-buds, or gemmae. Above 

 a single gemma, greatly magnified. 



to the conclusion that every cell of a liverwort is able to 

 reproduce an entire plant, just as effectually as though 

 it were a spore. Some species produce little multi- 

 cellular bodies called gemma (Fig. 161). Other species 

 produce fleshy tubers, richly stored with reserve food- 

 materials, 1 and specially valuable in helping the species 



1 Analogous to tuber-formation in the potato. 



