LIVERWORTS 129 



the veil of the Tubercled Liverwort (Frullania 

 dilatata) ; it was cut out of the cup, and inside 

 it, if dissected, would doubtless have heen found 

 the young, half -formed capsule, which in a liver- 

 wort reaches its full development before forcing 

 its way into the light and air. This small, round 

 ball, then, represents the original swollen base 

 of the fruit-bearing organ, which has become en- 

 larged out of recognition by the gradual increase 

 inside it of the young spore-vessel ; at the top 

 of this tiny ball will be seen the remains of what 

 was originally the neck of the organ, and which, 

 having now fulfilled its purpose, has more or less 

 shrivelled up. 



As the spore-vessel gets larger and larger, and 

 as the fruit-stalk, at the end of which it is formed, 

 lengthens, considerable pressure is exerted on the 

 walls of the veil, which, after a time, not being 

 able to stretch further, split open, thus allowing 

 the ripe but still closed spore-vessel to make its 

 way out, and eventually to emerge into the light 

 of day at the end of its long fruit-stalk. On 

 examining a colony of liverwort plants in the 

 early spring a number of slender, silky white 

 threads may often catch the eye lying on the 

 ground ; these are the long, flexible stalks of 

 the capsules ; and if a still closer inspection is 

 made many of these silky threads will be found 

 to be tipped with tiny, black, oval heads the 

 spore-vessels filled with the ripe spores which 



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