144 PEENS OP GEEAT BEITAIK 



greater paxt of Europe. It is called in France, La Pilu- 

 laire ; and in Germany, Pillenfarrn. It is the Pilularia 

 of tlie Italians and Spaniards ; and the Pillenlcruid 

 of the Dutch. 



This plant is never found in deep water, but forms 

 verdant masses on places occasionally overflowed. Its 

 long entanghng stem is hollow, and not larger than 

 a stout thread ; and its younger portion is invested with 

 small scale-like hairs. It is occasionally branched ; and 

 issuing from it at intervals of half an inch or more are 

 small tufts of slender roots, which descend into the soft 

 soil. Three or four fibres are in each tuft, and imme- 

 diately above each set of fibres rises, from the upper 

 part of the stem, a tuft of from two to six thread-like 

 leaves. These leaves are hollow, bristle-like, about two 

 inches long, and bright green. They are divided into 

 cells, and, when young, are roUed up Hke the leafy 

 ferns : they unroll gradually, at first hanging down like 

 a shepherd's crook, but by degrees they become erect. 



The capsules containing the spores are placed on 

 short stalks just at the base of the leaves, in the angle 

 formed by the leaf and stem. They are about the size 

 of a peppercorn, and closely covered with jointed hairs of 

 a light brown colour. They consist of four cells, and, 

 when quite ripe, they split open from the upper part into 

 quarters, which still remain on the little stalk. The 

 spores are placed along the centre of the valves, form- 

 ing four rowsi and the lower part is occupied by 

 granular bodies, and the upper by poUen-Uke powder. 

 The larger grains are believed to be perfected spores, 

 and the smaller to be spores in their imperfect condition. 



