18 MOSSES AND LIVERWORTS 



the Cotswold villages, the tops of the walls are 

 covered with a thick coating of mud ; these mud- 

 capped walls are often tenanted by certain small 

 but specially interesting plants, which seem to 

 prefer this form of abode, more particularly if 

 the district happens to be calcareous in nature, 

 and a careful scrutiny of them will frequently 

 result in a welcome addition being made to the 

 herbarium. 



The Hedgerows of our roads and lanes provide 

 shelter for numerous kinds, though many that 

 grow there will naturally also be found in the 

 woods or other shady places. Plate II. fig. 4, 

 the Common Pottia (Pottia truncatula), is a 

 pretty little moss that frequents the banks by the 

 roadside, where in the early spring it may often 

 be seen, with its small, golden-yellow spore- 

 vessels, like so many delicate amber cups. The 

 Green-tufted Weisia (Weisia viridula, fig. 9) 

 also grows abundantly in similar situations, and 

 in the spring produces a profusion of fruit; the 

 leaves are long and narrow, and when examined 

 under the microscope it will be found that the 

 margin is slightly rolled or folded inwards 

 (involute, as it is called), a feature which is very 

 characteristic of this particular plant. It is 

 wonderful to think that such a very minute trait, 

 in such a small organism, should nevertheless be 

 so constant as to form a never-failing means of 

 recognition. 



