STUDIES IN FERN LIFE 43 



of the underside of the leaflet. In their early 

 days the spore cases are covered with a pro- 

 tecting scale. 



After all, it is likely that one of the most 

 familiar ferns is the common Polypody {Poly- 

 podium vulgare). This plant is very happy in 

 many situations, but it is really most at home 

 on the trunks and branches of old trees, 

 especially oaks. The creeping stem, from 

 which the leaves arise at regular intervals, 

 pushes its way in and out through any leaf 

 mould which may have accumulated. The stem 

 is fleshy, and stands the plant in good stead 

 during very dry weather, when, often enough, 

 the shrivelled appearance of the fronds make it 

 appear that the Polypody is dead. A few 

 showers of rain soon revive the foliage, which is 

 evergreen in habit. The spore cases are chiefly 

 confined to the upper part of the leaf, and these 

 are arranged in clusters on either side of the mid- 

 rib of the sub-divisions. When in a ripe state the 

 groups are often very closely set, so that a good 

 deal of the back of the frond will appear to be 

 covered with an orange-coloured coating. This 

 often gives a very attractive appearance to the 

 leaves of the Polypody. For its supply of 



