51. 



C. EFFECT OP PHYSICAL CHARACTER OF THE BARK 

 ON THE DISTRIBUTION OP P.POLYPODIOIDES 



6lDservations in the field indicated that the 

 fern occurred abundantly on trees the "bark of 

 which possessed crevices.lt was particularly 

 abundant on bark which was deeply furrowed and 

 which was sufficient3.y soft to allov/ the young 

 roots of the fern to penetrate into the interlaminar 

 spaces oOn such bark the polypody was found 

 developing a copious root system in the interlaminar 

 spaces, where the young root hairs were always found 

 to be turgid and functioning regardless of the weather 

 conditions, A flaky bark such as that of the juniper 



Fig, 19 

 The underside of a mass of P« po lyppfli o i de s 

 showing the massive root system in* the interlaminar 

 spaces. 



