52. 



also appears to "be suitable for this epiphyte. The 

 thio^mess of the bark, is, apparently, also important 

 since in thick bark the young roots can make their 

 way into the spaces between the layers fartherst". 

 away from the surface and be protected from excessive 

 evaporation. The polypody has never been found on trees 

 with smooth bark nor on those the bark of v/hich breaks 

 or peels off frequently, as in the case of the pine 

 or sycamore, 



A study of the water absorbing power and water 

 losing power of the bark of different trees seems to 

 indicate that only those barks v/hich absorb and hold 

 water fast serve as satisfactory substrata for these 

 epiphj'-tes.The bark of the pine is not suitable for 

 the development and growth of the epiphyte, for water 

 is absorbed rapidly ani is lost just as rapidly so 

 that the bark becomes very dry shortly after it has 

 been wetted. Nor does a bark v/hich is horny or stony 

 in character, as that of the red oak or of the hickory 

 nake a desirable substratum, for such barks have a 

 TB ry low imbibing pov/er. These conclusions were reached 



after samples of bark of different trees were soaked 

 in v/ater for tvienty four hours suid then dried for 

 tv/enty four hours, their weight being detei^nined before 

 soaking, after soalcing and after drying.The 7/riter realizes 

 of course, that this methodjis not absolutely precise. 



