28, 



v/hich sufficient soil accumulates to allow the 

 bryopliytes to appear.He found the epiphytic 

 bryophytes to "be xerophyllous in character. They 

 possess high osmotic pressure in the cells and their 

 leaves in dry weather can fold and hug the stem. 

 He also found that most of the epiphytic bryophytes 

 can endure a high degree of slaade."^ 



In recent years the physiological and ecological 

 aspects of the epiphytic mode of life began to 

 interst botanists.Harris (10 ) after studying the 

 osmotic concentration of the tissue fluids of epiphytes 

 concludes that these plants shov/ a decidedly lov/er 

 Gonoentration than those from the terrestrial 

 vegetation.Harper (9) analyzed chemically the ash 

 of the fronds of Polypodium polypodioides and suggests 

 that this fern probably obtains some of the inorganic 

 material from the bark of the tree which it inhabits 

 as well as from the dust of the air. Wherry (31 ) 

 applyir-g the ^indicator tests to the "soils" on which 

 certain epiphytic ferns were growing found that 

 Polypodium Tulp:are frequently grows on calcareous 

 soil while P. oolypodioides is practically an acid plant,' 

 Johnson (13 ) suggests that the main difference between 

 the "half-parasite ", the mistletoe, and the epiphytic 

 P. wlgare is that ( p.lil) " the mistletoe exacts 

 its quota of salt (and of water also) from within 

 the living host, before they have been used by the 



