348 FRESH-WATER ECOLOGY 



been carried out to ascertain the effect of the host plant on the 

 microchemical environment. Summing up, it can be said that the 

 factors influencing the distribution of epiphytes are as follows : 



(i) Age of substrate. 



(2) Rate of growth of substrate. 



(3) Light intensity. 



(4) Screening. 



(5) Nature of the surface. 



(6) Chemical surroundings. 



Of these (3) is probably the most important, although it is 

 difficult to separate its effects from those of (i) and (4). 



REFERENCES 



Ponds. Brown, H. B. (1908). Bull. Torrey Bot. Club, 35, 223. 



Streams. Budde, H. (1928). Arch. Hydrobiol. Plankt. 19, 433. 



General. Fritsch, F. E. (193 i). J. Ecol. 19, 233. 



Ponds. Fritsch, F. E. and Rich, F. (191 3). Ann. Biol. Lac. 6, i. 



Epiphytes. Godward, M. (1934). Bei. Bot. Zbl. 52 A, 506. 



Lakes. Godward, M. (1937). jf. Ecol. 25, 496. 



General. Klebs, G. (1896). Die Beding. der Fortpfl. ein. Algen 



und Pilzen. Jena. 

 Ponds. LiND, E. M. (1938). jf. Ecol. 26, 257. 

 Ponds. Transeau, E. N. (19 13). Trans. Amer. Micr. Soc. 32, 31. 

 General. West, G. S. (1916). Algae, p. 418. Cambridge. 

 Streams. Fritsch, F. E. (1929). New Phytol. 28, 165. 



