EFFECT OF BOG WATER ON SWELLING 99 



and of living and dried sections of plants in distilled water, bog 

 water, and in a calcium solution of the same concentration as 

 the bog water are practically equal. So far as known to the 

 writer the effects of bog water are not attributable to any of its 

 known constituents, and its low oxygen content as tested by 

 Clements may be responsible for its morphogenic and physio- 

 logical effects and its domination as a factor in the habitat. 



Swamp water has been found to affect absorption and swelling 

 in the same manner as an equivalent solution of calcium sul- 

 phate. Swelling and absorption are retarded by swamp water 

 in salted biocolloids and in sections of plants containing a large 

 proportion of pentosans and a low protein content. Biocolloids 

 with a high protein and salt content on the other hand show an 

 enhanced absorption in swamp water. Inferentially, plants of 

 similar constitution would carry on absorption readily and thrive 

 in swamp waters. Whether adaptation to swamp habitats 

 actually takes this course is not known. 



