180 SOME RECENT RESEARCHES IN PLANT PHYSIOLOGY 



logical results follow in the constitution of the surface 

 layer of the protoplasm, and it is possible that cells may 

 in some cases be even ruptured by excessive intake of 

 water. 



Rapid changes in the sea-water brought about by the 

 increased volume of fresh water delivered by the rivers 

 during flood have been proved by Yendo to be the cause 

 of the serious injury to the algal flora known in Japan as 

 " reef -burning/' This often occasions losses in the sea- 

 weed industry of as much as 1,200 a mile per annum, 

 and the evil effects continue for several years. In addition 

 to the destruction of algae, there is the loss due to the 

 migration of molluscs and pelagic fishes. The presence 

 of strong coastal currents deflects the river-water from its 

 seaward course, so a region of brackish water along the 

 coast results. It is by the extension of this zone in time 

 of flood that the phenomenon of " reef -burning " is 

 occasioned. 



EPIPHYTES AND PARASITES. 



The relationship between the osmotic pressures of 

 epiphytes and parasites, and those of the plants upon which 

 they grow, has been investigated by Senn (1913) in a number 

 of instances. By means of the plasmolytic method it was 

 found that the pressures of the former were the greater, 

 so that the passage of water from the conducting tracts of 

 the host is easily understood. 



SECTION II. OSMOTIC PRESSURE AND MORPHOLOGICAL 

 VARIATIONS. 



NORMAL AND ABNORMAL FRUITS. 



Realizing that all morphological differences are ulti- 

 mately based upon chemical and physical differences of a 

 qualitative or quantitative nature, Gortner and Harris 



