A STUDY OF RELATIONS BETWEEN PLANT GROWTH. 



34^ 



First, in regions of very dense or even of fairly dense vegetation where 

 great contamination exists, a ehemieal determination of nitrates or nitrites 

 as an indicator of pollution in making a sanitary water analysis is absolutely 

 worthless in itself. 



Fig. 9— See Table 7 for Data 



(1) The nitrite and nitrate curves are extremely regular. 



(2) Compare with Station T of Plate .5. These two arc the only regions of ex- 

 tremely dense vegetation. 



(3) Note the effect of the windy weather of April 17. At this time theturbid, 

 very much contaminated water of Entrance Bay was brought in. t- 



(4) Absence of data covering hiatus of 60 days is very unfortunate. 



