l6 SMITHSOXIAX MISCELLANEOUS COLLECTIONS VOL. 92 



and 



also 



logc -J- = «^'^' = ^ 



•'0 



or 



act' = acsXs 



SO 



Cs X 



i.e., the concentrations are inversely proportional to the length (x). 

 Also 



— =z erowth. 



i.e., if 



X, 



.V 3 



then the increase or growth was 3 times. 



RESULTS 

 TOWER CULTURES 



The three cultures grown in natural conditions of light and dark in 

 the tower gave the following results : 



Galvanometer Growth Microscoinc Microscopic 



Window deflection factor count growth ratio 



North 551 -99 106.8 4-9 



South 65.5 .83 92.4 4-2 



West 52.5 1-04 116.0 5.3 



The pH was 5.8 in all three cultures. The cultures in the north and 

 south windows contained bright green cells, while those in the west 

 window were pale green and many of the chloroplasts were shrunken 

 and slightly abnormal. Possibly the afternoon sunlight in the heat of 

 the day is too strong for the cells. 



CHLOROPHYLL 



Samples of each culture when examined microscopically at the end 

 of the fourth and fifth experiments showed that chlorophyll was 

 present in all the cultures. The chloroplastids in some cultures were 

 in a more healthy condition than in others, as shown by table 3. In 



