NO. 23 STIMULATION OF ALGAE BY ULTRAVIOLET MEIER 



II 



Table 4. — Growth of the alga Stichococcus bacillaris Naegeli 



in relation to wave length 2967 A 



18 inches in length, was installed. The lights gave an intensity of 

 approximately 150 foot-candles on the bottom shelf and 300 foot- 

 candles on the top shelf. 



The flasks of algae were placed on the lower shelf of this chamber 

 and illuminated for 12 hours of each 24 hours (see pi. 2) during their 

 growth period of two weeks. 



RESULTS 



All the results have been tabulated in tables 1-10 for convenient 

 reference. 



THE STIMULATED GROWTH RATE 



The results of the cell counts are tabulated in tables 1-4 and 6-9. In 

 each case, the growth rate represents the final count made 2 weeks after 

 irradiation divided by the initial count made directly after irradiation. 

 Each growth rate of an irradiated culture was then divided by the 

 growth rate of the control to obtain the final growth ratio. 



