240 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



250- 



200 



CD 



O 



X 



tr 



I 50 - 



rr 



LU 

 Q. 



(J) 



UJ 



o 



100 



TIME IN DAYS 



Figure 15. — Comparison of typical growth curves of Nitzschia in culture medium prepared with Norit-washed and 

 autoclaved Nitzschia- and C7i/o/W/n-eonditioned medium, with A' itzuch in-conditioned medium, and with Chlorclhi- 

 conditioned medium. Dots represent growth curve in culture medium prepared with Norit-washed and autoclaved 

 Nitzschia- and (Vitorfi/a-conditioned medium; circles, growth curve in culture medium prepared with Xitzschia- 

 conditioned medium; X's, growth curve in culture medium prepared with t7i/o/c?/a-conditioned medium. 



