74 



P. M. COOK 



Fig. II — Horizontal tank farm in the continuous culture process. 



optimum conditions at all points because the flow of fresh me- 

 dium into the tanks depends on the growth and, therefore, on 

 the intensity of sunlight. Control is maintained by a simple 

 photoelectric cell circuit. 



Future Work 



A very considerable amount of work, primarily of a basic 

 nature, still remains to be done. Studies on the influence of light 

 are particularly important, including examinations of growth 



