100 APPENDIX 



4. Organic Media. (H. C. Bold) 



A. Volvox Solution (Moewus, Gruppe. Zeit. f. Induk. Abst. u. 

 Vererb, 78: 418-522. 1940). 



Autoclave 1 Kg. garden soil in 1 liter of distilled water at 

 15 lbs. pressure for 1 hour. Cool, decant and filter off liquid 

 extract "E." To make definitive solution: 



Distilled Water 300. ml. 



5% KNO3 1 .0 ml. 



•<£" 30 . ml. 



B. "Bristol's-Yeast" Solution (Bold). , 



Add 1 gram per liter of Difco Yeast Extract per liter o£ 

 modified Bristol's solution and sterilize. 



C. "Bristol's-Liver" Solution (H. C. Bold). 



Make a 10 ml. vial of Armour's Crude Liver Liquid Paren- 

 teral up to 100 ml. Add 5 ml. of this to each liter of modified 

 Bristol's Solution and sterilize. 



Comments: No. 3-A, 3-B and 4-A (above) are extremely useful 

 in uni-algal culture. No. 4-B and 4-C (above) are most useful in 

 effecting more rapid growth of bacteria-free cultures. The possibil- 

 ity should be considered that cultures grown for long periods in 

 organic media may mutate or become adapted. Any of the solutions 

 listed above may be solidified by the addition of 1.0-1.5% agar. 



