432 Bulletin 315 



The agar after washing was added to the solution, after being melted 

 over a free flame, cooked for one hour in a double boiler, filtered, and 

 fractionally sterilized. (This medium was used only during a part of 

 the summer of 191 1.) 



Potato decoction agar. — Prepared as follows: Two average-sized 

 potatoes were washed, pared, and sliced very thin. To these were added 

 about two times their volume of water. This was now heated for two hours, 

 but never a,llowed to boil. After cooking, it was filtered through cotton, and 

 30 grams of agar and 5 grams of glucose were added. The mixture was nov/ 

 cooked in the autoclave for twenty minutes at 17 to 18 pounds pressure. 

 After cooking and distribution to test tubes, it was sterilized in the auto- 

 clave for thirty minutes at 17 to 18 pounds pressure. 



Moist bread. — Prepared by adding only sufficient water to the bread 

 to allow it to remain solid after sterilization in the autoclave. 



Gelatin. — Prepared according to Thom ('10). It consisted of 15 per 

 cent gelatin in water; the whole cooked in a double boiler for thirty minutes, 

 then filtered and fractionally sterilized. 



Uschinsky's solution. — Prepared according to the formula as given by 

 Smith ('05). Sterilized in autoclave for twenty minutes. 



Distilled water i , 000 



Glycerin 30 to 40 



Sodium chlorid 5 to 7 



Calcium chlorid .1 



Magnesium phosphate 3 to .4 



Dipotassium phosphate 2 to 2 5 



Ammonium lactate 6 to 7 



Sodium asparaginate 3 to 4 



Raulin's culture fluid. — Prepared according to formula as given by 

 Smith ('05). 



Distilled water i , 500 . 



Granulated cane sugar 70 . 



Tartaric acid 4 . 



Ammonium nitrate 4 . 



Ammonium phosphate .60 



Magnesium carbonate .40 



Ammoniimi sulfate .25 



Zinc sulfate .07 



Ferrous sulfate .07 



Potassium silicate .07 



('05) Smith, E. F. Bacteria in Relation to Plant Diseases. Carnegie Inst. 

 Washington Pub. 27: 197. 1905. 



('10) Thom, Charles. Cultural Studies of Species of Penicillium. U. S. Dept. Agr., 

 Bur. Anim. Indus. Bui. 118: 22. 1910. 



