[VOL. 6 



36 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 



Solution A 



Mannite 20 



gms 



Dipotassium phosphate 0.2 gm. 



Double distilled water 500 



cc. 



Solution B 



Magnesium sulphate 0.2 gm 



Sodium chloride 0.2 gm 



Calcium sulphate 0.1 gm 



Double distilled water 500 cc. 



After all the salts were dissolved the two solutions were 



mixed, 2 drops of 10 per cent solution of FeCl.<? and a pinch of 



CaC03 added, and the whole heated to boiling to effect com- 



one-half 



grams of Bacto agar were then added and dissolved with the 

 aid of the 



while hot and then filtered, tubed, and aerain autoclaved 



plete precipitation of the phosphates. Seven and 



autoclave. The solution was thoroughly stirred 



Agar II (phosphates allowed to precipitate after the addi 

 tion of agar). 



Solutions A and B were prepared exactly as above, ant 

 then 3.25 gms. agar dissolved in each, the solutions filtered 

 and then united, tubed, and autoclaved. 



Agar III. This was the regular modified Ashby soil extraci 



■s 



described ab 



In tubing these agars 10-cc. portions were placed in Jena 

 st-tubes containing a pinch of CaC0 3 . Three slants of each 

 far were inoculated on the same date with triple strokes from 

 72-hour culture of the F 4 generation. The results are shown 

 the following summary: 



Agar 

 no. 



I 



TABLE XII 



SUMMARY OF GROWTH ON AGARS 



24 hours 



Faint growths 

 in 2 tubes, 

 doubtful i n 

 3rd 



Growth aft 



72 hours 



Raised streaks; 

 fair growths, 

 as compared 

 with No. 1 1 

 distinctly less 



6 days 



Slimy, 

 thin 



rather 



streaks; 

 only one tube 



shows spreading; 

 growths distinct- 

 ly less than in 

 No. II 



10 days 



Growths some- 

 what wrinkled 

 and showing 

 some pigmenta- 

 tion; growths 

 slightly less than 

 in No. II 



