[Vol. 10 



130 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



sterile needle, bits of this mycelium were transferred to agar 

 plates, (e) The entire seed was removed with sterile forceps 

 and without sterilization planted in agar. Typical cultures 

 developed in all three cases. 



5. Made January 3, 1921. (a) Five seeds were selected 

 from a lot which had been shelled from diseased pods in September 

 and stored in a covered dish in the laboratory. The 5 seeds 

 selected were plump but wrinkled on the back and very little 

 off color. Norton and Chenn's ('10) recommendations for seed 

 disinfection were followed. The seeds were soaked in tap water 



over night, shaken in alcoholic mercuric chloride solution 

 gr. HgCl in 1000 cc. of 50 per cent alcohol) for 4 to 5 minutes, 

 rinsed in 95 per cent alcohol, washed in several changes of sterile 

 water, then planted on potato glucose agar plates. In 4 days 



3 of the seeds had germinated and each of 4 was surrounded by 

 a broad colony of white floccose mycelium characteristic of the 

 Phomopsis stage of D. Sojae. Bits of mycelium from each of the 



4 colonies were transferred to sterile soybean stems and petioles. 

 A profuse growth of white cottony mycelium developed on stems 

 and a rather sparse growth on petioles. Numerous pycnidia 

 developed in these stem cultures from each of the 4 seeds and in 

 the original Petri dish cultures, (b) Five seeds from the same 

 lot as these described under "a" just above, but differing from 

 them in being plump, unwrinkled, and not discolored, were 

 similarly disinfected and planted in agar plates. Broad colonies 

 characteristic of the Phomopsis stage of the soybean fungus 

 had developed from 2 of these at the end of 19 days. 



6. Made January 14, 1921. These seeds were shelled from 

 a plant which had been kept in a wire cage in the laboratory. 

 The stem and pods of this plant bore many pycnidia and most of 



the seeds were wrinkled and discolored. Four lots of 5 seeds 

 each were selected and treated as follows: (a) These 5 seeds 

 were only slightly wrinkled and faintly discolored on the naturally 

 yellowish areas- When the seed-coats were removed, no dis- 

 coloration of the embryos was visible. The naked embryos were 

 disinfected by Norton's method and planted in agar plates. 

 Four of these seeds remained sterile, the fifth yielded a fungus 

 which was not the soybean organism, (b) The seeds of this lot 



