304 



Bulletin 240. 



Fig. 116. — Corn seedlings showing conditions of roots after grmving in mushroom 

 material. The two plants al the Icj't shozv the blaek root lips leliich are injured by 

 groiving in the fermenting inusJirooni inalerial. The tu'o at iJie right show Jiealthy 

 root tips which were growing in previously fenmnting mushroom material. 



