BREAD MOLD 137 



Strange to say, you very seldom get both kinds in the 

 same neighborhood. It all runs to either the plus or 

 the minus strand in any certain section of the coun- 

 try. So I had to send to one of the distant labora- 

 tories to get the needed strand with which to start 

 my cultures. This media in hand, I infected two tiny 

 crumbs of bread with each strand and placing them 

 about three fourths of an inch apart, the filaments 

 grew from each quite rapidly, spreading out in all 

 directions and some of them from the plus strand 

 would touch those from the minus and the union of 

 those two strands produced a zygospore at that point. 

 Watching the zygospore from under the microscope 

 was extremely interesting. It was more translucent 

 than the sporangia and the action going on inside 

 of it was visible with back lighting up until the 

 very last ripening process. The spores which formed 

 inside the zygospores were just as numerous, and 

 were discharged, as those from the sporangia. Gath- 

 ering these spores and putting them in almost any 

 kind of gelatinelike solution, they would germinate 

 at once and a tube grow from them, which first 

 would form a few little rootlike branches called the 

 holdfast, and from these the filament would grow, 

 a sporangia forming on its end. When working 

 with these spores under the microscope, not taking 

 any special care of them, one of my slides became 



