204 



SPORE DISSEMINATION 



radially arranged pseudoparenchyma, and finally (f) a thin layer 

 of small-celled pseudoparenchyma. 



Within this multiple periderm is the glebal mass. At maturity 

 the peridium splits and bends outward to expose the gleba. The 

 fruit body now consists of two tooth-rimmed cups, one fitting 

 inside the other and the two joined at the tips of the teeth. The 

 outer cup consists of the three outermost layers. The innermost 



Fig. 38. Feeding tracks made by the snail Polygyra thyroidcus on lilac 



leaves infected with powdery mildew. 



layer liquefies, and this liquid accumulates around the spherical 

 glebal mass, which is now free and can be rolled around in the 

 cup. The tanoentially arranged layer and the radially elongated 

 layer are left to constitute the inner cup. Everything is now ready 

 for discharge, provided that there is light, a temperature approxi- 

 mating 90° F, and high relative humidity. If these conditions pre- 

 vail, the inner cup suddenly everts itself and in so doing hurls the 

 gleba away. If the fruit body is tilted to get the most suitable 

 trajectory, the gleba may be projected a horizontal distance of 546 

 cm. Sphaerobolus holds the long-distance record among fungi 

 for spore projection. 



The inner cup may be ejected along with the glebal mass, but 

 more often it remains as a p;listenin«; dome. i\fter a time it may 

 assume its original position. Wax or plasticine spheres can then 



