Fig. 15-1 A Petri Plate on Which a Variable ad(P)MT Colony 

 has been Streaked. The white colonies are also ad MT. They are 

 smaller in size indicating a somewhat diminished vigor. This is 

 a depletion mutation since outcrossing the whites with any normal 

 will restore the pink color. The pink color "runs out" either in 

 inbreeding or in asexual reproduction and can be restored by 

 outcrossing. 



15-5 



