ASCOMYCETES 



iSl 



development of short, modified hyphal cells (Fig. 66, d). These 

 are properly the ascogenous cells, which by an abundant budding 

 process form frequently an almost continuous layer beneath the 

 cuticle. The asci develop from these ascogenous cells, as upward 

 prolongations, pushing through the cuticle, while the original 

 ascogenous cell is finally cut off by a cross wall as a stalk or foot 



Fig. 66. Exoascus on Peach: Asci, Germinating Spores, and Hyph^e 

 (6, c, and d after Pierce) 



portion. The ascus is usually somewhat truncated at the apex and 

 densely filled with protoplasm. It may measure 25-40 x 8-1 i/u. 

 (ave. 30-35 X 9-10). As a rule it contains at maturity eight 

 spores, although the number may vary from four to eight (Fig. 

 66, a). These asci often arise in such numbers that they form prac- 

 tically a continuous palisade-like layer over the fruiting surface. 



The ascospores may bud before being thrown out of the ascus, 

 but as a rule the spores are forcibly ejected from the ascus at 

 maturity. Budding results in the successive production of conidia, 



