APOTHECIAL DEVELOPMENT 



249 



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Fig. 99, Diagram of the development of an angiocarpous apothecium. 

 (After Corner.) The circle indicates the position of the ascogonium 

 within the apothecial initial. A. Branched hyphae rising from the stalk 

 cells of the archicarp invest the ascogonium. B. Tissue differentiation be- 

 gins within the spherical mass (apothecial initial) ; cortex is thick-walled, 

 internal tissues thin-walled; ascogenous hyphae appear as protrusions diverg- 

 ing from the ascogonium. C. Mucilage cavity appears in upper portion by 

 dissolution of internal tissues, a palisade of hyphae forms floor of cavitv, 

 coming in part from hyphae that ascend with ascogenous hyphae, which 

 together form hymenium. D, Pressure from expanding hvmenium ruptures 

 cortex above hymenium; as asci enlarge, the disk expands laterallv. Asci 

 at center of disk first to mature, and maturation continues centrifugally. 



