CHAPTEE XIV 



ASCIGEEOUS FUNGI ASCOMYCETES 



Whatever the form which the receptacle may assume, the 

 Ascomycetes have always this one feature in common — that the 

 spores are not naked or exposed, but are always enclosed within 

 a delicate external membrane or spore-sac, and these latter are 

 imbedded in the modified hymenium. It is quite true that the 

 hymenium itself may be exposed, but the spore-sacs, or asci, 

 are imbedded, and the spores are not visible externally until 

 they are mature and discharged. It was proposed some years 

 since that the term spor.e should be applied only to such repro- 

 ductive bodies as were produced naked, or not enclosed in an 

 investing membrane, whereas all such reproductive bodies as 

 were developed within an ascus, or investing sac, should be 

 termed sporidia. It will be obvious to all who consult the 

 most recent works, that this distinction has not been maintained, 

 at least with the old limitation ; so that conidia, spore, and 

 sporidium are employed without recognised definition, almost, 

 if not entirely, as if they were synonymous. "We still hold 

 that the spore which is produced naked, whether as a basidio- 

 spore or stylospore, should possess a name by which it may at 

 once be distinguished from such as are developed within an 

 ascus, whether it be ascospore, sporidium, or some equivalent. 

 When Saccardo elaborated his extensive work Sylloge 

 Fungorum he recognised this difficulty, and at the commence- 

 ment of the third volume defined the terms which he should 

 employ, and accepted sporidia as exclusively applicable to 

 ascospores. Spore, simply and without prefix, was practically 

 the same as basidiospore, for he applied it to all the Hymeno- 

 mycetes. These were the two distinctive terms for the primary 



