ASCIGEROUS FUNGI— ASCOMYCETES 167 



maturity. Thus a sporidium may at first be one-celled, then 

 it acquires a central septum and is two-celled ; each of these 

 cells may be again divided, so that the sporidium becomes tri- 

 septate, and by a further process of subdivision the triseptate 

 sporidium may ultimately become seven-septate. By means of 

 a less symmetrical subdivision we have also biseptate, four or 

 five septate, and even muriform sporidia, with the cells divided 

 in both directions. Whatever the number of cells into which 

 a sporidium may be divided, each cell appears to be a repro- 

 ductive unit, capable of germination and producing its kind ; 

 so that each septate sporidium is in itself compound — that is to 

 say, each of its component cells acts in the same manner as a 

 simple, undivided sporidium would act. The forms of sporidia 

 are so numerous that it would be tedious to enumerate them 

 here. Some of these are externally rough, but the majority 

 are smooth, and they may be hyaline or coloured. In the 

 Discomyceteae coloured sporidia are comparatively rare ; the 

 coloration is confined to the epispore in all cases, and the 

 contents remain colourless. 



Paraphyses are more slender than asci, with which they 

 are associated, being placed side by side with them in the 

 hymenium, and, when present, are more numerous than the 

 asci, and usually a little longer, but filiform or thread-like. 

 There has from time to time been much speculation as to 

 their functions and relationship. Some have regarded them as 

 abortive asci, amongst whom was the late Eev. M. J. Berkeley, 

 who wrote : " The essential character of this important division 

 consists in the development of definite or indefinite sporidia 

 within certain of the external cells of the hymenium, called 

 asci, which are frequently accompanied by inarticulate or 

 septate, simple or branched threads, which are abortive asci, 

 known under the name of paraphyses." This opinion seems 

 to have been based chiefly upon the occurrence of organs, 

 apparently paraphyses, mixed with normal paraphyses and asci 

 in the hymenium of certain Discomycetes. These bodies pre- 

 sented inflations at the apex or below it, such inflations enclos- 

 ing a sporidium resembling the genuine sporidia in neighbouring 

 asci ; and hence it was concluded that these abnormal bodies 

 were degraded asci, not yet fully degraded into paraphyses. 



