174 



PYRENOMYCETES 



[CH 



the " antherozoids " or spermatia of the Laboulbeniales have the same signi- 

 ficance as those of other fungi. They fall off when mature and the cells from 

 which they were formed may give rise to others in the same position. 



In Coreomyces instead of a segment of the branch being detached to form 

 the spermatium, a portion of its contents is extruded. This arrangement 

 leads to the more specialized endogenous organ which is found in Stigma- 

 tomyces (fig. 136) and in many other forms. Here the naked mass of proto- 

 plasm cut off from the parent cell may be regarded as the homologue of 

 the spermatium, or the parent cell may be recognized as an antheridium 

 and the detached segments as non-motile spermatozoids. They function, in 

 any case, as sperms or male elements. They are detached from the contents 

 of a flask-shaped cell and are extruded through an elongated neck opening 

 at maturity to the exterior. Between the neck and the venter a diaphragm 

 of cellulose is deposited and is perforated by a narrow opening so that the 

 sperms are nipped off as they pass into the neck. They are uninucleate, the 

 nucleus of the parent cell undergoing successive divisions so that a series of 

 sperms are produced. The parent cell has been termed an antheridium but 

 if the spermatium is antheridial in character the name cannot appropriately 

 be used for the cell in which it is borne, though the term spermogonium is 

 applicable. 



These sperm-forming organs may be produced singly or in groups, each 

 with its neck opening independently to the exterior, or they may form com- 

 pound structures (fig. 135), the necks of several cells 

 penetrating a single adjacent cell into the cavity of 

 which the sperms are discharged and from which they 

 escape by a common duct, the so-called secondary 

 neck, which may be a mere extension of the cell 

 forming the common cavity or, in a few cases, may 

 involve other cells also. The individual sperms are 

 formed in much the same way in the compound as 

 in the simple organs, but instead of being cut off 

 from the parent mass of protoplasm by a diaphragm 

 at the base of the primary neck they remain attached 

 till the neck widens abruptly at its end, and they 

 are extruded into the common chamber. Hundreds, 

 or even thousands, may be formed during the period 

 of activity of a single compound organ. The exo- 

 genously produced sperms are always walled where- 

 as those formed endogenously are naked when first 

 set free ; later a thin wall may be secreted. 



The female organs are formed from the basal 

 cell of the spore and are thus necessarily lateral. This condition is often 

 obscured in the mature plant where the developing perithecium may push 



Fisj. 135. Diiiieroinyces Afri- 

 canus Thaxter ; compound 

 spermatial organ ; after 

 Thaxter. 



