292 PART IV. CLASSIFICATION. 



(e.g. Eurotitim, E^sipheae, Ascobolus), the archicarp consisting 

 solely of the ascogonium. The form of the ascogonium is either 

 filamentous, sometimes spirally coiled (e.g. Eurotium, Fig. 175) ; 

 or, it is dilated, and spherical or oval (e.g. Pyronema, Fig. 172, 

 Erysiphese). 



The pollinodium may be filamentous (e.g. Eurotium), or dilated 

 and club-shaped (e.g. Pyronema, Erysiphese). The antheridium 

 of the Laboulbeniacese is unilocular, and produces several non- 

 motile male cells (spermatia) within it. 



Some of these plants bear receptacles termed spermogonia. 

 The spermogonium consists of a wall formed of coherent hyphse 

 from which a number of free hyphse, the sterigmata, grow into 

 the interior and produce, by repeated abstriction at their apices, 

 a number of small, rod-shaped cells, the spermatia, with a cell- 

 wall, as to the nature of which there is some doubt. These cells 

 reach the surface through the small opening of the spermogonium. 



A process of fertilisation has not been observed in all forms in 

 which sexual organs are present j but it has been observed in the 



c. 



FIG. 171. Sexual reproduction of Eremascus albus. A Sexual organs in contact. B 

 Fusion of the organs at the apex, with developing ascocarp. C Mature ascocarp, consist- 

 ing of a single ascus containing eight ascospores. ( x 1000 : after Eidam.) 



following cases which are representative of the various modes in 

 which it may take place. 



In Eremascus (Fig. 171) the apices of the undifferentiated sexual 

 organs come into contact, and, the cell-walls being absorbed at the 

 point of contact, the protoplasmic contents fuse. 



In Pyronema the trichogyne comes into close contact with an 

 adjacent pollinodium ; the cell-walls become absorbed at the point 

 where the apex of the trichogyne presses against the pollinodium, 

 and the contents of the two organs fuse (Fig. 172). 



In the Laboulbeniacese it appears that the male cells spermatia 



