370 COMPARATIVE MORPHOLOGY OF FUNGI 



Meanwhile the third cell is again divided by an oblique wall, parallel 

 to the first, so that there are now four cells in the row. Also cells 2 and 3 

 have divided successively by new oblique walls perpendicular to the first, 

 as earlier happened with cell 1, into a small apical and a larger basal cell. 

 Again these cells increase in size and push still further to the side the 

 series of cells above (Fig. 248, 5). 



Meanwhile cell 4 is divided by a septum again so that the cell row has 

 increased to 5. Besides, the apical cell has divided into a tip cell and 

 basal cell; the tip cell functions as a spermogenous cell and discharges tiny 

 bacilliform spermatia, at first naked or only covered by a very thin wall; 

 Gaumann prefers to call them conidia, consequently he calls the flask- 

 shaped antheridium a conidial mother cell from their superficial similarity 

 to the conidia of Thielavia. 



Meanwhile the basal cell of the ascospore, which had already cut off 

 the foot, has resumed its development. First, it divides by an oblique 

 septum into a small upper cell b and a larger lower cell y (Fig. 248, 6). 

 Later cell b becomes the stalk cell of the appendage and persists without 

 further development. 



On the other hand, cell y divides into a basal cell y' and into cell a 

 (Fig. 248, 7) which itself divides into the daughter cells a' and a" (Fig. 

 248, 8). The sequence of this division is not absolutely constant. Thus 

 it may also occur that, as in Fig. 248, 7, the basal cell is first cut off and 

 only then do cells a and b arise as daughter cells of a common mother 

 cell, completing the development of cell a"; in common with cell y', it 

 forms the extramatrical part of the vegetative body; with increasing age 

 these cells elongate to many times their original length and later, some- 

 what as indicated for Stigmatomyces Sarcophagae (Fig. 250, 2), bear the 

 perithecium in the form of a stipe. This extramatrical part of the thallus 

 in the Laboulbeniales is called the receptacle. In Laboulbenia e.g., L. 

 Gyrinidarum and L. chaetophora, the walls are formed of two to five layers; 

 outermost, a layer of radially placed plates which degenerate in age to a 

 granular network, and within, several layers of homogeneous, structure- 

 less plates penetrated by some thread-like veins. 



In contrast to cell a", cell a' continues to develop the ascogonia and 

 perithecium. At first it grows upwards and outwards (Fig. 248, 9) 

 and divides into two daughter cells c and d (Fig. 248, 10) ; the first forms 

 the primordial cell of the perithecial wall, the latter the primordial cell 

 of the archicarp, the so-called procarp. The cell c proceeds first to 

 divide by a more or less oblique wall into two daughter cells c' and c" 

 (Fig. 248, 11). Cell c" elongates and divides into the daughter cells z 

 and p (Fig. 248, 12). The latter has hereby completed its development; 

 it later forms the stalk cell of the perithecium ; the former z will divide 

 further. The cell c' divides also into upper and lower cells, i and h 

 (Fig. 248, 12). The lower cell we will call the secondary stipe cell of 



