MONOGRAPH OF THE LABOULBENIACEJ5. 



219 



outward (fig. 9), and by the formation of a septum is soon divided (fig. 10) into an 

 upper and a lower cell (d and c). From the upper of these cells, which may be 

 called the primordial cell of the procarpe, is formed the whole of the female sexual 

 organ, while from the lower (c), which may be similarly called the primordial cell of 

 the peritkecium, are developed the cells which form the perithecium proper. This 

 lower cell (c) is the first to show further signs of development, and becomes divided 

 by a more or less obliquely longitudinal septum (fig. 11) into two cells (c" and c). 

 The cell (c") then begins to grow upward, and becomes divided into an upper and a 

 lower port ion, fig. 12 (z) and (p). The lower cell (fig. 12, p) constitutes the "stalk- 

 cell," while the upper continues to divide, as will be presently described. The cell 

 (c') of fig. 11, on the other hand, becomes separated into two upper cells (fig. 12, 

 lying on opposite sides so that only one is shown in the figure, and a lower cell (/<), 

 which may be called the secondary stalk-cell. The cell (z) and the cells (i, i) then 

 continue to grow up around the base of the cell (d), the primordial cell of the procarpe. 

 One of the cells (/, i) then becomes separated into a single lower and two upper cells, 

 while the other becomes separated into a single lower (figs. 13, o) and a single upper 

 cell (n), as also does the cell (z); the cells (</) and (n) of fig. 13, resulting from its 

 divisions. There are thus formed three proper basal cells of the perithecium, two an- 

 terior (o, o) and one posterior (o'), but two of which are shown in the optical section 

 (fig. 13), and from them four cells are separated above which continue to grow up- 

 ward and surround the cell (d), the base of which is now (fig. 13) completely enclosed 

 and has become separated by a cross partition as the cell (/) from the part (c) which 

 still remains free above it. 



We then have this basal part (fig. 13) constituting a central cell (/), distinguished 

 from the free part above (e) by a cross partition, and completely surrounded by the 

 seven cells (o, o and n, n), but four of which are, of course, shown in the optical sec- 

 tion. The central cell ( /") then remains without further development until fertiliza- 

 tion has taken place ; the terminal portion of cell (e) in the mean time becomes 

 separated from the part below (fig. 14, e") as a usually very small cell (e 1 ), which im- 

 mediately begins to produce a terminal outgrowth, the young trichogyne. This 

 small cell is more marked in the genus illustrated thin in most others in which it is 

 not, as a rule, so clearly distinguished; the filamentous portion usually growing 

 directly from the apex of cell (e), from which it is separated by a septum (Plate II, 

 fig. 2). Cell (/•) and the projection (fr) from it must therefore be considered as con- 

 stituting together the trichogyne proper. As the latter develops, the cell (c) becomes 

 less well marked, while the filamentous portion reaches a development that varies in 



