592 
MR. H. M. WARD OR THE MORPHOLOGY AND THE 
A—are divided more regularly by tangential walls, followed by radial ones at right 
angles as the area enlarges. As the increasing small and delicate cells of the core 
become formed more rapidly, a certain tendency at least to a regular arrangement can 
be recognised in the later stages, as shown in such sections as figs. 28 and 29, 
(Plate 44), and fig. 27 (Plate 42) : this regularity becomes interfered with by the 
mutual pressure of the cells, and the outer ones, of which the walls are especially 
soft and swollen, become flattened and pulled in the tangential direction, and only 
marked by the very granular yellowish protoplasm in their diminishing cavities. In 
the central lower part of the core, vertical sections at this, and slightly later stages, 
show that certain cells, with very delicate outlines and finely granular refractive 
contents, maintain their larger size and upright arrangement, and are by these 
peculiarities well distinguished as a special group or tuft of cells (see Plate 44, fig. 28 
and Plate 42, fig. 31). In oblique (Plate 44, fig. 29) and horizontal (fig. 30) sections 
passing through the lower third of the developing perithecium, they can also he 
readily distinguished by their special peculiarities, and no question can be entertained 
as to their significance in the formation of the essential parts of the fruit-body. This 
group of cells is the forerunner of the young asci, and may be termed the Ascogonium. 
As development proceeds continuously, the outermost layers acquiring thicker and 
more deeply coloured walls, the above named group of upright cells become relatively 
larger, increasing slowly in number by a few divisions, while the diffluent, compressed 
cells between them and the outermost layers slowly give up their contents, and 
become reduced to mere granular streaks embedded in a jelly-like mass of swollen and 
fused cell-walls (see Plate 42, fig. 31). This process is exactly comparable to what 
takes place in the developing embryo-sac of certain phanerogams,* or of the pollen 
mother cells in the anther,! in so far as the larger cells clearly develop at the 
expense of material derived from those around. 
The tuft of successful cells thus nourished is, in fact, the “ascogonium” of this 
fungus. At a slightly later stage than the one last figured, the space formerly 
occupied by the deliquescent remains of small cells is filled with an almost trans¬ 
parent semi-fluid mucus, in which a few bright granules are embedded ; while the lower 
part of the perithecium contains a tuft of asci in various stages of development 
(see Plate 44, fig. 33), and which have evidently proceeded from the large cells of 
figs. 28 and 31 (Plates 44 and 42), which have devoured all, or nearly all, the 
smaller soft cells surrounding them. 
Sections of perithecia at a stage between those shown in figs. 31 and 33 (Plates 42 
and 44) have not been obtained, but enough evidence has been secured to enable me 
to conclude that the asci are the direct result of the transformation of the elongated 
upright cells of fig. 31 (Plate 42), which are nourished at the expense of the ceils of 
the inner layers. Partly from the brittle nature of the outer walls, enclosing a space 
* Cf., amongst others, Strasbueger, ‘ Angiospermer nnd Gymnosjaermen.’ 
t Cf, Strasburger, ‘ Bail nnd Wachsthum der Zell-lmute,’ 1882, 
