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MOXOGRAni OF TJIE LABOULBEXIACE.'E. 223 
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17-20. Tn fi<,^ 17, the primary wall-polls (fi<j. 15, «,;/)liavo imJcrgoiic their first 
division, having each separated into an upper and a lower cell (wandii). The four 
cells of the inner series (;/') have also been developed from the throe basal cells (0,0); 
but, although they extend upward above the septum which has divided the wall-cells, 
they are no 
but each of 
yet septate. In fig. IS, the wall-cells remain as before, 
inner series has divided into two, (p c) the pnrictal cells 
and (nc) the primary canal-cells. In fig. 20 the primary canal-cells have again 
divided into two (;i c' and nc"), and this division has been preceded by a correspond- 
ing separation of the upper wall-cells (^^',w) into the two cells (?('a" and ?rr'). This 
condition continues until the asci have reached a considerable development (fig. 23); 
but before any of them are mature a last division takes place, by which (he cell [nc") 
of the same figure is separated into the cells (cc) and {t c) of fig. 24, and the cells 
(/i'/)are separated into {iv^) and (i''z). In Stiginatomyces, then, there are present in 
the nuiture peritheciuni, before the spore discharge has cuiumenced, an outer series of 
tvall-ceUs disposed in four longitudinal rows of four cells each, the tennlnal cells of 
which may be conveniently called the lijj-cclls, and also an inner series of cells 
alternating with the outer, and also arranged in four longitudinal rows, each nuide 
up of four cells, the lower of which may be conveniently termed the parietal ccllSj 
the three others being distinguished as the caiial-cdls. There are thus four parietal 
I cells, twelve canal-cells and sixteen wall-cells, making a total of thirty-two cells in the 
. peritheciuni proper, exclusive of the three basal cells, the stalk-cell and the secondary 
stalk-cell previously alluded to (0, Ji, and p of fig. 15). 
The asci, in the mean time, have continued to bud from the ascogenic cells, so that 
their total bulk has greatly increased, and as a result the ascua mass begins to exert 
a considerable pressure in all directions on the surrounding cells. Tn this way the 
superior supporting cell, the secondary inferior supporting cell, and the parietal cells 
and in most instanpRs. thouo-h not usuallv in that which has 
gradually destroyed 
ferior supporting cell is eventually obliterated by 
been used as an illustration, the ii 
pressure. In Stigmatomyces the lower series of neck-cells (fig. 24, n c) become 
gi'adually inflated towards their distal ends and their walls are somewhat thickened, 
so that they act as guard-cells which control, to some extent, the passage of the spores 
from the general cavity of the perithccium to that of the neck. The asci as they 
mature are sloughed off from the ascogenic cells, and rapidly disappear, their walls 
bein^'- absorbed as soon as the spores arc completely formed, so that the latter lie 
free in the cavity of the perithccium. The spore mass thus formed, being constantly 
au<niiented, pushes between the guard-cells («c') just mentioned, and being forced still 
