230 MONOGRAPH OF THE LAB0ULBENIACEJ5. 
cells ; but in some species they maj lie wholly below them, being prolonged into a stalk, 
as in L longicollis, L. KwiMi, and their allies (Plate XIX, fig. 6, etc.; Plate XVIII, fig. 
In such instances the ascus and spore masses, as they lie in the perithecium, are 
iiost completely surrounded by the sub-basal cells of the series. In Slkjmatom?/ces 
Baeri, on the other hand, the basal cells of the series occupy a corresponding position 
(Plate I, fig. 23), while in >S'. virescens (Plate VIII, fig. 2) the basal cells of the perithe- 
cium (not the wall-cells) extend up above the ascogenic cell and the base of the ascns 
mass. In a few cases the wall-cells may give rise to projections or definite appen- 
dages, which originate as lateral branches. Such a projection from one of the basal 
wall-cells is found in Chiiononif/ccs spinifferus (Plate VIII, fig. 16). C. ajipendlculaius 
offers an example of a similar projection from one of the sub-basal cells; while in- 
of outgrowths from the terminal cells of 
found 
Stljynatom^ces virescens (Plate VIII, fig. 1), Laboidhcnia Gyrinidanim (Plate XXII, fig. 
37), and a few other cases. In the genus Ceratomyces, multicellular appendages may 
be thus developed which may be even copiously branched (Plates XXIV and XXV) ; 
but in all the instances cited these structures are only of specific importance. 
The terminal cells of the series of wall-cells have been already referred to as the 
" lip-cells " ; since it is b 
spores eventually force their way 
* 
from the perithecium. These lip-cells are often somewhat modified in shape, and are 
not, as a rule, similar and symmetrical, though sometimes so. They are usually 
modified to form a more or less elastic margin to the pore ', as, for example, in some 
species of Laboulbenia (Plate II, fig. 14), the lip-cells of which are in general very 
irrei^ular in form, and have their walls so modified as to <ji;Ive them (jrreat elasticity 
^..v. Q — ^ 
and thus regulate the discharge of spores. In this genus, and perhaps in some others, 
there is a peculiar structure at the apex of at least one of the lip-cells, represented in 
the figure just cited at (x), which may perhaps act as a valve, allowing the lip-cell, 
the cavity of which it terminates, to be more readily compressed, and at the same time 
to recover its form as soon as the pressure is removed. That the spore discharge may 
be regulated by modifications of cells other than the lip-cells has already been seen in 
the case of Stigmatom^^ces (Plate I, fig. 24) ; and in Sphaleromyces (Plate III, fig. 1), 
several sets of cells appear to assume this office. Rhadinomyces (Plate IX, fig. 13) 
affords an instance in which the lip-cells perform this function without any consider- 
able modification. 
Turning now for a moment to the inner series of cells which have been described 
as arising from the basal cells of the perithecium within, and alternating with, the 
wall-cells, we have seen that in Stigmatomyces their development follows that of 
} 
\ 
I 
1. 
