588 
MR. H. M. WARD ON THE MORPHOLOGY AND THE 
between the numbers, but also because the spores are too large to pass through the 
setce, even supposing the cavity continuous and ending in an ostiolum, which is not 
in the case. I have often tried to discover conidia or other bodies in connexion with 
the setce, but have been forced to the belief that they have no function whatever 
connected with spore-production. One is not now impressed with the necessity for 
assigning any special function to such structures : if the setce are merely free-growing 
branches of the otherwise oppressed, creeping mycelium, there is nothing surprising- 
in the fact that some differences in form and consistency are correlated with their 
sub-aerial habit. This is at least no more remarkable than that the looser branches of 
an alga, like Coleochcete, should have a facies slightly differing from that of the cell 
series comprising the lower, creeping, appressed parts of the tlmllus. 
The collection of setce immediately around the “ fruit-body ” simply results, imme¬ 
diately, from the vigorous development of hyphse which accompanies the later stages 
of formation of the perithecium : this mass of setigerous hyphse, which seems compar¬ 
able with the formation of haustoria and such-like organs in other fungi during the 
fruit development, was called the “receptacle” by Bornet. As to a possible 
protective influence of the circles of setce, the question must be left open until we 
know more of the conditions : in some cases, at any rate, the setce do not arise until 
the perithecium is completely formed, and the spores nearly ripe. 
The perithecium, when completely developed, is a globular or sub-globular body, 
consisting of a shining black or brown external case, the outer thick walls of which 
appear regularly embossed, and an internal mass composed of asci and spores, &c. 
The embossed pattern on the outer walls results from the tliick-walled cells, of which 
it is composed, projecting at their free surfaces : where the cells join each other 
forming polygonal figures they do not so project.* Wlrat may be termed the base of 
the perithecium is sessile on the mycelium: at the opposite pole, or apex, is frequently 
a slight papilla, not obviously pierced by any pore. Bornet, noting this fact, ima¬ 
gines that the dehiscence takes place below, the whole upper part of the perithecium 
becoming broken away by a circular rupture at the base. In some forms, at least, 
the spores escape through an opening at the apex : how far this is general I do not 
know (Plate 42, fig. 43), but facts exist to render it probable that a minute and 
dilatable pore occurs in others. 
Vertical sections of the mature perithecium show that within the firm, deep- 
coloured, external wall is a lining of softer cells, with swollen envelopes and of a more 
or less flattened form : this inner lining of the perithecium extends two or three cell- 
series deep, and is slightly yellow or pale-brown in colour (see Plate 44, fig. 33, and 
Plate 42, fig. 34). In the cavity thus enclosed are the groups of asci in various 
stages of development : these delicate, clavate sacs contain spores, or have emptied 
them into the semi-gelatinous, granular matrix around. With these preliminaries, I 
may pass on to consider and describe the development of the perithecium, as followed 
* See Boenet’s figures, Joe. cit., plates 21 and 22, 
