The Origin and Development of the Apothecium etc. 385 
a septum occurs, at least there is no nucleus between this region and 
the cross wall at 5. The septa appear sometimes to have beeil completely 
resorbed. IVl one case (Fig. 6) I found a nucleus exactly where one would 
have expected to find a septum. In the hyphae shown in Figs. 4 and 7, 
it is not possible to be certain of a membrane separating the cells. The 
diameter of the hyphae is so small and the mass of material on the outside 
of the wall is so dense that it is diffienlt to see clearly a median optical 
section. I have triecl to show these hyphae (Figs. 4, 6, 7) in median 
optical section, but the shaded portion which I have represented between 
the thickenings on the walls may be only a sliadow of what is above and 
below and not anything which is really found in the center of the cell. 
Some distance below the surface of the thallns, where growth is less 
active, hyphae composed of these larger cells with conspic-nous cross 
walls are espec-ially abundant. 
The vegetative hyphae in many ascomycetes have been described 
as composed of several or many nucleate cells — in some cases, as in 
Boudiera (Claussex, 18), the number varying with the size of the cells. 
In the Erysipheae (Harper, 47, 52), the cells are mostly uninucleate but 
may contain two to four nuclei each. Granules on the cross walls have 
been found in a number of cases. Harper has described them in Pyro- 
nema (51) and in the same species and in Boudiera, Claussex (18, 20) 
finds they have metachromatic properties and that they are single or in 
abnndance on the septa. Since he observed that granules may pass 
through the septa, Claussex believes that the latter are perforated. 
Miss Terxetz (77) has figured and described conspicuous granules either 
on the cross walls or elsewhere in the cells of Ascophanus carneus and 
observed that the cross walls offer no obstruction at all to the movement 
of these granules from one cell to another. In Collema pulposum the 
partitions between the cells appear to be continuous. I know of nothing 
reported for other forms similar to the mass of granules which I have 
described outside the hyphae but at the cross walls. 
Carpogones are formed as soon as growth begins in the spring, and 
in May or June they are found abundantly in both early and late stages 
of development. In lobes of small fruiting thalli at tliis time about half 
of the sections (25 microns thick) show parts of carpogones. The carpo- 
gones are found singly, or more often in groups of three or four, and are 
usually about one-fourth of the total thickness of the thallus below the 
upper surface. They may branch from cells of older vegetative hyphae, 
or they may arise from filaments in which growth is more active and 
which connect the older hyphae. The vegetative hyphae in tliis region 
Archiv f. Zellforschung. X. 26 
