1918] FITZPATRICK—RHIZINA 225 
Strictly speaking, however, these drawings are not composite, since the indi- 
vidual cells were outlined as they appear in a single section. In fig. 2 the 
terminal 6 cells were outlined from one section, and the basal 3 from the 
adjacent section. All of the central portion of the archicarp shown in fig. 3 
was pepe from one section, although portions of these cells appear in the 
two t sections. This explains the presence in the drawings of the deeply 
staining pads or open protoplasmic connections at certain septa and their 
absence at others where they lie outside the plane of the optical section. In 
those cases in which they are not shown, the examination of other optical 
sections usually shows either a pad or a pore, but in some cases they are 
obscured by the dense overlying protoplasm of one or the other of the adjacent 
cells. In fig. 4, due to the absence of winding in the archicarp, many of the 
open protoplasmic connections appear in one plane. . In drawing the terminal 
cell of the archicarp shown in fig. 3 an exception has been made to the general 
method of treatment. This cell on account of its coiled nature cannot be shown 
satisfactorily in a single plane, but since it lies wholly in one section it has been 
possible to draw it in perspective. The nuclei shown in figs. 1-4 have not 
been outlined with the camera lucida, and the writer has attempted to show 
in the cells of these archicarps merely the relative number and size of the nuclei, 
not their exact position. The dense nature of the cytoplasm at these stages, 
the crowding of the nuclei, and the use of several optical sections in the prepara- 
tion of the drawings renders a faithful portrayal of the nuclei impossible. The 
remainder of the drawings (figs. 5-27) have been made from a single optical 
section and the nuclei and other cell contents are accurately reproduced. 
PLATE III 
Fic. 1.—Terminal portion of young archicarp of Rhizina undulata Fries, 
X 500; note dense protoplasmic contents, numerous nuclei, and deeply stain- 
ing convex pads on transverse septa of lower and more nearly mature cells; 
the fact that the terminal cells are long and slender and contain relatively few 
nuclei indicates the origin of the archicarp from a vegetative hypha. 
Fic. 2.—Terminal portion of a somewhat older archicarp, X500; note 
attenuated terminal cell, trichogyne; deeply staining pads and open proto- 
plasmic connections cannot be seen on all — since they lie outside plane of 
section. 
Fic. 3.—An entire archicarp nearing maturity, X 500; 2 ascogonial cells 
have aieaay begun to put out ascogenous hyphae; deeply staining pads are 
prominent on several septa; open protoplasmic connections have resulted from 
their disappearance on others. 
Fic. 4.—An entire archicarp contrasted in size with ordinary hyphae of 
ascocarp, X 500; here open protoplasmic connections are visible at practically 
every septum. 
Fic. 5.—Cells in basal region of archicarp at time of general flow of nuclei 
and cytoplasm into ascogonial cells, X 500. 
