1918] FITZPATRICK—RHIZINA 209 
As the archicarp of R. undulata approaches maturity a very 
prominent, deeply staining, hemispherical or convex pad appears 
on each side of each cross wall at or near its center. Similar pads 
have been found in Humaria granulata (BLACKMAN and FRASER 9g), 
Ascophanus carneus (CUTTING 18), and other forms, but in no case 
have the figures presented by the investigator shown such striking 
and definite structures'as those in R. undulata. Since at a some- 
what later period a single large pore appears in each of the trans- 
verse septa at the point earlier occupied by the pads, it seems 
probable that the latter represent a swelling out of the septum due 
to gelatinization at this point. CutTtinG has suggested that the 
metachromatic granules mentioned may function in bringing about 
such a gelatinization. It is certain, in any case, that the pads are 
absent in young archicarps; that with the approach of maturity 
they are prominent; and that still later they disappear, leaving 
behind a well defined pore in the septum. Curtine found pads 
in Ascophanus carneus lying free in the cytoplasm of the archicarp 
following the appearance of the pores. Attached to these he 
observed what seemed to be bits of the wall on which they originally 
ay. The writer, however, has not seen any such detached pads 
in R. undulata. 
Near the apex of the archicarp shown in fig. 3 may be seen the 
union of the two pads which originally lay separated on the opposite 
faces of the septum. We may assume that this fusion represents 
the last stage in gelatinization. Currinc (18) figures a similar 
condition (his fig. 14) in an archicarp of Ascophanus carneus. 
Although the disappearance of these pads takes place suddenly, 
the process does not occur simultaneously on all the transverse 
septa. In fact, neither in the development of the pads nor in their 
removal is any definite sequence followed as regards the relative 
position of the septa in the archicarp. In the youngest archicarp 
shown (fig. 1) not all of the pads have been formed. In an older 
archicarp (fig. 4) all have disappeared, leaving definite open proto- 
plasmic connections. In intermediate stages (figs. 2, 3) some pads 
have disappeared while others remain.t Rarely a single pair of pads 
persists on a septum until the formation of ascogenous hyphae has 
‘Read the introductory paragraph in the explanation of plates. 
