1896] PROCARP AND CYSTOCARP OF PTILOTA 363 
the earliest stage, we find a cell at the end of a procarp closely 
attached to the cell of the trichophoric apparatus (jig. 77, ¢). 
Such a cell contains no distinct nucleus, but the cell contents 
often show a certain degree of differentiation into vacuoles and 
aggregations of granular matter. This cell begins to elongate, 
and as it does so carries up with it the substance of the inner 
zone of the cell-wall. Finally it pushes through the outer zone 
of the cell-wall (fig. 72), and then simply elongates until the 
full size is reached. The cell-wall of the upper portion of the 
trichogyne is composed entirely of the substance of the inner 
zone, the outer zone remaining around the base of the trichogyne 
as a sort of collar (fig. 73). As the trichogyne elongates the 
cells-contents become more homogeneous, until aside from some 
granular matter in the base of the structure there is no differen- 
tiation of the protoplasm. The trichogyne is united to the cell 
of the trichophoric apparatus by a narrow strand of protoplasm. 
The first indication that the trichogyne is about to wither 
appears in the formation of a cap like layer of cellulose, staining 
deeply with hematoxylin, over the cell of the trichophoric 
apparatus, severing the protoplasmic connection between these 
two Structures. An early stage in the differentiation of this cap 
is shown in fig. rg, and a later stage in fig. 75. Contemporane- 
ously with the formation of this cap begins the disintegration of 
the trichogyne, and this latter process is always associated with 
the development of a zooglcea of rod-shaped bacteria ( figs. 14 
and 7 5), with sometimes Leptothrix and Beggiatoa filaments 
around the ends of the trichogynes. The end of the trichogyne 
§radually collapses, and the cellulose wall appears to gelatinize, 
for the outline becomes vague and at last we cannot distinguish 
the end in the mass of slime. The contents of the trichogyne 
either disappear entirely, or there are left only small masses of 
®rganic matter in the basal portion of the structure. 
While the trichogyne is withering the cell of the trichoph 
@pparatus usually begins to push out at one side of the bas 
the trichogyne, and assuming the functions of an apical cell it 
Converts the procarp into a filament of several cells that forms 
oric 
e of 
