Biology of Fegatella conic a, 1 1 3 
sporogonium Is mature. In early spring the stalk of the receptacle 
becomes suddenly elongated, the receptacle, which has hitherto been 
practically sessile, becoming in three or four days carried up to a height 
of from two to six centimetres. The writer has found that this sudden 
elongation is due to growth of cells already formed, and not to rapid 
cell-division. Should none of the archegonia of the receptacle be fertilized 
the stalk remains very short, and the whole structure soon becomes brown 
and withered, but fertilization of even a single archegonium is soon followed 
by active cell-division in the receptacle-stalk. This process continues 
during the autumn and winter, so that in early spring, before elongation 
has taken place, the stalk consists of longitudinal rows of very short but 
broad cells, densely filled with small starch-grains (PL VII, Fig. 35). 
During the elongation of the stalk the starch disappears, and when growth 
in length has ceased the stalk is found to consist of long cells which contain 
little but sap (PL VII, Figs. 36, 37). On comparing the length of the whole 
stalk and the average length of each of its cells, before and after elonga- 
tion, it is found that the whole of this remarkable growth in length may be 
accounted for by the simple elongation of the cells, the starch being used 
up In the formation of the cellulose required to maintain the thickness 
of the cell-walls as they become stretched out. 
The process just described is exactly similar to that observed in the 
elongation of the sporogonium-stalk in Pellia and other Jungermanniaceae, 
but does not appear to have been described previously in the case of 
the receptacles. In Marchantia and Preissia the conditions are entirely 
different from those here described for Fegatella . In these highest forms 
of the Marchantiaceae the growth of the receptacle-stalk is a gradual 
process, accompanied throughout by repeated cell- division. 
In its final elongated condition the receptacle-stalk is a slender, pale- 
green filament, nearly as delicate in texture as the elongated sporogonium- 
stalk of Pellia , and very different from the rigid receptacle-stalk of 
M archantia or Preissia , with its dorsal layer of air-chambers and its deep 
ventral furrows which contain rhizoids and are completely enclosed by the 
overlapping marginal sheaths. In Fegatella the receptacle-stalk is, after it 
has become elongated and has carried up the head of sporogonia, a purely 
temporary organ ; It only lasts until the spores have been shed. Soon 
after this has taken place the whole carpocephalum withers, its remains 
usually becoming covered up by the new thallus-lobes. Hence the botanist 
who does not begin his outdoor observations before Easter is likely to 
receive the impression that Fegatella rarely fruits, even when the very 
patches examined by the belated observer had been a short time before 
covered with abundant carpocephala. The writer has found Fegatella 
to be one of the most freely fruiting of the Hepaticae growing in various 
localities which were visited at regular weekly or fortnightly intervals 
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