Biology of Fegatella conica , 1 1 1 
division into tetrads of spores. Moreover, the examination of longitudinal 
sections of the sporogonium shows that in nearly every case the branching 
really consists in a forking of that end of the elater that lies nearest the 
apex of the capsule, and that this is in the typical unbranched elater blunt 
and rounded, whilst the lower end tapers to a sharp point (PI. VII, Fig. 
52 b , c). From these facts it is obvious that the branching of the elaters 
is brought about by the loosening of the spores, in consequence of which 
the pressure on the upper portion of each elater becomes diminished, 
whilst its lower portion remains wedged in between the spores. In 
the lower part of the capsule the elaters either remain unbranched or slight 
branching takes place at their upper ends ; towards the middle of the 
capsule branching takes place more freely, but still only at the upper end 
of the elater ; but nearer the apex of the capsule branching may take place 
at both ends of the elater, the branches insinuating themselves between 
the spores. The writer has observed branching elaters in Reboulia 
hemispheric a and Targionia hypophylla , where the relative arrangement 
of spores and elaters is much the same as in Fegatella , the elaters being 
relatively short and the spores being loosely packed, whereas in Marchantia 
and Preissia , where the spores and elaters are arranged in extremely 
regular longitudinal series, the elaters being very long and narrow for the 
most part, branching does not appear to occur. It is hardly necessary 
to describe and figure the various and often bizarre forms assumed by 
the branched elaters of Fegatella ; this has already been done by a previous 
writer (Tilden, 1894). In most cases they are Y- or V-shaped, though in 
a few cases there were found towards the apex of the capsule a few 
X-shaped elaters in which both ends had become forked. The young 
elater contains numerous small starch-grains, but these become fewer 
as the differentiation of the bands proceeds, being evidently used up in 
the formation of these thickenings and disappearing by the time the bands 
have become brown. The bands at first, while colourless, give the 
reactions of cellulose, but later become lignified. 
It is probable that the primary function of the elaters is to aid in 
the nutrition of the developing spores. They present a relatively large 
surface through which food-materials, passing up in solution through the 
stalk of the capsule, can readily be distributed to the spore-producing 
cells. This primary function of nutrition, the only one performed by the 
sterile cells in the lower Marchantiaceae (e. g. Corsinia ), is in the higher 
forms superseded by a second, namely, that of assisting in the dispersal 
of the spores. This, however, only comes into operation after the dehiscence 
of the capsule, and it is probable that even after the elaters have ceased 
to be living cells and have become thickened, they still serve for the 
distribution of water to the developing spores. 
