358 MR. 8. LE M. MOORE’S STUDIES 
three days in the dark a similar disposition of the chlorophyll 
may be noted in the smaller axial cells; the ultimate cells at 
length contain either a mass of chlorophyll at their centre or at 
either end, or two such masses, one at the proximal, the other at 
the distal end. 
In Chetophora sp. the chlorophyll is disposed in the form of 
a central ring or irregular figure, from the borders of which broad 
or narrow, long or short bands extend upwards or downwards or 
both (figs. 12 a and 5). After three days in darkness conden- 
sation has occurred in many of the cells, the chlorophyll being 
now in the form of a central band or x-shaped figure, or of one, 
two, or three such bands situated anywhere in the cell, or of a 
couple of bands at or near the centre (figs. 12 c and d). Under 
these latter circumstances, should the bands protrude at places, à 
figure somewhat similar to that in a Zygnema-cell results (fig. 
12 d). The greatest change, however, is seen in some of the 
older cells after six days in the dark, the chlorophyll having now 
condensed into a spheroidal or ovoidal mass at the centre or on a 
side of the cell (fig. 12 e). 
The chromatophore of Chantransia pyjmea, Kütz., is uniformly 
disposed upon the cell's walls (fig. 13 a); but in specimens shut 
up for some time from the light this arrangement is departed from 
in many cases. The contents are now seen to have collected 
either in bands or irregular figures at the proximal and distal 
ends of the cell, or interspaces shut off entirely or partially by 
cross-bridges of varying width have appeared in the chromato- 
phore, showing that condensation has occurred at some points 
(figs. 18 b, c, d). Modifications similar, though less in degree, 
are to be discovered in the cells of Batrachospermum moniliforme, 
Roth, after ten weeks’ darkness. 
Another instance of the alteration of position wrought by 
withdrawal from light is furnished by the chlorophyll plate of 
Mesocarpus scalaris, Hass. In some of the cells of threads shut 
up in darkness for several days the only change observed is that 
the plate has receded from the fore and hinder ends, the chloro- 
phyll betraying an evident tendency to collect at the centre of 
the cell (fig. 22 a). This shrinkage of the plate is frequently 
accompanied by its movement towards a side-wall, as will be 
‘explained further on (see p. 369). Occasionally the two halves 
of the plate may separate with or without an intervening plasma- 
bridge, in which latter—when it is absent, then in the interspace— 
