6 4 
M c NicoL — The Bulbils and Pro-embryo of 
the protoplasm a short distance from the apex, the apex itself being 
occupied by a number of small, round, shining bodies (Glanzkorper), which 
are constantly in oscillatory motion. The function of these Glanzkorper is 
disputed by Zacharias (’05) and Giesenhagen (’01), the latter considering 
them to be statolithic in function, the former holding that they have 
some function to perform in the thickening of the cell-walls of the 
rhizoid. 
In these tubercles the nuclei are fragmented, a point which Giesenhagen 
failed to determine in the case of the tubercles of C. aspera owing to the 
difficulty of cutting sections, but it is probable from analogy that fragmen- 
tation is the condition there also. The nuclei can be best seen if tubercles 
are used from which the starch has been wholly or almost wholly with- 
drawn for the formation of young plants at the node. These tubercles 
should be fixed with chrom-acetic acid or Flemming’s solution and stained 
with Delafield’s haematoxylin or brazilin. 
The nuclei resemble the fragmented nuclei of the internodal cells of 
the plant, but are somewhat more irregular in shape. They are much the 
same size, and divide similarly by the appearance of a constriction and the 
subsequent pinching off of a part of the nucleus. 
The Pro-embryo. The pro-embryos arising from the rhizoid-nodes 
appear first as filamentous processes, at the end of which four horizontal 
walls are formed, thus dividing the filament into five cells, the three upper- 
most of which form the apex of the pro-embryo (Vorkeimspitze of Prings- 
heim). Two more walls then arise close to and parallel with the two 
lowest horizontal walls, thus cutting off two nodal cells ; shortly afterwards 
three vertical walls are formed in the second nodal cell, and then peripheral 
cells are cut off. From these cells the first leaves are formed. From the 
cells of the first or rhizoid-node rhizoids are formed. 
At this stage the pro-embryo has not appeared above the mud in 
which the plant grows and has formed no chlorophyll. I found no case in 
which the ‘ Vorkeimspitze ’ had more or less than three cells, though in Char a 
the number is four or five. In Tolypella intricata and some species of 
Nitella the number is two (De Bary, ’75). The three cells differ in size : 
at first the apical cell grows until it is three or four times as long as the 
others ; the protoplasm in it can be seen rotating, whilst the two lower cells 
are still filled with frothy protoplasm. With further growth the two lower 
cells become very much larger than the apical cell, which remains compara- 
tively small. The middle cell elongates, and soon after the 4 Vorkeimspitze * 
appears above the surface of the mud it begins to swell and becomes 
sometimes spherical, though generally remaining elongated (see Figs. 6 and 
1 8). The lowest cell elongates greatly, and. very often becomes turgescent 
and swells up, but it never becomes spherical as in the case of the middle 
cell. The cells which become spherical, or nearly so, are very easily 
