66 
M e NicoL — The Bulbils and Pro-embryo of 
in the centre and the nucleus begins to fragment, so that in one of the 
large swollen cells there may be a hundred or more nuclei. 
The fragmented nuclei of the large cells of Lamprothanmns resemble 
those described by Kaiser in Char a foetida (Kaiser, O., J 96 ) to a great extent, 
but there appear to be a larger number which are elongated in shape than 
occur in the latter plant. The nuclei are varied and irregular in form : 
many are elongated, and divide by a gradual constriction of the middle 
portion of the nucleus (Fig. 17). In this figure of the nuclei of one of the 
swollen cells, various stages are seen : to the right is a nucleus which is just 
dividing across the middle, the two daughter-nuclei being connected only 
by a narrow neck. Other nuclei are rounded, or crescent-shaped. 
Nordstedt, in referring to the pro-embryo arising from the spore, 
remarks that in Lychnothamnus Wallrothii (an old name for the plant) 
there occurs an embryo having an oblique node between the primary 
rhizoid-node (Samenknoten, or node at the apex of the spore from which 
rhizoids are formed) and the rhizoid-node or * secondary rhizoid-node ’ of 
Nordstedt. Such an extra node I found in many of the pro-embryos 
formed at the root-nodes, and also in some produced from spores (Fig. 7). 
In the formation of this extra node an Shaped wall is formed and a cell 
then cut off, which later divides into four, as in the node-formation in 
rhizoid structures (Fig. 7 A). By further division and growth rhizoids are 
formed, and these spread out in all directions, though they are actually 
formed in a tuft on one side only of the pro-embryo. This extra node 
varies in position : it is generally midway between the rhizoid-node proper 
and the point of origin of the pro-embryo, and is easily distinguishable 
from the rhizoid-node proper by the oblique wall. This extra or interposed 
node is by no means of constant occurrence : in the case of the pro-embryos 
arising from the underground nodes of the plant, taking nearly a hundred 
cases, I found that the proportion of plants having this extra node was one 
in three. In the case of the embryos grown from the spores, I was unable 
to determine the proportion, as the spores germinated so rarely. It is 
probable that this extra node is formed in embryos originating from a level 
at a somewhat greater distance below the surface of the mud than that 
from which the majority originate. The rhizoids of this interposed node 
would serve both to fix the young plant firmly and to provide it with 
nourishment, though probably the former function is the more important, 
as such large food supplies are available in the root tubercles. This 
hypothesis is borne out by the fact that if several pro-embryonic shoots arise 
from a single node, they are alike as regards the presence or absence of this 
extra node. 
Pro-embryos may arise on underground nodes on which no root- 
tubercles occur, but, as is to be expected, the young plants generally arise 
in proximity to the stores of food material. Pro-embryos also very 
occasionally arise in the axils of the leaves. 
