518 
REVIEWS. 
nor indeed are the barefooted shoots generally of much importance, 
for Dr. Pringsheim himself admits that they are only ordinary shoots 
unessentially modified. 
The proembryonal shoots are of more interest. They appear to 
pass into normal shoots in their upper parts, but are quite irregular 
below. Every normal lateral shoot of Cliara fragilis begins with a 
green joint exhibiting the characteristic rows of chlorophyll, and 
bears immediately above it the first leafy node. The proembryonal 
shoots on the other hand begin with a colourless joint, followed by a 
deficient and leafless node, which is sometimes wanting, sometimes 
replaced by an elongated cell. Next comes a naked joint, bearing 
apparently the first whorl of leaves, but this whorl is remarkable 
from having one (apparent) leaf developed far more than the others, 
and to an extent never seen in a normal shoot. Erom this point the 
shoot becomes normal; that is to say, its subsequent internodes, 
nodes, and leaves are like those of ordinary shoots, leading to the 
supposition that the normal shoot originates laterally in the axil of 
the abnormally developed (apparent) leaf # abovementioned. This 
pseudo-leaf does not proceed from the 2- or 3-celled node beneath it, 
for observation shows that the latter is not formed until after the 
pseudo-leaf has begun to be developed. Dr. Pringsheim, therefore, 
arrives at the following conclusion. He says, “ it is clear therefore 
“ that the terminal process before-mentioned is not a leaf, but the 
“ apex of a special organism having a very simple law of growth. I 
“ call this organ a proembryonal shoot (Zweigvorkeim), because the 
“ first bud of the normal shoot is subsequently developed at a defi- 
“ nite spot on this proembryonal shoot, and because the latter exactly 
“ resembles the proembryos which are produced in the germination 
“ of Chara-spores, and on which, in like manner, the first leafy shoots 
“ of the Charse are produced from subsequently-developed lateral 
“ buds.” 
Tracing the proembryonal shoot from its commencement, its 
history (setting aside occasional irregularities not essential to be 
here noticed) is as follows. A cell is protruded from the node of an 
old plant, which cell elongates and has its apex cut off by a trans¬ 
verse septum. The division of the terminal cell is repeated several 
(3-6) times, and thus the pseudo-leaf, or proembryo-apex (Vorkeim- 
spitze), above mentioned is formed. In the meantime the elongated 
cell swells up close underneath the pseudo-leaf, and the enlarged 
portion is cut off from the part beneath it and becomes a special 
cell, which the author calls the bud-base (Knospen-grunde). Two 
new septa, not parallel to the former septa , are formed in this special 
cell, which thus becomes divided into three cells, of which the lower 
one divides and forms a sort of node, the middle one divides no more, 
and the upper one becomes a vegetative cell, protrudes itself laterally, 
and eventually forms the first leafy shoot. This protrusion is effected 
* Hereafter, for convenience, we will call this organ the “pseudo-leaf.” It is 
the apex of the proeinbiyonal shoot, but is not, according to Dr. Pringsheim, a true 
leaf. 
