339 
plants there is no longer any evidence of an immediate connec- 
tion between archegonia (which must occur on the upper ridge 
of the prothallus) and the suspensor. In the later stages of the 
development of the embryo, the place of the latter is changed 
by its attachment to the vigorously growing sporophyte. 
Plant 4, and the stage described by Lyon, represent very 
young stages in which the first 
root is still short and the second 
leaf. not yet developed. Photo- 
graph I shows a young plant with 
the suspensor. 
The next period of development 
is one in which the first root is 
very much elongated. The three 
plants which represent this stage 
all show a similar position of the 
suspensor attached at a much 
Fig. 4. lower place. In all the cases exa- Fo 
mined, the root emerged from the 
lower surface, the cotyledon (a little later) from the upper 
surface of the prothallus. 
There does not seem to be a definite relation between the 
suspensor and the position of the first leaf. In Lyon’s photo- 
graph, the dorsal side of the leaf points towards the suspensor. 
This is also the case in plant | and 3, while in plant 2 the 
suspensor is apparently attached at the ventral side of the 
cotyledon. Plant 4 represents an intermediate stage. 
We can conclude, therefore, that the suspensor has no 
influence on the position of the cotyledon, but that the place 
of the suspensor is determined more or less by the develop- 
mental stage of the sporophyte. 
The first Root. The first Leaf. 
Lyon finds a conspicuous apical cell. This was possible 
because of his very young material. As Bruchmann (7) 
