298 
GEO. S. BRYAN 
at the time of fertilization there occurs in the venter of Sphagnum the 
development of a considerable amount of mucilaginous matter which entirely 
invests the fertilized egg, and which thus far has proven difficult to penetrate 
Fig. 6. Embryo of 7 cells. Slender type. Fig. 7. Embryo of 7 primary segments. 
First vertical wall appears in one segment. Fig. 8. Embryo of 6 primary segments three 
of which show vertical walls. The two cells of the basal segment are rounding away from 
each other. Fig. 9. Embryo of 6 primary segments, the basal portion much larger than 
the apical. FiG. 10. Embryo of 7 primary segments. All X 300. 
with fixing agents. Since the results are not entirely satisfactory, because 
of plasmolysis, statements concerning the structure of the fertilized egg will 
be omitted. 
The first wall is at right angles to the axis of the archegonium and divides 
the young sporophyte into two approximately equal cells which elongate 
in the direction of the axis of the archegonium (fig. i). The basal cell is 
characterized at its lower extremity by a peculiar greenish zone which is 
probably related in some fashion to the digesting action of this cell. This 
zone is clearly visible in all the early stages (figs. 1-15) and serves as a 
convenient means of distinguishing the basal from the apical end of the 
embryo when dissected from the venter of the archegonium. After the 
two-celled stage has been reached there are further divisions by walls 
parallel to that first formed, resulting in the production of a filament of 
