146 Campbell . — The Gametophyte and 
soon before the opening of the archegonium and almost immediately ejected. 
It is also not unlikely that there may be no division wall formed and that 
the ventral canal cell is represented merely by a nucleus. 
When the archegonium opens the terminal neck cells diverges widely, 
presenting a decidedly characteristic appearance (Text-fig. 3, F). 
Text- fig. 4 a. Recently fertilized archegonium containing unicellular embryo, x 270. 
b-d. Older unicellular embryos, x 270. 
Text-fig. 5. a. Archegonium containing much elongated unicellular embryo, x ioo. 
b. First division in the embryo, x 270. c. An older stage, x 270. d. Two sections of an 
older embryo, x 270. Fshows the large suspensor, susp. ; b-b , basai wall. 
In both B. Lunaria and B. virginianum a somewhat larger part of the 
neck is free than in B. obliquum . In this respect the latter shows a certain 
resemblance to Ophioglossum and the Marattiaceae, 
