294 



BOTANY 



zoids, the presence of a blepharoplast, from which the cilia are derived, has been 

 demonstrated. 



Archegonium. The archegonium is formed upon the lower side of the apical 

 meristem, much as in the Ferns ; but each archegonium is formed in connection 

 with a lobe which grows out on one side of the apex of the gametophyte, and 

 grows for some time from an apical cell. The young archegonium appears near 

 the base of this, and is pushed over to the upper side of the prothallium by the 

 growth of the adjacent tissue. Each archegonium thus lies between two lobes, 



B 



A 



FIG. 260. Eqvisetum telmateia. Archegonium. A, section of nearly ripe arche- 

 gonium, with two neck canal-cells. B, section of open archegonium (X 275). 

 C, D, two cross-sections of a young archegonium (x 550) ; L, lobe. 



its own and that of the next younger archegonium. In its structure it closely 

 resembles that of the Ferns. The terminal cells, however, are longer, and when 

 it opens these bend outward. There are usually two distinct neck canal-cells. 



The Embryo 



As in the eusporangiate Ferns, the primary, or basal, wall of the embryo (Fig. 

 261) is transverse. The next divisions, which are somewhat oblique, divide the 

 stem and first leaf in the upper (epibasal) part, while in the hypobasal half the 

 root is separated from the foot. 



The larger of the two epibasal cells becomes at once the apical cell of the 



