26o 



MOSSES AND FERNS 



CHAP. 



behind and tapering to a fine point in front ; attached to a 

 point just back of the apex are several fine cilia. The body 

 shows only about two complete coils. 



The youngest archegonia are met with some distance back of 

 the growing point, and apparently any superficial cell is poten- 

 tially an archegonium mother cell. The latter divides usually into 

 three superimposed cells (Fig. 134, A), of which the lowest {b) 

 forms the base of the archegonium. 



From the central one by a 



Fig. 133. — Marattia Douglasii (Baker). Development of the antheridium. A-D, Longitudinal 

 section, X515; E-G, surface views, X257; H, ripe sperm, cells ; I, free spermatozoids, X 1030. 



transverse division are formed the primary neck canal cell and 

 the central cell. Each of these divides again transversely. In 

 the upper one this division is often incomplete and confined to 

 the nucleus ; but in the central cell the division results in the 

 separation of the ventral canal cell from the ovum. Before the 

 separation of the primary neck canal cell from the central cell, 

 the cover cell divides as in the Liverworts into four cells by 

 intersecting vertical walls, and each of these cells by further 



