FERTILIZATION AND FRUIT-FORMATION IN CRYPTOGAMS. 



63 



concave inner face of each plate a cylindrical or conical cell projects, carrying upon 

 its summit another, capitate, cell. Each of these head-cells is surmounted by long 

 strings of cells, of which the lowest segments are spherical or cylindrical, whilst the 

 rest are short discs (see fig. 206 '). The whole structure may be likened to a whip 

 with many thongs, and the stalk-cell projecting from the plate has hence been 

 called the " manubrium " or handle. So long as the eight plates of the sphere are 



Fig. 206. — I'ruit-formation in Stoneworts (Characese). 



1 Chara fragSis. 2 Piece of the same with amphigonia and antheridia on the branches. » A single branch with amphigonia 

 and antheridia. * An antheridium. « A plate of the antheridinm with mannbrium and cells grouped in the form of thongs 

 and containing spermatozoids. 6 Several cells from one of the whip-like filaments ; the cells in the middle contain each a 

 spermatozoid, the spermatozoid is escaping from the uppermost cell, the lowest cell is already vacated. 7 A single sperma- 

 tozoid. 8 Amphigoniujn inclosing the oogonium. 1 natural size ; 2x10; ^xlS; 4x35; =xlOO; 8x300; »x600; 8x60 



closed, these manubria project towards the centre of the hollow sphere, and the 

 rows of cells proceeding from the manubria are conglomerated into a ball. But as 

 soon as the plates separate and the sphere falls to pieces, the ball is untwisted and 

 its parts assume the appearance shown in fig. 206®. By this time a spiral sper- 

 matozoid has developed from the protoplasm in each of the discoid segments of the 

 filaments, and may be seen lying within its cell (see fig. 206*). But almost 

 immediately afterwards these cells open, and the spermatozoids, which are provided 

 at one end with a pair of long cilia, escape and whirl about in the surrounding 



