THE ARCHEGONIAT^E 



229 



mass of sperm-cells has been discharged, the opening closes, so that the anther- 

 idiuna looks very much as it did before it opened. The spermatozoids are coiled 

 filaments, with two extremely long cilia (Fig. 193, C). 



The early development of the archegonium (Fig. 194) in the Musci is much 

 like that in the Hepaticse. However, a difference is soon evident. The terminal 

 cell of the neck, which in the Hepaticse divides by intersecting walls to form 

 the cover-cells, in the Musci becomes the apical cell of the archegonium, 

 whose further growth is due to its divisions. It has the form of a truncated, 

 three-sided pyramid. Segments are cut off from the three lateral faces, and 

 from the inner, truncated portion. The latter segments contribute to the 



D 



H. 



FIG. 192. Funaria hiff/rometrica. Development of the antheridium. A-D, longi- 

 tudinal sections (X (i<)0). D, section in a plane at right angles to C. E, optical 

 section (X300). F, G, cross-sections, //.diagram of cross-section, showing the 

 early divisions. J, young spermatozoids (X 1200). 



neck canal-cells, the lateral segments, which undergo a longitudinal division, 

 add to the six rows of outer neck-cells. The egg-cell and its sister cell, the 

 ventral canal-cell, are formed as in all the Archegoniates. 



Fertilization. Fertilization is effected when the sexually mature 

 plants are covered with water. The substance which attracts the 

 spermatozoids to the open archegonium has been shown to be cane- 

 sugar. 



The reproductive organs are sometimes surrounded by somewhat 

 modified leaves, which gives the end of the shoot the appearance 



