240 



MOSSES AND FERNS 



CHAP. 



Still later the archegonia appear along the base of the anther- 

 idial ridge (Fig. 126, B). 



The development of the antheridium (Fig. 128) is much 

 like that of Ophioglossum, but the outer wall of the antheridium 

 has normally two layers of cells. The spermatozoids, accord- 

 ing to Jeffrey, probably correspond with those of the true Ferns. 

 In a few cases observed by myself (Fig. 128, C) the primary 

 division walls of the central part of the antheridium were not 

 broken down by the separation of the sperm cells, but formed a 

 number of chambers. 



The complete spermatozoid has about one and a half coils. 



B. 



A. 



Fig. 128. — Boirychium Virginianum. Development of the antheridium, X about 450; 

 in C, the primary division walls within the antheridium have persisted, forming 

 large chambers, from which the ripe sperm-cells are ejected successively. 



and closely resembles that of the true Ferns and Equisetum, 

 like them having numerous cilia. They swarm within the 

 antheridium, and according to Jeffrey's account, escape through 

 on opening formed by the destruction of two superimposed 

 cells of the outer wall. They do not all escape at once, but are 

 ejected in separate swarms. It is possible that the formation 

 of the separate chambers, noted by the writer, may have some- 

 thing to do with this phenomenon. 



The development of the archegonium (Fig. 129) is much 

 like that of Ophioglossum, but the neck of the archegonium is 

 much longer and projects conspicuously above the surface of 



