8 HANDBOOK OF BRITISH MOSSES. 



quently called, a capsule or theca, which, with various modifi- 

 cations, gives rise to the spores. 



In many cases life ceases in the parent plant after the for- 

 mation of the sporangia, but in others a new growth is pro- 

 duced, which in time gives rise to a new set of archegons and 

 antheridia, and in some species this is repeated indefinitely. 



The whole process, then, from the formation of the spore 

 to the fertilization of the embryonic cell in the Fern, answers 

 to the same process in the Moss up to the fertilization of the 

 rudiment of the sporangium in the archegon, but in the latter 

 case there are two distinct stages, the one extending to the 

 formation of the first cell of the young plant, the other to the 

 fertilization of the cell in the archegon ; and it is well to dis- 

 tinguish these as the prothalloid and thalloid stages respec- 

 tively ; while in Ferns the first result of germination may more 

 fitly be called the pro-embryonic stage. It is not right to 

 give the same name to organisms which are by no means 

 strictly analogous in the two cases. 



Having made these general remarks on the relations of 

 Mosses and Ferns and their respective allies, I shall proceed 

 in the next chapter to offer a few observations on the several 

 parts, beginning with the germination of the spores, their 

 primary development in the sporangia being reserved till I 

 speak of the structure of the fruit. 



