18 BRITISH MOSSES. 



The column under the head " Fern " in like manner 

 epitomizes the course of development of a fern, and a 

 comparison of these two columns reveals at once the like- 

 ness and the unlikeness of the life-histories of the Moss 

 and of the fern. In each case the spore produces a growth 

 of a form and nature entirely unlike the mother-plantin 

 one case a hypha, in the other a thallus, i.e., a flat leafy 

 cellular plate. But whilst in the Moss the protonema 

 produces the Moss plant, in the fern the prothallus itself 

 is the home of the male and female organs, and of the 

 sexual process, so that the fern plant belongs to the 

 sporophytic, and the Moss plant to the oophytic generation ; 

 the fern plant is the result of the sexual union, whilst the 

 Moss plant is produced from the asexual spore ; the fern 

 plant produces spores asexually, the Moss plant produces 

 the sporogone as the result of the sexual union. 



The observations which arise in connection with this 

 comparison are numerous. (1) It is the belief of botanists, 

 ever since the investigations of Hofmeister, that not 

 Mosses and ferns only, but all the phanerogams, go 

 through an alternation of generations consisting of the 

 oophytic and sporophytic generations. (2) It appears that 

 the Mosses and the Characese are the only groups of plants 

 in which the conspicuous and vegetative organism the 

 plant, in ordinary parlance belongs to the oophytic 

 generation. (3) That, in consequence, the plant of the 

 Moss is in no sense the ancestor of the plant of the fern, 

 or of the phanerogams, but belongs to a different genera- 

 tion from these ; and further, that the leaves, the stem, 

 and the epidermis of the Moss have no genetic connection 



