CHAPTER II. 



THE LIFE-HISTORY OF A FERN. 



THE middle years of the nineteenth century marked an important epoch 

 in the history of Plant Morphology. Before that period this branch of 

 botany could hardly be said to exist as a science. What gave distinction 

 to that period was the publication of observations which made it possible 

 for the first time to give a consecutive account of the various stages in 

 the life-history of the Higher Cryptogamia. Up to that time it had been 

 the custom to compare Ferns with Flowering Plants, notwithstanding that 

 the facts, so far as they were known, gave little support to any view of 

 their close similarity ; and to attempt to express the life-story of these 

 and others of the lower plants in terms of the higher. But the investigations 

 of that period, by following out the actual facts of development, showed 

 not only that there was no correlative of the seed in the life-cycle of a 

 Fern, but also that there was in the prothallus of Ferns a phase of the 

 life-cycle which differed in essential points from anything which was then 

 known to exist in the development of Seed-Plants. 



The spores of Ferns were experimentally recognised as reproductive 

 organs by Morison (1699), who raised young plants from them. But Kaulfuss 

 first observed their germination (1825), and the formation of the prothallus, 

 which had already been described by Ehrhart (1788) : it was Bischoff (1842) 

 who first recognised the embryo attached to the prothallus. Naegeli (1844) 

 discovered the antheridia and spermatozoids, while Suminski (1848) 

 ascertained the true nature of the archegonium, and its relation to the 

 embryo.. But it remained for Hofmeister to put together, and complete 

 the story. In 1849 his description of the germination of Pilularia and 

 Salvinia appeared, and two years later, in 1851, he gave to the world his 

 Vergleichende Untersuchungen, a work which dealt in the most com- 

 prehensive way with the life-story of a number of Liverworts, Mosses, 

 Ferns, Fern-Allies, and Gymnosperms. 



It is impossible to exaggerate the importance of the advance in view 

 which the publication of Hofmeister's book brought. The middle years 



