27 



development, upon another host plant, diifering so much that 

 the two forms have been named and looked upon as distinct 

 plants. By careful researches their life history is being traced 

 out, and many are now known to be different forms of the same 

 Fungus. We may refer students on this subject to the excellent 

 monograph of the British Uredineae and Ustilagineae, by Dr. 

 Charles H. Plowright, f.l.s., etc. 



Group 2. — Bryophyta (or Muscinese). — -The plants forming 

 this group are the Hepaticw, or Liverworts, and the Miiscinece, or 

 Urn Mosses. All the plants in this group show simple cellular 

 structure, though a higher stage of plant growth takes place. 

 Some of the Hepatica; have only a thallus or frond-like growth 

 whilst in the foliose Jungermaniae true branches and leaves 

 become developed, and in some genera of Hepaticae both a 

 thallus and stem with leaves are combined. It is among the 

 Hepaticae that the transition from a simple unbranching thallus 

 to a more organised plant with stem and leaves becomes differ- 

 entiated. 



The sexual characters for spore reproduction may be dis- 

 cerned and traced out, although, like the previous more simple 

 structured Algae and Fungi, they are able to reproduce them- 

 selves by bud growth, for every cell of the plant is capable of 

 growth, and thus materially assists to aid in their wide dis- 

 tribution. 



Hooker's "British Jungermannia," a work published so long 

 ago as 1820, first laid the foundation for the true knowledge of 

 these plants. About eighty species were beautifully figured in 

 this work, and accurately described. Since that period students 

 of this tribe have not been very numerous. The few workers 

 who have devoted themselves to their study have increased the 

 number of Hepaticae now known in Britain to more than 200. 



No separate descriptive work, however, of the new species 

 'added to the " British Jungermannia" has yet been published. 

 The new discoveries have been given in the Journal of Botany, 

 and other botanical periodicals. Recently a Handbook of the 

 British Hepaticae has been issued by Dr. M. C. Cooke. It is, 

 however, mainly a compilation from the works of others, and 

 can only be considered as a synopsis. 



