CHAPTER XVIII 

 BRYOPHYTES 



The Bryophytes, comprising the two groups of Liverworts 

 (Hepaticae) and Mosses (Musci), present a great diversity of struc- 

 ture, some being so delicate that good preparations are very uncer- 

 tain, while others are so hard that it is difficult to get satisfactory 

 sections. Between these extremes, however, there are many forms 

 which readily yield beautiful and instructive preparations. 



If but one fixing agent should be suggested for the entire group, 

 it would be chromo-acetic acid with 1 g. chromic acid and 2 c.c. 

 acetic acid to 200 c.c. of water. It should be allowed to act for about 

 24 hours. For morphological study, excellent sections can be secured 

 from material fixed in formalin alcohol, about 6 c.c. of commercial 

 formalin to 100 c.c. of 70 per cent alcohol. Material may be left 

 in this solution until needed for use. The convenience of this fixing 

 agent will hardly be appreciated by those who are always within 

 reach of a laboratory. 



For general study, the small, delicate forms may be mounted 

 whole in Venetian turpentine. 



Instead of treating forms in a taxonomic sequence, we shall 

 consider first the gametophyte structures under the headings thallus, 

 antheridia, and archegonia, and shall then turn our attention to the 



sporophyte. 



HEPATICAE 



Some of the liverworts are floating aquatics, but most of them 

 grow on logs or rocks or upon damp ground. They are found at their 

 best in damp, shady places. Many of them may be kept indefinitely 

 in the greenhouse. Rictia, Marchantia, Conocephalus, Asterella, and 

 many others vegetate luxuriously, and often fruit if kept on moist 

 soil in a shady part of the greenhouse, and they do fairly well in the 

 ordinary laboratory if covered with glass and protected from too 

 intense light. Riccia natans (Ricciocarpus natans) is a valuable type 



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