THE MOSSES, 99 



extinct unknown Mosses, which were very nearly related 

 to the lowest liverworts of the present day. In the 

 history of creation, Ferns are of greater importance than 

 Mosses. 



The branch of Mosses (Muscinse, also called Musci, or 

 Bryophyta) contains the lower and more imperfect plants of 

 the group of Prothallophytes, which as yet do not possess 

 vessels. Their bodies are mostly so tender and perishable 

 that they are very ill-suited for being preserved in a recog- 

 nizable state as fossils. Hence the fossil remains of all 

 classes of Mosses are rare and insignificant. It is probable 

 that Mosses developed in very early times out of the Thallus 

 plants, or, to be more precise, out of the Green Algae. It is 

 probable that in the primordial period there existed aquatic 

 forms of transition from the latter to Mosses, and in the 

 primary period to those living on land. The Mosses of the 

 present day — out of the gradually difierentiating develop- 

 ment of which comparative anatomy may draw some infer- 

 ences as to their genealogy — are divided into two different 

 classes, namely : (1) Liverworts ; (2) Leafy Mosses. 



The first and oldest class of Mosses, which is directly 

 allied to the Green Algse, or Confervse, is formed by the Liver- 

 worts (Hepaticse, or Thallobrya). The mosses belonging to 

 them are, for the most part, small and insignificant in form, 

 and are little known. Their lowest forms still possess, 

 in both generations, a simple thallus like the Thallus plants ; 

 as for example, the Iliccise and Marchantiacese. But the 

 more highly developed liverworts, the Jungermanniacefe 

 and those akin to them, gradually commence to difierentiate 

 stem and leaf, and their most highly -developed forms are 

 closely allied to leaf-mosses. By this transitional series 



