CHAPTER XI. 
BRANCH V. BRYOPHYTA. 
THE MOSSWORTS. 
382. This Branch includes plants of much greater com- 
plexity than any of the preceding. In very many cases 
they have distinct stems and leaves, whose tissues often 
show a differentiation into several varieties. In the sexual 
organs the cell to be fertilized (the germ-cell) is from the 
first enclosed in a protective layer of cells, and after fer- 
tilization it, develops into a complex spore-fruit. 
383. Mossworts are all chlorophyll-bearing plants, and 
none are parasitic or saprophytic. They are of small size, 
rarely exceeding ten or fifteen centimetres in height. They 
generally prefer moist situations upon the ground, or on 
the sides of trees or rocks. A few are aquatic. 
384. Two classes of Bryophytes may be distinguished, as 
follows: 
1. Mostly thalloid creeping plants with splitting spore-fruits, and 
having elaters..............e0seeeee Hepatica. Liverworts. 
2. Leafy stems, mostly erect, with spore-fruit opening by a lid, and 
having no elaters..........c.ce eee e cece eeeeee Muscr. Mosses. 
Crass I. Heparicz (the Liverworts). 
385. In the Liverworts, the plant-body is for the most 
part either a true thallus or a thalloid structure. When 
there is a differentiation into stem and leaves, in most cases 
the plant-body has two distinct and well-marked surfaces, 
