COHORTS AND ORDERS. (BY THE EDITOR.) 1023 



Sporangia solitary, placed at the base of the 

 leaves, or in the scales of terminal cones, 2-3- 

 valved, containing either minute quaternary 

 microspores full of antherozoids, or large 

 sub-globose macrospores with a trierural mark 

 on one hemisphere. Macrospores developing 

 a prothallus in germination, on the surface of 

 which archegonia ave produced . 



PAGE 



911 



7. IgOBZRjc. Submerged or terrestrial 

 plants, with a tumid caudex clothed with 

 the sheathing bases of elongate fronds. Spo- 

 rangia enclosed in the bases of the fronds ; 

 those of the outer frond 'bearing macrospores, 

 of the inner microspores. Germination, &c., 

 as in Lycopodiacece 



915 



Cohort II. Muscales. Plants composed of cellular tissue only. Archegonia oranthe- 

 ridia, or both, formed on the stem or branches of a new plant that is developed from the spore 

 on its germination. 



8. CHARACE^E. Aquatic branched plants, 

 with whorled branches, consisting of a series 

 of long superimposed fascicles (internodes) 

 of inarticulate tubes. Antheridia consisting 

 of spherical vescicles containing articulate 

 tubes, each joint (cell) of which contains an 

 antherozoid. Archegonia consisting of a 

 single spore, covered with spirally arranged 

 tubes, and fertilized in situ .... 917 



9. MTJSCI. Stems leafy ; leaves alternate 

 or distichous. Antheridia consisting of 

 delicate open sacs full of cells containing an 

 antherozoid. Archegonia consisting of a 

 flask-shaped body enclosing a vesicle which 

 developes, after fertilization, a stalked urn- 

 shaped sporangium, full of spores . . 921 



10. SPHAGNA. Moss-like plants, differing 



from Mosses in their regular fascicled branches 

 arising from the stem by the sides of the 

 leaves, by some peculiarities in the structure 

 of the stem and leaves, and stalk of the 

 sporangium, and by having dimorphic spores 929 



11. HEPATIC^E. Stems leafy, with alternate 

 or distichous leaves, or frondose. Antheridia 

 and archegonia as in Musci, but these are in 

 some tribes buried in the substance of the 

 frond, in others borne on the under surface of 

 a stalked disk, in others axillary or terminal. 

 Archegonia after fertilization giving rise to 

 a sporangium that usually bursts into 4 

 spreading horizontal valves, but is sometimes 

 1-2-valved, or consists of a simple sac sunk 

 in the frond. Spores usually mixed with 

 spiral filaments (elaters) .... 933 



CLASS IV. THALLOGENS. 



Axis of growth indeterminate, growth taking place chiefly peripherically and hori- 

 zontally. Plants wholly composed of cellular tissue. Reproductive organs various. Spores 

 not developing a prothallus in germination. 



12. LICHENES. Terrestrial plants. Thallus 

 coriaceous and irregularly lobed, or erect, or 

 a mere crust, various in colour and consistence. 

 Fructification of two sorts : 1. Apothecia, 

 which are superficial, marginal, or sunk in 

 the frond, and contain, or consist of vertical 

 densely packed tubes or sacs (sporangia) 

 containing 2-8 spores ; 2. Spermogonia, which 

 are spherical bodies sunk in the substance of 

 the frond, whose inner surface is lined with 

 filaments (sterigmata) which support slender 

 transparent corpuscles, called spermatia (sup- 

 posed to represent antherozoids) . 



13. FUNGI. Usually terrestrial polymor- 

 phous plants, sometimes subterranean, often 

 parasitic, destitute of chlorophyll or starch, 

 of most varied form, colour, and con- 



940 



sistence, sometimes reduced to a few fila- 

 ments or cells. Vegetative organs con- 

 sisting of a mycelium (or tissue of slender 

 simple threads). Spores most minute, 

 sometimes superficial, at others borne upon 

 projections called basidia, at others enclosed 



in cells or sacs 949 



14. ALG^:. Usually highly coloured 

 plants, aquatic or natives of damp rocks, 

 walls, &c., sometimes frondose, at others 

 reduced to a few cells or a single cell. 

 Fructification monoscious or dioecious, some- 

 times of special cells of two sexes, sometimes 

 of simple mobile spores, sometimes of anther- 

 idia and sporangia, which are free or enclosed 

 in capsules. . . . . . 965 



