THE LIVERWORTS OR HEPATICS 



513 



of offspring less important for the w(>lfaro of the species than rapid 

 and prohfic midtiplication. 



189. The liverworts or hepv^tics (Class Hepaticae) take 

 their name from a fancied resemblance of the broad-Iolied 

 thalliis of certain lower forms to the lobed liver of an animal. 



iyk. 







jr 





Fig. 338. — Crystal worts {Riccui spp., Crystal wort Family, Ricciacece). 

 A-C, R. Bischoffii; A, B, clumps of the plant growing on mud, (§) 

 a, male plant; b, female plant. C, male plant, enlarged, showing the 

 male gametangia or anthcridia (a). D-H, R. minima. D, plants (|). 

 E, fruiting plant enlarged, top view. F, a lobe, side view. G, a fruiting 

 lobe, cut vertically through the young "fruit" or sporophyte, still more 

 enlarged. //, spore-groups and spores. J-M, R.glauca. J, iv, plants (§). 

 L, M, lobes, enlarged. N, O, R. ciliata. N, two plants (5). 0, lobes, 

 enlarged. PS, R. canaliculata. P, plant (i). 0, fruiting lobes, en- 

 larged, top view. R, same, under side. S, lobe cut vertically through 

 the sporophyte. (Bischoff.) — -Plants growing in moist places. 



There are al30ut 3,000 species in the group. The most 

 primitive liverworts belong to the group known as crystal- 

 worts, occurring in all parts of the world and including 

 many species. Some of these grow floating on the surface 

 of still, fresh water and finally come to lie upon the mud 

 when the water subsides in dry seasons. Other forms grow 



