THE LIVERWORTS OR HEPATK'S 



513 



of offspring less important- for the welfare of the species than rapid 

 and prolific multiplication. 



189. The liverworts or hepatics (Class Hepaticse) take 

 their name from a fancied resemblance of the broad-lobed 

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



Fig. 338. — Crystalworts {Riccia spp., Crystalwort Family, Ricciacece) . 

 A-C, R. Bischoffii; A, B, clumps of the plant growing on mud, (3) 

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

 male gametangia or antheridia (a). D-H, R. minmia. D, plants (5). 

 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, if , plants (|). 

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

 enlarged. PS, R. canaliculatn . P, plant (3). Q, 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 about 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 



