HEPATIC^. 



345 



and by the repeated division of their apical cells produce 

 upon each a little flattened mass of cells, the gemma. These 



A 



Fig. 281.— Male organs of Matrchantla polymorpha. A, a portion of the thallus, *, 

 with two ascending branches bearing the antheridial receptacles, hu. B, vertical sec- 

 tion through young antheridial receptacle, hu ; a, antheridium enclosed in a cavity 

 whicli has a narrow opening, o,* t, portion of thallus ; ^, root-hairs ; ft, leaf-like bod- 

 ies seen in section. C, a nearly ripe antheridium \ 8t, its pedicel ; to, the wall, i), 

 two spermatozolds. Variously magnified. J> X 800.— After Sachs. 



gemmae, when full-grown, fall to the ground, and grow di- 

 rectly into new plants. In some cases the gemmae are much 



Pig. 232.— Development of the antheridia of Eiccia glama. A, longitudinal section 

 through the npex of the thallu" : «, apical cell of the thallus ; ft, soale-like leaves, in 

 section ; a, a very young antheridium ; a', an older antheridium, surroucded by a 

 growth of 'thallus tissue, w. B, a young antheridium, a, overarched by a growth oi 

 the thallus. C, an older antheridium, in longitudinal Eection. x 500.— After Hof- 

 meister. 



simpler than those just described ; in the Jungermanniaceffi, 

 for example, they consist of a few cells which are spontane- 

 ously detached from the tissues in the margins of the leaves, 



