43,0 SOUTH AFKUAX HEPATIC^. 



Sexttal reproduction i> by means of antheridia (^male 

 organs) and archegonia (female organs) almost as in the mosses. 



The sexual arrangements are found to take four principal 

 forms, z'i::;. : Synoicous, when the antheridia and archegonia occur 

 mixed together; monoicoiis. when they occur on ditierent parts 

 'of the same plant; dioicoiis. wlten they occur only on different 

 plants; paroicous, when the antheridia occur in the axils im- 

 mediately below the archegonia; but it occasionally happens that 

 more than one of these conditions cati be found on the ^anie 

 species. 



In the greater numl)er of foliaceous Hepaticje the fertile 

 inflorescence is at first terminal on a stem or branch, but by the 

 growth of one or two innovations immediately below it, its 

 position often appears a little later to be either lateral or in a 

 dichotomous fork.- This constitutes the section AcroiiytKc. 



In the section Anacro(jy}uc it is not terminal, but either on 

 the surface of the stem or thallus, or on short special l)ranch- 

 lets. 



Among the thalloid llepaticae highly specialised modifica- 

 tions of parts of the thallus occur, in some cases as elevated 

 organs acting as common receptacles of the sexual ]3arts ; in 

 others, pits are sunk into the thallus itself, in which these sexual 

 organs occur,' and it is mostly upon the variations in this res]:)ect 

 that systematic arrangement is based. 



In addition to sexual reproduction, many species have the 

 power and habit of producing plants from gemma;, which are 

 adventitious asexual reproductive organs, produced in some 

 cases on the leaf margin, in other> on a special di.scoid stem- 

 apex, and in the thalloid genera in special gemmae cups. This 

 means of reproduction is freriueiit in certain si')ecie-, and is 

 altogether absent in others. 



In some species it occurs usually on .--terile parts or plants; 

 in others this is not so, but its effectiveness is seen in Lnindaria, 

 apparently an important plant to Soutli Africa, in which sexual 

 reproduction has not been observed here, though its reproduction 

 by gemmae and distribution with greenht)use plants has carried 

 it to many localities, and the same has happened to it in Northern 

 Europe, its home being the Mediterranean region. 



Goebel goes .so far as to say: " I have been led by my 

 investigations to the view that every cell in the Hepatic^e has the 

 latent capacity to develop furth.er. like the spore, but this is only 

 called forth if there is an enfeeblememt of the vegetative body."* 

 Certain species have also an abnormal multiplication of 

 parts, a sort of crested or double condition which seems to be 

 vegetative only. This occurs in Anthoccms, Fossombronia, 

 Aneura, and possibly others. 



In most of the foliose Hepaticse the leaves are alternate and 

 comi^lanate, i.e., flat in two rows, though the mode of attach- 



* Goebel, "Organography of Plants," (1905) 2, 52. 



