V THE ANTHOCEROTEyE 125 



wall apparently intact. The spermatozoids are small and 

 entirely like those of the other Hcpatica;. 



Leitgeb ^ found in abnormal cases that the anthcridia might 

 arise superficially, as in the other Hepaticai. Whether this is 

 a reversion to the primitive condition would be hard to say, 

 but it is at any rate possible. 



At first the cell from which the antheridial complex arises 

 is not separated from its neighbours by any space. About 

 the time that the first divisions in it are formed, the young 

 antheridial cells begin to round off and separate from the 

 cells above them. With the growth of the surrounding cells 

 this is increased, so that before the divisions in the separate 

 cells begin, the group of papillate cells is surrounded by a 

 cavity of considerable size. To judge by the readiness with 

 which the walls of the cavity stain, it is probable that the 

 separation of the cells is accompanied by a mucilaginous 

 change in their outer layers. 



The first account of the archegonium was given by Hof- 

 meister, who, however, overlooked the peripheral cells and only 

 saw the axial row. Later Janczewski ~ showed that AntJioceros 

 did not differ essentially in the development of the archegonium 

 from the other Hepatica^, and his observations were confirmed 

 by the later researches of Leitgeb '" and Waldner.^ The forma- 

 tion of archegonia does not begin until the older antheridia are 

 mature, and very often, especially in A. icBvis, few or no 

 antheridia were found on the plants with well -developed 

 archegonia. After the formation begins, each dorsal segment 

 gives rise to an archegonium, so that they are arranged in quite 

 regular rows, in acropetal order. After the transverse wall by 

 which the segment is divided into an inner and an outer cell is 

 formed, the outer cell becomes at once the mother cell of the 

 archesfonium, much as in Aneura. In this cell next arise three 

 vertical intersecting walls, by which a triangular (in cross- 

 section) cell is cut out as in the other Hepatica;. Sometimes 

 it looks as if one of these walls was suppressed, but even in 

 such cases the triangular form of the central cell is evident. 

 The main difference between the archegonium at this stage in 

 AntJioceros and the other Hepaticae lies in the complete sub- 

 mersion of the archegonium rudiment in the former. In this 



1 Leitgeb (7), vol. v. p. 19. - Janczewski (2). 



'^ Leitgeb (7), vol. v. p. 19. ■* Waldner (2). 



