476 Campbell.— Studies on some Javanese Anthocerotaceae. I. 
rence of superficial antheridia, but he recognizes that these are not normal 
cases. Two instances of a condition approaching this were seen in the 
course of these investigations. One of them is shown in Fig. 27, where 
the cavity containing the antheridium was open on one side so as to expose 
the top of the young antheridium. Apparently in this instance the primary 
cover cell of the antheridial cavity had been very early pulled away from 
the adjacent surface cells and the cavity thus became open, and no doubt, 
by the further lateral growth of the superficial cells, the antheridium would 
soon have stood in a shallow depression such as Leitgeb describes in the 
specimens seen by him. More recently Lampa (Untersuchungen an einigen 
Lebermoosen. Sitzungsber. der Kais. Akad. der Wiss., Wien, cxi, 
pp. 477, 489, 1902) has described exogenously-formed antheridia in 
Anthoceros ; but Howe has criticized her work, and thinks that the 
structures described as antheridia were tubers, as the figures do not agree 
with the structure of normal antheridia (Howe, Torreya, iv, p. 175, 1904). 
From a study of the development of the antheridium it is quite 
impossible to say whether or not the endogenous origin is primary or 
secondary, nor do the exceptional cases where the origin is superficial 
throw much light on the question. Such a condition as that shown in 
Fig. 27 is not unlike what is found in Sphaerocarpus or Riccia , where the 
antheridium is surrounded by an involucre ; but whether this is any 
indication of a possible relationship between these forms and the Antho- 
cerotaceae is another question. There can be no doubt that in all the 
Anthocerotaceae the antheridia are normally of endogenous origin. 
The Archegonium. 
The researches of Janczewski (loc. cit.) and those of Leitgeb, 
show that although the form of the archegonium is apparently quite 
different from that of the true Hepaticae, nevertheless in its essential 
structure it agrees closely with the other Bryophytes. All of the genera 
are much alike in the development of the archegonium, and Megaceros 
shows no marked differences when compared with the others. The 
youngest stages are not easily recognizable, as the archegonium does not 
project at all above the level of the thallus at first, and the mother-cell is 
not usually markedly different in appearance from the neighbouring cells 
(Fig. 20 9). Transverse sections of the young archegonium (Fig. 38) show 
that the axial row of cells is cut out by three intersecting walls as in the 
typical bryophytic archegonium, and longitudinal sections of the younger 
stages (Figs. 33—6) present an appearance not very different from similar 
sections of archegonia of true Hepaticae, except that in the latter the whole 
archegonium is free, while in the Anthocerotaceae only the upper surface 
is exposed. Nevertheless the limits of the neck cells are pretty well 
