166 BOTANICAL GAZETTE [MARCH 
and late in the season on plants that fail to produce sporophytes 
these groups may be inclosed in definite common integuments 
terminating above in a sort of beak. It was this kind of a 
group on which Leitgeb (6) based his classification. The 
plants marked d and e in fig. r have completed the series of 
antheridia and, if growth should continue, at once there would 
begin a series of from three to five rows of archegonia in posi- 
tion and arrangement a continuation of the antheridial rows 
(jigs. 4, 6). The archegonial series is complete in a plant like 
h (fig. 1), from which the diagram (fig. 4) was made. 
The cavities inclosing the sex organs are morphologically air 
chambers. The organ is graduated in length to the depth of 
the cavity, so that its apex is always approximately on a level 
with the floor of the dorsal furrow (jigs. 7. 6). It may be noted 
that most of the antheridia are found in the narrower and less 
fleshy portions of the plants, while the archegonia are located 
in the more vigorous portions. The antheridial portions of the 
plant are produced early in the season, when conditions for 
growth are comparatively unfavorable. In this it reminds one 
of the prothallium of a polypod fern, which while young and 
delicate or in unfavorable conditions produces only antheridia, 
but if circumstances become more favorable, the enlarging, more 
vigorous plant begins the production of archegonia, Antheridia 
are produced during April, and by May 1 the youngest ones ae 
half developed, the oldest having already discharged their 
sperms. The mature organ is a short-stalked, oval body, coml- 
cal at the apex, with a wall consisting of a single layer of cells. 
Though anthericia are produced earlier in point of time than 
archegonia, their development is so much slower that both are 
mature at the same time. The sperms are of the usual biciliate 
type and have two complete coils. 
A complete series of stages in the development of the arche- 
gonium was found on plants collected May 1. The course of 
development is the same as that outlined by Janczewski (11) 
for the typical liverwort archegonium. In the outer cell of the 
archegonium rudiment three successive vertical walls inclose 4 
triangular cell which shortly divides by a transverse wall (jig: 15) 
