1922] BUCHHOLZ—VASCULAR PLANTS 259 
rise to several sporophytes of some size with or without embryonic 
selection, these smaller female gametophytes of Selaginella that are 
contained within the megaspore coats do not produce more than 
one maturing sporophyte. There are, however, a number of 
archegonia per gametophyte in Selaginella, and several figures 
have been published showing two or three embryos in the same 
section. One of these is PFEFFER’s well known illustration of 
S. Mertensii (fig. 13). When : : 
we consider the occasional 
character of fertilization and 
some of the difficulties that 
usually attend this event for 
a land plant, it is very prob- 
able that the fertilization pro- 
ducing these several embryos 
occurred simultaneously. 
BRUCHMANN (2) states in 
his monograph on S. spinulosa 
that although several embryos 
may start to grow, but one 
comes to maturity. Miss 
Lyon (31), in her paper on 
Selaginella, also shows several \ 
instances of polyembryony. e gametophyte of Sela- 
The one shown in fig. 14 is _sinella Mertensii showing two embryos, 
given as a possible fertiliza- ste nla hemmed 
tion of two eggs in one arche- 
gonium, or of the fertilization of the ventral canal cell and egg. It 
is also possible that these embryos were derived from neighboring 
archegonia, as fig. 15 (drawn to the same scale as fig. 14) would seem 
to indicate, the embryos having digested the single layer of gameto- 
phytic cells that separated their venters. In any event, this shows 
polyembryony. These embryos are still so small that they are 
evidently formed from a simultaneous or nearly simultaneous 
fertilization, and one has already begun to grow a little faster than 
the other, indicating that embryonic selection is taking place. 
It appears at least that in some species of Selaginella embryonic 
