1922] BUCHHOLZ—VASCULAR PLANTS 255 
universal among gymnosperms, and its character or type is of 
considerable importance in a. study of phylogeny. For the origin 
of simple polyembryony, we must turn to a study of pteridophytes, 
as it is very evident that the plurality of archegonia in gymnosperm 
gametophytes was derived from a similar plurality among their 
pteridophyte ancestors. 
Embryonic selection among pteridophytes 
Many living pteridophytes have simple polyembryony, that is, a 
plurality of young sporophytes growing on a single gametophyte. 
Whenever the number of these sporophytes greatly exceeds the 
ability of the gametophyte to nourish all of them through their 
period of embryonic development, so that some of them are starved 
out in their early stages, a selection must occur among them. 
If this selection takes place in the earliest stages, before these young 
sporophytes are exposed to the external environment and become 
independent, we have embryonic selection as truly as that: found 
in gymnosperms. When the several embryos in this competition 
are the result of a simultaneous fertilization, this embryonic selec- 
tion has all of the advantages, as a measure of merit, that may be 
found in the gymnosperm polyembryony, and will be certain to 
result in the survival of the embryos that are strongest and most 
vigorous as determined by their actual performance. The facts 
that are definitely known concerning polyembryony and embryonic 
selection in various groups of pteridophytes may be considered 
as follows. 
Lycopop1ALes.—The occurrence of several embryos per gameto- 
phyte in Lycopodium was definitely reported and shown by Brucu- 
MANN (3). Figs. 7-9 definitely show this plurality of embryos. 
These embryos do not all mature, but some of them remain in an 
arrested but viable condition for a considerable period, and are 
able to resume their growth if the larger sporophytes are injured 
by drought or otherwise. The smaller embryos probably fall into 
two groups, those which owe their origin to a fertilization simulta- 
neous with that forming the successful embryo, and those which 
originate by a subsequent fertilization. It is very evident that the 
conditions for fertilization, even in these subterranean gameto- 
