134 
JOHN T. BUCHHOLZ 
The Cephalotaxus embryo shown here in figures 28-32 doubtless has 
been modified from something Hke this Podocarpus spicatus type of embryo. 
It has, however, a feature which would relate it more directly to Pinus 
Figs. 25-26. Stages in embryogeny of Podocarpus spicatus, showing terminal cap cell, 
suspensor cells beginning to elongate, and the group of embryo-forming cells between. 
After photomicrographs by Sinnott (39). Figs. 27-32. Stages in embryogeny of Cephalo- 
taxus, showing terminal group of cap cells, embryo-forming cells, suspensor, and what is 
probably a group of rosette cells in 32a, Fig. 27. C. drupacea, after Lawson (25). Figs. 
28-32. C. Fortunei; figure 28 after Coker (10), and figures 29-32 after Strasburger (41). 
namely, a conspicuous group of rosette embryos (fig. 32a) above the suspen- 
sor. The figures here shown are taken from Strasburger (41), who de- 
lineated this feature without comment. A similar condition of the rosette 
may yet be found in the podocarps, for it seems to be suggested by figure 26. 
The group of cap cells in this case is probably also a device to prevent 
cleavage of polyembryony or apical cell growth, for this cap is also sloughed 
off (fig. 32Z?) soon after the proembryo stage, the stage in which cleavage 
polyembryony is found, if at all. 
Araucarineae 
While I would not derive the araucarian type of embryo with its 
elaborate cap (figs. 33-36) from these podocarp embryos, it is probable that 
these two groups had a common origin, that the caps of the embryos of 
both were derived in response to similar conditions, and that these peculiar 
structures in both instances serve to prevent cleavage polyembryony. 
The increase in the number of free nuclear divisions in the proembryos of 
both these groups may be due to a past history of greater cleavage poly- 
embryony, which might well have been overcome by a mechanical device. 
