206 BOTANICAL GAZETTE [SEPTEMBER 
of the total number of preparations examined in connection with 
the study summarized in text fig. 2. 
A condition which demonstrates that these rosette cells are 
potentially embryos, even when they elongate to form suspensors 
or embryonal tubes, is shown in fig. 54, in which a mitotic figure 
may be seen in the lower portion of one of these elongated cells. 
Fig. 55 shows this mitotic figure of fig. 54 enlarged. An ordinary 
suspensor cell or embryonal tube has never been found to undergo 
division after elongation. The origin of the cells intermediate 
between the elongated rosette and the primary suspensor of fig. 56, 
‘and of 1 rosette in fig: 57, seemed a puzzle until the case shown 
in fig. 54 made it apparent that these cells may arise from the 
rosette tube. They are terminal cells of the rosette embryos that 
were formed after the rosette cell had begun to elongate. The 
rosette cell at the left, in fig. 53, has a nucleus in spirem stage, 
probably preparing for the first mitosis in the formation ‘of an 
elongated rosette embryo of this kind. 
POLYEMBRYONY 
In Pinus polyembryony is a much more extensive phenomenon 
than is generally known. Since the rosette produces 4 embryos, 
and 4 others are always produced by the splitting of the lower 
primary embryos, 8 embryos may be formed from each fertilized 
egg. The greatest number of embryos possible is 8 times the num- 
ber of archegonia, which might. reach as high as 48 if all 6 of the 
archegonia, present in some species, were fertilized. Fertilization 
must be very nearly simultaneous in all the archegonia, and other 
conditions very favorable if the maximum number of embryos 
is to be produced. Fig. 69 shows an embryo complex, which had 
a delayed start and was stunted from the beginning, a condition 
which is frequently found where more than 3 archegonia are 
fertilized, with 1 more or less delayed. 
In the various pines studied, 4 is the maximum number of 
embryo sets that were actually found, each related to one of the 
4, 5, or 6 archegonia. Two or 3 archegonia were the usual number 
fertilized. In P. Banksiana, with only 2 or 3 archegonia, as large 
a number is not possible as in P. Laricio. Since the cones of the 
