198 BOTANICAL GAZETTE _— [SEPTEMBER 
consist of 4 tubes, as in fig. 50, they look very much like the lower 
part of a group of primary suspensors. For example, if the e; 
group of fig. 50 were studied from sections only, with the upper 
part of the suspensors confused as they are in fig. 45 (making it 
impossible to trace any of the tubes back to the rosette), it would 
be natural to mistake this perfect suspensor division as the group of 
primary suspensors. It is quite possible that a study of such 
sections has given rise to the statement that in Pinus all 4 of the 
embryonal cells may contribute to the formation of 1 embryo, or 
they may form 4 embryos. 
The initial cell for the second embryonal tubes (e2) and for the 
third and subsequent embryonal tubes are cut off as segments of the 
apical cell, first by transverse walls, and later as oblique segments. 
The initial cell of an early embryonal tube may elongate into a 
t-celled suspensor division, resembling a primary suspensor cell, or 
it may first divide by a vertical wall as e. in figs. 6 and 8. Fig. 16 
shows e, as a single elongated cell and e, with 3 cells, while fig. 20 
shows e, of 4 cells. There is considerable variation in the number 
of cells found in the embryonal tube groups of corresponding sus- 
pensor divisions, and variations are frequently found among the 
individuals of the same embryo system. 
After the initial cells of the embryonal tubes begin to divide 
by vertical walls and elongate to form the suspensor divisions, 
each succeeding bundle of embryonal tubes consists of more cells 
than the tier above it (figs. 46-52). Only one exception to this has 
been found among the 500 or more dissected preparations of 
various pines, and this one was P. Laricio, shown in fig. 24. Here 
s and e, (not shown) are single-celled, e, is of 2 cells, and e, again 
1-celled, while e, and e, will undergo other divisions before beginning 
to elongate. Careful examination of many preparations indicates 
that the separation of the 4 primary embryos precedes the division 
of any of the embryonal tube initial cells by vertical walls. 
The primary suspensor, that is, the first suspensor division, is 
often collapsed and withered by the time 4 or more divisions have 
formed. The upper parts of collapsed suspensors are shown in figs. 
65 and 68, while fig. 46 still has a turgid primary suspensor. The 
primary suspensors frequently collapse in about the stage shown 
