1914] BURLINGAME—ARAUCARIA BRASILIENSIS 493 
Very soon after the cone is externally recognizable, the sporo- 
phylls show the first signs of the meristem that forms the ovule. 
At this time the sporophyll differs from a leaf in being differentiated 
into two regions. The outer part is slender and leaflike, while the 
basal portion is colorless, short, and stout, and tapers back slightly. 
The meristem is developed on the adaxial surface in a median posi- 
tion close to the base. It consists of many cells and grows rapidly. 
Figs. 1-3 show various views of it about this time. Although 
growth takes place throughout the sporophyll, yet four distin- 
guishable meristems are established that determine its ultimate 
shape and form. The first of these is the meristem of the nucellus, 
already mentioned. As soon as it has made a beginning, another 
secondary meristem arises as a curved band across its upper sur- 
face. This curved meristematic band has its convex side directed 
toward the cone axis. By its growth is produced that part of the 
integument free from the scale. It is continuous below with the 
meristematic region of the scale located at its base. The fourth 
meristem is also a curved band, with its convexity directed toward 
the tip of the scale. It produces the ligule. 
Not more than one sporophyll in twenty is fertile. Of those 
that do form ovules, many fail to mature them. Whether this 
tendency to sterility is equally marked in the native habitat of the 
tree I have not yet ascertained. It seems not unlikely that it may 
be due to the effects of cultivation in an alien habitat differing con- 
siderably from that of the highlands of Brazil. It has nothing to 
do with pollination, I am convinced, for all the cones are abundantly 
pollinated, both sterile and fertile sporophylls alike. The pollen 
tubes develop on the sterile ones, at least up to a length of 0.5 cm. 
or more. 
The meristems very quickly produce the ovular structures. On 
account of this fact, and the further fact that one cannot distinguish 
sterile from fertile sporophylls until after sectioning them, I did 
not secure a complete series showing the development of the ovule. 
The outlines of the process, however, are clear. The basal meristem 
of the sporophyll elongates it, and the integument keeps pace. 
The result is a deep tubular cavity, deepest on the side next the 
sporophyll. At the base of this the nucellar meristem has been 
