326 BOTANICAL GAZETTE [Noveuser 
vertical series of ducts, and from this vertical series again other hori- 
zontal ducts passed outward beyond the limits of the piece of wood at 
my disposal. In another case I was able to follow the course of a 
horizontal duct through over seventy annual rings before it finally 
tapered off and ended blindly. Although the horizontal canals 
always start from a vertical series, they by no means always end in 
the next outward vertical series, even when one is present. More 
frequently they end blindly, as in the one last described above. The 
formation of new series of vertical canals may recur in remote rings 
of growth, and these are nearly always united by horizontal canals. 
It will be convenient at this stage to consider more particularly the 
structure of the wood parenchyma, since it is of considerable diag- 
nostic importance. Our jig. 2 shows the scantiness of the parenchyma 
as seen in transverse section through the wood, and also that it occurs 
on the face of the summer wood. Both these features are unusual, 
for in the living Sequoias the resiniferous parenchyma is particularly 
abundant and is found throughout the annual ring. Our fossil also 
presents a contrast in this respect to the woods of other extinct Sequolas. 
PENHALLOW‘ describes his S. Langsdorfii as having abundant resia 
cells throughout the annual ring and appearing also in a rudimentary 
form on the face of the summer wood. In another species, 5. Bur 
gesstt, according to this author, resin cells abundant throughout the 
ring are most numerous on the face of the summer wood. 
S. magnifica of KNow.ton’ the distribution of resin cells throughout 
the annual growth seems to be somewhat uniform. Longitudinal 
sections of the wood of the species under discussion, taken 1m ee 
bers both in the tangential and radial planes, show clearly that 
absence of resin cells from all locations except the face of the ee 
wood is not due to disappearance through decay, for there is no 2 
dence of the existence of parenchymatous elements elsewhere a < 
the face of the summer wood. Fig. 11 shows the appearance a 
resin cells of our species in longitudinal section. They are long inlet 
row elements comparable among living species to those of 5- §'8 
4 PENHALLOw, D. P., Notes on Tertiary plants. Trans. Roy. Soc. Canada 9 
5 Op. cit. 
6 Know ton, F. H., Geology of the Yellowstone Park. Mo 
Geological Survey 32: pt. 2. 
