1904] JEFFREY—A FOSSIL SEQUOIA 331 
if it is possible to recall experimentally morphological characters, 
which have entirely disappeared (as in the case of the ligneous resin 
ducts of S. sempervirens), the range of possibility in tracing phylo- 
genetic relationships will be greatly extended. In our fossil the 
traumatic resin ducts occur in both the horizontal and the vertical 
planes, and thus present a very close approximation to the condition 
occurring normally in Pinus. There is, however, a difference in the 
arrangement of the canals, for in Pinus they are distributed regularly 
throughout the wood and form an anastomosing system, while in 
5. Penhallowii the vertical canals are confined to remote annual 
tings and the horizontal canals form a very incomplete system of 
connecting commissures. It is interesting to note that S. Langs- 
dorfii as described by PENHALLOW has only vertical canals, while 
S. Burgessii described by the same author has only radial ones. 
Had the material of the latter species been as abundant and as easily 
manipulated as in the case of our fossil, I am disposed to think that 
vertical canals would have been found as well. It is a noteworthy 
fact that-in three out of the four woods of fossil Sequoias which have 
been recently described, resin canals similar to those of the Abietineae 
have been found; or, to state it in another way, the oldest woods of 
Sequoia of which we have any reasonably complete knowledge more 
nearly approximate in structure the wood of the Abietineae than do 
lose of their living descendants. This fact, taken in connection 
with the great geological age of the Abietineae, makes it very probable 
t the Sequoias, and as a consequence the Cupressineae in a broader 
“yee have come from an abietineous ancestry. This conclusion 
“egg in harmony with evidence derived from the study of the 
_ and other important data, as I have pointed out at 
na forthcoming memoir on the Abietineae. 
SUMMARY. 
Sierra quoia from the Auriferous Gravels (Miocene) of the 
structur yada Mountains, although presenting features of wood 
aa which unite it with the living Sequoias, possesses other 
resin oo Strongly suggest the Abietineae. The paucity of 
high} Present only on the outer face of the summer wood, the 
Y developed medullary rays, and the traumatic resin canals 
A fossil Se 
