from the Tertiary of Japan. 105 
the wood. Medullary rays somewhat prominent and unisenate, distant by 
two to ten or more rows of tracheides. 
Radial. Ray cells rather straight, somewhat resinous, equal to two to 
four tracheides ; horizontal walls thick and without pits, terminal walls thin and 
unpitted, lateral walls with large oval narrowly bordered pits, two to six in 
number per tracheide and generally in two rows ; radial pits of the tracheides 
round or oval in one or two rows and then opposite ; ‘ bars of Sanio ’ promi- 
nent and staining strongly in haematoxylin. 
Tangential. Rays somewhat resinous and from two to eleven cells 
high. Bordered pits on the tangential walls of the summer tracheides small 
and in one or two rows. Traumatic resin canals absent in the horizontal 
plane, and as a consequence seen only in the radial and transverse 
sections. 
The traumatic resin canals occur in tangential series in remote annual 
rings. They are surrounded by strongly pitted parenchyma cells, with 
a few so-called ‘ resin cells ’, and more externally by septate tracheides (the 
‘ parenchyma tracheides ’ of Penhallow). 
The occurrence of the wood of a fossil Sequoia in the Tertiary of 
Japan completes in an interesting way the evidence for the existence of that 
genus in Cenozoic time throughout temperate regions of the whole Northern 
hemisphere. The ligneous structure of N. hondoensis also adds somewhat 
to our knowledge of the phylogeny of the Coniferales. The question of the 
presence of' the genus Sequoia in the Mesozoic period need not be raised in 
this connexion, although it has been pointed out by Professor Jeffrey and his 
students that it is extremely doubtful if our modern genus antedated 
the Tertiary, since the types referred to it in the Cretaceous are clearly not 
anatomically in agreement with the living genus, and do not exhibit even 
the organization of the Cupressinoxylon type. 
At the present time there are two opposed views in regard to the 
phylogenetic position of the Cupressinoxylon type of wood. One school 
recognizes this type as young among the Coniferales and as ancestral to the 
Pityoxylon type characteristic of the Abietineae. A more recent view, 
for which Professor Jeffrey is sponsor, is that the simpler type of wood found 
in Sequoia and its allies has originated as the result of simplification and 
specialization from the ligneous type characteristic of Pinus and related 
genera. The genus Sequoia stands always at the critical point in these 
two opposed hypotheses. The study of the living Sequoia appears to have 
made it clear that the view which regards it as more primitive than the 
Abietineae is due to the error of mistaking the resin canals which occur in 
the wood of Sequoia as a normal feature of structure instead of as the result 
of traumatic reaction. The discovery in the Mesozoic of Japan of a member 
of the genus manifesting the same interesting abnormality of the presence of 
ligneous resin canals appears to furnish another good proof of the derivation 
