319 
Two Palaeozoic Stems from India. 
Podocarpineae, but also in the Taxodineous genus Sciadopitys and the 
Abietineous genus Pinus. Among extinct genera, they have been found 
by the writer in the Araucarian P araphyllocladoxylon } From their presence 
in this fossil, they must be considered as an interesting case of parallel 
development, to which no phylogenetic significance should be attached. 
Perhaps the most interesting feature of the secondary wood remains to 
be mentioned — the well-marked growth rings (Figs, i and 2, PI. XVII). 
Arber was the first to call attention to this peculiarity in Permo-Carboni- 
ferous stems from Australia ; i 2 since then Seward has called attention to the 
same phenomenon in Antarcticoxylon from the Antarctic, 3 and Halle records 
rings in two genera from the Falkland Islands. 4 At the same time, David 
White 5 states that some at least of the South American forms resemble their 
contemporaries in the Northern Hemisphere in the uniform nature of the 
spring and summer wood. This fact is of especial interest in view of the well- 
known mixture of northern and southern floras of Brazil and the Argentine, 
and may probably best be explained by assuming that the glaciation of this 
part of Gondwanaland was not as severe or as protracted as elsewhere. 
That this Indian stem should show distinct annual rings is to be expected 
from the particularly pure character of the Glossapteris flora of that 
country. 
Summary. 
To sum up, the chief points of interest in this fossil are : 
Pith\ large, non-discoid ; differentiated into an inner parenchymatous 
and an outer, partly secretory, portion ; separated from the vascular stele by 
a distinct transfusion sheath. 
Leaf-traces : paired and invariably separated by an intercalary bundle. 
Primary wood', localized into bundles ; strictly endarch ; large amount 
of protoxylem parenchyma at the nodes ; broad transition zone between 
primary and secondary wood. 
Secondary wood : typically coniferous ; tracheides unpitted tangentially, 
covered radially by closely crowded, flattened pits with elliptical pores ; rays 
uniseriate, low, with large fusion pits on radial wall ; annual rings distinct. 
Conclusion. 
A detailed comparison of this stem with others of the same age has 
been attempted as the different structures were described, and it is evident 
that it is closely allied to the other members of the Cordaitales, though it is 
identical with none. To indicate this relationship it maybe called Dadoxylon 
indicum , with the diagnosis as given above. This stem is not without its 
i Holden (1913). 2 Arber (1905). 3 Seward (1914). 
4 Halle (1912). 6 White (1908). 
