1915] BURLINGAME—ARAUCARIANS 7 
so close a homology as to afford strong indications of real affinity. 
The method of attachment of the single megasporangium by a 
stalk and the similar cone scales serve to form the basis of a com- 
parison with Spencerites (49). 
The resemblance of the sbieebeporipleyli to those of Equisetum 
is noticed, but is not held to indicate a direct relationship. Though 
they admit that the typical lycopod did not have its microsporangia 
on the dorsal side of the microsporophyll, they think they see a 
certain significance in the fact that the Araucaria type is found in 
Cheirostrobus (50), a genus that has been thought to be one of those 
generalized types which serve as finger-posts to the paths which 
evolution has followed, and which is considered to be intermediate 
between club mosses and horsetails (54). 
These investigators assert that not only are the ovulate cones 
simpler and more primitive in structure than those of other conifers 
and more like those of paleozoic lycopods, but they are more 
nearly like those fossils from the Mesozoic than are those of any 
other group. This accords with their view; whereas, if they had 
been derived directly from Cordaitales or indirectly through the 
Abietineae, they should show some approach to the supposed leafy 
shoot predicated by the brachyblast theory, as the fossil history 
is followed backward toward the ancestral forms. They are of the 
Opinion that no such transitional forms are known. On the con- 
trary, they are of the opinion that the older forms show an approach | 
to the lycopod situation in having smaller leaves and cone scales, 
with a gradual transition between the two organs. 
They point out that the stem apex more closely resembles that 
of lycopods than that of ferns, though they do not attach much 
value to this fact. The exarch veins of the leaf may be regarded, 
they think, as a possible “ancestral feature which has disappeared 
from the vegetative stems.” The leaf traces are accompanied by 
a group of cells in the cortex which the authors compare to the 
“parichnos” in lepidodendroid stems. 
While they admit that there are many points of dissimilarity 
between araucarian stems and those of the lycopods, they do not 
think that any of them constitute an insuperable barrier to the 
derivation of the one from the other. They point out that the 
