1915] BURLINGAME—ARAUCARIANS 23 
Not enough is known about female gametophytes to make a 
comparison of much value. The cordaiteans apparently possessed 
apical archegonia in the manner of all modern conifers. A compari- 
son of embryos of course is at present impossible. 
3. THE ARAUCARINEAE ARE VERY ANCIENT PLANTS.—Although 
wood of the Araucarioxylon type is known from the Paleozoic to the 
present, it is not yet possible to say with certainty just how old are 
plants corresponding in other essential points with modern arau- 
carians. SEWARD and Forp (54) have given us a very careful 
review of the fossils that have been assigned to the araucarians, 
to which Scott (53) has given general agreement. It appears 
probable, though not beyond question, that such genera of the 
Permo-Carboniferous as Walchia and Voltzia were more nearly 
allied to araucarians than to any other known conifers (54). Volizia 
and Ullmannia appear very probable triassic representatives (24). 
There is abundant evidence of impressions, cones, and wood of 
araucarians in the Jurassic and Cretaceous (53, 54). 
The Abietineae have been said to extend to the Paleozoic (33), 
and this assertion has been vigorously disputed. The carbonif- 
erous form has been discredited on the ground that its source is 
not known to be from rocks of that age (21,22). The form from the 
Permian is said by THomson and ALLIN not to be a Pityoxylon at 
all, but a cordaitean or Araucarioxylon. PENHALLOW appears to 
have originally regarded it as a Pityoxylon on account of what he 
supposed were horizontal resin canals (46). These are now (71) 
said, on a reexamination, not to be resin canals at all, but leaf 
traces. If these forms are rejected, no true Abietineae are known 
that can be compared in age with the araucarians. 
4. TRANSITIONAL FOSSIL FORMS.—Of late there have been 
described (particularly by JEFFREY) a number of mesozoic plants 
with wood more or less intermediate between the true Araucari- 
oxylon and abietinean wood. As will be shown in a subsequent 
section, the Jerrrey school interprets these as evidence of the 
origin of araucarians from the Abietineae. THomsoN (70), how- 
ever, points out that the earliest of these transitional forms, 
Woodworthia (38), is much more like true Araucarioxyla than the 
later ones (as Araucariopitys), while the latter are much more 
