252 Holden.— Some Fossil Plants from Eastern Canada . 
Brachyphyllum , Widdringtonites , Thuyites , &c., all previously referred to 
the Taxodineae or Cupressineae, are really, judged by anatomical structure, 
Araucanian Conifers . 1 A similar fate seems destined for Voltzia coburgensis. 
As regards external features, the size and general appearance of the leaves 
are Araucarian, while the double cone scale and two seeds are distinctly 
Abietineous. As regards internal structure, the nature of the medullary 
rays, absence of wood parenchyma, and large pith are Araucarian ; while 
the scattered position of the pits is Abietineous. By far the most reliable 
criterion for diagnosing coniferous woods is the occurrence of ‘ bars of 
Sanio ’, since, as shown by Miss Gerry (op. cit.), they are present invariably 
in all coniferous tribes except the Araucarineae. Voltzia accordingly 
appears to be beyond question Araucarian. Within the last few years 
a number of fossil woods have been described by Gothan, Seward, Jeffrey, 
Sinnott, and others, which possess different combinations of structures 
which to-day are confined exclusively to either the Abietineae or Arau- 
carineae. That these are transitional forms between the two great groups 
of Conifers seems evident, the question being whether they represent 
Araucarians on the way to becoming Abietineae, or vice versa. Dr. Jeffrey , 2 
by a study of comparative anatomical, experimental, and palaeobotanical 
evidence, appears to have demonstrated that the Abietineae are older, and 
that it is the Araucarineae which become progressively more and more like the 
Abietineae in successively older geological formations. Voltzia is probably 
one of the earliest of these intermediate types ; W oodworthia, which presents 
other combinations of Abietineous and Araucarian characters, is also 
Triassic. The antiquity of these genera does not in any way discount 
Dr. Jeffrey’s phylogeny, for the distinguished and experienced palaeo- 
botanist Nathorst, as a result of his extensive studies of the Mesozoic 
coniferous flora of northern Europe, has reached the conclusion that the 
Abietineae were abundant in circumpolar regions in the Trias . 3 
Voltzia is of especial interest in view of the different theories which have 
been advanced to explain the organization of the female cone of the Conifers. 
The generally accepted interpretation is that the Abietineous ovuliferous scale 
and sterile bract have, in the Taxodineae and Cupressineae, become more 
and more fused, though their double nature is still evident in some genera, 
e. g. Cryptomeria. It has been suggested by Seward 4 and Thomson 5 that 
the cone scale of the Araucarineae is entirely different morphologically from 
that of the remaining Conifers. It seems more probable, however, that in 
1 Hollick, A., and Jeffrey, E. C. : loc. cit. 
2 Jeffrey, E. C. : The Araucarioxylon Type. Proc. Am. Acad. Arts and Sciences, vol. xlviii, 
No. 13, Nov., 1912. 
3 Nathorst : Beitrage zur fossilen Flora Schwedens. 4 0 , Stuttgart, 1878. 
4 Seward, A. C., and Ford, Sibille O. : The Araucarineae, recent and extinct. Phil. Trans. 
Royal Soc., series B, vol. cxcviii, pp. 305-41 1, Pis. XXIII and XXIV. 
6 Thomson, R. B. : The Megasporophyll of Saxegothea and Microcachrys. Bot. Gazette, 47, 
345-54, Pis. XXI-XXV, 1909. 
