Stiles — The Podocarpeae. 
49 7 
and Abietineae, suggested in cautious terms the possibility of a common 
ancestry for the three orders. 1 The investigation of Saxegothaea enabled 
a more definite statement to be made, so that Dr. Noren and the present 
writer in 1908 put forward independently . the view that the two orders 
Podocarpeae and Araucarieae are related through Saxegothaea. Mr. Thomson 
and M. Tison, also working independently on Saxegothaea , have reached 
a similar conclusion. As the resemblance between Saxegothaea and the 
Araucarieae is not confined to a single character, but extends to the 
external features of the female cones, the internal structure of the cone 
scales, the male gametophyte, and, though not to so marked an extent, to 
the structure of the microsporangium and the wood of the stem, and in the 
case of Araucaria Rulei to the leaf, there can, I think, be little doubt that 
the resemblance is an indication of real affinities. One point of resemblance 
between the two orders, namely, the inversion of the ovule, appears to be 
due to parallel evolution. The primitive position of the ovule in the 
Podocarpeae, as Miss Young justly observes, 2 appears to be erect and 
axillary, as pointed out in the preceding paragraph. 
The only recent paper in which an opposed view is taken is that of 
Miss Gerry, 3 who thinks that her work on the distribution of ‘ bars of Sanio ’ 
in the Coniferae indicates a relationship of the Podocarpeae with the 
Abietineae rather than with the Araucarieae. The evidence consists in the 
fact that { bars of Sanio ’ are recorded as occurring in the tracheides of the 
xylem, either of stem or root, but not necessarily of both, in all recent 
Conifers except Araucaria and Agathis. Whether this is actually the case 
cannot be decided for certain, as, judging from the statements in Miss Gerry’s 
paper, only one species of each genus appears to have been examined (at 
least no more are described), out of the fourteen species of Araucaria and 
ten of Agathis. Nor is the additional evidence derived from fossils any 
more convincing, for although it is stated that ‘ bars of Sanio ’ are absent from 
fossil Araucarian woods and present in woods of an Abietineous affinity, 
yet the statement means little, for in no case have the so-called Araucarian 
woods been found in connexion with reproductive organs that are un- 
doubtedly Araucarian, which would alone render certain their reference. 
As an example of this, mention may be made of Professor Jeffrey’s remarks 
on Geinitzia gracillima . 4 The * purely systematic botanists ’ referred the 
plant to Sequoia. The author of the paper also says that the cone scales 
alone, although furnishing him with ample evidence of Araucarian relation- 
ships, ‘ might by those less experienced in the details of Coniferous anatomy 
still be considered as belonging to the strobili of the Taxodineae or 
Cupressineae.' Next we learn that ‘ the pits in no case are contiguous or 
in more than a single row’, which means, of course, that the pitting is 
1 Young (’ 07 ), p. 194. 
3 Gerry (’ 10 ), p. 122. 
2 Young ( 10 ), p. 93. 
4 Jeffrey (’ll), p. 21. 
